Mega cisterna magna in bipolar mood disorder: a case report

Mega cisterna magna (MCM), one of the members of the Dandy-Walker complex, is a developmental malformation of the posterior fossa that is larger than 10 mm but morphologically does not affect the vermis and cerebellar hemispheres. Reports of psychiatric disorders associated with this anomaly are rare. We present the case of a patient with MCM who presented with a psychotic manic attack and was diagnosed with bipolar disorder. A 28-year-old female, single housewife, university graduate, presented with irritability, decreased sleep and appetite, distraction, and agitation. The patient also had a delusion of reference. In the clinical follow-up, an increase in energy and an increase in the amount of speech were observed. Her neurological examination was normal, and cranial magnetic resonance imaging revealed an MCM. The relationship and clinical significance of MCM with psychosis and mood disorders have not yet been fully elucidated. It is not known whether this association is accidental or based on etiological commonality. The purpose of this case report is to review the relationship between the cerebellum and psychiatric symptoms and to contribute to the literature.