Conjugate eye deviation in acute stroke: incidence, hemispheric asymmetry, and lesion pattern.

BACKGROUND AND PURPOSE The authors studied clinical features and lesion patterns associated with conjugate eye deviation (CED) in acute stroke. METHODS Consecutive patients with supratentorial stroke (<6 hours after symptom onset) were prospectively recruited. CED was classified according to the National Institute of Health Stroke Scale (NIHSS) item "gaze palsy" as being forced, partial, or absent. Lesion patterns on diffusion-weighted images (DWI) were analyzed in 46 patients using a normalization procedure for direct comparisons between patients. Perfusion data were analyzed for a subset of patients. RESULTS Partial CED was found in 7 (6%) and forced CED in 31 (26.7%) of 116 patients. Forced and partial CED were associated with higher initial NIHSS scores compared with patients without CED (16 and 10 versus 5; P<0.05). DWI lesion volume was larger in patients with CED (103.24+/-102.4 mL, mean+/-SD) as compared with patients without CED (17+/-34.98 mL, P<0.001). CED was more frequent in right hemispheric stroke (44.6% versus 23%, P<0.02). DWI pattern analysis in patients with CED with right hemispheric stroke revealed a network of affected regions, including basal ganglia and temporoparietal cortex. In left hemispheric CED, lesions were larger than in patients without CED, but no consistent pattern could be established. In a subset of selected patients with CED, a small temporoparietal perfusion deficit was sufficient to elicit CED. CONCLUSIONS Selective dysfunction of cortical areas involved in spatial attention and control of eye movements is sufficient to cause CED in patients with acute stroke. However, in the majority of cases, CED is an indicator of large infarcts involving more than one area, including both cortical and subcortical structures.