Abstract
BACKGROUND: Mania usually occurs secondary to organic etiologies such as head trauma within a short time of the primary condition's onset; however, there have been a few cases reported in the literature of long time spans before the manifestation of mania. The orbitofrontal cortex has been reported to be associated with manic states in bipolar disorder and with mania-inducing lesions. Head trauma commonly disrupts various cognitive functions, including attention and information processing. Traumatic brain injury patients have been shown to have greater posterior cingulate cortex and precuneus functional connectivity to the rest of the default mode network. We describe a case of secondary mania after head trauma 24 years ago with low blood flow in the orbitofrontal cortex, high blood flow in the posterior cingulate cortex, and impaired cognitive functioning, including impaired attention and lowered processing speed. CASE PRESENTATION: We describe a 30-year-old Japanese man with secondary mania and a medical history of head trauma 24 years ago. After head trauma at 6 years of age, the patient first showed apathy as a sign of frontal lobe impairment. After recovering, he experienced no psychiatric problems during adolescence, although he did show disinhibited behavior. At the onset of mania, low blood flow in the OFC and high blood flow in the PCC were observed as well as impaired cognitive function, including inattention and lowered processing speed. Abnormal cerebral blood flow was less prominent and cognitive dysfunction was partially recovered following recovery from mania, but his processing speed remained low. CONCLUSIONS: Although functional recovery from head trauma in childhood is better than that in adulthood, the brain may remain vulnerable for a long time. The risk of psychotic symptoms such as mania should be considered, even if sufficient superficial brain functional recovery is shown.