Posterior fossa intracranial arachnoid cyst or Infratentorial are classified into supracerebellar arachnoid cyst, infracerebellar, hemispheric, clivus,
Endoscopic Neurosurgery is currently recommended as the first choice to treat posterior fossa arachnoid cysts. It has proven to be effective, providing improved outcome, and safe, having a low complication rate. Compared to craniotomy and shunt placement, it has lower surgical morbidity, minimizing or avoiding risks of subdural fluid collections, shunt infection, malfunction, overdrainage, and dependence. Usually, rigid scopes maneuvered through a suboccipital approach are used. When symptomatic obstructive hydrocephalus develops, CSF diversion is the first aim of surgery.
In these patients, a flexible endoscope introduced through a frontal burr hole allows not only immediate and efficient management of hydrocephalus with endoscopic third ventriculostomy, but in selected cases also direct cyst inspection and fenestration. Navigation of an enlarged cerebral aqueduct is actually safe when performed by experienced neurosurgeons.
This minimally invasive technique gives the possibility of performing both endoscopic third-ventriculostomy and cyst fenestration, which alone may not be enough to efficiently treat hydrocephalus 1).
Verghese et al. report an Posterior fossa arachnoid cyst that caused Painful tic convulsif (PTC) in a 50-year-old woman. Her radiological evaluation revealed a median, well-circumscribed, cystic lesion of the posterior fossa suggestive of arachnoid cyst, pushing the cerebellum and brainstem anteriorly. Midline suboccipital craniotomy and marsupialization of cyst was performed with complete recovery of symptoms. This is the first report of a retrocerebellar arachnoid cyst causing PTC 2).