New lumbar method for monitoring cerebrospinal fluid pressure in rats.
OBJECTIVE
Monitoring cerebrospinal fluid pressure or intracranial pressure (ICP) is crucial in the study of neurosurgical disorders. In the present study, we report a new lumbar method for monitoring ICP in rats.


METHODS
A PE10 catheter connected to a pressure transducer was placed into the subarachnoid space of L5 through the duramater after laminectomy to record lumbar cerebrospinal fluid pressure (lumbar-ICP). ICP at the cisterna magna (cisterna-ICP) was recorded simultaneously via a catheter in the subarachnoid space at the cisterna magna. Eighteen anesthetized adult male S-D rats were subjected to baseline recording followed by either experimental subarachnoid hemorrhage (SAH) induced by intravascular puncture method or experimental intracerebral hemorrhage (ICH) induced by blood injection with a stereotaxic system.


RESULTS
Baseline lumbar-ICP and cisterna-ICP varied between 6 and 8 mmHg, and respiratory variation could be detected. A similar acute response to SAH was recorded in both the lumbar-ICP and cisterna-ICP in all rats. In rats subjected to SAH, the lumbar catheter continuously and accurately monitored lumbar-ICP, and reliable pressure tracings were obtained for up to 24 h after SAH. However, continued cisterna-ICP monitoring was abandoned in two rats in the cisterna magna method due to obstruction of the catheter by blood clots (hematoma).


CONCLUSIONS
This new lumbar-ICP method is simple, safe, easy, and reliable in rats. Continued lumbar-ICP measurements provided monitoring for up to 24 h after experimental manipulation.
Kusaka
Gen
G
Department of Neurosurgery, Louisiana State University Health Sciences Center-Shreveport, 1501 Kings Highway, P.O. Box 33932, Shreveport, LA 71130-3932, USA.
Calvert
John W
JW
Smelley
Christopher
C
Nanda
Anil
A
Zhang
John H
JH
D000818:Animals; D002408:Catheters, Indwelling / Q000600:supply & distribution; D002543:Cerebral Hemorrhage / Q000134:cerebrospinal fluid / Q000503:physiopathology; D015170:Cerebrospinal Fluid Pressure / Q000502:physiology*; D002946:Cisterna Magna / Q000502:physiology; D004195:Disease Models, Animal; D007427:Intracranial Pressure / Q000502:physiology*; D007796:Laminectomy / Q000379:methods; D008297:Male; D008991:Monitoring, Physiologic / Q000379:methods*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013345:Subarachnoid Hemorrhage / Q000134:cerebrospinal fluid / Q000503:physiopathology; D013997:Time Factors; D014160:Transducers, Pressure / Q000600:supply & distribution