• vestibular stimulation
• mania

Caloric vestibular stimulation is a common clinical procedure, routinely employed during testing of vestibulocochlear nerve function. The procedure involves stimulation of vestibular afferents by the application of cooled water to the tympanic membrane. Vestibular afferents are distributed widely to areas of the diencephalon and cortex, including areas believed to be involved in the regulation of mood. In accordance with these observations, imaging studies have shown widespread though largely contralateral hemispheric activation following the procedure.¹

Caloric vestibular stimulation has been associated with a rapid but short lived improvement in stroke induced functional deficits,² but the effect of the procedure on psychiatric symptomatology has not been reported. In the case described here, an improvement in manic symptoms was observed after caloric vestibular stimulation in a 29 year old woman with a 10 year history of bipolar affective disorder. The patient was admitted to an acute psychiatric ward with several weeks of increasingly elevated and irritable mood. Her symptoms fulfilled DSM-IV criteria for a manic episode. Resistance to therapeutic drug use and intolerance of side effects had limited effective management of her condition. Previous episodes of mania had often responded to ECT. At the time of admission her treatment regimen included olanzapine and carbimazole. Carbimazole had been started following the identification of abnormal thyroid function tests on routine testing.

The …