Chiari i malformation as a cause of trigeminal neuralgia: Case report

Abstract Trigeminal neuralgia (TN) is usually associated with vascular compression of the trigeminal nerve, but some cases are associated with central lesions such as tumors, aneurysms, or arteriovenous malformations. In this article, we report the 19th case of TN associated with Chiari I malformation and review clinical outcomes and pathophysiology. A 63-year-old right-handed man initially presented in 1993 with left-sided lancinating facial pain in the V2 distribution of the trigeminal nerve; the pain was triggered by certain movements, tactile stimulation, or a hot shower. Magnetic resonance imaging revealed a Chiari I malformation associated with a syrinx from C1 to C3. The patient underwent uncomplicated suboccipital craniectomy, C1 laminectomy, and duraplasty for Chiari decompression. Postoperatively, his pain resolved over a period of 1 year. Chiari I malformation has been found to be associated with TN in 19 cases in the English-language literature. In patients refractory to medical treatment, suboccipital decompression leads to resolution of pain in about two-thirds of patients. Potential mechanisms for the pathogenesis of TN in the setting of Chiari I malformation are discussed. Chiari I malformation is important to consider as a rare cause of TN that responds to surgical therapy.