Trigeminal involvement in intracranial tumours. Anatomical and clinical observations on 73 patients.

Neoplastic involvement of the trigeminal nerve was observed in 73 patients operated on in our institution for extra-axial tumours of the posterior and middle cranial fossae. It was defined as contact, compression, or infiltration. The nerve root was involved in 58 patients, the ganglion and/or the peripheral divisions in 9, all portions of the Vth nerve system in 6. A clinical trigeminal dysfunction was present in 44 patients (60%). Anatomico-surgical findings are correlated with clinical features and with tumour type. Typical trigeminal neuralgia was the complaint in 7 subjects; all of them presented an involvement of the sensory root. Post-operatively, 11 patients were relieved of their symptoms. The outcome is correlated with the anatomical findings and with the extent of surgical removal of the tumours. The importance of a careful evaluation of patients with trigeminal symptomatology is stressed.