title: Herniation of the cerebellar tonsils after suprasellar arachnoid cyst shunt: case report.
abstract: It is known that the caudal dislocation of the cerebellar tonsils may occur associated with clinical conditions such as an intracranial mass lesion or Chiari I and II malformation. It may also be acquired after repeated lumbar punctures or lumboperitoneostomy. The occurrence of cerebellar herniation after derivation of intracranial arachnoid cyst is extremely rare, and there are only three cases reported in the medical literature. We present the case of a 9-year-old boy with precocious puberty and suprasellar arachnoid cyst who developed a symptomatic herniation of the cerebellar tonsils three years after a cystoperitoneostomy. The patient underwent a suboccipital craniectomy with duraplasty and partial tonsillectomy, showing afterwards, remission of the symptoms. We discussed the pathogenesis suggested in the literature.
authors.affiliation: Neurosurgery Service, Hospital Cristo Redentor, Rua Domingos Russo 20/Sala 260, 91040-000 Porto Alegre RS, Brazil.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Mendonça
authors.forename: Telmo Tibúrcio Fortes
authors.initials: TT
authors.lastname: Lima
authors.forename: Paulo Petry
authors.initials: PP
authors.lastname: Oppitz
authors.forename: Sérgio Fernando
authors.initials: SF
authors.lastname: Raupp
mesh_terms: D016080:Arachnoid Cysts / Q000601:surgery*; D002525:Cerebellar Cortex; D002526:Cerebellar Diseases / Q000175:diagnosis / Q000209:etiology* / Q000601:surgery; D002648:Child; D003399:Craniotomy; D006547:Hernia / Q000175:diagnosis / Q000209:etiology*; D059685:Herniorrhaphy; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D016896:Treatment Outcome; D017287:Ventriculoperitoneal Shunt