Chapter 11 - Neurologic Tests Many tests are used specifically
for the evaluation of neurologic illnesses (Table 11-1). The
general physician should be familiar with the diagnostic
capabilities of all these tests and should be able to interpret
the results of the lumbar puncture. The technique of lumbar
puncture is learned in the ward, so only a few points are made
here. Spinal taps should not be done above the L2-3 interspace
because the spinal cord may be present above this level. If the
flow of spinal fluid is not brisk, the following check is simple
(Fig. 11-1): The manometer is tilted horizontally to increase
the flow and then brought back to the vertical position so that
the fluid falls to the true spinal fluid pressure. If this
maneuver fails to increase the flow, the needle is not properly
placed or a nerve root has blocked the needle. Fluid should not
be aspirated because this may trap and damage nerve roots. If
the initial CSF pressure is high (more than 180 mm H2O), the
physician should try to let