Abstract
In a clinical series of electromanometric recordings on combined cisterno-lumbar punctures for the detection of spinal block, 3 patients with complete spinal block were investigated. Through a separate lumbar needle, saline was injected under simultaneous cisterno-lumbar electromanometric pressure recording. In one of the patients fluid was aspirated down to a sub-atmospheric CSF pressure of [long dash]25 cm H2O. On myelography the lower levels of the blocks were found to be situated between T 3 and T 6. The relations found between volume increment and CSF pressure indicated a compliance of the spinal CSF sac. The pressure-volume curves were plotted and it appeared that the CSF pressure, within the range studied, was an exponential function of volume increment. Similar findings were obtained in a 4th case with complete block only at CSF pressures below +30 cm H2O. From the spinal block diagnostic point of view the compliance found appeared considerable. It was inferred from the spinal CSF pressure-volume curves that the CSF flow past the midthoracic level induced by jugular compression is of the magnitude 2[long dash]7 ml. The introduction of a lumbar narrow-bore open-end water manometer should not increase this flow considerably. A CSF pressure reduction of a given magnitude caused the largest volume reduction of the spinal CSF sac at CSF pressures around zero.