Slit ventricle syndrome after cyst-peritoneal shunting for temporal arachnoid cyst in children--a clinical entity difficult to detect on neuroimaging study.

Slit ventricle syndrome, known to occur from malfunction of the shunt procedure for hydrocephalus, is reported after cyst-peritoneal shunt for temporal arachnoid cyst. Two children aged 12 and 10 years, who underwent cyst-peritoneal shunting for a large temporal arachnoid cyst at the age of 10 and 5 years, respectively, recently experienced several episodes of severe headache. Prior to admission, repeated CT scans did not reveal any morphological change in either of these two patients. Evidence of high intracranial pressure by lumbar tap revealed shunt malfunction. Both patients became free of neurological complaints and deficits after shunt revision. Despite elevated intracranial pressure due to shunt malfunction, neuroimaging studies showed no morphological changes in slit ventricle syndrome. Delay in both the diagnosis and prompt treatment may result in complete loss of visual acuity and even death. It is important to suspect this complication in patients with persistent elevated intracranial pressure symptoms and signs after any shunting procedure, regardless of unchanged neuroimaging studies. Once this is suspected, lumbar tap may be necessary and the choice of treatment is shunt revision.