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

Given that she had never had any imaging performed, MRI of brain and cervical spine with and without gadolinium was obtained and revealed downward displacement of the cerebellar tonsils 2 cm below foramen magnum along with a cervical syrinx, consistent with a radiographic diagnosis of Chiari I malformation ( figure 1 ). The spinal nucleus, the first relay of trigeminal fibres sensitive for pain in the spinal trigeminal pathway, extends from pontomedullary junction to C2 segment of the spinal cord, and compression of this pathway by cerebellar tonsillar herniation as well as cervical spinal syrinx could cause TN. 4 Improvement in symptoms upon decompression of posterior fossa lends further support to this hypothesis. 2 4 Third, it has been proposed that the presence of a cervical syrinx may contribute to TN symptoms.