Atrophy of the corpus callosum associated with cognitive impairment and widespread cortical hypometabolism in carotid artery occlusive disease
H. Yamauchi, H. Fukuyama, Y. Nagahama, Y. Katsumi, Y. Dong, J. Konishi and J. Kimura
Department of Neurology, Faculty of Medicine, Kyoto University, Japan.
OBJECTIVE: To investigate whether atrophy of the corpus callosum is
associated with cognitive impairment and widespread cerebral cortical
hypometabolism in carotid artery occlusive disease. PATIENTS: Twelve
patients with unilateral internal carotid artery occlusive disease (1 with
severe stenosis and 11 with occlusion) and no cortical infarction in the
chronic stage (mean +/- SD age, 64 +/- 5 years). MAIN OUTCOME MEASURES:
Midsagittal corpus callosum area-skull area ratio (on T1-weighted magnetic
resonance images), the sum of the scaled scores of the 6 subtests on the
Wechsler Adult Intelligence Scale-Revised (Digit Span, Arithmetic, Picture
Arrangement, Object Assembly, Block Design, and Digit Symbol), and cerebral
metabolic rate of oxygen (measured with position emission tomography by
using the oxygen 15 steady-state technique). RESULTS: The degree of
cognitive impairment varied but was strongly correlated with the severity
of callosal atrophy (r = 0.92, P < .001). Patients with callosal atrophy
and cognitive decline also showed decreased oxygen consumption in the
bilateral cerebral cortices. Stepwise regression analysis revealed that the
severity of white matter lesions, especially in the centrum semiovale, and
that of cortical atrophy in the hemisphere with arterial disease were 2
important factors for callosal atrophy. CONCLUSIONS: Callosal atrophy is
associated with cognitive impairment and widespread cerebral cortical
hypometabolism in carotid artery occlusive disease without cortical
infarction. Callosal atrophy might reflect the severity of the
disconnection between cortical regions, and this may be an important factor
in the development of cognitive impairment with widespread cortical
hypometabolism in carotid artery occlusive disease without large cortical
lesions.