What are the symptoms of basal ganglia infarction?

Symptoms of Basal Ganglia Infarction

The most common presenting symptom of basal ganglia infarction is contralateral hemiplegia, occurring in approximately 83% of patients, often accompanied by sensory changes, altered consciousness, aphasia, and movement disorders such as choreoathetosis or hemichorea-hemiballism. 1

Primary Motor Manifestations

• Contralateral hemiplegia is the hallmark presentation, affecting 30 of 36 patients (83%) in pediatric series, though this pattern holds across age groups 1
• The weakness is typically contralateral to the side of infarction and can range from mild paresis to complete plegia 2, 1
• Hemiparesis with ipsilateral choreoathetosis represents a distinctive presentation pattern when basal ganglia structures are involved 2

Movement Disorders

• Hemichorea-hemiballism (HCHB) presents as acute-onset involuntary movements contralateral to the basal ganglia lesion, particularly with involvement of the subthalamic nucleus or striatum 3
• These movement disorders can persist for months and typically respond to GABA-agonists (clonazepam 0.5-1 mg/day) or anti-dopaminergic medications (haloperidol 0.375-0.75 mg/day) 3
• Choreoathetoid movements may appear acutely or develop subacutely as the infarct evolves 2

Sensory and Cortical Signs

• Hemisensory changes occur in approximately 14% of patients, presenting as contralateral sensory loss or altered sensation 1
• Aphasia develops in roughly 14% of cases, particularly when the dominant hemisphere basal ganglia or adjacent structures are affected 1
• Altered consciousness presents in approximately 14% of patients, more commonly with bilateral lesions (4 of 6 patients with bilateral infarctions) or thalamic involvement 1

Seizures and Other Neurological Features

• Seizures occur in approximately 14% of patients as a presenting feature, though this is less common than motor deficits 1
• The location of unilateral infarction within the thalamus or basal ganglia does not reliably predict the specific clinical presentation pattern 1

Bilateral Infarction Patterns

• Bilateral basal ganglia infarctions present more frequently with altered mental status rather than isolated motor deficits 1
• Patients with bilateral lesions have a higher likelihood of consciousness impairment as the dominant presenting feature 1

Temporal Evolution and Associated Features

• Symptoms typically develop acutely or subacutely, with most presentations occurring within hours to days of the vascular event 3
• In pediatric cases, mild head trauma may precede symptom onset by a brief interval, particularly in the context of underlying lenticulostriate vasculopathy 4
• Recurrent infarctions can occur, with some patients experiencing contralateral basal ganglia strokes in follow-up 4

Common Pitfalls

• Do not dismiss basal ganglia infarction in children or young adults without traditional vascular risk factors, as the etiology is diverse and systemic hypertension does not play a major role in pediatric cases 1
• Recognize that movement disorders like hemichorea-hemiballism may be the primary or sole manifestation, particularly with smaller lacunar infarcts affecting specific basal ganglia nuclei 3
• Be aware that bilateral presentations carry different prognostic implications and more commonly present with encephalopathy rather than focal motor signs 1