What are the symptoms and management of lacunar infarcts?

Lacunar Infarct Symptoms and Management

Lacunar infarcts present with distinct clinical syndromes including pure motor hemiparesis, pure sensory syndrome, sensorimotor stroke, ataxic hemiparesis, and dysarthria-clumsy hand syndrome, resulting from small subcortical lesions (<1.5 cm) caused by occlusion of a single penetrating artery. 1

Clinical Presentation

Classic Lacunar Syndromes

• Pure motor hemiparesis: Weakness affecting face, arm, and leg on one side without sensory, visual field, or cortical deficits
• Pure sensory syndrome: Isolated sensory symptoms affecting one side of the body
• Sensorimotor stroke: Combined motor and sensory deficits
• Ataxic hemiparesis: Combination of weakness and incoordination on the same side
• Dysarthria-clumsy hand syndrome: Slurred speech with awkward hand movements

Atypical Presentations

• Memory, speech, or hearing difficulties may occur with severe carotid stenosis 2
• Language dysfunction may be seen in patients with lacunar stroke, with studies showing increased interhemispheric functional connectivity correlating with worse aphasia 2

Diagnosis

Neuroimaging

• MRI is more sensitive than CT for detecting small infarcts, particularly in the brainstem and posterior fossa 1
• Lacunar infarcts are defined as cystic lesions <1 cm in size located in the basal ganglia, brain stem, or deep white matter (not cerebral cortex) 2
• Diagnosis requires:
  • Clinical presentation with a typical lacunar syndrome
  • Neuroimaging showing a small subcortical infarct or normal findings
  • Exclusion of other potential causes 1

Differential Diagnosis

• Non-focal neurological events (transient global amnesia, acute confusion, syncope, isolated vertigo) are not clearly attributable to extracranial carotid and vertebral artery disease 2
• When symptoms are purely sensory, consider radiculopathy, neuropathy, microvascular cerebral or spinal pathology 2

Prognosis

Lacunar infarcts have a paradoxical clinical course:

• Short-term: Favorable prognosis with low early mortality and reduced functional disability on hospital discharge 1, 3
• Long-term: Less favorable with increased risk of:
  • Recurrent stroke (similar to other ischemic stroke subtypes)
  • Cognitive decline and dementia
  • Death, mainly from cardiovascular causes 1, 3, 4, 5

Management

Acute Treatment

• Intravenous thrombolysis if presenting within the treatment window 1, 4
• Response to thrombolysis appears similar to other ischemic stroke subtypes 4

Secondary Prevention

1. Antiplatelet therapy: First-line for most lacunar stroke patients 1, 3, 4
2. Blood pressure control: Aggressive management is crucial as hypertension is a major risk factor 1, 3
3. Statin therapy: Recommended regardless of baseline cholesterol levels 1, 4
4. Diabetes management: Important as diabetes is a major risk factor 3
5. Lifestyle modifications: Smoking cessation, weight management, physical activity, and dietary changes 1

Important Considerations

• Lacunar infarcts should be regarded as a potentially severe condition rather than a benign disorder, requiring rigorous management and follow-up 3
• Silent small vessel disease in the brain at the time of an index stroke has significant prognostic implications 4
• Asymptomatic progression of small-vessel disease is a typical feature of lacunar infarcts 3
• Lacunar stroke is heterogeneous with various mechanisms, including lipohyalinosis (most common), atheromatous disease, and cardioembolism 6

Monitoring and Follow-up

• Regular assessment of cognitive function is important given the increased risk of cognitive decline 1, 5
• Monitoring for recurrent stroke and cardiovascular complications is essential 5
• Continued management of vascular risk factors is critical for long-term outcomes 5

By recognizing the characteristic symptoms of lacunar infarcts and implementing appropriate management strategies, clinicians can help mitigate both short-term disability and long-term complications associated with this common stroke subtype.