title: Spinal accessory nerve schwannomas masquerading as a fourth ventricular lesion.
abstract: Schwannomas are benign lesions that arise from the nerve sheath of cranial nerves. The most common schwannomas arise from the 8(th) cranial nerve (the vestibulo-cochlear nerve) followed by trigeminal and facial nerves and then from glossopharyngeal, vagus, and spinal accessory nerves. Schwannomas involving the oculomotor, trochlear, abducens and hypoglossal nerves are very rare. We report a very unusual spinal accessory nerve schwannoma which occupied the fourth ventricle and extended inferiorly to the upper cervical canal. The radiological features have been detailed. The diagnostic dilemma was due to its midline posterior location mimicking a fourth ventricular lesion like medulloblastoma and ependymoma. Total excision is the ideal treatment for these tumors. A brief review of literature with tabulations of the variants has been listed.
authors.affiliation: Department of Neurosurgery, Achantha Lakshmipathy Neurosurgical Centre, Voluntary Health Services, Chennai, Tamil Nadu, India.
authors.forename: Shyam Sundar
authors.initials: SS
authors.lastname: Krishnan
authors.affiliation: Department of Neurosurgery, Achantha Lakshmipathy Neurosurgical Centre, Voluntary Health Services, Chennai, Tamil Nadu, India.
authors.forename: Sivaram
authors.initials: S
authors.lastname: Bojja
authors.affiliation: Department of Neurosurgery, Achantha Lakshmipathy Neurosurgical Centre, Voluntary Health Services, Chennai, Tamil Nadu, India.
authors.forename: Madabhushi Chakravarthy
authors.initials: MC
authors.lastname: Vasudevan
keywords: 11th nerve schwannoma; Accessory nerve schwannoma; cisternal variant; cranial nerve schwannoma; fourth ventricular tumor; jugular foramen tumors; neurinoma; schwannoma