Tectal plate glioma: Lessons learned from a patient with hydrocephalus, Chiari malformation-1 and concomitant aqueductal stenosis

摘要

1. Introduction: Chiari malformation type I (CM-1) is characterized by a reduced volume in the posterior fossa and by the caudal displacement of the cerebellar tonsils through the foramen magnum. CM-1 is usually congenital, although rarely may be acquired. Since its initial description in 1891, many clinical symptoms of brainstem, cerebellar, and spinal cord pathology have been attributed to this disease. Hydrocephalus, in particular, has been noted in approximately 4-18% of patients with CM-1 [1]. The exact pathogenesis is unknown, but the association between hydrocephalus and CM-1 is believed to be multifactorial. The standard treatment for CM-1 is decompressive suboccipital craniotomy. Though short-term improvements have been reported in up to 75-90%, there is a subset of as many as 35% of CM-1 patients whom experience symptom recurrence years after surgery [2]. This subset of patients may represent a symptom etiology that is not localized to the hind-brain decompression, but rather one that is related to a separate pathology. We report a case of an adult patient with hydrocephalus and CM-1 that had symptom recurrence after surgical decompression following years of uneventful follow up. The patient was subsequently found to have a tectal plate glioma that was not initially evident due to its relatively small size.