Aneurysmal subarachnoid hemorrhage (SAH) can lead to hydrocephalus (HCP). Two types exist: acute (occuring within days) and chronic (occuring within weeks to months). Acute HCP, temp ventriculostomy is performed to improve drainage of CSF. About 20% requires permanent ventriculostomy. Some patients do not develop acute HCP but are subsequently at risk for delayed HCP.
This study defined the risk factors for delayed HCP. Signs and symptoms include headache, urinary incontinence, gait difficulty and cognitive decline. Obvious risk factors include increased SAH volume, meningitis, clipping (versus coiling) and EVD placement. Other risk factors probably reflect the severity of the underlying disease and/or comorbidities s.a. increased LOS, mechanical ventilation and discharge to a nursing home.
Incidence of delayed HCP is small, 1.3%. Majority 90% occur within first year. It is good to remember the graph below that illustrates the incidence of delayed HCP after aneurysmal SAH.