Elevations in cerebrospinal fluid norepinephrine during unilateral and bilateral cerebellar stimulation in man

Lumbar cerebrospinal fluid (CSF) norepinephrine concentrations determined by radioenzymatic assay in four epileptic patients were significantly higher during either chronic unilateral or bilateral cerebellar stimulation than those determined after a 7-day period without stimulation. The mean CSF norepinephrine levels noted during these two modes of cerebellar stimulation were not significantly different. The percentage of increase in CSF norepinephrine in one patient receiving 200/sec stimulation was 3 times higher than those noted in the three patients undergoing 10/sec stimulation. These evoked alterations in norepinephrine metabolism may relate to the reported modulation of spasticity and cerebral neuronal excitability during chronic cerebellar stimulation. Lumbar CSF cyclic adenosine monophosphate levels determined by radioimmunoassay were not significantly altered by either mode or frequency of cerebellar stimulation.