A Man Made Manic: Levodopa-Carbidopa-Induced Mania in Traumatic Brain Injury

Traumatic brain injury (TBI) has had increased notoriety in light of chronic traumatic encephalopathy in professional sports. However, despite the increased rate at which mood disorders affect this population, there remains little information on management of these disorders. TBI has also been implicated in the development of Parkinson disease, increasing the likelihood that patients may be treated with dopaminergic agents. Management of coexisting pathologies can become challenging, especially when confounded by medication side effects. A case is presented of a 58-year-old man who was admitted to the hospital in a manic state 15 years after having suffered a closed head injury. Several psychiatric admissions during the past 2 years were noted, with various diagnoses including different iterations of bipolar disorder. Among his medications, levodopa-carbidopa was present for an unsubstantiated Parkinson disease diagnosis. His mania resolved after discontinuation of the agent. This case is presented with a review of the relevant literature pertaining to the use of levodopa-carbidopa in this context, the use of other dopaminergic agents, and a biological hypothesis for the potential increased likelihood of manic symptoms in TBI patients who receive levodopa-carbidopa. Currently, there is a lack of research in this area, which emphasizes a need to review treatment guidelines for Parkinson disease patients with TBI.