Psychosis following a stroke to the cerebellum and midbrain: a case report

There is growing evidence that the cerebellum serves an important role in controlling affect and cognition, and its pathology has been implicated in several psychiatric disorders. Furthermore, the brainstem's role in cognition and affect has been historically overlooked. Neuroimaging studies and an increasing number of case reports indicate cognitive deficits and hallucinatory phenomena after isolated brainstem lesions.

We report a 56-year-old man who developed persistent persecutory delusions, hallucinations, cognitive impairment and flattened affect following an extensive bilateral cerebellar stroke with involvement of the midbrain.

This is one of the few reported cases of unremitting psychosis secondary to cerebellar and mesencephalic vascular infarction. We suggest, based on the distribution of the patient's lesions, that his corresponding symptoms are a result of a disruption to cerebrocerebellar pathways. This article briefly reviews recent pathophysiological explanations behind the psychosis associated with brainstem and cerebellar lesions, the treatment, as well as the relation of these structures to each other.