Neuropsychological, Neuropsychiatric, and Quality of Life Issues in DBS for Dystonia
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SUPPLEMENT
Neuropsychological, Neuropsychiatric, and Quality
of Life Issues in DBS for Dystonia
Marjan Jahanshahi, PhD,1* Virginie Czernecki, PhD,2 and Mateusz Zurowski, MD3
1
UCL Institute of Neurology, The National Hospital for Neurology and Neurosurgery, Queen Square, London, United Kingdom
2
Inserm CRICM U975, Department of Neurology, Groupe Hospitalier Pitié-Salpêtrière, Paris, France
3
Department of Psychiatry, Toronto Western Hospital, University of Toronto, Toronto, Canada
A B S T R A C T : We review the impact of dystonia and dystonia seem to do well post-GPi DBS despite often
its surgical treatment with deep brain stimulation (DBS) having a history of depression or even having active
on cognitive function, psychiatric morbidity, and health- severe depression. We make recommendations for
related quality of life. The current evidence suggests that screening and basic management strategies of patients
globus pallidus internus (GPi) DBS does not cause cogni- identified as having a major psychiatric illness pre- or
tive decline in primary dystonia. However, we recommend postoperatively. Quality of life in dystonia patients quanti-
general preoperative screening of cognition in patients fied by generic measures such as the SF36 showed
with dystonia to evaluate baseline cognitive status and improvement in both mental and physical categories fol-
monitor for possible postoperative changes. Patients with lowing DBS surgery. V C 2011 Movement Disorder Society
mild to moderate depression appear to do well postoper-
atively; however, there are scant data about those with Key Words: DBS; dystonia; cognition; psychiatric
severe depression. This is particularly problematic given quality of life; surgery
reports of postoperative suicide. Patients with tardive
In addition to movement difficulties patients with dys- Methods
tonia often also have cognitive and psychiatric comor-
bidities that affect their quality of life (QoL). In this Search Strategy
chapter, we will review the evidence for these co-mor- We conducted three separate searches in ‘‘Pubmed’’
bidities and their relevance to patient screening and with ‘‘cognition and dystonia,’’ ‘‘psychiatric and dysto-
selection for deep brain stimulation (DBS) surgery. Infor- nia,’’ ‘‘quality of life and dystonia’’ as the key words.
mation is grouped into cognitive, psychiatric, and QoL We included all studies that emerged from this search
sections for ease of reference. Primary dystonia is the that provided relevant information. We also included all
focus of most of the evidence, with secondary dystonia relevant studies provided by the Task Force and other
mentioned where data are available. Unlike other sec- relevant publications known to the authors of this arti-
tions, pre- and postoperative data will be presented to- cle. Studies published until June 2010 were included.
gether before specific questions being answered. This
format was adopted because selection of preoperative Process of Generating Clinical
screening is driven by preoperative cognitive and psychi- Recommendations
atric problems as much as postoperative problems that The clinical recommendations are partly based on the
have been documented following DBS. review of the literature and partly on the consensus
reached during the meeting of the Task Force.
------------------------------------------------------------
* Correspondence to: Marjan Jahanshahi, Sobell Department of Motor
Neuroscience and Movement Disorders, Institute of Neurology and the
National Hospital for Neurology and Neurosurgery, University College
Section 1: Cognitive Function
London, Queen’s Square, London. WC1N 3BG, United Kingdom; m.
jahanshahi@ion.ucl.ac.uk Preoperative Cognitive Function in Dystonia
Potential conflicts of interest: Nothing to report. Available Data
Received: 24 April 2010; Revised: 12 July 2010; Accepted: 11 October Cognitive function in dystonia has been investigated
2010 in a number of studies and their results are reviewed
Published online in Wiley Online Library (wileyonlinelibrary.com).
DOI: 10.1002/mds.23511 below. Taylor et al.1 examined the impact of high-
S68 Movement Disorders, Vol. 26, No. S1N E U R O P S Y C H O L O G I C A L , N E U R O P S Y C H I A T R Y , A N D Q O L I N D B S
dose anticholinergic medications (used to treat the nificantly impaired on any of the tests of cognition,
motor symptoms) on cognition in patients with dysto- with the exception of the ID/ED set-shifting test of the
nia. They found that when assessed before starting CANTAB the ED portion of which was failed by 71%
medications, dystonia patients did not differ from age- (10 of 14 subjects) of the sample. Only 12% of a
and IQ-matched controls on any of the tests of cogni- healthy control sample failed this test in a previous
tion used, including assessment of explicit memory study4 although it is unclear whether these healthy
(Wechsler Memory Scale), implicit skill (Tower of controls were age- and IQ-matched with the dystonia
Toronto), learning (Buschke Selective Reminding, sample in the study by Scott et al. Considering that
Conditional Associative Learning), executive function patients with a primary depressive illness also fail the
(Stroop, Wisconsin, word fluency), and visuospatial ID/ED shifting test of the CANTAB (e.g., Purcell
function (block counting). Once anticholinergic drug et al.5 and Michopoulos et al.6), it is possible that the
treatment was started, high doses of this medication deficits reported by Scott et al.3 on this test relate to
affected performance on the test of explicit memory the presence of depression in their sample. Although
and reduced speed of information processing on the this is unlikely given that depression and anxiety
Stroop compared with the matched healthy controls. scores of the 10 patients who failed did not differ
Jahanshahi et al.2 assessed cognitive function in 10 from the 4 patients who passed as assessed by the
patients with idiopathic dystonia (3 with generalized Hospital Anxiety and Depression Scale.
dystonia; 5 with CD, and 2 with focal arm dystonia) Balas et al.7 compared cognitive function in 20
and 12 age- and IQ-matched healthy controls. All par- DYT-1 gene carriers with childhood onset generalized
ticipants completed tests of executive function and dystonia to 20 education- and IQ-matched healthy
working memory including phonemic, semantic, and controls. The cognitive battery used included tests of
alternating category word fluency, the Wisconsin Card intellectual ability (Matrices estimated IQ), memory
Sorting test, the Stroop Colour Word Naming test, the (Rey Auditory Verbal Learning Test, Rey Complex
missing digit test of working memory, a test of ran- Figure), executive function (Stroop, Trail-making),
dom number generation, a test requiring generation of language (phonemic and semantic verbal fluency), spa-
self-ordered random number sequences, the paced se- tial function (Judgement of Line Orientation), verbal
rial addition test, a test of conditional associative abstraction (WAIS-III Similarities), motor speed and
learning, and finger tapping and peg insertion under manual dexterity (Symbol Search subtest of WAIS-III,
unimanual, bimanual, and dual task conditions. Purdue pegboard) as well as several subtests of the
Patients with dystonia were comparable with controls CANTAB (spatial span, spatial working memory,
on all measures of executive function and working Tower of London, ID/ED shift). Their results showed
memory except semantic word fluency. They also that patients with dystonia had higher retroactive in-
showed a greater decline in tapping with one hand terference on the Rey Auditory Verbal Learning Test
under dual task conditions when simultaneously and that they recalled fewer words from a previously
inserting pegs with the other hand. learned list after a new list was learned. After control-
Fourteen patients with focal, segmental, or general- ling for group differences in medication and anxiety,
ized dystonia were assessed by Scott et al.3 on a bat- dystonia patients and controls did not differ on the
tery of neuropsychological tests including tests of ED shift test. However, when only medications but
intellectual ability (National Adult Reading Test and not anxiety was controlled for, patients with dystonia
Raven’s Standard Progressive Matrices), memory (Rec- did show a poorer performance on this test suggesting
ognition Memory Test, story recall, copy, and recall that results of the ED shift test are sensitive to higher
of complex figure), language (Boston Naming Test), levels of anxiety present in dystonia patients. It is
spatial functioning (Judgement of Line Orientation), interesting to note that dystonia patients generated sig-
attention (digit span), executive function (Stroop, Trail nificantly more words on the semantic fluency test
Making; phonemic and semantic verbal fluency), and compared with healthy controls. None of the other
speed of information processing (Symbol Digit Modal- tests of cognition used showed significant differences
ities Test, Speed of Comprehension from the Speed between the two populations.
and Capacity of Language Processing). Dystonia Bugalho et al.8 compared the performance of 45
patients also completed a number of tests of executive patients (31 focal, 14 segmental) with primary dysto-
function and attention from the Cambridge Neuropsy- nia (15 with cervical dystonia [CD], 15 with writer’s
chological Test Automated Battery (CANTAB), cramp, and 15 with blepharospasm) and 27 matched
including reaction times, spatial span, spatial working controls on tests of executive function (Wisconsin
memory, the tower of London, and the intra/extradi- Card Sorting Test, Stroop) and visuospatial memory/
mensional (ID/ED) set-shifting test. No control group function (Benton Visual Retention Test, Block Assem-
was assessed, and results were compared with norma- bly subtest of WAIS). Patients with dystonia had a sig-
tive data for each test. Dystonia patients were not sig- nificantly higher number of perseverative errors on the
Movement Disorders, Vol. 26, No. S1, 2011 S69J A H A N S H A H I E T A L .
Wisconsin Card Sorting Test than the controls, on the higher susceptibility to retroactive interference,7 defi-
basis of which it was concluded that dystonia patients cits on the Wisconsin Card Sorting,8 and inconsistent
had difficulties with set shifting. findings with regards to the presence/absence of a selec-
Several investigators have specifically focused on tive deficit in ED shifting on the CANTAB,3,7 which
visuospatial function and perception of egocentric and might be partly related to higher anxiety or depression
allocentric space in cervical dystonia (CD) and have in dystonia patients. In contrast, higher IQ20,21 and
reported deficits in perception of egocentric space in semantic verbal fluency7 have also been reported in
this disorder.9–12 patients with dystonia as compared to controls.
Cognition in secondary dystonia has also been inves- Patients with secondary dystonia related to
tigated, although not systematically. Several studies HSS13,16,17 and TD in schizophrenia19 often have cog-
highlighted cognitive impairment in Hallervorden- nitive deficits. Available evidence is hampered by a
Spatz syndrome (HSS). Thomas et al.13 reviewed 34 number of methodological limitations: small size and
affected individuals from 10 different families and heterogeneity of the samples, inclusion of a limited
found that more than 30% presented with dementia. range of tests of cognition, and lack of control groups.
This proportion is larger than the 10% previously Information from bigger samples including larger
reported.14,15 A subset of HSS patients exhibit a subgroups of patients with different types of focal or
pantothenate kinase-associated neurodenegeration segmental or generalized dystonia with age- and IQ-
(PKAN) due to a mutation of the panthothenate ki- matched controls is necessary for more definitive con-
nase (PANK) 2 gene that is associated with younger clusions about the general integrity or impairment of
age at onset and higher frequency of dystonia and in- cognition in dystonia.
tellectual impairment.13 There are few published stud-
ies investigating cognitive functioning in PKAN. Effect of DBS on Cognition in Dystonia
However, the presence of cognitive impairment, such Available Data
as problems in executive functioning, attention, spatial
Globus pallidus internus (GPi) DBS has been used
and verbal learning, and memory, are known to be in-
for the treatment of Parkinson’s disease (PD) and does
tegral features of patients with PANK2 mutations.16,17
not appear to produce any major cognitive adverse
Marelli et al.17 evaluated two brothers presenting with
effects, other than decline in verbal fluency.22,23
an adult-onset form of PKAN, who showed normal
Nevertheless, some cases of cognitive deterioration
global cognitive efficiency evaluated with MMSE, but
have been reported after pallidotomy (mainly bilat-
impairments in executive functioning and attention.
eral)24 in PD, and the occurrence of these deficits
Freeman et al.18 described a series of 16 patients with
could be related to a more anteromedial lesion loca-
PANK2 who completed measures of global intellectual
tion.25 Detailed assessment of cognitive function
functioning and measures of adaptive skills. Their care
before and after GPi DBS surgery in dystonia has been
providers also assessed the patients’ day-to-day func-
the focus of two reports.26,27 These two studies
tional limitations. The results highlighted a broad het-
focused essentially on patients with primary dystonia.
erogeneity in cognitive profile ranging from high level
There are a number of other clinical studies on the
to severe impairment. Measures of adaptive behaviour
impact of GPi DBS for dystonia that included assess-
correlated with measures of intellectual functioning and
ment of some aspects of cognition.28–36 These studies
severity of the disease. Early onset of disease correlated
are summarized in Table 1.
with measures of lower intellectual functioning.
Cognition has not been adequately evaluated in the
Primary Dystonia
heterogenous population with tardive dystonia (TD). 27
However, patients with schizophrenia are widely Pillon et al. evaluated cognition before and 12
regarded as having executive dysfunction (for a months after bilateral GPi DBS surgery in 22 patients
review, see Velligan and Bow-Thomas19). with primary generalized dystonia (7 of them had the
DYT-1 mutation). The battery of tests included the
Raven Progressive Matrices, Similarities and Arithme-
Conclusions tic subtests of the WAIS-R (adults) or WISC-R (chil-
The results of the three studies that used detailed dren), tests of executive function (simplified version of
assessment on a range of tests of cognitive function in the Wisconsin Card Sorting Test, Trail Making Test,
idiopathic dystonia unanimously agree that patients phonemic and category word fluency), and the Gröber
do not show any significant deficits in intellectual abil- and Buschke test of verbal learning and memory. At
ity, attention, memory, language, or executive func- 12 months, there was no significant change in
tion relative to healthy controls.2,3,7 However, studies cognition on the majority of the tests administered,
revealed specific deficits in dystonia patients on coupled with mild but significant improvement of per-
tests of visuospatial function relating to egocentric formance on the Raven Progressive Matrices, WAIS-R
space,9–12 lower than normal semantic verbal fluency,2 Similarities subtest, free verbal recall and reduction of
S70 Movement Disorders, Vol. 26, No. S1, 2011TABLE 1. Cognitive outcome studies in patients with dystonia and GPi/STN Voa DBS
Time of
postsurgical
N/age range Surgical Neuropsychological cognitive Cognitive
Investigators Sample (yr) target battery assessment exclusion criteria Cognitive conclusion
Primary dystonia
Pillon et al.27 Primary generalized dystonia 22 (14–54) GPi bilateral Large battery 12 mo MMSE 24/30 No change and improvement
Vidailhet et al.35 Same as above 22 (14–54) GPi bilateral Large battery 3 yr MMSE 24/30 No change and improvement
Kleiner-Fisman et al.33 Cervical dystonia 4 (41–56) STN bilateral Large battery 12 mo MMSE 24/30 No change
Kupsch et al.34 Primary segmental and 40 (14–75) GPi bilateral Mattis DRS 9 mo Mattis DRS < 120/144 No change
generalized dystonia
Halbig et al.26 Different forms of dystonia 15 (13–68) GPi bilateral Large battery 12 mo Clinical interview No change and improvement
(13 primary þ 2 tardive) (no exclusion)
N E U R O P S Y C H O L O G I C A L ,
Hung et al.32 Cervical dystonia 10 (25–67), 6/10 GPi bilateral Details not Data not available Yes but no details given No change
had preoperative given
neuropsych
Valldeoriola et al.37 Primary generalized and 22 (12–70) GPi bilateral MMSE 6 and 12 mo MMSE < 24/30 No change
segmental
cervical dystonia
Secondary dystonia
Vidailhet et al.36 Secondary dystonia (CP with 13 (20–44) GPi bilateral Large battery 12 mo MMSE 24/30 No change
dystonia-choreoathetosis)
Damier et al.29 Tardive dyskinesia 10 (27–69) GPi bilateral MMS, Mattis DRS, 6 mo MMSE 24/30 (except No change
FAB, FBS one patient who has 22/30)
Gruber et al.31 Tardive dystonia 9 (38–76) GPi bilateral Large battery 18–80 mo Mattis DRS < 123/144 No change
Andaluz et al.28 Torticollis 1 (61) GPi bilateral Details not given Data not available No change
Ghika et al30 Generalized postanoxic 1 (26) Thal Voa bilateral Details not given Yes No change
N E U R O P S Y C H I A T R Y ,
dystonia
A N D
Q O L
Movement Disorders, Vol. 26, No. S1, 2011
I N
D B S
S71J A H A N S H A H I E T A L .
nonperseverative errors on the Wisconsin. These cluded that the aspects of cognitive function assessed
improvements in performance were maintained at 3 were not significantly altered by surgery. No adequate
years follow-up.35 trials of thalamic DBS in dystonia evaluating cognition
Halbig et al.26 assessed cognitive function before were identified.
and 3 to 12 months after surgery in 15 GPi DBS
patients with various forms of multifocal, segmental, Other Forms of Dystonia
or generalized dystonia (13 primary and 2 tardive). TD has been shown to improve with pallidal
The battery of tests included the Mattis Dementia Rat- DBS.29,31 In a series of 10 patients (mainly suffering
ing Scale, assessment of alertness (simple and precued from major depressive disorder or schizophrenia),
reaction time tasks), and tests of executive function Damier et al.29 reported no cognitive change 6 months
(Stroop, Trail Making Test, phonemic and category after surgery using global cognitive efficiency scales
word fluency) and memory (Digit span and Rey audi- (MMSE, Mattis DRS) and frontal scales (Frontal
tory verbal learning test). The only significant change Assessment Battery and Frontal Behavior Scale). Nine
from before to after surgery was a slight improvement other consecutive patients with TD reported by
on form A of the Trail Making test, which was at Gruber et al.31 who underwent GPi DBS showed sta-
least partially explained by motor improvement. Indi- ble performance before surgery and between 18 and
vidual patients showed improvement or decline on 80 months after surgery on verbal intelligence, atten-
several measures at least some of which may be tion, executive, and verbal learning tasks. Five of these
explained by postoperative changes in pharmacother- patients presented mild to moderate cognitive deficits
apy. The five patients in this study who were tested before surgery (Mattis DRS scores ranges between 116
under identical pharmacological medication before and 130/144).
and after surgery did not show any change on any GPi DBS has also been shown to have no cognitive
cognitive measures. impact in a group of 13 adults with dystonia-choreoa-
In agreement with the above studies, three other stud- thetosis cerebral palsy without cognitive impairment
ies in patients with bilateral GPi DBS32,34,37 that used before surgery. Performance on global cognitive effi-
more global measures of cognitive function did not ciency tasks (MMSE, Progressive Matrices of Raven
show a significant postoperative change in cognition. In PM38), executive functions (Similarities and Arithme-
contrast, Kiss38 reported significant declines greater tic subtests of the Revised Wechsler Adult Intelligence
than two standard deviations in phonemic verbal flu- Scale, Modified Wisconsin Card Sorting Test), and
ency in one case and in verbal memory in another, 12 free and cued selective reminding (Gröber and
months after GPi DBS surgery. Although no details of Buschke test) appeared to remain stable 1 year after
the neuropsychological assessment were provided, these surgery.36 Two other case studies28,30 reported no sig-
cases were part of a sample of 10 patients with CD nificant cognitive change after GPi DBS in patients
with secondary dystonia.
who were found to have normal cognitive function
before surgery. However, the authors noted that despite
these cognitive changes patients’ daily life and working Conclusions
ability was not impacted. Bilateral GPi DBS in dystonia does not produce any
Kleiner-Fisman et al.33 assessed four patients with CD major adverse effects on cognition. In fact, perform-
before and 3 to 12 months after bilateral stimulation of ance on some tests of cognition is reportedly improved
the subthalamic nucleus. The neuropsychological tests after DBS surgery (concept formation, reasoning, and
used were attention/working memory (WAIS III Digit executive function). However, there are a number of
span, Letter-Number Sequencing, and Arithmetic), exec- caveats to this conclusion. First, in the majority of
utive function (Wisconsin Card Sorting Test, Stroop these studies, patients have been cognitively screened
Test, Trail Making Test, phonemic and category word before surgery using global evaluation tools and sub-
fluency), language (Boston naming test, BDAE Complex jects scoring below 24/30 on MMSE or below 120/
Ideational Material Test, WAIS-III Similarities), memory 144 on Mattis DRS have largely been excluded.
(Hopkins verbal learning test-revised, Brief Visuospatial Therefore, the conclusion of lack of adverse cognitive
Memory Test-revised), processing speed (Tapping Test, effects applies largely to a preselected group of
WAIS-III Symbol search, and Digit symbol), and visuo- patients with no major cognitive problems before sur-
spatial functions (Clock-drawing test). Preoperative gery. Second, where parallel forms of tests were not
verbal and visual memory was poor in three and all four available or have not been used, and in the absence of
of the patients, respectively. At 1-year follow-up, all four a ‘‘waiting list’’ dystonia control group who did not
patients showed a mild and nonsignificant decline in ex- have surgery, practice effects are likely to confound
ecutive functions. Furthermore, one patient showed a postsurgical cognitive results, particularly when the
significant decline in verbal memory and two others in duration of follow-up was short. Third, postsurgical
visual memory after surgery. Nevertheless, it was con- changes in antidystonia pharmacotherapy, particularly
S72 Movement Disorders, Vol. 26, No. S1, 2011N E U R O P S Y C H O L O G I C A L , N E U R O P S Y C H I A T R Y , A N D Q O L I N D B S
TABLE 2. Brief and more comprehensive cognitive assessments recommended in dystonia before and after DBS
surgery to be used in clinical practice or for research evaluation, respectively
Clinical practice Research evaluation
Global cognitive efficiency MMSE MMSE
Non verbal reasoning Raven’s PM38 (adults) or Raven’s PM47 (children)
Verbal IQ Similarities (WAIS-III); Comprehension (WAIS-III); Vocabulary
(WAIS-III); Arithmetic (WAIS-III); Digit Span (WAIS-III)
‘Frontal’ executive function Frontal Assessment Battery; Stroop task; Frontal Assessment Battery; Stroop test; Verbal Fluency
Verbal literal fluency
Attention Computerized tests
Memory language Selective Reminding Task; Recognition Memory for Faces;
Graded Naming Test;
Visuospatial function Judgment of Line Orientation
MMSE: Mini Mental State Examination, WAIS-III: Wechsler Adult Intelligence Scale.
reductions of anticholinergic medications that can nonverbal reasoning/cognitive efficiency such as Rav-
influence memory, also operate as another confound- en’s Standard Progressive Matrices (adults) or Colour
ing factor possibly masking any cognitive decline Progressive Matrices (children) would be appropriate
resulting from pallidal surgery. Fourth, when muscle cognitive screening tools.
cramps or postural deviations are severe, patients with
dystonia allocate considerable attentional resources in Should Neuropsychological Assessment Be
controlling their motor symptoms. Postsurgically, the Comprehensive or Not? What Areas Should Be
symptomatic improvement of the dystonia may liber- Examined? What Is an Optimal Selection of
ate such attentional resources that can now be allo- Assessment Tools?
cated to performance of cognitive tasks. Finally,
individual patients have shown significant postopera- Detailed neuropsychological assessment is recom-
tive decline on specific cognitive tests in some studies mended for research purposes mainly. In fact, this
(e.g., Halbig et al.,26 Kiss,38 and Kleiner-Fisman would provide precious information if used in well-
et al.33), which were masked by lack of significant controlled and randomized studies. The following
change at the group level. Report of individual patient guidelines can aid in the optimal selection of tests:
data along with group means would provide a fuller
picture of cognitive change after surgery. 1. Include tests for assessment of intellectual ability
(WAIS III (adults) or WISC-R (children), with pri-
Pragmatic Recommendations for the mary focus on vocabulary, comprehension, simi-
Preoperative Cognitive Assessment larities, and arithmetic scales), memory, attention,
language, as well as tests with specific focus on ex-
Is Neuropsychological Screening Essential?
ecutive and visuospatial functions where deficits in
What Screening Tools Should Be Used?
cognition have been reported in dystonia.
Primary dystonia does not share the degenerative pro- 2. Aim for short duration (less than 90 minutes) of
cess of PD and does not produce major cognitive neuropsychological assessment to minimize fa-
impairment. Bilateral GPi DBS in dystonia does not tigue effects.
produce any major adverse effects on cognition in the 3. Utilize tests requiring minimal writing or hand use
majority of cases. Even in secondary dystonia, such as to minimize the frequently severe motor disability.
HSS or TD, there is no evidence that GPi DBS worsens 4. Select tests that can be performed in adults and
the patient’s cognitive profile. Nevertheless, we recom- children (with equivalent forms).
mend a cautious approach to be adopted and a brief 5. Select tests with parallel equivalent versions or
neuropsychological screening applied to all patients which are less sensitive to test-retest effects.
with dystonia about to undergo DBS surgery (see Table
2).We recommend that cognition is also monitored
Pragmatic Recommendations for the
postoperatively, as any form of brain surgery poten-
Postoperative Period
tially carries a risk of adverse cognitive effects.
Based on the literature, the cognitive functions likely What Problems Are Expected After DBS?
to be impaired in dystonia patients are nonverbal What Factors May Adversely Influence the
reasoning, executive functions, and memory. Rapid Cognitive Outcome?
assessment of global cognitive functioning using the There is no direct empirical evidence available from
Mini-Mental State Examination, frontal executive patients with primary or secondary dystonia allowing
function (verbal fluency and Stroop) or measures of identification of specific risk factors for adverse
Movement Disorders, Vol. 26, No. S1, 2011 S73J A H A N S H A H I E T A L .
cognitive outcomes. To aid in identifying any such sion BDI >25)34 (see Table). This approach excludes a
risk factors, a follow-up of the cognitive state, using sizeable minority of patients with dystonia.44 However,
the same neuropsychological tests on pre- and postop- there has been one study recently published in which
erative assessment a minimum of 12 months after sur- patients scored in the severe range (>28) on the BDI.37
gery to minimize practice effects, is recommended as What these studies demonstrate is that depression, as
part of future randomized trials. measured using the BDI, appears stable at 12 months and
3 years follow-up35,45 and BDI scores may in fact show
Points to Be Addressed statistically significant improvement at 6 months34 and at
The influence of depression, anxiety, and obsessive- 1 year.37 These same studies have also shown that anxiety
compulsive disorder (OCD) on cognition in patients with scores tend to remain stable in this patient population.
dystonia requires clarification. Indeed, depression is rela- The case for close psychiatric follow-up of patients af-
tively common in dystonia39 with about 25% to 30% of ter GPi DBS is perhaps strongest with reports of two sui-
patients being moderately to severely depressed,40–43 and cides following the procedure.46 The report of Foncke
it is known to affect cognitive function,39 making compar- et al.46 causes great concern as there were two suicides in
ison of cognitive function in subgroups of dystonia a cohort of 16 patients reported. Both patients were male
patients with and without depression interesting. and had a previous history of depression. One of the sui-
Comparison of cognitive function in patients with cides was within a month of surgery before any motor
the DYT1 gene versus those with idiopathic or second- improvement was noted. The other occurred 14 months
ary dystonia would also be a topic of interest for postoperatively in an individual who was not apparently
future studies. Finally, the effect of discontinuation or depressed and who benefited greatly from the DBS inter-
reduction of anticholinergic medication on cognition vention in terms of ability to work, socialize, and func-
should be examined. tion. These reported suicides are of clinical concern and
suggest that there may be an increased risk of suicide
post-DBS for dystonia.
Section 2: Psychiatric Disorder
Preoperative Psychiatric Status of Patients Other Forms of Dystonia
With Dystonia
Other than primary dystonia, TD has been most
Available Evidence studied. Gruber et al.31 recently reported a case series
The majority of the existing literature on the psychi- of nine patients who underwent GPi DBS for TD. Of
atric aspects of dystonia has focused on CD. This litera- note is that five of those patients had a significant his-
ture has been previously reviewed by Jahanshahi.42 tory of depression that was apparently the original in-
Depression, anxiety, and OCD seem to be the most dication for neuroleptic use. The use of these
common psychiatric diagnoses in dystonia.42 Available medications in the treatment of depression suggests
evidence indicates that psychiatric morbidity is higher that the depressions were either severe or refractory to
in dystonia than in community samples or patients with therapy with antidepressant agents alone. However, at
other chronic illnesses. In a recent study of 329 patients the time of surgery, none of the study patients had
with focal, multifocal, segmental, hemi-, or generalized severe depression (MADRS > 29), which was used as
dystonia 30% of the sample was moderately to severely an exclusion criterion. In the postoperative period,
depressed as assessed by the Beck Depression Inventory mild to moderate depression improved.
(BDI).44 Given the severity and frequency of psychiatric In another study, 10 TD patients treated with bilateral
illness in this population, suicide is of particular con- GPi DBS were investigated.29 In this case series, six
cern; however, the rate of suicide and its determinants patients had a history of depression, with one subject still
in this population is unknown. suffering from active and severe depression (MADRS ¼
44). The results of this study are not altogether clear;
Effect of DBS on Psychiatric Disorders however, the one subject with severe depression
in Dystonia improved significantly in terms of her depression,
Available Evidence whereas three other patients developed symptoms of
depression. One of these other patient’s depressive symp-
Studies that have examined the effect of DBS sur- toms was severe enough to warrant treatment. Kosel
gery on psychiatric illness in dystonia are summarized et al.78 also report successful GPi DBS for a patient with
in Table 3. TD who had a severe depression with many months of
preoperative hospitalization. After surgery, the depressive
Primary Dystonia symptoms showed ‘‘clinically significant improvement.’’
The effects of GPi DBS on primary generalized or seg- Another secondary dystonia patient group that has
mental dystonia have largely excluded any candidates who recently been investigated is patients with dystonia-
had ‘‘major psychiatric disturbances’’35,37 or severe depres- choreoathetosis in cerebral palsy.36 These were adult
S74 Movement Disorders, Vol. 26, No. S1, 2011TABLE 3. Investigations of the impact of DBS for dystonia on mood
Illness Length of
Mean age, duration, DBS follow-up Exclusion
Investigator N Sample range (yr) range (yr) target (mean in mo) criteria Mood measures (SD) Mood conclusions
Primary dystonia
Krauss et al.77 2 Generalized dystonia 51 and 58 39 and 12 Bilateral GPi 24 ‘‘Major psychiatric disorders’’ HDRS 10–2 and 18–4 Mild to moderate
depression resolves
26
Halbig et al. 15 13 various primary 45.5, 13–38 12.6, 6–62 Bilateral GPi 6.5 (3–12) ‘‘Able to cooperate with BDI 13.6 (9.5) to 9.4 (11.3) P ¼ 0.06; MADRS Mild to moderate
dystonias (3 DYT1 þve), surgery and follow-up’’ 13.1 (9.6) to 7.7 (7.7) P ¼ 0.01; depression improves
2 tardive dystonia BAI 15.0 (12.8) to 10.9 (12.3) P ¼ 0.2;
BPRS 27.7 (11.4) to 19.4 (8.5) P ¼ 0.09
Vidailhet et al.45 22 Primary generalized dystonia 30, 14–54 18, 4–37 Bilateral GPi 12 ‘‘Absence of psychiatric BDI 11.3 (7.0) to 8.3 (7.9) P ¼ 0.15 (3 of 5 No change in mood (at most
disturbances’’ stopped antidepressants) moderate depression at start), but
some were able to discontinue
antidepressants
Vidailhet et al.35 As above As above As above As above As above 36 As above BDI 11.3 (7.0) to 7.8 (8.0) P ¼ 0.23 As above
Kupsch et al.34 40 Primary segmental (16 pts) 39.5 19.5 GPi bilateraleral 9 BDI > 25 BDI 10.1 (6.5) to 7.1 (6.7) P ¼ 0.008; BAI BDI scores fell, at most
and generalized 12.9 (10.7) to 9.4 (7.6) P ¼ 0.09; moderate depression at start
dystonia (24 pts) BPRS 27.4 (7.6) to 25.3 (7.1) P ¼ 0.19
Piacentini et al.52 1 Generalized dystonia 30 11 Bilateral GPi; left 9 mo depression ‘‘No premorbid psychiatric At 5 mo became depressed with delusions. Electrode migration to region of
electrode migration with delusions features, including NPI—severe apathy, depression; moderate amygdala can cause severe
to stria terminalis, depression’’ anxiety; mild agitation, and irritability, psychiatric disturbances.
fimbria delusions. These cleared with left
electrode replacement
N E U R O P S Y C H O L O G I C A L ,
Kiss et al.38 10 Cervical dystonia 57.5, 47–64 16.5, 5–28 Bilateral GPi 12 ‘‘Psychiatric diagnosis’’ BDI 14.2 (7.2) to 6.0 (3.5) P 29, dementia P ¼ 0.004 improves even in those with
neuroleptic use (5 patients history of significant depression
with history of depression)
Q O L
continued
Movement Disorders, Vol. 26, No. S1, 2011
I N
D B S
S75J A H A N S H A H I E T A L .
patients with secondary dystonia since birth and aver-
For all scales, higher numbers indicate greater pathology. Beck Depression Inventory (BDI; 0–63): 28 severe; Hamilton Depression Rating Scale (HDRS; 0–50): 23 very severe; Montgomery-Asberg Depression Rating Scale (MADRS; 0–60): 18 moderate to severe; Neuropsychiatric Inventory (NPI; 0–
age length of illness of 33 years. Patients were
improves, anxiety increases
Mood conclusions
psychiatrically ill patients
screened for psychiatric illness, and only those with
Psychological status of not
post surgery following
medication changes
‘‘no psychiatric disorders’’ were included in the study.
Despite this criterion, one patient was taking two anti-
Risk of suicide
depressant agents and a benzodiazepine when enrolled
with DBS
in the study, whereas four others were taking benzo-
diazepines only presumably for the treatment of dysto-
nia symptoms. After surgery, depression as measured
by the BDI was ‘‘not affected,’’ and the one patient
taking antidepressants was able to stop those medica-
ideations, and psychotic symptoms
SCL-90 subscales of interpersonal
improved P > 0.05. Five patients
Mood measures (SD)
dysfunction and memory deficits
sensitivity, depression, paranoid
anxiety, 1 patient stopped SSRI
tions. However, five other patients were started on
previous history of depression,
drug dependency þ executive
One patient completed suicide;
specific serotonergic reuptake inhibitors for anxiety.
were started on SSRIs for
There has also been one reported suicide in a 26-year-
aggressive behavior,
near time of death
TABLE 3. Investigations of the impact of DBS for dystonia on mood (Continued)
old man with secondary, postanoxic dystonia 4 months
BDI ‘‘not affected’’
following surgery.47 He had had DBS in the Voa of the
thalamus before the suicide and previous DBS of the
GPi. He also had a history of substance dependence, ex-
ecutive dysfunction, and memory deficits.
severely depressed’’, ‘‘all had
low scores on’’ MADRS
‘‘No psychiatric disorders’’
depression, ‘‘none was
Conclusions
Some had past history of
Exclusion
criteria
It appears that GPi DBS is safe in dystonia patients
MMSE > 24
with mild to moderate depression. Depression may in
fact improve with this intervention. However, as pri-
mary dystonia patients with severe depression have
largely been excluded from DBS surgery, the potential
4 mo post second
(mean in mo)
psychiatric outcome for this group remains uncertain.
Length of
follow-up
DBS (Voa)
One recent study of 22 patients who scored in the
severe range on the BDI showed some improvement at
12
1 year, although the same study excluded patients
with ‘‘active psychiatric symptoms.’’37 There are also
1st Bilateral GPi 2nd
Bilateral nucleus
some case reports suggesting safety of GPi DBS in TD
oralis anterior
target
DBS
patients with a history of severe depression and in
Bilateral GPi
ventralis
144); Beck Anxiety Inventory (BAI; 0–63); Brief psychiatric Rating Scale (BPRS; 0–168).
those who are still severely depressed.
Anxiety is not generally affected, but there are some
suggestions that it may be exacerbated after GPi DBS
range (yr)
From early
duration,
childhood
Illness
surgery, although the withdrawal of benzodiazepine
6
treatment in the postoperative period may be a con-
founder.36 Although OCD is another common psychi-
Mean age,
range (yr)
33, 20–44
26 at time
atric problem in dystonia,42 no information about the
of death
effect of DBS surgery on OCD in dystonia is available.
What is of clinical concern is the relatively high
incidence of suicide following DBS for dystonia. Risk
Dystonia-choreoathetosis
factors for suicide in this population are relatively
Postanoxic generalized
Sample
unknown but may include male gender.
cerebral palsy
dystonia
Pragmatic Recommendations in the
Preoperative Period
Is Neuropsychiatric Screening Essential? What
1 of ?
N
Screening Tools Should Be Used? What Areas
13
Should Be Examined? What Is an Optimal
Burkhard et al.47
Vidailhet et al.36
Selection of Assessment Tools?
Investigator
Screening of dystonia patients for severe psychiatric
illness before surgery is highly recommended. Short of
all patients being seen by a psychiatrist for preoperative
S76 Movement Disorders, Vol. 26, No. S1, 2011N E U R O P S Y C H O L O G I C A L , N E U R O P S Y C H I A T R Y , A N D Q O L I N D B S
TABLE 4. Recommended psychiatric assessment for patients with dystonia candidate for DBS surgery
Depression: current; Screen for using any one of Mild: proceed to surgery
the following: Moderate:
1. Beck Depression Inventory, 1. Decision based on individual patient factors
2. Hospital Anxiety and Depression Scale, 2. Evaluate use benefit ratio of current medications, e.g., tetrabenazine
3. Hamilton Rating Scale for Depression, 3. Consider antidepressant treatment
4. Montgomery-Asberg Depression Rating Scale Severe:
1. Refer to psychiatry
2. Surgery when depression treated
3. Use antidepressants
4. Ensure antidepressants continued postoperatively
5. Psychoeducation for potential relapse
6. Close postoperative follow-up with adequate postoperative psychiatric management and support
7. Patients with nonmodifiable high suicide risk are relatively contraindicated from surgery
Treatment-refractory severe depression: relative contraindication from surgery
Depression: past history Mild: single episode, responded to treatment
1. Proceed to surgery
Moderate-Severe, hospitalization, suicidal ideation, psychosis, and electroconvulsive therapy
1. Refer to psychiatry for treatment optimization
2. Psychoeducation for potential relapse
3. Ensure adequate postoperative psychiatric management and support
4. Ensure antidepressants continued postoperatively
5. Close postoperative follow-up
Suicidal ideation Refer to psychiatry for assessment of suicidal ideation severity, management, and appropriateness for
surgery
Anxiety Moderate-severe
1. Optimize treatment
2. Proceed to surgery
if agoraphobia present,
1. Consider referral to psychiatry
2. Optimize anxiolytic treatment
3. Continue treatment postoperatively
4. Gradual postoperative medication reduction especially of benzodiazepines
assessment, there are a number of screening tools that patients with dystonia who have undergone DBS sur-
have commonly been used in studies to stratify patients gery.46,47 All three patients were males and aged 26,
into levels of severity of symptoms. These include the 44 and 53 years at the time of death. Thus, male gen-
BDI48 and the Beck Anxiety Inventory.49 There are der may be a potential risk factor for suicide in this
other patient-rated measures of mood such as the Hos- population. There is also one case report of the onset
pital Anxiety and Depression Scale50 or clinician-rated of postoperative depression secondary to electrode
measures such as the Hamilton Rating Scale for Depres- migration.52 This possibility should be kept in mind in
sion51 that can also be used to screen patients. Based on the differential diagnosis in cases of increased depres-
the scoring of these tools, patients can be stratified into sive symptoms following DBS.
mild, moderate, or severely depressed for screening pur- In assessing for suicide, risk it is important to con-
poses. Each of these scales also contains an item asking sider that the act of suicide is driven by a complex
about suicidal ideation. Patients identified to have severe interaction of variables, including gender and a host
depression and those with prior suicidal attempts or cur- of physical and psychosocial factors. A single factor
rent suicidal ideation should be assessed by a psychia- such as depression is insufficient in predicting suicide
trist experienced in the treatment of this population as each factor accounts for only a small proportion of
before consideration of DBS surgery (see Table 4). There the variance in risk and lacks specificity.53 Known sui-
is insufficient evidence to suggest that severe mental cide risk factors in the general population include
illness is an absolute contraindication to surgery but psychiatric disorders, especially depression, previous
should be treated as a relative one. psychiatric hospitalization, male gender, older age,
being single, comorbid physical illness, and previous
What Problems Are Expected After DBS? suicide attempts.54–56 There may also be an increased
What Factors May Adversely Influence the risk of suicide with definitive or ‘‘end of the line’’
Psychiatric Outcome? treatments of chronic debilitating illness given that sui-
Mild to moderate and maybe even severe depression cide rates are higher after DBS for PD,57 epilepsy sur-
appears to improve in the postoperative period. How- gery,58 and bariatric surgery for obesity.59 There have
ever, three suicides have been documented among not been any specific risk factors for suicide identified
Movement Disorders, Vol. 26, No. S1, 2011 S77J A H A N S H A H I E T A L .
in those undergoing DBS for dystonia. Therefore, no TABLE 5. Postoperative management of specific
single psychiatric factor is sufficient to predict risk and psychiatric symptoms following DBS for dystonia
serve as an absolute surgical contraindication. How- Depression Mild to moderate
ever, we would recommend that patients be screened 1. evaluate medication use especially tet-
for suicidal ideation and the presence of major mental rabenazine and benzodiazepines
illness before surgery. Those identified should be 2. consider antidepressants 6
psychotherapy
assessed further by a psychiatrist and any reversible 3. evaluate suicidal ideation
risk factors, such as major depression, directly treated. 4. consider psychiatric referral
Clinicians should also continue to actively inquire Severe or treatment refractory
about suicidal ideation in the postoperative period. 1. refer to psychiatry
We provide basic algorithms for psychiatric treatment 2. evaluate suicidal risk
3. assess electrode placement/migration
of identified psychiatric pathology in the postoperative 4. evaluate temporally associated simulator
period in Table 5. parameter changes
5. optimize pharamacological management
using antidepressant switching and aug-
Points to Be Addressed mentation strategies
The relationship of dystonia and major psychiatric 6. safety of electroconvulsive therapy
illness has not been clearly elucidated especially in pri- uncertain but one case report of efficacy
in Parkinson’s disease and DBS has
mary dystonia. It is conceivable that the treatment of been published (Chou KL Park Relat
psychiatric illness could markedly improve patients’ Disord 2005;11:403)
QoL and satisfaction with operative outcome. Simi- Suicidal ideation 1. Refer to psychiatry
larly, refractory psychiatric illness may have a mark- 2. Evaluate for presence of depression,
edly negative impact on patients’ QoL and subjective mania, substance/medication withdrawal
3. assess electrode placement and
postoperative well being. parameter setting changes
Elucidating the relationship of major mental illness 4. consider need for hospitalization
and personality disorders to subjective and objective
outcome measures would be helpful in providing fur-
ther guidance in patient selection. These factors may
also be relevant in assessing patient expectations of ities particularly affected.41,44 The negative impact of
postoperative outcome and ability to work with the dystonia on marital status, employment status, and
treatment team in follow-up. annual income has been documented.43,61 The ‘‘visi-
Age of dystonia onset and patient gender are possi- ble’’ focal dystonias such as CD and spasmodic dys-
bly important determinants of susceptibility to psychi- phonia, which affect physical appearance and patients’
atric morbidity in dystonia. Future studies should ability to communicate verbally, respectively, are the
consider focusing on prevalence of psychiatric prob- most likely to affect social interaction and have been
lems among cases with childhood onset generalized found to be associated with high perceptions of
dystonia compared with those with adult-onset stigma.62 The perceived disfigurement, negative body
dystonia.42 concept, and low self-esteem associated with dystonia
have been shown to be major contributors to
Section 3: Social Functioning depression.40,41,44
Gudex et al.63 administered the SF-36 and EuroQol
and QoL measures to 130 adults with various forms of dysto-
Social and QoL Issues in Dystonia nia. On the EuroQol, patients with dystonia were
Available Data significantly worse on the mobility, self-care, usual
activities, pain/discomfort, and anxiety-depression sub-
Health-related QoL (HRQoL) encompasses the sum
scales relative to normative data from the general pop-
total effect of a chronic illness such as dystonia and its
medical treatment on the individual’s physical, psycho- ulation. Those with nonfocal dystonia had more
logical, social, and occupational functioning. It is problems on the mobility, self-care, and usual activ-
uniquely individual. The most common tool used to ities subtests than patients with focal dystonia, differ-
assess HRQoL in dystonia is the generic short form ences on usual activities being the only significant one.
(SF)-36, which provides a score from 0 (worst health Patient scores on the SF-36 also indicated poorer QoL
state) to 100 (best health state) calculated for eight than the general population norms, but the differences
domains.60 Scores can also be aggregated to generate were not significant.
physical and mental groupings. The SF-36 was administered by Muller et al.64 to 89
Patients with dystonia are frequently disabled by patients with blepharospasm and 131 patients with
their illness with social functioning and leisure activ- CD. Both dystonia groups scored significantly worse
S78 Movement Disorders, Vol. 26, No. S1, 2011N E U R O P S Y C H O L O G I C A L , N E U R O P S Y C H I A T R Y , A N D Q O L I N D B S
on all eight domains of the SF-36 compared with an Little data are available concerning other types of dys-
age-matched community sample in this study. Pain tonia. Furthermore, available data relate mainly to
was significantly worse for the CD group. There were HRQoL as measured by the SF-36. The impact of sur-
no other significant differences in any of the other gery on other aspects of social functioning such as
QoL domains between the two dystonia groups. employment, income, marital relationship, social, and
Women with blepharospasm scored significantly lower leisure activities have not been evaluated in any great
on all SF-36 scales than male patients. Blepharospasm detail.
patients, particularly males with a longer duration of Vidailhet et al.35,45 investigated the impact of pal-
illness, had a significantly better QoL, perhaps sug- lidal stimulation on HRQoL 1 year and 3 years after
gesting some form of adaptation to the illness over surgery in 22 patients with primary generalized dysto-
time. nia using a French-validated version of the SF-36.
The Epidemiological Study of Dystonia in Europe They reported significant improvement on general
Collaborative Group administered the SF36 to 289 health and physical functioning subscales of the SF-36,
patients with CD in seven European countries.65,66 with the change in vitality approaching significance
Patients with CD had worse QoL on all eight domains (0.07) 1 year after surgery.45 Changes in physical role,
of the SF36, compared with a cross-section of the gen- emotional role, social functioning, pain, and mental
eral population of similar age. QoL scores showed sig- health subscale of the SF-36 did not change signifi-
nificant effects of age (worse QoL with older age), cantly following surgery. At 3 years follow-up, a simi-
gender (better QoL for males), and education (worse lar pattern of significant improvement in general
QoL for those with lower education). Positive self- health, physical functioning, and pain was observed,
esteem and self-deprecation, retired status, duration of together with no change in the social functional and
illness, and severity of CD were the only factors that emotional role components of the SF-36.35 Halbig
remained significant predictors of SF-36 physical sum- et al.26 used the PDQ-39 to assess changes in HRQoL
mary scores after multivariate analysis. For the SF36 with GPi DBS in 15 consecutive series of patients with
mental summary score, anxiety and depression, disease multifocal, segmental, or generalized dystonia. Scores
duration and severity, cohabitating status, self-depre- on the PDQ-39 were significantly better after surgery,
cation, and social support were all important with an average improvement of 24.7 points.
predictors. Bereznai et al.68 used the SF-36 to assess the effect
QoL in those with focal, segmental, or generalized GPi DBS in 6 patients with CD, segmental, or general-
dystonia was investigated in a community sample of ized dystonia. After surgery, an average improvement
276 patients using the SF-36 and the EuroQoL.67 of 36% on the SF36 was documented with a signifi-
Compared with normative data for the United King- cant improvement on the physical functioning, pain,
dom population, dystonia patients reported worse vitality, social functioning, and general mental health
QoL on all domains, particularly those related to subscales.
physical and social functioning. Patients with general- In the closed label phase of their trial on 40 patients
ized dystonia reported significantly worse QoL than with primary segmental or generalized dystonia, Muel-
those with focal dystonia. There was no age or gender ler et al.69 observed a significant improvement of the
effect on QoL. Disability, body concept, disfigure- HRQoL on the following SF-36 subscales: physical
ment, depression, extent of dystonia, and employment functioning, bodily pain, general health, and vitality in
status were the predictors of HRQoL in this popula- the active stimulation group compared with the sham-
tion. These results confirm previous work in CD that stimulation group 3 months postsurgery. In the open
established disfigurement and body concept as key label phase at 6 months postsurgery, all SF-36 domains,
determinants of psychosocial adjustment in with both the physical and mental components, were
dystonia.40,41,43,65 significantly improved with DBS. No difference
between segmental and generalized dystonia was noted.
For their sample of four CD patients with subthala-
Impact of DBS Surgery on QoL in Dystonia mic nucleus DBS, Kleiner-Fisman et al.33 reported no
Available Evidence change on the SF-36 relative to the preoperative scores
Together with the Burke-Fahn-Marsden Dystonia assessed at 3 months after surgery, but marked
Rating Scale, measures of HRQoL have become stand- improvement on the mental component at 12 months.
ard outcome measures to evaluate DBS surgery in dys- In the sample of 10 patients with CD, Kiss38 also
tonia (see Table 6). Generally, studies report that found a significant (24%) improvement of HRQoL on
HRQoL is significantly improved following DBS of the SF-36 after GPi DBS surgery.
the GPi, in both aspects of physical and mental health. Blahak et al.70 investigated the impact of bilateral
Most of the studies report on patients with primary pallidal stimulation on HRQoL in 10 patients with id-
generalized dystonia or primary segmental dystonia. iopathic segmental dystonia. The total scores on the
Movement Disorders, Vol. 26, No. S1, 2011 S79S80
TABLE 6. Quality of life outcome studies in patients with dystonia and GPi DBS
Investigators Sample N Target QoL Measure Conclusions
Primary dystonia
Vidailhet et al.45 Primary generalized dystonia 22 GPi bilateral SF-36 Improvement on the general health and physical functioning
subscales (N E U R O P S Y C H O L O G I C A L , N E U R O P S Y C H I A T R Y , A N D Q O L I N D B S
SF-36 improved as did both physical and mental sub- givers.73 Patients reported a median improvement of
scores. After the first postsurgical follow-up (mean 7.5 80.4% at 3 months and 83.3% at 9 to 15 months post-
months, range 4–10 months), an improvement in 9 of DBS. A 20% improvement of HRQoL was reported by
10 patients was observed with a significant increase of 70% of the 20 caregivers at 2 to 6 months and 64.7% of
the total score by approximately 40%. After the sec- the caregivers at 9 to 15 months post-DBS.
ond evaluation (mean 17 months; range 12–20
months), all patients showed a significant increase of
51% on the SF-36. Although several preoperative SF- Conclusions
36 scores were impaired (physical functioning, role
The effectiveness of GPi stimulation for several types
limitations due to physical problems, general health,
and social functioning), the majority of patients of dystonia is highly suggested by the improvement in
achieved postoperative scores within the normal range both physical and mental aspects of HRQoLand
encourages its application to patients not responsive
of the German population.
to other treatments.
Pretto et al.71 investigated nine patients with second-
ary dystonia and four patients with primary torticollis.
All patients assessed their own HRQoL using a stand-
ardized 7-point Global Rating Scale with a range of Pragmatic Recommendations
scores from markedly worse (3) to markedly HRQoL measures that rely on patient self-report are
improved (þ3). The physician also rated pre- and now considered important indices of the impact of
postoperative HRQoL. A marked improvement was chronic illness and its treatment along with measures
reported by 7 of 13 patients, moderate by three of impairment or disability. Evaluation of HRQoL
patients, slight by one patient, and no change by one should be incorporated in the routine pre- and postop-
patient (one was lost to follow-up). Self-reported erative assessment of DBS surgery in dystonia. Opti-
scores and examiner evaluations were concordant. mal points for such an assessment are within a month
By using the SF-36 and the Hopkins Symptom before surgery and then 6 and 12 months after surgery
Checklist (SCL-90) for psychiatric evaluation, Vidail- and subsequently at yearly intervals.
het et al.36 reported a significant improvement of the
‘‘body pain’’ and ‘‘mental health’’ subscores 12
months after surgery in 13 patients with dystonia sec- Points to Be Addressed
ondary to cerebral palsy. GPi DBS seems also benefi-
All studies have used generic HRQoL measures such
cial for the HRQoL of patients with TD, as shown by
as the EuroQol or the SF-36 to assess HRQoL in dys-
the improvement of physical components and social
tonia. Reliance on such generic measures allows com-
functioning score of the SF-36 in 9 patients.31
parisons of HRQoL in dystonia with normative data
Skogseid72 reported the results of a GPi DBS
for the general population and with other neurological
randomized sham-controlled trial performed by the
disorders such as PD. However, it is also possible that
Dystonia Study Group on HRQoL measured using the the lack of disease-specific HRQoL measures in dysto-
SF36. QoL was measured in 40 patients with segmen- nia means that disease specific effects are missed. Stud-
tal or generalized dystonia at baseline, 3 months, and ies have shown that disfigurement, negative body
6 months. The first 3 months were sham-stimulation image, and self-deprecation associated with postural
controlled. During this period, the active-stimulation abnormality may be central features of patients’ emo-
DBS group showed significant improvement of dys- tional well being in these disorders40,43,65,74 but
tonic movements, pain and disability, and 4 of the 8 missed when using generic HRQoL measures. A dis-
SF36 domains relative to the sham-stimulation group. ease-specific cranio-CD questionnaire (CDQ-24) has
In the next phase in which all subjects received active been developed by Muller et al.75 There is a need for
stimulation, significant improvement in all domains of a disease-specific HRQoL measure applicable across
the SF36 was reported. all types of dystonia. In addition to standard HRQoL
In the Spanish multicentre study of 22 patients (plus assessments, the impact of surgery on other aspects of
two dropouts) with primary generalized or segmental social functioning, such as employment, marital rela-
CD, Valldeoriola et al.37 reported significant improve- tionship, and social and leisure activities of patients
ment of HRQoL, mainly the physical and to a lesser with dystonia, would be of future interest.
extent in the emotional domains, were obtained on the The Reliable Change Index method of estimating
SF36 and the EuroQoL scales at 12 months follow-up. clinically significant change has been applied to the
Finally, a retrospective multicentre study of the effect SF-36 total and subscale scores by Ferguson et al.76
of GPi DBS to treat dystonia in 23 patients with neurode- Such Reliable Change Index could be used to evaluate
generation with brain iron accumulation relied on global the clinical significance of change in HRQoL with
subjective 1 to 10 ratings of HRQoL by patients and care- DBS surgery for dystonia.
Movement Disorders, Vol. 26, No. S1, 2011 S81You can also read
