Chiari I malformation manifesting as bilateral trigeminal neuralgia: case report and review of the literature.

INTRODUCTION Trigeminal neuralgia (TN) is characterised by recurrent episodes of sudden, intense, usually unilateral, lancinating pain confined to the distribution of one or more branches of the trigeminal nerve. It is most commonly associated with compression of the trigeminal nerve root by an artery or vein, which is thought to lead to irritability of the nerve root due to demyelination and remyelination at the root entry zone. However, some cases are associated with central lesions such as multiple sclerosis, tumours, arteriovenous malformations and brainstem infarcts. There are also several case reports of unilateral TN in the setting of Chiari I malformation, where decompression of the posterior fossa or shunting procedures for associated hydrocephalus have led to relief from TN symptoms. We present the first reported case of bilateral TN as the sole manifestation of Chiari I malformation. Unlike previous cases where unilateral TN was accompanied by other Chiari malformation symptoms, bilateral TN was the sole manifestation of this patient’s Chiari I malformation.