Aggressive CSF diversion reverses delayed cerebral ischemia in aneurysmal subarachnoid hemorrhage: a case report.
BACKGROUND
External ventricular drain (EVD) placement temporarily provides cerebrospinal fluid (CSF) diversion and is indicated in patients with aneurysmal subarachnoid hemorrhage (aSAH) to relieve hydrocephalus.


METHODS
Case report.


RESULTS
A 56-year-old woman was admitted to our hospital with aSAH complicated by acute hydrocephalus. An EVD was placed and set to 15 mmHg. After nearly 72 h, she clinically deteriorated. A computed tomography (CT) perfusion scan showed hypoperfusion in the watershed regions in both hemispheres and CT angiogram showed mild segmental arterial narrowings. After the EVD was lowered to 5 mmHg, the radiologic perfusion abnormalities and clinical symptoms resolved.


CONCLUSIONS
We postulate a mechanism by which CSF diversion could decrease the risk of delayed cerebral ischemia after aSAH: CSF drainage at low levels of intracranial pressure (e.g., 5 mmHg) could improve blood flow in the microcirculation, and thus improve tissue perfusion.
Division of Critical Care Neurology, Mayo Clinic, Rochester, MN 55905, USA.
Jennifer E
JE
Fugate
Alejandro A
AA
Rabinstein
Eelco F M
EF
Wijdicks
Giuseppe
G
Lanzino
D002545:Brain Ischemia / Q000209:etiology* / Q000601:surgery*; D002557:Cerebrospinal Fluid Shunts / Q000379:methods*; D003422:Critical Care / Q000379:methods; D005260:Female; D006801:Humans; D006849:Hydrocephalus / Q000209:etiology / Q000601:surgery; D008875:Middle Aged; D013345:Subarachnoid Hemorrhage / Q000150:complications*; D014696:Ventriculostomy / Q000379:methods*