004 Ataxic hemiparesis: a lacunar syndrome? Lessons from the front line

A 50-year-old female developed problems using her right hand and a right sided facial droop; she described drooling of liquids and difficulty operating a computer mouse. She was assessed at 4 h post onset for inclusion in the IST-3 trial. She was found to have a mild dysarthria and right arm weakness but a more obvious ataxia affecting the right side, arm more than leg. A diagnosis of ataxic hemiparesis was made. CT imaging was normal but follow-up imaging revealed a small cortical infarct in the left frontal lobe and a severe left internal carotid stenosis. Ataxic hemiparesis is widely thought to be a lacunar or pontine vascular syndrome, but it can result from cortical infarcts. This case illustrates an important lesson for the neurologist faced with increasing involvement in hyperacute care. Impairment such as weakness, ataxia and sensory loss can be immature and changing in the hyperacute setting, making it difficult for the clinician to be confident about their origin and relevance. The same applies to the resulting disabilities the patient has not yet had a chance to understand or assimilate. Awareness of this is crucial when faced with the need for immediate decision making, particularly if plain CT, effectively an ‘excludogram’, is the imaging modality used. A new ‘rule book’ may be required for the neurologist basing important diagnostic and treatment decisions on the clinical signs in the first few hours after the onset of a significant neurological disability.