Simultaneous measurement of intraosseous and cerebrospinal fluid pressures in lumbar region.

Intraosseous pressure (IOP) and cerebrospinal fluid pressure (CSFP) in the lumbar region were measured simultaneously in two groups of patients with either spinal canal stenosis or disc herniation, to compare dynamic changes with positional changes, and to learn whether these pressure changes may have some role in the onset of claudication. IOP and CSFP showed almost the same change patterns with positional changes in two groups. They were lowest in the prone position and highest at the standing position. In standing with flexion, they were almost the same as in the prone position, but in extension they increased above the standing pressure. These dynamic pressure changes could act as a compression force to the cauda equina in the patient with spinal canal stenosis.