Mania following left hemisphere injury.

A case of mania following closed head injury to the left hemisphere is reported. The patient presented with a self-limiting manic episode that recovered without treatment. It is postulated that the head injury is the causative factor in this case. This was supported by laboratory results as well as psychological investigations. It is believed that non-dominant right hemisphere injury is related to the development of mania. However, a search of the literature revealed five other cases of mania following left hemispheric injury. Although the mechanisms implicated in the pathogenesis of secondary mania have not been established, this case adds to the growing evidence that head injury may be directly causative in affective psychoses. Therefore, it is premature to conclude that mania is a pathology of the non-dominant right hemisphere.