Trigeminal neuralgia secondary to Chiari's malformation—treatment with ventriculoperitoneal shunt

Trigeminal neuralgia (TN) is most commonly related to vascular compression of the trigeminal nerve. Trigeminal neuralgia associated with Chiari's malformation and associated hydrocephalus are rare. A 31-year-old male presented with classical TN affecting the mandibular division of the right trigeminal nerve. His symptoms were poorly controlled with increasing doses of carbamazepine. Magnetic resonance imaging scan of brain revealed Chiari's type I malformation and associated hydrocephalus. Approximately 1 month after insertion of a programmable ventriculoperitoneal shunt, his TN resolved. Chiari's malformation and hydrocephalus are rare associates of TN. The pathophysiology of TN in these cases may be due to neurovascular conflict, related to raised intracranial pressure from the hydrocephalus and/or the small posterior fossa volume in these patients. Drainage of associated hydrocephalus may be an effective surgical treatment.