Arnold Chiari Type I malformation presenting as a trigeminal neuralgia: Case report

OBJECTIVE AND IMPORTANCE: Arnold Chiari Type I malformation usually present s as headache, arm numbness, dysesthesia, upper weakness, or gait difficult y. We report a case of Chiari malformation presenting as a left trigeminal neuralgia. CLINICAL PRESENTATION: A patient with a history of 29 years of trigeminal n euralgia was admitted. He was treated with three thermocoagulations. Microv ascular decompression was planified. Magnetic resonance imaging was perform ed, and it demonstrated an Arnold Chiari malformation. After surgery, the p atient was asymptomatic. INTERVENTION: Posterior fossa decompression by enlarging the foramen magnum and aspiration of the cerebellar tonsils was performed. CONCLUSION: The trigeminal neuralgia could be attributable to a compression of the trigeminal nucleus. The compression of the nucleus could explain bo th the pain and the regression after surgery. This is the second reported c ase of pure trigeminal neuralgia in Arnold Chiari malformation.