Trigeminal Nerve Tumor

+ Pathophysiology

  • Types: nerve sheath (common) and LSA
  • Trigeminal nerve sheath tumors tend to be locally invasive with a low metastatic rate
  • Trigeminal nerve sheath tumors tend to spread proximally into the central neural axis

+ Clinical Features

  • Trigeminal nerve sheath tumors present with unilateral temporalis and masseter muscle atrophy and unilateral dysfunction of ophthalmic, maxillary ± mandibular branches (i.e., poor or altered sensation around the eyelids and lips with poor blink reflex and wrinkling of face)
  • Diagnosis: EMG of masticatory muscles and MRI
  • Surgical resection via lateral rostrotentorial craniectomy or trans-zygomatic craniectomy (for ventral access)
  • Radiation therapy may be indicated for primary treatment or as an adjunct to surgical resection
  • Prognosis: guarded to poor