Spatial impairment following right hemisphere transient ischaemic attacks in patients without carotid artery stenosis.

Neuropsychological testing was performed on: 10 right-handed patients who had had 1-4 right hemisphere transient ischaemic attacks (TIAs), 10 normal controls, 10 house painters with long-term exposure to organic solvents, and 10 patients with liver cirrhosis. The subjects in each group were matched for age and education. No TIA patient had significant internal carotid artery stenosis, and CT was normal except in one patient, although magnetic resonance imaging (MRI) performed 3 years after the testing was abnormal in 4/8 cases. No patient reported additional distinct TIAs during the period between neuropsychological testing and MRI. The TIA patients showed lateralized signs of spatial impairment, whereas the cirrhotics and also (but to a lesser degree) the house painters showed signs of diffuse cerebral dysfunction. The study shows that hemispheric TIAs in patients without significant internal carotid artery stenosis may result in persistent focal cognitive impairment. This can be demonstrated with sensitive neuropsychological instruments even when MRI is normal.