Testing cerebrospinal fluid shunt capacity and adequacy by the lumbar route in adults.

The pressure of the cerebrospinal fluid with the patient in a lateral position, the level of zero pressure in sitting position, and the infusion cisternography were evaluated as a test for determining shunt function. The lumbar infusion test gave information about shunt capacity, while the opening pressure in lateral and sitting position reflected shunt adequacy. A reduction in shunt capacity preceded the rise of the opening pressures when the shunt capacity preceded the rise of the opening pressures when the shunts became inadequate. Cisternography was relatively reliable in determining shunt adequacy when shunt capacity was near its high or low extreme, but unreliable in the middle ranges. In non-communicating hydrocephalus, the lumbar infusion test resulted in a correct conclusion as to shunt capacity provided the subarachnoid space was patent and the test was terminated before the ventricular system was empty.