ABSTRACT
Only about 50% of central pain patients respond to motor cortex stimulation in the long run. There is a need for prognostic factors. Here we show that propofol test and TMS both predict short-term effect in nine patients with central pain. This may help reduce the number of failures.
Subject(s)
Electric Stimulation Therapy/methods , Magnetics/therapeutic use , Motor Cortex/physiology , Pain Management , Adult , Aged , Female , Humans , Hypnotics and Sedatives , Male , Middle Aged , Pain/diagnosis , Pilot Projects , Predictive Value of Tests , PropofolABSTRACT
Extradural cortical stimulation for neurogenic pain is a recent addition to the field of functional neurosurgery. About 50% of patients with central pain draw benefit in the long run. However, there is an urgent need for prognostic factors in order to cut the costs of the procedure. In this paper we report a statistically significant correlation between the subhypnotic propofol test, transcranial magnetic cortical stimulation (TMS) and the actual short-term outcome of extradural cortical stimulation in 9 patients. The propofol test and TMS appear to predict short-term effects of extradural cortical stimulation.
Subject(s)
Motor Cortex , Pain Management , Adult , Aged , Electromagnetic Phenomena , Female , Humans , Male , Middle Aged , Motor Cortex/pathology , Motor Cortex/physiology , Pain/drug therapy , Propofol/pharmacology , Propofol/therapeutic use , Statistics, NonparametricABSTRACT
The site of S1-S2 root activation following percutaneous high-voltage electrical (ES) and magnetic stimulation were located by analyzing the variations of the time interval from M to H soleus responses elicited by moving the stimulus point from lumbar to low thoracic levels. ES was effective in activating S1-S2 roots at their origin. However supramaximal motor root stimulation required a dorsoventral montage, the anode being a large, circular surface electrode placed ventrally, midline between the apex of the xiphoid process and the umbilicus. Responses to magnetic stimuli always resulted from the activation of a fraction of the fiber pool, sometimes limited to the low-thresholds afferent component, near its exit from the intervertebral foramina, or even more distally. Normal values for conduction velocity in motor and 1a afferent fibers in the proximal nerve tract are provided.
