From perimenopause to neuroinflammation: Rethinking a case of late-onset mania.

Background: This case report explores the evolution of diagnoses in a 46-year-old female whose perimenopausal symptoms and psychiatric history shaped the diagnostic interpretation, delaying recognition of her underlying neurologic condition. Case Presentation: This patient, who had been stable for over a decade on a serotonin reuptake inhibitor (SSRI), first experienced mania that warranted hospitalization at age 46. She appeared to have late-onset mania, as perimenopausal symptoms preceded the episode. When she developed painless weakness in her legs and became wheelchair bound, the lumbar spine magnetic resonance imaging (MRI) findings were normal, leading to a suspicion of conversion disorder. A later MRI of the brain and neurologic workup ultimately revealed primary progressive multiple sclerosis as the cause of both her psychiatric and physical symptoms. Conclusion: While there is growing evidence of first-time perimenopausal onset of mania, it is hard to estimate how many of these cases are attributable to autoimmune illnesses with perimenopausal onset. This case outlines the importance of including a brain MRI and autoimmune serum panel in the workup for women presenting with new-onset mania in their perimenopausal years.