Clinical and prognostic correlates of stroke subtype misdiagnosis within 12 hours from onset

Pure motor hemiparesis and sensorimotor stroke syndromes are not accurate predictors of lacunar infarct when described in the first 12 hours of stroke onset. We evaluate here whether this inaccuracy of clinical diagnosis might have influenced the planning of patient management either in routine practice or in therapeutic trials.

A consecutive hospital series of 517 first-ever ischemic hemispheric stroke patients presented lacunar or nonlacunar syndromes at the first examination within 12 hours of the event. A distinction was subsequently made, by means of a CT scan or autopsy performed within 15 +/- 2 days of stroke, between patients affected by lacunar or nonlacunar infarcts. We compared stroke risk factors, considered to be indicative of potential pathogenetic mechanisms, and the clinical outcome of lacunar infarct versus nonlacunar infarct patients and those of lacunar syndrome versus nonlacunar syndrome patients.

Two hundred nineteen patients (42%) presented a lacunar syndrome and 298 (58%) a nonlacunar syndrome, while 170 (33%) had lacunar infarcts and 347 (67%) nonlacunar infarcts. Lacunar infarct patients were more frequently associated with hypertension and a previous transient ischemic attack and less frequently with atrial fibrillation when compared with their nonlacunar infarct counterparts, whereas no differences were apparent between lacunar syndrome and nonlacunar syndrome patients. Logistic regression analysis showed that hypertension and a previous transient ischemic attack on the one hand and atrial fibrillation on the other were strongly correlated with the diagnosis of lacunar infarct and nonlacunar infarct, respectively, while no risk factor was correlated with the diagnosis of lacunar syndrome. Twenty-two percent of lacunar infarct patients and 68% of nonlacunar infarct subjects had a poor outcome (death plus disability of survivors) as opposed to 40% of lacunar syndrome and 63% of nonlacunar syndrome patients. Logistic regression selected age, severity of neurological deficit at entry, cardiopathies, diabetes, and lacunar infarct, but not lacunar syndrome, as predictors of outcome.

The inaccurate clinical diagnosis of lacunar infarct made in the first 12 hours of stroke might lead to no distinction being made between stroke subgroups with potentially different pathogenetic mechanisms and prognostic estimates, thus negatively influencing the planning of patient management.