Case Report

Pure Mutism Due To Simultaneous
Bilateral Lenticulostriate Artery
Territory Infarction
By Dilek Evyapan Akkus, MD

ABSTRACT

FOCUS POINTS

A case of pure mutism without pseudobul-

• Lenticulostriate artery territory infarctions are
typically associated with severe motor or sensorimotor deficits.
• In all reported cases of subcortical vascular mutism, the responsible bilateral lesions are mostly
sequential.
• The case presented here has acute simultaneous bilateral lenticulostriate artery territory infarction. This case is the first reported case of acute
subcortical pure vascular mutism without other
neurological signs and simultaneous development of lesions which is an interesting and rare
encountered feature.

bar palsy and other neurological findings resulting from simultaneous bilateral lenticulostriate
artery territory infarction is presented. A 45-yearold woman suffered a transient ischemic attack
with nonfluent aphasia and right hemiparesis.
Six months later, she developed pure mutism
without oral apraxia, pseudobulbar signs, and
motor deficits. Magnetic resonance imaging
revealed bilateral infarction in the lentiform
nucleus regions. In the available data, there is
only one report of simultaneous bilateral lenticu-

INTRODUCTION

lostriate infarction.To date, in all reported cases

Mutism is a well-known clinical condition
described as the inability or unwillingness to
speak, resulting in an absence or marked paucity
of verbal output. Mutism usually refers to a complete or nearly complete absence of speech. It has
a wide differential diagnosis. In almost all neurologic conditions, mutism is associated with other
neurological findings. 1 I observed an unusual
case of pure mutism due to acute bilateral subcortical infarctions resulting from bilateral simultaneous occlusion of lenticulostriate arteries.

of mutism of subcortical vascular origin there
are also various degrees of pseudobulbar signs
and motor deficits and the responsible lesions
are mostly consecutive.The case presented here
is the first to show pure vascular mutism without other neurological findings.
CNSSpectr. 2006;11 (4)257-259

Dr. Evyapan Akkus is associate professor in the Department of Neurology's Stroke and Neuropsychology Unit in the Faculty of Medicine at Ege
University in Izmir, Turkey.
Disclosure: The author does not have an affiliation with or financial interest in any organization that might pose a conflict of interest.
Submitted for publication: August 24, 2005, accepted December 8, 2005.
Please direct all correspondence to: Dilek Evyapan Akkus, MD, Ege University, Faculty of Medicine, Neurology Department, Stroke and
Neuropsychology Unit, Bornova, Izmir, Turkey; Tel: 90-532-6846244, Fax: 90-232-3427363; E-mail: dilekevyapan@yahoo.com.
CNS Spectr 1 1:4

257

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April 2006

Case Report

There is only one report in literature regarding
"simultaneous" bilateral lenticulostriate artery
territory infarction5 and this case also has severe
tetraplegia and mutism. In previous reports of
cases with subcortical vascular mutism, the
responsible lesions are mostly sequential. 7
Also, pure vascular mutism without pseudobulbar palsy or other neurological findings has not
been reported previously as a result of subcortical lesions. In the light of this feature, the present case is the first in literature.
In this patient, simultaneous development of
bilateral infarctions, the presence of a cardiac
embolic source and microembolic signals positivity are strong evidences supporting the cardiogenic embolism. Absence of the pseudobulbar and
pyramidal signs may be due to capsular sparing
influenced by many factors, such as variations in
the anatomic distribution of arteries, lysis of the
embolic material, and selective occlusion of the
arterial branches distant from internal capsule.2
Disturbed initiation of speech can be seen in
the focal lesions of the basal ganglia.8 Each of
the basal ganglia nuclei has distinct functional
subdivisions.9 Because mutism had occured isolated from a movement disorder in this case one
may suggest that the functional subdivision of
striatum only connected with supplementary
motor area or cingulate gyms may be affected.

CASE REPORT
A 45-year-old woman was admitted to Ege
University Neurology Clinic 2 hours after sudden onset of speech disorder and right hemiparesis. On admission, there was a mild right
hemiparesis and a nonfluent aphasia.These findings disappeared ~1 hour after the first examination. Dupplex sonography of carotid and vertebral
arteries was normal. Computerized brain tomography showed no pathology. The case was diagnosed as transient ischemic attack.
After 6 months, the patient suddenly developed
inability to speak.The patient was seen by a village physician and the symptoms could not be
explained by him.The patient spent 2 days at home
with her relatives' belief that the disorder was psychogenic in origin. Showing no signs of improvement, the patient was brought to Ege University
Hospital. On examination, she was found to be
mute; there was no spontaneous speech activity, either voice or word. She made no effort to
speak. Nevertheless, her daughters stated that the
patient could use some emotional phrases (such
as "God!," "Ooofl," "That's enough!" and "Ugh!").
During neurologic examination, the patient had a
smiling tendency. Obedience to verbal and written
commands was complete but exceedingly slow.
She could name and repeat after a long latency.
Her writing was comprised of intelligible words
and sentences.The remaining neurological examination was entirely normal and there was no
buccolingual apraxia, swallowing, or phonation
difficulty. In daily living, the patient was able to
carry out housework.
Echocardiography revealed the mitral stenosis. Diffusion and T2-weighted magnetic
resonance images showed bilateral acute infarctions in the lentiform nucleus regions (Figure).
Embolic signal monitoring of middle cerebral
arteries with transcranial Doppler sonography
revealed bilateral microembolic signals compatible with embolism.

FIGURE.
Axial T2-weighted MRI demonstrating
infarctions of both lentiform nuclei

DISCUSSION
In the acute stage, the typical clinical syndrome
of pure striatocapsular infarction presented with a
severe motor or sensorimotor deficit.2 In the rare
cases of bilateral striatocapsular infarctions, tetraplegia and akinetic mutism was observed.23
Contrary to the previous reports of bilateral
lenticulostriate infarctions, 26 the clinical picture of the present case is pure mutism without
severe pseudobulbar signs and quadriparesis.
CNS Spectr 1 1:4

MR=magnetic resonance image.
Evyapan Akkus D. CNSSpectr. Vol 11, No 4. 2006.

258

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April 2006

Case Report

CONCLUSION
Acute subcortical pure vascular mutism without other neurological findings has not been
reported previously as a result of bilateral simultaneous lesions. This case is interesting in that
vascular mutism occured purely without other
neurological findings and it is unique in that
responsible etiology is "simultaneous" bilateral
lenticulostriate infarction. CNS
REFERENCES
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Trimble MR, eds. Concise Guide to Neuropsychiatiy and Behavioral Neurology.
Washington, DC: American Psychiatric Press; 1999:73-89.
2. Ringelstein EB, Weiller C. Lenticulostriate arteries. In: Bogousslavsky J, Caplan L,
eds. Stroke Syndromes. New York, NY: Cambridge University Press; 1995:259-269.
3. De Smet Y, Rousseau JJ, Brucher JM. Bilateral, symmetrical and simultaneous
putamino-capsulo-caudal infarction. HevNeurol. 1990; 146:415-419.
4. Bladin PR Berkovic SF. Striatocapsular infarction. Neurology. 1984;34:1423-1430.
5. Boiten J, Lodder J. Large striatocapsular infarcts: clinical presentation and pathogenesis in comparison with lacunar and cortical infarcts. Ada Neurol Scand.
1992:86:298-303.
6. Levine RL, Lagreze HL, Dobkin JA, Turski PA. Large subcortical hemispheric infarctions. Arch Neurol. 1988:45:1074-1077.
7. Helgason C, Wilbur A, Weiss A, Redmond KJ, Kingsbury NA. Acute pseudobulbar
mutism due to discrete bilateral capsular infarction in the territory of the anterior
choriodal artery. Brain. 1988:111:507-524.
8. Foti DJ, Cummings JL. Neurobehavioral aspects of movement disorders. In: Watts
RL, Koller WC. eds. Movement Disorders: Neurologic Principles and Practice. New
York, NY: McGraw-Hill; 1997:15-30.
9. Alexander GE. Anatomy of the basal ganglia and related motor structures. In: Watts
RL, Koller WC, eds. Movement Disorders: Neurologic Principles and Practice. New
York, NY: McGraw-Hill; 1997:73-85.

CNS Spectr 11:4

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April 2006

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Lithium toxicity is closely related to serum lithium concentrations and can
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There has been a report of transient syndrome of acute dystonia and
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The ability to tolerate lithium is greater during the acute manic phase and
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The distribution space of lithium approximates that of total body water.
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Renal excretion of lithium is proportional to its plasma concentration.
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Safety and effectiveness in pediatric patients below the age of 12 have not
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ADVERSE REACTIONS
The occurrence and severity of adverse reactions are generally directly
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mEq/L. Mild to moderate adverse reactions may occur at concentrations
from 1.5-2.5 mEq/L, and moderate to severe reactions may be seen at
concentrations from 2.0 mEq/L and above.
Fine hand tremor, polyuria and mild thirst may occur during initial
therapy for the acute manic phase and may persist throughout treatment.
Transient and mild nausea and general discomfort may also appear
during the first few days of lithium administration.
These side effects usually subside with continued treatment or with a
temporary reduction or cessation of dosage. If persistent, a cessation
of lithium therapy may be required. Diarrhea, vomiting, drowsiness,
muscular weakness and lack of coordination may be early signs of lithium
intoxication, and can occur at lithium concentrations below 2.0 mEq/L. At
higher concentrations, giddiness, ataxia, blurred vision, tinnitus and a
large output of dilute urine may be seen. Serum lithium concentrations
above 3.0 mEq/L may produce a complex clinical picture involving
multiple organs and organ systems. Serum lithium concentrations should
not be permitted to exceed 2.0 mEq/L during the acute treatment phase.
The following reactions have been reported and appear to be related
to serum lithium concentrations, including concentrations within the
therapeutic range:
Central Nervous System: tremor, muscle hyperirritability
(fasciculations, twitching, clonic movements of whole limbs), hypertonicity,
ataxia, choreoathetotic movements, hyperactive deep tendon reflex,
extrapyramidal symptoms including acute dystonia, cogwheel rigidity,
blackout spells, epileptiform seizures, slurred speech, dizziness, vertigo,
downbeat nystagmus, incontinence of urine or feces, somnolence,
psychomotor retardation, restlessness, confusion, stupor, coma, tongue
movements, tics, tinnitus, hallucinations, poor memory, slowed intellectual
functioning, startled response, worsening of organic brain syndromes.
Cases of Pseudotumor Cerebri (increased intracranial pressure and
papilledema) have been reported with lithium use. If undetected, this
condition may result in enlargement of the blind spot, constriction of visual
fields and eventual blindness due to optic atrophy. Lithium should be
discontinued, if clinically possible, if this syndrome occurs.
Cardiovascular: cardiac arrhythmia, hypotension, peripheral circulatory
collapse, bradycardia, sinus node dysfunction with severe bradycardia
(which may result in syncope); Gastrointestinal: anorexia, nausea,
vomiting, diarrhea, gastritis, salivary gland swelling, abdominal pain,
excessive salivation, flatulence, indigestion; Genitourinary: glycosuria,
decreased creatinine clearance, albuminuria, oliguria, and symptoms of
nephrogenic diabetes insipidus including polyuria, thirst and polydipsia;
Dermatologic: drying and thinning of hair, alopecia, anesthesia of skin,
acne, chronic folliculitis, xerosis cutis, psoriasis or its exacerbation,
generalized pruritus with or without rash, cutaneous ulcers, angioedema;
Autonomic Nervous System: blurred vision, dry mouth, impotence/
sexual dysfunction; Thyroid Abnormalities: euthyroid goiter and/or
hypothyroidism (including myxedema) accompanied by lower T3 and
T4. 131 Iodine uptake may be elevated. Paradoxically, rare cases of
hyperthyroidism have been reported. EEG Changes: diffuse slowing,
widening of frequency spectrum, potentiation and disorganization of
background rhythm.
EKG Changes: reversible flattening, isoelectricity or inversion of
T-waves. Miscellaneous: Fatigue, lethargy, transient scotomata,
exophthalmos, dehydration, weight loss, leucocytosis, headache,
transient-hyperglycemia.hypercalcemia,
h y per- pa rath y ro id i sm,
albuminuria, excessive weight gain, edematous swelling of ankles or
wrists, metallic taste, dysgeusia/taste distortion, salty taste, thirst,
swollen lips, tightness in chest, swollen and/or painful joints, fever,
polyarthralgia, and dental caries.
Some reports of nephrogenic diabetes insipidus, hyperparathyroidism
and hypo-thyroidism which persist after lithium discontinuation have
been received.
A few reports have been received of the development of painful
discoloration of fingers and toes and coldness of the extremities within
one day of starting lithium treatment. The mechanism through which
these symptoms (resembling Raynaud's Syndrome) developed is not
known. Recovery followed discontinuance.

OVERDOSAGE
The toxic concentrations for lithium (1.5 mEq/L) are close to the
therapeutic concentrations (0.6-1.2 mEq/L). It is therefore important that
patients and their families be cautioned to watch for early toxic symptoms
and to discontinue the drug and inform the physician should they occur.
(Toxic symptoms are listed in detail under ADVERSE REACTIONS).
Treatment: No specific antidote for lithium poisoning is known. Treatment
is supportive. Early symptoms of lithium toxicity can usually be treated
by reduction or cessation of dosage of the drug and resumption of the
treatment at a lower dose after 24 to 48 hours. In severe cases of lithium
poisoning, the first and foremost goal of treatment consists of elimination
of this ion from the patient.
Treatment is essentially the same as that used in barbiturate poisoning:
1) gastric lavage, 2) correction of fluid and electrolyte imbalance and,
3) regulation of kidney functioning. Urea, mannitol, and aminophylline
all produce significant increases in lithium excretion. Hemodialysis is an
effective and rapid means of removing the ion from the severely toxic
patient. However, patient recovery may be slow.
Infection prophylaxis, regular chest X-rays, and preservation of adequate
respiration are essential.

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