Lacunar Stroke Syndrome

Overview

Lacunar stroke syndrome refers to a group of clinical syndromes caused by lacunar infarcts - small, deep cerebral strokes that affect the penetrating arteries of the brain. These strokes typically occur in the basal ganglia, thalamus, internal capsule, or pons. Lacunar strokes account for approximately 20–30% of all ischemic strokes and are often associated with chronic hypertension and diabetes. Although smaller in size, lacunar strokes can lead to significant neurological deficits depending on the location of the infarct.

Causes

Lacunar strokes are primarily caused by occlusion of small, penetrating arteries that supply deep structures of the brain. The most common underlying causes include:

• Chronic hypertension – leads to lipohyalinosis, a degenerative process affecting small blood vessels

• Diabetes mellitus – contributes to microvascular damage and atherosclerosis

• Small vessel atherosclerosis – buildup of fatty deposits in small arteries

• Embolic sources – less common, but emboli can occasionally affect small vessels

• Genetic or inflammatory vasculopathies – rare contributors to small vessel disease

Symptoms

Lacunar stroke syndromes present with distinct neurological patterns that reflect the specific area affected. Common lacunar syndromes include:

• Pure motor hemiparesis – weakness on one side of the body without sensory loss or higher cortical dysfunction

• Pure sensory stroke – numbness or sensory impairment affecting one side of the body

• Sensorimotor stroke – combination of motor and sensory deficits on one side

• Ataxic hemiparesis – weakness and incoordination, usually affecting the same side

• Dysarthria-clumsy hand syndrome – slurred speech and clumsiness of the hand

Unlike cortical strokes, lacunar strokes typically do not involve visual field deficits, aphasia, or cognitive changes.

Diagnosis

Diagnosing a lacunar stroke involves clinical evaluation, imaging studies, and identifying vascular risk factors. Key diagnostic steps include:

• Neurological examination – to assess for specific lacunar syndromes

• Brain imaging:

  • MRI – the preferred modality, detects small infarcts with high sensitivity

  • CT scan – may miss small lesions but is often used initially to rule out hemorrhage

• Vascular studies – such as Doppler ultrasound or MR angiography to assess larger vessel disease

• Laboratory tests – including blood sugar, lipid profile, and inflammatory markers

Treatment

Treatment of lacunar stroke focuses on acute management, secondary prevention, and rehabilitation:

• Acute stroke care – may include thrombolysis (tPA) if within the treatment window and no contraindications

• Antiplatelet therapy – such as aspirin or clopidogrel to prevent future strokes

• Blood pressure control – essential for preventing recurrence

• Diabetes and cholesterol management

• Physical and occupational therapy – to regain lost function and improve quality of life

Prognosis

The prognosis for lacunar stroke is generally better than that of large-vessel or cardioembolic strokes. Many patients recover well, especially with early intervention and rehabilitation. However, recurrence is a concern, particularly if vascular risk factors are not managed. In some cases, multiple lacunar infarcts over time can lead to a condition known as lacunar state or subcortical vascular dementia, characterized by progressive cognitive decline and gait disturbances.