NEUROTOXICITY TO THE BASAL GANGLIA SHOWN BY MAGNETIC-RESONANCE-IMAGING (MRT) FOLLOWING POISONING BY METHANOL AND OTHER SUBSTANCES

Objective: To define specific brain magnetic resonance features in met hanol intoxicated patients and to evaluate the clinical relevance of m onitoring these features. Background: During the past decade magnetic resonance imaging has proven to be an exquisitely sensitive modality i n depicting subtle water changes in diseased areas of the brain, allow ing the definition of high-risk structures in numerous pathological co nditions, Method: Four patients admitted to our institution for acute methanol intoxication were repeatedly evaluated by brain magnetic reso nance imaging or a combination of computed tomography and magnetic res onance imaging, Common features of initial brain status were shown in all four cases and compared to those of patients presenting with other intoxications or critical deprivation states, Results: Preferential l ocalization of methanol-induced lesions within the putamina was observ ed in all four cases, This finding is specific compared to intoxicatio n by other substances like carbon monoxide, or in the critical phase o f metabolic disorders, The striking regression of the putaminal lesion s on follow-up magnetic resonance examinations correlated with complet e neurological recovery and the absence of extrapyramidal disturbance, Two patients exhibited discrete symmetric additional lesions in the m edial areas of the parieto-occipital lobes, In a third one, the occipi tal lesions were severe, All three suffered from permanent visual impa irment, The fourth patient, in whom magnetic resonance examinations fa iled to reveal any occipital lesion, never complained of visual distur bance though signs of optic neuropathy were detected in the visual evo ked potentials, Conclusion: Magnetic resonance imaging appeared as a w ell suited neuroimaging modality in methanol intoxicated patients both in revealing a specific pattern of brain lesions and in demonstrating valuable correlation between evolution of brain changes on magnetic r esonance images and clinical outcome.