Change in Magnetic Resonance Imaging and Clinical Signs in a Case of Chronic Toluene Intoxication by Sniffing

Abstract

Change in Magnetic Resonance Imaging and Clinical Signs in a Case of Chronic Toluene Intoxication by Sniffing: Ikuko AIBA, et al. Department of Neurology, Nagoya University School of Medicine-A 22-year -old man with an 8-year history of toluene abuse was admitted for disturbance of consciousness due to acute thinner overdose on June 19, 1990. On admission, he had distal dominant muscle atrophy with areflexia. Computed tomography revealed cerebral atrophy predominantly in the frontal lobe. Magnetic resonance imaging (MRI) of the brain in Oct 1990 revealed the following abnormalities: (1) cerebral atrophy predominantly in the frontal lobe and atrophy of vermis cerebelli and corpus callosum; (2) loss of differentiation between gray and white matter; (3) high intensity of middle cerebellar peduncle, brain stem and internal capsule on T2-weighted images; and (4) low intensity in the ventrolateral part of the thalamus on T2-weighted images. Muscle weakness gradually resolved, but the patient started thinner sniffing again in Sept, 1991. Cerebellar ataxia appeared in July, 1992 and pyramidal sign developed in Mar, 1993. MRI in May, 1993 also revealed high intensity of white matter on T2weighted images. Low intensity on T2-weighted images spread to the caudate nucleus, globus pallidus, and the dorsolateral part of the thalamus. Diffuse cerebral atrophy was found, and atrophy of the cerebellar hemisphere became prominent. High intensity of middle cerebellar peduncle, brain stem and internal capsule on T2-weighted MR images preceded clinical signs (cerebellar ataxia, pyramidal sign). The neuropathology of toluene-induced encephalopathy and the possiblity of MRI as a marker to detect changes in the brain were discussed. (J Occup Health 1996; 38: 13-19)