[Horner type anisocoria associated with brain infarction of the internal carotid artery axis].

Brain infarction caused by arterial occlusion of the internal carotid axis sometimes develops Horner syndrome. The purpose of this study is to clarify the characteristics and mechanism of "Horner type" anisocoria, which is one of the symptoms of Horner syndrome, in patients with brain infarction in regions supplied by the internal carotid artery (ICA). We studied 112 consecutive patients (71 males and 41 females, mean age of 60.8 +/- 12.3 years) with brain infarction with either ICA or the middle cerebral artery (MCA) occlusion, who were admitted to the National Cardiovascular Center within seven days after the onset of stroke. We examined differences in frequency of Horner type anisocoria and its duration after onset by the mechanism (embolic or thrombotic) and site (ICA proximal, ICA distal or MCA) of arterial occlusion. Horner type anisocoria was seen in 26 of 66 cases (39.4%) with embolic occlusion, which was more frequent than in those with thrombotic occlusion (8 of 46 cases, 17.4%) (p < 0.05). In the embolic occlusion group, Horner type anisocoria was seen in 17 of 32 cases (53.1%) with ICA occlusion, which was more frequent than in those with MCA occlusion (9 of 34 cases, 26.5%) (p < 0.05). Horner type anisocoria was more frequently seen in embolic (17 of 32 cases, 53.1%) than in thrombotic ICA occlusion (2 of 21 cases, 9.5%) (p < 0.01). The duration of Horner type anisocoria was shorter in patients with either distal ICA or MCA occlusion than in those with proximal ICA occlusion (p < 0.05). In patients with thrombotic occlusion, there was no distinct characteristics in between those ICA and MCA occlusion.(ABSTRACT TRUNCATED AT 250 WORDS)