[Basilar impression as a cause of trigeminal neuralgia: report of a case].

A case of basilar impression associated with Arnold-Chiari malformation and with trigeminal neuralgia is reported. The radiological examination of the skull showed marked asymmetry of the petrous bone with the tip of the odontoid apophysis located 30 mm above the McGregor line. Treatment consisted of craiectomy of the posterior fossa and cervical laminetomy (C1 to C3). The postoperative course was uneventful with total disappearance of the trigeminal neuralgia.