Lower limb monochorea from a globus pallidus infarct

Area of Science:

• Neurology
• Neuroscience
• Movement Disorders

Background:

• Cerebrovascular accidents (CVAs) frequently cause movement disorders, categorized as hyperkinetic (e.g., hemichorea, hemiballismus) or hypokinetic (e.g., parkinsonian disorders).
• Monochorea, a specific type of hyperkinetic movement disorder affecting a single limb, is an uncommon sequela of stroke.

Observation:

• A 47-year-old male presented with sudden-onset choreiform movements exclusively in his left lower limb.
• Neurological examination revealed normal motor power and absence of abnormal movements in other extremities.

Findings:

• Brain magnetic resonance imaging (MRI) indicated an infarct in the right globus pallidus interna, extending into the posterior limb of the internal capsule.
• The patient received treatment with clonazepam and trihexyphenidyl, resulting in significant improvement of choreiform movements within three months.

Implications:

• This case highlights an unusual presentation of monochorea in a lower limb attributed to a globus pallidus interna infarct.
• The findings emphasize the complex pathophysiology of chorea and the diverse neurological deficits that can arise from focal cerebrovascular lesions.