[Effects and indications of spinal cord stimulation on the vegetative syndrome]

The effects of spinal cord stimulation (SCS) on the vegetative syndrome were studied in six patients. Factors affecting the results were mentioned with a view to establishing indications as to whether or not the SCS should be performed. "Persistent vegetative states" were thought to be identical with Ohta's "vegetative syndrome" which consists of eleven signs. Six of these signs--polyphasic cycle of waking and sleeping, urinary incontinence, being bedridden and being tube fed etc--were important criteria of the vegetative syndrome. SCS was thought to be effective if one or more of the 6 signs disappeared after SCS. SCS was performed at level from C2 to C4 with a frequency of 25 to 120 Hz, an intensity of 2.5 to 6 volts, a pulse duration of 0.3 to 0.5 msec. and a duration of 3 to 11 hours per day. Neurological signs, ABR, CT/MRI, EEG and the grade of the vegetative syndrome were estimated before and after SCS. In the course of SCS, 2 of the 6 patients recovered from the vegetative syndrome. Both had a localized lesion in the brain stem without a cerebral lesion on CT/MRI, with bilateral appearance of the fifth peak with prolonged latency and decreased amplitude of main peaks on ABR. The other 4 patients showed little or no improvement. They all had diffuse cerebral atrophy or low density areas on CT and almost normal ABR. One of these patients, who suffered a cerebral contusion leading to transtentorial herniation with unilateral cerebral contusion on CT and unilateral disappearance of the fifth peak on ABR, showed no recovery from the vegetative syndrome.(ABSTRACT TRUNCATED AT 250 WORDS)