CLINICALSCIENTIFIC NOTES

182

8. Jackson MJ, Schaefer JA, Johnson MA, Morris AAM, Turnbull
DM, Bindhoff LA. Presentation and clinical investigation of mitochondrial respiratory chain disease: a study of 51 patients. Brain
1995;118:339-357.
9. Ho VB, Fitz CR, Chuang SH, Geyer CA. Bilateral basal ganglia
lesions: paediatric differential considerations. Radiographics
1993;13~269-292.
10. Kellermann K, Heuser L, Mertens T. Stammganglien-Enzephalitis
ndch Mumps. Monatsschrqt Kinderheilkuiunde 1982;310:624-627.
11. Pettigrew LC, Jankovic J. Hemidystonia: a report of 22 patients
and a review of the literature. J Neurol Neurosurg Psychiatry
1985;48:650-657.
12. Marsden CD, Obeso JA, Zarranz JJ, Lang AE. The anatomical
basis of symptomatic hemidystonia. Brain 1985;108:463483.

Focal Myoclonus Associated With Posterior
Thalamic Hematoma

Lee and Marsden recently reviewed the reports of abnormal
movements associated with focal lesions of the thalamus and
subthalamic region.‘ The presence of myoclonic jerks was reported in a single case; however, negative myoclonus or acute
asterixis occurred in 13 of 62 cases. They concluded that thalamic lesions, mainly those affecting the ventrolateral thalamus, may cause asterixis.’
Lera et al. documented movement disorders with a complex
dystonic pattern, choreic movements, and pseudorhythmic,
slow, predominantly distal jerks in patients with lesions of the
posterolateral area of the contralateral thalamus.’ Ghika et al.
described a syndrome they called “jerky dystonic unsteady
hand,” characterized by a delayed display of hyperkinetic features (dystonia, chorea, tremor, and myoclonus), associated
with motor and sensory disorders in patients with posterior
thalamic i ~ c h e m i a . ~
We report a patient with a hemorrhagic lesion in the region
of the posterior thalamic nucleus who developed a delayed
form of complex myoclonus in the contralateral upper limb.

hematoma in the left posterior thalamic region, involving the
posterior limb of the internal capsule. Hemiparesis and hemihypesthesia gradually improved. At the time of discharge, 20
days after onset, slight hemiparesis and hemihypesthesia persisted on the right side.
Six months later, the patient developed involuntary movements in her right arm. Neurologic examination disclosed facial
hypomimia, a mild right hemiparesis with hyperreflexia, and
hemihypesthesia. Rapid alternating movements of the hand
were normal, with superimposed myoclonic jerks of variable
amplitude and duration. Ataxia or dysmetria was difficult to
exclude in the right arm because of superimposed involuntary
movements, although the findings on heel-shin testing were
normal and pathologic rebound was absent on the right side.
The right arm displayed hyperkinetic involuntary movements,
which were brief, sudden, non-stimulus-sensitive, with variable
amplitude. These mainly involved the hand and were present at
rest, during posturing, and with action. Rhythmic appearance at
times suggested a rest tremor.
However, an electromyographic (EMG) recording at rest
with needle electrodes disclosed irregular burst lengths of <300
ms (range, 50-200 ms) with synchronous activity of agonist
and antagonist muscles (Fig. I), without proximal EMG activity. At this time, the EMG recording with action excluded
irregular brief lapses corresponding to asterixis. A polygraphic
recording including electroencephalographic (EEG) tracing
with electrodes placed on the left frontoparietal region failed to
show a cortical component. Back averaging was not available
at this time. Transcranial brain magnetic stimulation, performed using a coil centered over the vertex with surface electrode recording from thenar and anterior tibia1 muscles at rest

t

Case Report
A 68-year-old hypertensive woman suddenly developed
weakness on her right side on July 18, 1992. Initial neurologic
examination performed 6 h after onset showed her to be alert
and oriented, with a right hemiparesis and hemihypesthesia.
Deep tendon reflexes were symmetric, with a right extensor
plantar response. Cranial nerves and visual fields were normal.
No involuntary movements or ataxia were discerned. Clinical
examination disclosed moderate hypertension. Laboratory findings, including blood count, erythrocyte sedimentation rate
(ESR), and routine serum biochemistry, were normal. A computed tomographic scan of the brain showed a large cerebral

A videotape accompanies this article.
Received July 17, 1996; revisions received January 9 and May 28,
1997. Accepted May 30, 1997.
Address comespondence and reprint requests to Dr. E. M. Gatto at
Sanatorio Mitre, Departamento de Neurologia, Sanchez de Bustamante
2190, (1425) Buenos Aires, Argentina.

Movement Diwrders. Vol. 13, No. 1. 1998

R.F.FLEX

Ij
J loomv
loo rm

FIG. 1. Electromyographic recording of myoclonus at rest in right
finger extensor and finger flexor muscles. The shortest electromyographic bursts are in the 50- to 250-ms range,

CLINICAUSCIENTIFIC NOTES

183

0

A

FIG. 2. (A) Sagittal section using T2-weighted magnetic resonance image (4000/100) showing sequelar left posterior cerebral hematoma and
hemosiderin findings, located in posterior thalamic nucleus. (B) Axial echo-gradient T2-weighted magnetic resonance image showing only paratnagnetic hemoglobin-derived residue in the pulvinar region (350/14),according to Hassler’s atlas.

and during voluntary contraction demonstrated normal motorevoked potential latency, threshold, amplitude, and central motor conduction time. Magnetic resonance imaging (MRI) 2 and
4 years after the stroke disclosed a reabsorbing thalamic hematoma mostly involving the posterior or pulvinar nucleus (Fig.
2). The patient was treated with piracetam, clonazepam, valproic acid, and trihexiphenydil, although without benefit.
Physical examination performed in March 1996 disclosed a
moderate residual right hemiparesis, with partial recovery of
superficial and deep sensory sensation, and myoclonus in the
right arm at rest, enhanced during posture and action, with
distal predominance (see the videotape). As before, it was difficult to exclude the presence of ataxia on the finger-nose test
because of abnormal movements.

arising from alternating contraction of antagonist muscle
groups).‘’
Ghika et al. were the first to report a complex delayed hyperkinetic motor syndrome associated with Dejerine-Roussy
syndrome, hemiataxia, and quadrantopsia after a circumscribed
thalamic lesion secondary to a posterior choroidal artery infarcti or^.^ In our case, the hemorrhagic posterior thalamic nucleus
lesion induced a delayed myoclonus with a mild hemiparesis
and sensory disturbances. Such cases lend support to the hypothesis that the topographic distribution of the lesions within
the thalamus are not uniform, making accurate clinicoanatomic
correlation difficult.

Discussion

This video shows a patient 2,4, and 5 years after a posterior
thalamic hematoma. At rest, a focal myoclonus was present
mimicking tremor, which increased during action. An indexfinger test was inconclusive in excluding ataxia, because of
superimposed involuntary movements. Alternating movements
and finger tapping were normal.

Our patient presented with delayed-onset myoclonus after
posterior thalamic h e r n a t ~ m a MRl
. ~ performed 2 and 4 years
after onset demonstrated a residual lesion primarily affecting
the contralateral posterior thalamic nucleus.’-’
Myoclonus has rarely been reported secondary to thalamic
lesions, mainly described as following involvement of the ventrolateral nucleus or surrounding structures. Paradoxically,
ventrolateral thalamotomy has reportedly been useful in refractory essential myoclonus and myoclonic dystonia.8 Although
the pathophysiological mechanism remains obscure, a probable
loss of inhibitory influence of the internal globus pallidus and
substdntia nigra reticulata on the thalamus has been hypothesized.’ Furthermore, the delayed onset and progression imply
that the syndrome could hardly be caused by the initial lesion
itself, but rather by the development of postsynaptic supersensitivity or secondary reorganization of involved pathways.”
Lesions of the posterior thalamic nucleus have been related to
a variety of delayed movement disorders, including tremor,”
asterixis, myoclonus, and
As in our case, frequent
positive or negative myoclonus may mimic the appearance of
trernor.l4 In our patient, the EMG was consistent with a classification of hyperkinesia as myoclonus and excluded other
types 01 abnormal movements such as “rubral” tremor (defined as a tremor of large amplitude, frequency of 1 4 Hz, and

Legend to the Videotape

Emilia M. Gatto
Maria C. Zurrd
Carlos Rugilo
Sanatorio Mitre
Ana M. Pardal
Manuel Martinez
Manuel M. Fernandez Pardal
British Hospital
Buenos Aires
Argentina

’

References
1. Lee MS, Marsden CD. Review: movement disorders following
lesions of the thalamus or subthalamic region. Mov Disord 1994;

5:493-507.
2. Lera G, Scipioni 0, Garcia S, Fischbein G, Gershanik 0. A peculiar pattern of movement disorders due to contralateral focal thalamic lesions [Abstract]. Moil Disord 1994;9(suppl 1):145.
3. Ghika J, Bogousslavsky I, Henderson J , Maeder P, Regli F. The

Movmient Disorder.s, Vol. I S , No. I , 1998

184

CLINICAUSCIENTIFIC NOTES

‘jerky dystonic unsteady hand’: a delayed motor syndrome in posterior thalamic infarctions. J Neurol 1994;241:537-542.
4. Obeso JA, Artieda J, Marsden CD. Different clinical presentations
of myoclonus. In: Jankovic J, Tolosa E, eds. Parkinson’s disease
and movement disorders. Baltimore: Williams and Wilkins, 1993:
3 15-328.
5. Steinke W, Sacco RL, Mohr JP, et al. Thalamic stroke: presentation and prognosis of infarcts and hemorrhages. Arch Neurol 1992;
49:703-710.
6. Bogousslavsky J, Regli F, Uske A. Thalamic infarcts: clinical syndromes, etiology and prognosis. Neurology 1988;38:837-848.
7. Lehemy S, Vidailhet M, Dormont D, et al. Striatopallidal and
thalamic dystonia: a magnetic resonance imaging anatomoclinical
study. Arch Neurol 1996;53:241-250.
8 . Segawa M. Pathophysiologies of dystonia and myoclonus: consideration from the standpoint of treatment. Rinsho Shinkeigaku 1995;
35~1390-1393.
9. Miwa H, Hatori K, Kondo T, Imai H, Mizuno Y. Thalamic tremor:
case reports and implications of the tremor-generating mechanism.
Neurology 1996;46:75-79.
10. Louis DE, Lynch T, Ford B, Greene P, Bressman SB, Fahn S.
Delayed-onset cerebellar syndrome. Arch Neurol 1996;53:450454.
11. Kim JS. Delayed onset hand tremor caused by cerebral infarction.
Stroke 1992;23:292-294.
12. Donat JR. Unilateral asterixis due to thalamic hemorrhage. Neurology 1980;30:83-84.
13. Milandre L, Brosset C, Gabriel B, Khalil R. Mouvements involuntaires transitoires et infarctus thalamiques. Rev Neurol (Paris)
1993;149:402-406.
14. Hallett M. Electrophysiologic evaluation of tremor and central disorders of movements. In: Aminoff MJ, ed. Electrodiagnosis in
clinical neurology. 2nd ed. New York Churchill Livingstone,
1986:385-401.
15. Deuschl G , Krack P, Lauk M, Timmer J. Clinical neurophysiology
of tremor. J Clin Neurophysiot 1996;13:110-121.

Abrupt Onset of Transient
Pseudochoreoathetosis Associated With
Proprioceptive Sensory Loss as a Result of a
Thalamic Infarction

The most common movement disorder following a focal lesion in the thalamus has been a delayed onset of hemidystonia,
usually involving the distal part of the limbs. The most common lesion responsible for this has been described as being a
vascular lesion in the posterolateral part of the thalamus,’
which is supplied by the thalamogeniculate artery originating
from the posterior cerebral artery (PCA).2.3
Obstruction of the PCA proximal to the origin of the thalamogeniculate artery may cause posterolateral thalamic, temporal, and occipital i n f a r ~ t i o n .However,
~,~
in a recent review
A videotape accompanies this article.
Received September 3, 1996; revision received February 20, 1997.
Accepted February 25, 1997.
Address correspondence and reprint requests to Dr. M. S. Lee at
Department of Neurology, Youngdong Severance Hospital, Yonsei
University College of Medicine, 146-92 Dogok-dong, Kangnam-koo,
Seoul, South Korea.

Movement Disorders, Vol. 13, No. I , I998

of movement disorders following a focal lesion of the thalamus,
only a few patients with delayed-onset movement disorders
following thalamic and occipital infarction caused by PCA obstruction have been identified.I4
We describe the case of a 41-year-old woman who developed a sudden onset of left hemisensory loss, hemianopia,
and hemichoreoathetosis resulting from right posterolateral thalamic, temporal, and occipital infarction. She had no motor
weakness. As the proprioceptive sensory disturbance improved,
the involuntary movement disappeared. These findings may
suggest that intact pyramidal tract and transient abnonnal proprioceptive sensory inputs to the motor control system caused
the abrupt onset of transient pseudochoreoathetosis seen in our
patient.

Case History
A 41-year-old woman developed a sudden onset of stroke
9 h after an uneventful operation to remove creases from her
forehead. The stroke began with left hemisensory disturbances
and choreoathetoid movements of her left arm and leg. She lost
her fine manual skills and was unable to stand or walk.
Her blood pressure was normal. She did not have a cardiac
murmur or arrhythmia. Neurologic examination disclosed a left
homonymous hemianopia and a full range of eye movement
without nystagmus. She had no facial weakness. While lying
down, she had athetoid movements in the distal part of her left
arm and leg. While sitting, her left arm shook at times. While
she stretched out both hands to the front, choreic movements of
her left arm were enhanced to involve the proximal part. Her
left arm was affected more severely than her leg, but her face
was spared (videotape segment 1). She could not suppress the
involuntary movements by mental concentration. The fine finger movements of her left hand were clumsy. Her muscle tone
was normal. On manual motor tests, she had no motor weakness in any of her limbs. Her tendon reflexes were hyperactive
on the left side, and her left plantar reflex was equivocal.
Sensory examination revealed complete absence of joint position sense, vibration sense, and light-touch sense over the left
side of her body. The pain sense over the left side of her body
was decreased to approximately half that of the right side.
Because of the involuntary movements, cerebellar function
tests were difficult to assess. The results of routine laboratory
examinations were normal. Prolonged electrocardiographic
monitoring and echocardiography showed no abnormalities.
The results of a serum lupus anticoagulant test and antiphospholipid antibody test were normal, as were those of a serum
anticardiolipin antibody test. The findings of antinuclear antibody, anti-DNA, and LE cell tests were normal, as were the
results of anti-Ro and anti-La tests.
A T2-weighted brain magnetic resonance imaging study
showed high-signal-intensity lesions at the right posterolateral
thalamus and temporo-occipital lobe (Fig. I). A magnetic resonance cerebral angiographic study showed an obstruction at the
proximal part of the right PCA. As the sensory disturbances
improved over a period of 3 months, the involuntary movements changed to a fixed dystonia involving distal parts of her
left hand. Around that time, she resumed independent walking.
At the follow-up examination 6 months after the onset of the
stroke, her position and light-touch sense had returned to normal. She had hypalgesia over the left side of her body and
decreased vibration sense on the left medial malleolus. While