Toxic and Metabolic Diseases of the CNS

Toxic and metabolic disorders affecting the central nervous system (CNS) may manifest in a wide variety of patterns on imaging. Severe disorders can produce nonspecific imaging appearances with overlapping characteristics, while less severe cases may demonstrate distinct patterns of brain parenchymal involvement which can aid in diagnosis. This review presents characteristic imaging features of the most common toxic and metabolic disorders of the CNS, which can be used to distinguish between different toxic etiologies and formulate a differential diagnosis. The imaging patterns are organized by the predominant site of involvement and divided into seven categories: cerebral cortex, deep white matter, brainstem, basal ganglia, cerebellum, corpus callosum, and spinal cord.