Lacunar stroke syndrome

Lacunar stroke syndrome (LACS) is a description of the clinical syndrome that results from a lacunar infarct.

Each of the five classical lacunar syndromes has a relatively distinct symptom complex. Symptoms may occur suddenly, progressively, or in a fluctuating manner (e.g. the capsular warning syndrome).

The 5five classic syndromes are as follows.

Pure motor stroke / hemiparesis/hemiparesis

This is the most common ( 33 - 50 (33-50%) lacunar syndrome usually occurs with infarction of the posterior limb of the internal capsule, which carries the descending corticospinal and corticobulbar tracts, or the basis pontis. It is marked by hemiparesis or hemiplegia that typically affects the face, arm, or leg of one side. Dysarthria, dysphagia, and transient sensory symptoms may also be present.

Ataxic hemiparesis

This is the second most frequent lacunar syndrome and usually occurs with infarction of the posterior limb of the internal capsule, basis pontis, and corona radiata. It displays a combination of cerebellar and motor symptoms, including weakness and clumsiness, on the ipsilateral side of the body. It usually affects the leg more than it does the arm; hence, it is known also as homolateral ataxia and crural paresis. The onset of symptoms is often over hours or days.

Dysarthria/clumsy hand

This is sometimes considered a variant of ataxic hemiparesis (above), but usually still is classified as a separate lacunar syndrome. The lesion is in the pons and the main symptoms are dysarthria and clumsiness (i.e. weakness) of the hand, which often are most prominent when the patient is writing.

Pure sensory stroke

Marked by persistent or transient numbness, tingling, pain, burning, or another unpleasant sensation on one side of the body, this infarct is usually in the contralateral thalamus.

Mixed sensorimotor stroke

This lacunar syndrome involves hemiparesis or hemiplegia with ipsilateral sensory impairment, with infarct typically in the thalamus and adjacent posterior internal capsule.

Differential diagnosis

Occasionally, cortical infarct and intracranial haemorrhage may mimic lacunar infarcts. In a lacunar infarct, cortical signs (e.g. aphasia, neglect, visual field defects) are absent.