title: Cystic trochlear nerve schwannoma. Case report.
abstract: BACKGROUND
  Twenty-six cases of pathologically verified schwannomas of the trochlear nerve have been reported in the literature. Five of them had a large cystic component and a smaller solid portion. Complex skull base approaches have been usually applied for their removal.
  
  
  METHODS
  We report on a rare case of cystic trochlear schwannoma in a 52-year-old female patient. The patient presented with double vision, facial palsy, decreased hearing, hemiparesis on the right side, and severe gait instability. Magnetic resonance imaging revealed a 2.5-cm left-sided extra-axial lesion compressing the brain stem at the lower midbrain and upper pontine level. Total resection was performed via a retrosigmoid craniotomy. After the surgery, the neurological deficit diminished considerably. At 28 months follow-up, her only complaint was mild double vision when walking down the stairs and hypesthesia in the right half of her face.
  
  
  CONCLUSIONS
  This case represents a rare pontomesencephalic lesion removed successfully via the simple retrosigmoid route.
authors.affiliation: International Neuroscience Institute- Hannover, Otto von Guericke University- Magdeburg, Hannover 30625, Germany. vgerganov@gmail.com
authors.forename: Venelin
authors.initials: V
authors.lastname: Gerganov
authors.forename: Samii
authors.initials: S
authors.lastname: Amir
authors.forename: Andrei
authors.initials: A
authors.lastname: Koerbel
authors.forename: Almuth
authors.initials: A
authors.lastname: Brandes
authors.forename: Alex
authors.initials: A
authors.lastname: Stan
authors.forename: Samii
authors.initials: S
authors.lastname: Madjid
mesh_terms: D003390:Cranial Nerve Neoplasms / Q000473:pathology* / Q000601:surgery; D005260:Female; D006801:Humans; D008875:Middle Aged; D009442:Neurilemmoma / Q000473:pathology* / Q000601:surgery; D020432:Trochlear Nerve Diseases / Q000473:pathology* / Q000601:surgery