Trochlear nerve schwannomas: a case report and literature review.

Trochlear nerve sheath tumours are extremely uncommon, only six cases diagnosed during life having been presented previously. In none of these earlier cases were magnetic resonance imaging studies obtained. We report here upon the clinical presentation, surgical management and post-operative course of a case where the diagnosis was suspected pre-operatively from MRI studies. The radiological appearances are described, together with a review of all previously published accounts of this rare tumour.