Major depression and carbon monoxide-induced parkinsonism: diagnosis, computerized axial tomography, and response to...

A case of major depressive disorder complicated by carbon monoxide (CO)-induced Parkinson's syndrome is reported. Computerized axial tomography (CAT) revealed bilateral globus pallidus necrosis. Clinical, CAT, and neuropathological findings in other cases of CO encephalopathy with and without parkinsonism are reviewed. The utility of CAT in the diagnostic workup and in following clinical course is discussed, as are the difficulties of making a diagnosis of an antecedent primary psychiatric disorder in the presence of neurological and psychiatric sequelae of CO intoxication. There was no clinical response to a tricyclic antidepressant, but both the mood and movement disorders responded fully to L-dopa. The implications of these findings with regard to the central neurochemical pathophysiology in this patient and in major depressive disorder in general are discussed.