What are the symptoms and management of posterior basal ganglia infarction?

Symptoms of Posterior Basal Ganglia Infarction

Posterior basal ganglia infarctions present with a range of symptoms including hemiparesis, sensory deficits, movement disorders, and potential cognitive impairment, requiring prompt recognition and management to improve outcomes.

Clinical Presentation

Common Symptoms

• Loss of consciousness, headache, nausea, vomiting, dizziness, and unilateral extremity weakness are frequently observed in posterior circulation strokes affecting the basal ganglia 1
• Hemiparesis (weakness on one side of the body) is the most common presenting symptom, occurring in approximately 83% of patients with basal ganglia infarction 2
• Visual disturbances including double vision, blurred vision, and visual field defects may occur 1
• Slurred speech (dysarthria) and hearing loss can develop due to involvement of relevant neural pathways 1

Neurological Signs

• Ataxia (impaired coordination) and balance problems are common, with truncal ataxia being particularly notable 1
• Nystagmus (involuntary eye movements) may be present on examination 1
• Hemisensory changes occur in approximately 14% of patients 2
• Reflexes are often diminished or absent in the affected limbs 1

Movement Disorders

• Some patients may develop choreoathetosis (involuntary, irregular, flowing movements) on the side opposite to the infarction 3
• Dystonia, hypertonia, and rigidity with Parkinsonian characteristics may develop, particularly with involvement of specific basal ganglia structures 1
• Tremors and dysarthria can occur as part of the movement disorder spectrum 1

Cognitive and Behavioral Symptoms

• Altered mental status may occur, especially with bilateral lesions 2
• Cognitive impairment is a significant risk following basal ganglia stroke 4
• Aphasia (language difficulties) occurs in approximately 14% of pediatric patients with basal ganglia infarction 2

Special Considerations

Diagnostic Challenges

• Posterior circulation strokes can present with non-specific symptoms that mimic other clinical conditions, leading to delays in diagnosis 1
• National Institutes of Health Stroke Scale (NIHSS) has limitations in detecting posterior circulation strokes as it focuses more on limb and speech impairments rather than cranial nerve lesions 1
• Patients with posterior circulation emergent large vessel occlusion (pc-ELVO) can have an NIHSS score of 0, presenting only with headache, vertigo, and nausea 1

Age-Related Differences

• In young children (<6 years old), presentation may be atypical with nonspecific features such as poorly localized pain, refusal to bear weight, irritability, or unsteady gait 1
• Pediatric patients with basal ganglia infarcts may present with seizures (14% of cases) 2
• In adults, etiologies differ by age: thromboembolism is more common in younger patients, while intrinsic atherosclerosis typically occurs in the sixth/seventh decades of life 1

Functional Outcomes

• Patients with stroke confined to the basal ganglia and internal capsule may have diminished response to rehabilitation efforts compared to those with cortical lesions 5
• Hypotonia, flaccid paralysis, and persistently impaired balance and ambulation are more common in patients with isolated basal ganglia/internal capsule injury 5
• Mortality from posterior circulation strokes ranges from 45% to 86%, with good clinical outcomes occurring in only approximately 20% despite advanced care 1

Management Considerations

• Early recognition is critical as these strokes are often devastating events 1
• Physicians must maintain a high index of clinical suspicion for posterior circulation strokes even with subtle symptoms 1
• Neuroimaging with MRI or CT angiography is preferred over ultrasound for evaluation of the vertebral arteries in patients with symptoms suggesting posterior circulation ischemia 1
• Patients with suspected basal ganglia infarction should be evaluated for potential causes including thromboembolism, atherosclerosis, dissection, and vasculitides 1

Pitfalls to Avoid

• Relying solely on NIHSS scores may lead to missed diagnoses of posterior circulation strokes 1
• Delayed recognition is common due to non-specific symptoms that may mimic other conditions 1
• Failure to consider posterior circulation stroke in patients presenting with isolated vertigo, headache, or nausea without obvious focal neurological deficits 1
• Overlooking the possibility of basal ganglia infarction in children with new-onset movement disorders or unexplained hemiparesis, even after trivial trauma 6