Ataxic hemiparesis

J Neurol Neurosurg Psychiatry 40 1182-1189 Fisher CM (1978) Ataxic hemiparesis. A pathologic study. Arch Neurol 35 126-128... 

While physicians may not recognize up to 80% of lacunes (Tuszynski et al. 1989), several clinical syndromes have been correlated with relevant lacunes detected at subsequent autopsy. Five of these are regarded as the classic lacunar syndromes pure motor hemiparesis, sensorimotor stroke, pure sensory hemiparesis, dysarthria clumsy hand syndrome, and ataxic hemiparesis (Donnan et al. 2002 Fisher 1982 Bamford 2001). Pure motor stroke is the commonest lacunar syndrome in clinical practice, while pure sensory stroke is encountered less frequently. The involvement of the face, arm and leg of one side is the characteristic feature of the first three syndromes while reductions of consciousness, cognitive or visual field defects are absent. Even though lacunar infarcts have been linked to lacunar syndromes, the latter are of course not specific for this stroke subtype and mimicked by cortical infarcts, intracerebral hematomas, and non-vascular causes (Bogousslavsky et al. 1988 Bamford 2001). 

Subcortical white matter infarcts may mimic a superficial MCA infarct causing a partial anterior circulation syndrome or present as a lacunar syndrome (pure motor, ataxic hemiparesis or sensori motor stroke). Superficial perforating artery infarcts (medullary branches) are often accompanied by cortical spotty lesions. Borderzone and white matter medullary branches infarctions are usually caused by hypoperfusion due lo large vessel occlusion or stenosis (Bogousslavsky 1993 Donnan and Yasaka 1998), but white matter medullary branches infarction can also be caused by cardioembolism (Lee et al. 2003). 

Ataxic hemiparesis constitutes about 10% of cases. It is the combination of corticospinal and ipsilateral cerebellar-like dysfunction affecting the arm and/or leg. It includes a syndrome in which there is little more than dysarthria and one clumsy hand. The lesion is usually in the pons, internal capsule or cerebral peduncle. Dysarthria, with or without upper motor neuron facial weakness, may also be a lacunar syndrome with similar lesion localization as ataxic hemiparesis, but there are other localizing possibilities as well. 

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