Diagonistic dyspraxia - Clinical characteristics, responsible lesion and possible underlying mechanism
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Brain (1996), 119, 859-873
Diagonistic dyspraxia
Clinical characteristics, responsible lesion and possible
underlying mechanism
Y. Tanaka,1 A. Yoshida,3 N. Kawahata,4 R. Hashimoto1 and T. Obayashi2
Departments of ^Neurology and 2Clinical Pathology, Jichi Correspondence to: Yasufumi Tanaka, MD, Department of
Medical School, Tochigi and the Departments of ^Speech Neurology, Jichi Medical School, 3311-1 Yakushiji
Therapy and ^Neurology, Narita Memorial Hospital, Minamikawachi, Tochigi 329-04, Japan
Toyohashi, Japan
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Summary
We present three patients who showed, in addition to signs be excluded from diagonistic dyspraxia. Comparison ofMRls
of callosal interruption, a variety of abnormal motor of the three patients with those of five patients who developed
behaviour of the left hand dissociated from conscious volition, no diagonistic dyspraxia following an infarction of the corpus
in the absence of pathological grasping phenomena. The callosum, with or without medial hemispheric involvement,
abnormal movements of the left hand consisted of (i) revealed that damage to the ventral part of the posterior end
antagonistic movements to the right; (ii) non-antagonistic, of the body of the corpus callosum was crucial for the
irrelevant movements to the right; (Hi) symmetric movements development of diagonistic dyspraxia. Since the commissural
to the right in which the left hand sometimes preceded the fibres between the superior parietal lobules pass through the
right, and (iv) occasional inability to move at will during a caudal part of the body of the corpus callosum, and also
bimanual task. From these observations and a review of since there is accumulating evidence that the human superior
previous publications, we propose that, in most right-handed parietal lobule is concerned with selection of movement
subjects, diagonistic dyspraxia could be defined as abnormal based on the integration of visual and/or somatosensory
motor behaviour of the left hand activated by voluntary information, we infer that diagonistic dyspraxia is produced
movements of the right hand. Motor phenomena similar to by a disconnection of the right superior parietal lobule from
diagonistic dyspraxia but attributable to impulsive groping the left which is dominant for volitional control of movement
movements induced by medial frontal lobe pathology should in most right-handed subjects.
Keywords: diagonistic dyspraxia; alien hand; corpus callosum; superior parietal lobule
Abbreviations: AHS = 'alien hand' syndrome; rCBF = regional cerebral blood flow
Introduction
One of the most fascinating phenomena in recent behavioural 'alien' or at least 'uncooperative', thus redefining it as an
neurology is the 'alien hand' syndrome (AHS). Brion and active phenomenon. As an example of this, he described the
Jedynak (1972) coined this term in their report of four following abnormal motor behaviour of the left hand in a
patients with posterior callosal disconnection syndrome. They young patient who received corpus callosotomy 3 weeks
used the phrase Me signe de la main etrangere' (literally, 'the before: while he was doing a block design test unimanually
sign of the foreign hand') to describe their subjects' lack of with the right hand, his left hand came up from beneath the
recognition of their own left arm and hand as belonging to table and was reaching for the blocks when he slapped it
them, despite no sensory loss when the left hand was held with his right hand and said, 'That will keep it quiet for a
by the right behind the back. None of their patients had while'. Bogen (1979) considered the alien hand as possibly
involuntary movements. Bogen (1979) expanded the concept a lesser form of intermanual conflict, which is synonymous
of the alien hand to mean a 'circumstance in which one of with diagonistic dyspraxia that will be described in detail
the patient's hands, usually the left hand in the right-handed below. Since Bogen's description, the concept of the alien
patient, behaves in a way which the patient finds 'foreign', hand has been expanded to indicate a variety of unwilled
© Oxford University Press 1996860 Y. Tanaka et al.
and uncontrollable action of one hand. Goldberg et al. (19
used the term 'alien hand sign' to describe two patients w
left medial frontal cortex infarction. Their patients shov
tenacious groping and grasping movements for any nea
objects as well as a strong grasp reflex in the right ha
which sometimes interfered with tasks being performed
the left hand. Motor perseveration and purposeful moveme
such as picking up a pencil and scribbling were also no
in the right hand. Levine and Rinn (1986) reported, un
the terms opticosensory ataxia and AHS, a patient who, al
large right basal temporo-occipital and small ventral poste
lateral thalamic infarcts, showed spontaneous left s
movements such as involuntarily striking her face, trying
choke her, reaching for the neckline of her gown, pinch
her right arm or leg and knocking her glasses off. Althoi
these spontaneous movements are similar to those of
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patients described by Goldberg et al. (1981), this patient 1
no tendency toward prehensile movements and no gr.
reflex in either hand. Instead, this patient had severe ata
and sensory loss of the left hand. Levine and Rinn (19i
thought that their patient's spontaneous left arm moveme
might be an ill-controlled exaggeration of motor acts t
normally occur without intention or effort because of sev
ataxia and the lack of sensory feedback to the left a
and hand.
Recently, Feinberg et al. (1992) suggested two disti
types of AHS: a frontal form (frontal AHS) associated w
grasp reflex, groping and compulsive manipulation of toe
and a callosal form (callosal AHS) characterized
intermanual conflict and the absence of frontal features. T
classification, however, appears to be incomplete, becai
the case of Levine and Rinn (1986) cannot be classified i
either type. Also, not all patients with frontal AHS manif
compulsive manipulation of tools placed before them. There Fig. 1 CT (upper image) and T r weighted MRI (para-sagittal
is a report of patients who exhibited merely impulsive groping view, 7 mm left from the midline; lower image) of Patient 1.
movements toward any nearby objects without compulsive Damage to the corpus callosum is localized to the posterior half
of the body with some involvement of the most anterior part of
manipulation of tools (Mori and Yamadori, 1982). The
the splenium. Small lesions are also visible in the subcortical
extent and location of the lesion responsible for compulsive white matter underlying the left posterior cingulate gyrus, the
manipulation of tools may be different from that for mere deep white matter underlying the left temporo-parietal lobe, and
groping movements within the medial frontal lobe (Tanaka, the left anterior corona radiata (upper image).
1991).
More recently, another group of patients has been reported
to have AHS. Leiguarda et al. (1993) reported four patients abnormal behaviour patterns, we suggest that the term 'alien
who showed brief, paroxysmal episodes of abnormal motor hand' should not be used indiscriminately.
behaviour of the contralateral arm originating in the medial The concept of diagonistic dyspraxia was introduced by
frontal region, or short lasting episodes of unawareness of Akelaitis and colleagues (Akelaitis et al., 1942; Akelaitis,
the location of the contralateral arm, lack of recognition of 1945) to describe a peculiar motor behaviour in two patients
the arm as their own and illusion of movement or actual who received corpus callosotomy for intractable epilepsy.
movements originating in the posterior parietal region. The One of his patients (case 1) demonstrated typical conflict
authors thought that these might be ictal in nature. between the two hands, which began 2 months after division
As seen above, several different types of abnormal motor of the posterior half of the genu and the body of the corpus
behaviour of one hand have been reported under the term callosum and lasted for ~3 weeks. For example, as she was
'alien hand', whose responsible lesions and underlying neural putting on her clothes with her right hand, she involuntarily
mechanisms are probably different from one another. In order pulled them off with her left hand. On another occasion,
to establish the clinicopathological relationships in these when she was opening a door or drawer with her right hand,Diagonistic dyspraxia 861
she simultaneously pushed it shut with the left hand. She A variety of peculiar motor behaviour dissociated from
exhibited no grasp reflex or forced groping in either hand. conscious volition was observed in his left hand during a
Thus, diagonistic dyspraxia is a distinct neurobehavioural test of language evaluation. For example, when asked to
entity which cannot be attributed to disorders such as place a toothbrush in front of the mirror, he took the
pathological grasping phenomena, ataxia and sensory loss. toothbrush with the right hand and tried to do so, but his left
We recently had an opportunity to observe diagonistic hand snatched it from the right hand and put it back where
dyspraxia of the left hand in three right-handed patients after it was; to the command 'take a handkerchief, his right hand
an infarction in the corpus callosum. In this report, we tried to pick it up, but the left hand held it down. On another
describe the clinical characteristics of this disorder and try occasion, when asked to place a pen and a 100-yen coin on
to reveal its neuroanatomical basis. the handkerchief, he picked up the coin with his right hand
and the pen with his left hand. The right hand then placed
the coin on the handkerchief, but his left hand halted at the
side of the handkerchief, holding the pen. Then his right
Case reports hand took up the pen from the left hand and tried to place
Patients with diagonistic dyspraxia it on the handkerchief, when his left hand picked up the coin
Patient 1 already placed on the handkerchief. On still another occasion,
when asked to take a toothbrush and a pencil, he correctly
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A 63-year-old right-handed man with a history of
hypertension suddenly developed mild right hemiparesis and picked up both items with his right hand, while his left hand
speech disturbance. A few days later, he noticed peculiar simultaneously picked up a comb which was not a target.
movements of his left hand. For example, when he was When he was asked to take a toothbrush with his right hand,
trying to change a TV channel with his right hand, his left his left hand spontaneously turned up ahead of the right and
hand suddenly thrust itself at the TV channel, interfering touched it first, although he understood the request correctly.
with the task being performed by the right hand. Two weeks Even when the examiner indicated that the response was not
later, he was admitted to a local hospital, where a cerebral correct and repeated the same command, his left hand again
infarction was revealed in the left hemisphere by CT. Two came over ahead of the right and seized the toothbrush first.
months after the stroke, the attending physician referred him He stated on several occasions: 'When I am trying to do
to us for further evaluation. something with the right hand, my left hand will move
spontaneously against will.'
The patient was attentive and cooperative. He had mild
dysarthria and slight weakness in the right upper and lower These abnormal left hand movements, however, did not
extremities. Muscle stretch reflexes were symmetric without always occur in the same situations. There were times when
pathological reflexes. He also had mild loss of sensation to the left hand cooperated well with the right and the patient
touch and pinprick on the right. Cerebellar function was could perform bimanual tasks with ease. For example, when
normal. He exhibited no grasping or groping movements in asked to take a comb with the left hand and transfer it to the
either hand. right, he could do so well. He could also clap his hands well.
CT and MRI of the brain revealed a cerebral infarction in
the posterior half of the body of the corpus callosum with Clinical course. The abnormal motor behaviour of the
some involvement of the most anterior part of the splenium. left hand had already disappeared when he was re-examined
Small lesions were also seen in the subcortical white matter 4 months after the stroke. He showed only a slight improve-
underlying the left posterior cingulate gyrus, the deep white ment in the left-hand agraphia, but the left-hand apraxia
matter underlying the left temporo-parietal lobe, and the left and the right-hand visuoconstructive impairment remained
anterior corona radiata (Figs 1 and 4). unchanged.
Neuropsychological evaluation revealed a mild anomic
aphasia with occasional word-finding difficulties during
spontaneous speech and naming of objects. Reading aloud Patient 2
and repetition were well performed. Auditory and reading This case is fully described in our previous reports (Tanaka
comprehension were also excellent. In contrast to his mild etal., 1990a, b). Thus only the main features will be presented
speech disturbance, he had marked difficulty in writing with here. A 51-year-old right-handed man was admitted to our
his left hand, characterized by scrawl or no response. Also hospital for evaluation of unusual motor behaviour of the
noted was a left-hand apraxia characterized by amorphous left hand dissociated from conscious volition. Three months
or incomplete movements and perseveration on responding' before admission, he suffered a subarachnoid haemorrhage
to a verbal command. Performance improved substantially from a right anterior cerebral artery aneurysm, which was
with the use of an actual object. He showed marked clipped 7 days later.
constructional difficulty with his right hand in drawing On physical examination he was attentive, cooperative and
geometric figures such as cube and square. With his eyes fully oriented. Cranial nerves, motor, sensory and cerebellar
closed, he could identify all 10 objects placed in either of functions were all normal. There was no evidence of grasping
his hands. or groping movements of the hands or feet.862 Y. Tanaka et al.
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Fig. 2 T r weighted MRIs of Patient 2 (upper two images, axial; lower image, mid-sagittal) showing
destruction of the corpus callosum from the rostrum to the most caudal part of the body with sparing of
the dorsal portion of the caudal part of the body. The lesion also involves the rostral and lower portions
of the right medial frontal lobe and a small portion of the left medial frontal lobe.
In the previous reports, we described that this patient had characterized by perseveration, neologism and substitution
a lesion in the anterior two-thirds of the corpus callosum of a letter entirely different from the intended letter. He also
with sparing of the splenium on MRI. Review of the MRI, had a left-hand apraxia characterized by clumsiness and
however, revealed that the callosal lesion extended from the hesitation on responding to a verbal command. Performance
rostrum to the most caudal part of the body with sparing of did not improve with imitation, but improved substantially
the dorsal portion of the caudal part of the body. In the right with the use of an actual object. With his eyes closed, he
hemisphere, the anterior one-third of the cingulate gyrus and could identify an object placed in either hand, and imitate
the rostral and lower portions of the medial superior frontal with one hand the finger postures of the other hand imposed
gyrus and their underlying white matter were involved. In by the examiner. Constructional ability was well preserved
the left hemisphere, a small portion of the anterior cingulate for both hands.
gyrus and the lower portion of the medial superior frontal Several types of peculiar dissociative motor behaviour
gyrus were destroyed. Supplementary motor area was spared were observed in the patient's left hand. For example, when
on either side (Figs 2 and 4). his right hand was trying to grasp a target in the left visual
Neuropsychological evaluation revealed a mild trans- field during a visual-guided reaching test, his left hand would
cortical motor aphasia with occasional phonetic paraphasias thrust itself into the field and grasp the target first against
and word-finding pauses in spontaneous speech and in naming his will. While he was trying to remove his underpants with
of objects. Reading aloud and repetition were well performed; his right hand, his left hand would suddenly reach over and
although occasional stuttering and phonetic paraphasias were raise the underpants. When he was picking up his trousers
observed with long sentences, most of those mistakes were from the floor with the right hand, the left hand would
self-corrected. Auditory and reading comprehension were simultaneously begin to unbutton his shirt. When he was
excellent. In contrast to his mild speech disturbance, he asked to form two interlocking circles by joining the thumb
showed marked difficulty in writing with his right hand, and index finger of each hand, his left hand withdrew as hisDiagonistic dyspraxia 863
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Fig. 3 Tpweighted MRIs of Patient 3 (upper three images, coronal; lower image, mid-sagittal)
demonstrating an infarction in the corpus callosum from the genu to the most caudal part of the body
with sparing of the dorsal portion of the body, especially at its posterior end. A small lesion is also seen
in the anterior part of the left anterior cingulate gyrus (lower image).
right hand approached it, or the left fingers would close in a The next day he was admitted to our hospital. General
tight grasp. Even though he opened the left hand using his physical examination was unremarkable. He was alert and
right fingers, the left fingers immediately returned to the fully oriented; his digit span was six numbers forward and
previous posture. However, when we repeated the same four backwards. Cranial nerves, motor, sensory and cerebellar
command several minutes later, he was able to do it. Also, functions were all normal. Muscle stretch reflexes were
when asked to fold a letter and put it into an envelope, he symmetric without pathological reflexes. There was no trace
succeeded in using both hands with good cooperation between of grasping or groping in either hand.
the hands. Thus, although he often manifested marked MRI demonstrated an infarction in the corpus callosum
abnormal motor behaviour of his left hand, there were times from the genu to the most caudal part of the body with
when the two hands cooperated well. We could not determine sparing of the dorsal portion of the body, especially at its
conditions that would elicit abnormal behaviour of the left posterior end. A small lesion was also seen in the anterior
hand, which was observed in both simple and complex tasks. part of the left anterior cingulate gyrus around the genu and
the most anterior part of the body of the corpus callosum
Clinical course. The right-hand agraphia, left-hand (Figs 3 and 4).
apraxia, and dissociative behaviour of the left hand gradually
On admission, he showed a mild transcortical motor
resolved. When he was re-examined 7 months postoperatively,
aphasia with occasional phonetic paraphasias and word-
the abnormal motor behaviour of the left hand and left-hand
finding pauses during spontaneous speech and naming of
apraxia had already disappeared, and he showed only a mild
objects. Reading aloud and repetition were well performed.
right-hand agraphia.
He had mild disturbance in writing with the right hand,
characterized by some phonetic errors. Auditory and reading
Patient 3 comprehension were excellent. In contrast to his mild speech
A 41-year-old right-handed man suddenly developed disturbance and right-hand agraphia, he had marked difficulty
weakness in his right lower extremity and speech disturbance. in writing with his left hand characterized by repetitions,864 Y. Tanaka et al.
Patient 1 writing his name and address on a sheet of paper with his
right hand, his left hand would spontaneously reach for the
paper and move it to the left corner of the table. When asked
to make a sign for money (forming a circle with the thumb
and index finger) with the left hand, he formed a circle with
the thumb and little finger, and as his right hand approached
the left hand for correction, his left hand withdrew. Even
when he formed the correct sign with the left hand with the
help of the right, the left fingers immediately resumed the
previous posture. In this way, he often manifested marked
abnormal motor behaviour of his left hand; however, there
were times when the two hands cooperated well. For example,
Patient 2
when asked to drive a nail with a hammer using both hands,
he held a hammer with the right hand and a nail with the
left, and could hammer it down with good coordination
between the hands. He could also turn pages of a book using
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both hands smoothly.
Clinical course. His mild transcortical motor aphasia
disappeared 4 days after the stroke. The left-hand agraphia
and apraxia and dissociative behaviour of the left hand
gradually resolved. When he was re-examined 5 months later,
Patient 3 these callosal disconnection signs and the abnormal behaviour
of the left hand had already disappeared.
Patients without diagonistic dyspraxia
To determine the exact location of the lesion responsible for
diagonistic dyspraxia, we compared the lesions of the three
patients described above with those of another five patients
(mean age 54.4±12.1 years), who developed no diagonistic
dyspraxia after an infarction of the corpus callosum with or
Fig. 4 Schematic sagittal views of the lesions in Patients 1, 2 and without medial hemispheric involvement (Fig. 5). All the
3. Areas of destruction in the corpus callosum are shown in black patients were right-handed except for one (Patient 7 in Fig. 5)
and those in the hemisphere in shading. Although Patients 1 and who was ambidextrous. Each patient was observed within 6
3 had damage to the left hemisphere, the lesions were represented
on the right in order to facilitate the comparison of lesions
weeks of onset of stroke and underwent MRI of the brain.
between the patients. Note that these three patients have a lesion Of the five patients, only one patient (Patient 4), who had
in the ventral part of the posterior half of the body of the corpus damage to the anterior four-fifths of the body of the corpus
callosum in common (arrows). callosum, demonstrated a left unilateral apraxia without
agraphia which persisted for ~1 month after the stroke. The
remaining four patients had a callosal lesion in the anterior
distortions, omissions and letter inversions. He also had a
half or two-thirds of the body and manifested no unilateral
left-hand apraxia characterized by amorphous or incomplete
apraxia or agraphia. Patients 4 and 7 demonstrated compulsive
movements, clumsiness and hesitation on responding to a
verbal command. Performance did not improve with imitation, manipulation of tools placed before them as well as grasp
but improved substantially with the use of an actual object. reflex and visual groping movements in the right (Patient 4)
Several types of peculiar dissociative behaviour were or the left hand (Patient 7) contralateral to the lesion. These
observed in the left hand. For example, when he attempted two patients had a medial frontal lobe lesion involving the
to turn on a water tap with his right hand, his left hand anterior cingulate gyrus and extending more rostrally than
involuntarily came over ahead of the right and turned it on the lesion of Patient 5 who showed only grasp reflex and
first. On another occasion, while he was trying to remove visual groping movements in the right hand contralateral
his pajama trousers with his right hand, his left hand suddenly to the lesion. All patients, including these two, however,
reached over and raised the trousers; after he put his sock demonstrated no such abnormal motor behaviour of the left
on with both hands, his left hand pulled it off. While he was hand as observed in the three patients described above, andDiagonistic dyspraxia 865
Patient 4 Patient 7
Patient 5 Patient 8
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Patient 6
Fig. 5 Schematic sagittal views of the lesions involving the corpus callosum in five patients without
diagonistic dyspraxia. Areas of destruction in the corpus callosum are shown in black and those in the
hemisphere in shading. These patients were all right-handed except Patient 7 who was ambidextrous.
All these patients were observed within 6 weeks of onset of stroke and underwent MRI of the brain.
Although Patients 4 and 5 had an infarction in the left hemisphere, the lesions were represented on the
right in order to facilitate the comparison of lesions between the patients. Note that the posterior end of
the body of the corpus callosum is preserved in all patients (arrows). None of these patients had any
callosal disconnection sign except Patient 4 with an infarction in the anterior four-fifths of the body of
the corpus callosum, in whom a left unilateral ideomotor apraxia without agraphia was observed for
~1 month after stroke.
the posterior end of the body of the corpus callosum was the left hand often acted at cross-purposes to the right, a
preserved in common. finding consistent with the characteristics of diagonistic
dyspraxia described by Akelaitis (1945). Our patients,
however, showed additional various types of abnormal motor
Discussion behaviour of the left hand during a right-hand or a bimanual
Characteristics of diagonistic dyspraxia task: symmetric movements to the right which sometimes
In addition to signs of callosal interruption, all three patients occurred in the left hand just ahead of the right; non-
exhibited peculiar dissociative behaviour of the left hand in antagonistic, irrelevant movements to the right; and
the absence of pathological grasping phenomena in the hand: occasional inability to move the left hand at will during a866 Y. Tanaka et al.
bimanual task. These various types of abnormal behaviour an attempt to take the pencil from the hand' (McNabb et al.,
of the left hand have been reported in patients with a callosal 1988, case 3).
lesion: for example, 'on the command to touch the left ear Although seemingly similar to diagonistic dyspraxia, these
with the right hand, the left hand flew up and touched the abnormal movements, which they called intermanual conflict,
left ear first as the right hand approached the ear' (Fisher, should be attributed to a disorder related with pathological
1963), 'the left hand would sometimes pick up a piece of grasping phenomena, and be discriminated from diagonistic
food and try to put it in his mouth when the right hand was dyspraxia. Such contention has already been suggested by
attempting the same manoeuvre, resulting in a collision' Akelaitis (1945, case 1), the proponent of the term diagonistic
(Banks et al., 1989, case 2), 'during a finger-to-nose test dyspraxia. Thus diagonistic dyspraxia should be used when
with the right hand, the left hand suddenly started slapping there are no pathological grasping phenomena or when the
his chest like Tarzan' (Bogen, 1979), 'while the patient abnormal motor behaviour cannot be explained by
shaved with the right hand, his left hand unzipped his jacket' pathological grasping phenomena alone if present, as will be
(Banks et al., 1989, case 2), 'on putting a letter into an discussed in detail later.
envelope, the left fingers clung to the letter and pulled it out There are reports of patients who, in addition to cross-
of the envelope again' (Fisher, 1963), or 'when the patient purpose movements of the left hand to the right, manifested
tried to transfer an object held by the left hand to the right, similar abnormal motor behaviour of the right hand to the
his left fingers clung to it despite the fact that he had no
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left (Barbizet et al., 1978; Ohigashi et al., 1983; Leiguarda
forced grasp in that hand, so that he could not transfer it et al., 1989). These patients, however, had pathological
readily to the right hand' (Iwata, 1981, case 3; Leiguarda grasping phenomena in the right hand, except the case of
et al., 1989, case 3). Thus most of the reported cases as Barbizet et al. (1978) for whom no reference was made to
well as ours manifested, in addition to mere cross-purpose
grasping phenomena. Accordingly, abnormal motor behaviour
movements, a variety of abnormal motor behaviour of the
of the right hand in these patients is most likely to be the
left hand when the patient tried to initiate movements with
results of pathological grasping phenomena.
the right hand, or while the patient was doing a right-hand
or a bimanual task, or immediately after the patient finished
tasks with the right hand.
Lesion responsible for diagonistic dyspraxia
Some patients exhibited spontaneous left hand movements Our three patients had suffered damage to a hemisphere in
just before the right hand movements. For example, when addition to the corpus callosum. The location and extension
our first case tried to take a toothbrush with the right hand of hemispheric damage, however, were not uniform, while
at request, his left hand came over just before the right and the posterior half of the body of the corpus callosum,
seized it first. Fisher (1963) also reported similar abnormal especially its ventral part, was damaged in common (Fig. 4).
motor behaviour of the left hand in a patient with a callosal By contrast, our other five patients, who developed no
lesion: when the patient was suddenly asked to snap her right diagonistic dyspraxia after an infarction of the corpus
fingers as quickly as possible, the left fingers snapped just callosum with or without medial hemispheric involvement,
before the right. Such abnormal motor behaviour of the left had no damage to the posterior end of the body of the corpus
hand appears to have occurred without being activated by callosum (Fig. 5). This indicates that damage to the posterior
voluntary movements of the right hand. According to Kenny end of the body of the corpus callosum, particularly to its
(1963), however, a sequence of motor events consists of ventral part, is crucial for the development of diagonistic
three steps: motive, intention and voluntary action, and dyspraxia.
intending to do something is itself a voluntary action whereas A disruption of callosal fibres was also suggested in our
having a particular motive is not. From this point of view, patients by the presence of unilateral apraxia and agraphia.
the spontaneous left hand movements just before the right Geschwind (1975) surmised that the anterior or middle
hand movements in these patients can also be interpreted as portion of the body of the corpus callosum was the site of
abnormal motor behaviour elicited by voluntary movements the lesion responsible for callosal apraxia. Some cases,
of the right hand. Accordingly, diagonistic dyspraxia in most however, have been reported in which no callosal apraxia
right-handed subjects can be more appropriately defined as was observed after a lesion in the anterior two-thirds (Gordon
abnormal motor behaviour of the left hand activated by et al., 1971; Leiguarda et al., 1989; Risse et al., 1989) or in
voluntary movements of the right hand. the anterior half of the corpus callosum (Kazui et al., 1992).
Motor phenomena similar to diagonistic dyspraxia may be In recent years, there is accumulating evidence that the
observed in patients with impulsive groping movements involvement of the posterior part of the body of the corpus
induced by medial frontal lobe pathology: for example, 'when callosum is most crucial for the development of callosal
the patient began to remove the glasses with one hand, the apraxia (Iwata et al., 1980; Volpe et al., 1982; Kawamura
other hand contralateral to the lesion came up to keep them and Hirayama, 1986; Yasumurae/a/., 1987; Kawamuraetal.,
on' (Goldberg et al., 1981, case I); 'when the patient was 1989; Risse et al., 1989; Kazui et al., 1992; Kazui and
attempting to write with one hand, the other hand contralateral Sawada, 1993). Our findings in the eight patients described
to the lesion would frequently be raised and reach over in here support this idea: all the four patients who manifestedDiagonistic dyspraxia 867
a left unilateral apraxia had a lesion involving at least the motor behaviour might be ascribed to impulsive groping
posterior part of the callosal body, while the remaining four movements of the left hand caused by right medial frontal
patients who developed no unilateral apraxia had a callosal lobe infarction (Joynt, 1977; Lejeune and Caparros-Lefebvre,
lesion in the anterior half or two-thirds of the body. Similarly, 1993), even if the terms diagonistic dyspraxia or alien
unilateral agraphia or tactile anomia is also reported to be hand had been applied to indicate the abnormal behaviour.
caused by a lesion in the posterior part of the body of the However, we included those patients whose abnormal motor
corpus callosum (Sugishita et al., 1980; Gersh and Damasio, behaviour was inexplicable by pathological grasping
1981; Kawamura and Hirayama, 1986; Degos et al, 1987; phenomena alone as having diagonistic dyspraxia. For
Kawamura et al., 1989). example, Jason and Pajurkova (1992) reported a patient who
Ferguson et al. (1985) reported a patient (case POV) who had lesions in the bilateral inferomedial frontal lobes, more
exhibited diagonistic dyspraxia after division of the remaining extensive on the right, as well as in the genu and body of
posterior part of the corpus callosum following an anterior the corpus callosum. This patient manifested the following
corpus callosotomy. Motor phenomena similar to diagonistic abnormal motor behaviour of the left hand: when he started
dyspraxia in humans have been reported in split-brain to go downstairs, his left hand would keep grabbing the
monkeys or baboons, such as bilateral simultaneous reaching nearby door jamb and could not let it go, and so he was
for an object with both hands (Kennard and Watts, 1934; unable to go downstairs. This abnormal behaviour of the
Lehman, 1972; Brinkman and Kuypers, 1973) and a tug of
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left hand was probably produced by pathological grasping
war between hands after having taken hold of food phenomena, such as impulsive visual groping movements for
(Trevarthen, 1965; Brinkman and Kuypers, 1973). Kennard a nearby object, caused by extensive damage to the right
and Watts (1934) reported that no abnormal motor behaviour medial frontal lobe involving the anterior cingulate gyrus
was observed in a baboon when the anterior two-thirds of and its underlying white matter. This patient, however,
the corpus callosum was divided, but that the baboon exhibited exhibited other abnormal motor behaviour of the left hand:
bilateral simultaneous reaching for food with both hands for example, when he tried to catch and hold his left hand
when the remaining posterior callosum was sectioned. These with his right, the left hand moved out of the way as the
observations suggest that a callosal lesion, especially that in right hand approached the left, or when he was asked to clap
the posterior part, seems to play a primary role in the with both hands, the right hand tried to clap while the left
production of diagonistic dyspraxia. hand went to his face. These motor phenomena cannot be
Three patients who exhibited diagonistic dyspraxia after a accounted for by pathological grasping phenomena. Similarly,
lesion virtually confined to the corpus callosum as determined the patients of Goldenberg et al (1985), Gottlieb et al (1992,
by MRI or autopsy, have been reported (Watson and Heilman, case 1), and Kawasaki et al (1992), after infarction of the
1983; Watson et al., 1985; Nishikawa et al, 1986; Degos left or bilateral medial frontal lobes and the corpus callosum,
et al, 1987). As in our cases, all these patients had a callosal exhibited abnormal motor behaviour which could not be
lesion involving at least the ventral part of the posterior end explained easily by pathological grasping phenomena, i.e. as
of the body. By contrast, Kazui and Sawada (1993) reported the right hand approached the left hand to get the object held
a patient who showed no diagonistic dyspraxia after a callosal in the left hand, the left hand withdrew (Goldenberg et al,
infarct virtually confined to the posterior half of the body 1985; Kawasaki et al, 1992), or when the patients tried to
with sparing of the posterior end of the body. This patient take out a match from a matchbox or to open a drawer with
merely demonstrated a left unilateral apraxia without the right hand, the left hand would close the box or drawer
agraphia. Leiguarda et al (1989) reported three patients (Goldenberg et al, 1985; Gottlieb et al, 1992, case 1).
with damage to the anterior corpus callosum caused by As seen in Table 1, all had a callosal lesion and exhibited
haemorrhage. Based on CT sagittal reconstructions, they any of the callosal disconnection signs except three cases
showed that two of the patients (cases 1 and 3) with callosal (Akelaitis, 1945; Hanakita and Nishi, 1991), in which no
lesions extending to the most caudal part of the body, detailed descriptions about the signs were given. This shows
exhibited diagonistic dyspraxia, and that the other patient that damage to the corpus callosum is crucial for the
(case 2) with an anterior callosal lesion with sparing of the production of diagonistic dyspraxia. However, since unilateral
caudal one-third of the body manifested no diagonistic
apraxia was definitely absent in three of the patients when
dyspraxia. These findings support our contention that a lesion
diagonistic dyspraxia was observed (Degos et al., 1987;
in the posterior end of the body of the corpus callosum,
Kawasaki et al, 1992; Tei et al, 1993), diagonistic dyspraxia
especially in its ventral part, is responsible for diagonistic
appears to have a different neural mechanism from callosal
dyspraxia.
apraxia. Admittedly, there were several patients whose
Table 1 summarizes the reported cases of presumed callosal lesions were located in the anterior part (Beukelman
diagonistic dyspraxia. Those patients whose abnormal motor et al., 1980; Nakatani et al, 1984; Goldenberg et al., 1985;
behaviour was not or almost not fully described were excluded Fukui et al, 1987; Banks et al, 1989, case 2) even though
(Gazzaniga et al, 1967; Wilson et al, 1977; Zaidel and they had some of the callosal disconnection signs which are
Sperry, 1977; Sine et al., 1984; Graff-Radford et al., 1987; known to be caused by a lesion in the posterior part of the
Loring et al., 1989; Nagumo et al, 1993) or whose abnormal callosal body, as mentioned above. The locations of lesions868 Y. Tanaka et al.
Table 1 Summary of the reported cases of presumed diagonistic dyspraxia
Authors Reported sites of lesions Main disconnection signs*
Apraxia Agraphia Tactile anomia
Akelaitis (1945)+
Case 1 Posterior half of GCC, BCC (ope) _7
Case 2 Entire CC (ope) _9
Gazzaniga et al. (1962) Entire CC (ope)
Fisher (1963) CC, bilateral hemispheres
Schott et al. (1969) CC?
Barbizet et al. (1974) Posterior CC?
Barbizet et al. (1978) CC (Marchiafava-Bignami disease)
Beukelman et al. (1980) Anterior CC (CT)
Iwata (1981)
Case 2 Posterior half of BCC (CT) ND
Case 3 CC, right frontal lobe (CT) ND
Ohigashi et al. (1983) BCC, bilateral medial frontal lobes (CT)
Watson etal. (1983, 1985) Anterior three-quarters to four-fifths
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of BCC (CT, MRI)
Nakatani etal. (1984) RCC, GCC, rostral and lower parts
of both frontal lobes (CT)
Ferguson et al. (1985)
Case POV Entire CC (ope) ND
Goldenberg et al. (1985) Anterior two-thirds of CC,
bilateral medial frontal lobes (CT)
Nishikawa et al. (1986) GCC, entire BCC (MRI)
Degos et al. (1987)* Posterior one-quarter of BCC, SCC
(autopsy)
Fukui et al. (1987) GCC, anterior half of BCC, white
matter underlying the anterior
cingulate gyri (CT)
Levin et al. (1987)
Case 1 GCC, BCC, part of SCC (CT)
Banks et al. (1989)
Case 2 GCC, anterior BCC, ND
bilateral medial frontal lobes (CT)
Leiguarda et al. (1989)
Case 1 GCC, entire BCC (CT)
Case 3 GCC, entire BCC, dorsal SCC (CT)
Kashiwagi et al. (1990) Posterior half of GCC, entire BCC,
part of left medial frontal and
temporo-occipital lobe (MRI)
Hanakita and Nishi (1991) RCC, GCC, BCC involving the ventral ND
part of the posterior end, left medial
frontal lobe (CT, MRI)
Tanemura et al. (1991) CC, left medial frontal, parietal and
occipital lobes (MRI)
Gottlieb et al. (1992)
Case 1 CC?, right medial frontoparietal lobe (CT)
Case 2 BCC?, multiple lacunae (CT) ND
Jason and Pajurkova (1992) GCC, BCC, bilateral inferomedial ND
frontal lobes (CT)
Kawasaki el al. (1992) RCC, GCC, entire BCC, ND
left medial frontal lobe (MRI)
Tei et al. (1993) GCC, anterior half and part of
posterior half of BCC (MRI)
CC = corpus callosum; GCC = genu corpus callosum; BCC = body corpus callosum; RCC = rostrum corpus callosum; SCC = splenium
corpus callosum; ope = operation;-!-= present; - = absent; ND = no description. *These signs are confined to the left hand except in
case 3 of Leiguarda et al. (1989). fCases 1 and 2 reported in 1945 are the same as cases 13 and 9 reported in 1942 by the same authors,
respectively. Case 1 was also reported as case 3 by Van Wagenen and Herren (1940). ^Although a mild left-hand ideomotor apraxia was
observed in this case 1 month after stroke, it disappeared in ~4 months. Other disconnection signs persisted afterward.Diagonistic dyspraxia 869
reported in these patients, however, were based on CT with Functions of the superior parietal lobule
which the extent of a lesion cannot be as clearly delineated There is accumulating evidence that the human superior
as with MRI. If these patients had been examined by MRI, parietal lobule is concerned with selection of movement
the callosal lesion might have been seen to extend well into based on the integration of visual and/or somatosensory
the posterior part of the body. information. In an earlier study with xenon-133, Roland et al.
(1980) reported that regional cerebral blood flow (rCBF)
increased in the bilateral superolateral premotor areas,
Interhemispheric fibres through the posterior supplementary motor areas, superior parietal regions and
part of the corpus callosum inferior parietal regions, especially the anterior part, when
In monkeys, the corpus callosum from the caudal one-third subjects moved their index finger following a maze as
of the body to the most anterior part of the splenium carries instructed, or when they drew a spiral in the air with the
fibres between the superior parietal lobules, the caudal parts arm. Using PET, Roland and Seitz (1989) studied changes
of the inferior parietal lobules and the caudal parts of the of rCBF in normal subjects while they were learning a
superior temporal regions (Pandya et al., 1971; Seltzer and complicated sequence of movements with the right fingers.
Pandya, 1983; Caminiti and Sbriccoli, 1985; Cipolloni and They reported that rCBF increased significantly in the bilateral
Pandya, 1985). A case of diagonistic dyspraxia reported by premotor areas, supplementary motor areas and superior
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Degos et al. (1987) is particularly interesting in that it parietal lobules during the early phase of learning. When the
provides an important clue to the understanding of the task was learned well, however, there was no longer a
neuroanatomical basis for this condition. The autopsy of their significant increase in blood flow in the bilateral superior
case revealed complete ischaemic destruction of the posterior parietal lobules, the right premotor area, and the right
one-quarter of the body and the splenium of the corpus supplementary motor area. Deiber et al. (1991), also using
callosum. The white matter underlying the superior parietal PET, compared the rCBF during tasks that require movement
lobule and occipital lobe had degenerated bilaterally. Since selection with that during fixed movements. They found that
the callosal connections between the occipital lobes course when selection of movement was made under voluntary
only through the splenium both in monkeys (Pandya et al., intention, the rCBF increased significantly in the premotor
1971) and in humans (de Lacoste et al., 1985), this case cortex, supplementary motor area and superior parietal cortex
suggests that the human callosal fibres from the superior bilaterally. Singh and Knight (1993) have shown electro-
parietal lobule course through the posterior one-quarter of physiologically that patients with a discrete unilateral parietal
the body of the corpus callosum. On the other hand, de lesion involving the superior parietal lobule and rostral
Lacoste et al. (1985) maintained that interhemispheric fibres parts of the inferior parietal lobule had markedly reduced
from the superior parietal lobule coursed exclusively through amplitudes of motor-related potentials over the bilateral
the splenium of the corpus callosum in man, based on the hemispheres. These studies indicate that, in humans at least,
autopsy study on the distribution of Wallerian degeneration the superior parietal lobule participates in the process of
in the corpus callosum following focal lesions. One of their voluntary motor selection and preparation.
patients (case A-223-77), however, had a degeneration of
the caudal part of the body and the splenium secondary to Perenin and Vighetto (1988) investigated a lesion
damage to the temporo-parietal-occipital junctional region responsible for optic ataxia (unilateral impairment of pointing
with extension into the white matter underlying the superior or reaching a target accurately under visual guidance) and
parietal lobule and part of the temporal lobe. Another found that the most commonly injured region was in the
patient (case A-133-77), on the other hand, had a callosal contralateral interparietal sulcus extending into the superior
degeneration limited to the splenium secondary to a lesion parietal lobule and the precuneus. This finding is concordant
in the temporo-parietal-occipital junctional region with almost with that of a functional imaging study of visually guided
no extension into the superior parietal lobule. In view of the movement with PET. Grafton et al. (1992) investigated
assertion by Degos et al. (1987) that, contrary to what has changes of rCBF in normal subjects tracking a moving target
been described in the monkey, the callosal pathway from the with the index finger. They found that the spatial complexity
temporal lobe courses rostral to the one from the superior of voluntary movements increased rCBF in the bilateral
parietal lobule in man, the cases of de Lacoste et al. (1985) superior parietal and precuneate cortices, and indicated that
also appear to suggest that the caudal part of the body of the the medial and dorsal parietal cortex was involved in the
corpus callosum contains the interhemispheric fibres between integration of spatial attributes during selection of movement.
the superior parietal lobules. Thus the human callosal Pause et al. (1989) investigated the relationship between
connections from the superior parietal lobule appear to course somatosensory and motor disturbances of the hand in patients
through the caudal part of the body and the most anterior with parietal lobe lesion. They found that patients with a
part of the splenium as in the monkey (Seltzer and Pandya, lesion in the posterior parietal lobe involving the superior
1983; Caminiti and Sbriccoli, 1985). Accordingly, it is most parietal lobule showed preferential impairment of complex
likely that diagonistic dyspraxia results from an interruption somatosensory and motor functions such as exploratory and
between the two superior parietal lobules. manipulative finger movements, whereas in patients with870 Y. Tanaka et al.
anterior parietal lobe lesion closer to the postcentral gyrus, one-hand movements has also been reported in normal
somaesthesis was clearly more disturbed than motor function. subjects, especially when selection of movement was made
Thus, it is likely that the human superior parietal lobule is under voluntary intention in complex tasks (Deiber et al.,
critical for the integration of visual and/or somatosensory 1991; Grafton et al., 1992). One possible explanation for this
information into movement selection. is that the activity in the motor control system contralateral
to the hand to be moved, arouses appropriate movements of
the hand and that the activity in the ipsilateral system induces
an inhibitory control of the opposite hand. When bimanual
Possible mechanism underlying diagonistic cooperation is necessary, these activities may induce an
dyspraxia arousing process of appropriate movements and an inhibitory
As described above, our three patients often exhibited process of inappropriate movements of each hand, contra-
spontaneous left hand movements during a right-hand task, lateral to the hemisphere. In the normal state, such volitional
as well as occasional inability to move the left hand at will control of motor activity may be achieved by sending motor
during a bimanual task. These motor phenomena cannot be control information from the left superior parietal lobule to
explained by a mere failure of transcallosal inhibition from the right via the posterior part of the corpus callosum when
the left hemisphere upon the right as suggested by Feinberg neurons of the left superior parietal lobule were activated
etal. (1992). We infer that the most likely level of dysfunction under voluntary intention.
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is at a higher motor control system of the right hemisphere, Some abnormal motor behaviour of the left hand observed
which probably induces an arousing process of appropriate in our patients may be explained by a failure in functional
movements as well as an inhibitory process of inappropriate association between volitional control and visuomotor and/
movements of the left hand. In normal individuals, this or sensorimotor integrative function in the right superior
system would inhibit inappropriate movements of the left parietal lobule. For example, our patients' left hand often
hand in the case of a unimanual task with the right hand, and reached out for an object placed in front of them during a
arouse appropriate movements as well as inhibit inappropriate right-hand task, took away an object held in the right hand,
movements of the left hand in the case of a bimanual task. or interfered with tasks being performed by the right hand.
However, our patients could perform spontaneous activities These spontaneous left hand movements may be interpreted
flawlessly using only their left hand in a free behaviour as follows: voluntary intention to act with the right hand
condition and even in a testing situation such as the called forth neural activation in the right superior parietal
examination of praxis function with the use of actual objects. lobule as well as in the left, but transcallosal inhibitory
Another important feature in our patients is temporal control from the left superior parietal lobule upon the
variability of abnormal movements of the left hand. Even right was disturbed. Consequently, the visuomotor integrative
though the left hand did not always cooperate during a function in the right superior parietal lobule which would be
bimanual task, it sometimes cooperated well. There were activated by seeing the objects and/or movements of the right
also times when the right hand could perform purposeful arm and hand might have been released, resulting in the
movements without spontaneous abnormal behaviour of the emergence of spontaneous left hand reaching-out and
left hand. This implies that the motor control system was grasping.
represented, to some degree, in the right hemisphere in our
Our patients also sometimes exhibited other types of
patients, and that the system of the right often became
abnormal motor behaviour of the left hand, such as the
unstable when the motor control system of the left hemisphere
inability to move their left hand at will during a bimanual
was activated under voluntary intention. On the other hand,
task and withdrawing their left hand as the right hand
the motor control system of the left hemisphere seems to
approached it. Such abnormal behaviour of the left hand
have been well preserved and stable, since at no time did
might have been produced by a confusion in selection of
our patients exhibit abnormal behaviour of the right hand,
elements of impending movements—such as direction, joint
which indicates that the left hemisphere in our patients was
angle and arm posture—in the right superior parietal lobule
dominant for volitional control of movement. Thus, the
due to a failure in transfer of motor control information via
dissociative behaviour of the left hand in our patients appears
the callosum from the left superior parietal lobule to the right.
to have been produced by a failure in transfer of motor
control information from the left hemisphere to the right In most patients with diagonistic dyspraxia, abnormal
during tasks requiring the left hemisphere volitional motor motor behaviour of the left hand gradually subsides and
control. disappears with time, as in our patients. The right superior
parietal lobule may gradually acquire the ability to control
The fact that the left hand moved spontaneously when our its motor system volitionally and independently of the left.
patients tried to perform a unimanual task with the right Some patients have been reported, however, who had
hand and even when they merely intended to do something diagonistic dyspraxia for > 9 months after an infarction of
with the right hand, indicates that voluntary intention to act the corpus callosum (Tei et al., 1993), for 15 months after
with one hand calls forth neural activation in the motor-related post-traumatic damage to the corpus callosum and the rostral
areas of both hemispheres. Such bihemispheric activation by and lower portions of the frontal lobes (Nakatani et al.,Diagonistic dyspraxia 871
1984), and for 38 months after total callosotomy (Ferguson Akelaitis AJ, Risteen WA, Herren RY, Van Wagenen WP. Studies
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Barbizet J, Degos JD, Duizabo Ph. Chartier B. Syndrome de
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Acknowledgments
Degos JD, Gray F, Louarn F, Ansquer JC, Poirier J, Barbizet J.
The authors wish to thank Dr Jin Kaneko (Department of
Posterior callosal infarction: clinicopathological correlations. Brain
Neurology, Ohta General Hospital), Dr Tetsushi Atsumi
1987; 110: 1155-71.
(Department of Neurology, Seirei Hamamatsu Hospital), and
Ms Mutsuko Sato (Department of Neuropsychology, Southern Deiber M-P, Passingham RE, Colebatch JG, Friston KJ, Nixon PD,
Research Institute for Neuroscience) for referring the patients. Frackowiak RSJ. Cortical areas and the selection of movement: a
study with positron emission tomography. Exp Brain Res 1991; 84:
393-102.
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