<b>Indication of various kinds of surgical treatment </b><b>for central (thalamic) pain </b>

Abstract

We studied the effect and the indication of various kinds of surgical treatment for central (thalamic) pain in 10 cases. In 3 cases with localized pain, epidural spinal cord stimulation was effective. In 7 cases with diffuse pain (hemibody), stereotactic Vim-Vcpc thalamotomy was performed with the aid of depth microrecording. In 4 of these cases in which pain relief was obtained, we could find responses to peripheral natural stimulation on the sensory thalamus during the operation. Preoperative PET study also revealed an increase of rCBF on the sensory cortex ipsilateral to the thalamic CVD lesion during contralateral thumb brushing. On the other hand, in the 3 cases in which we failed to obtain pain relief, we frequently encountered irregular burst discharges on the thalamus. Gamma thalamotomy was added after the conventional thalamotomy in these 3 cases. Though transient pain relief was obtained, pain recurred thereafter. Precentral electrical cortical stimulation was also carried out in 3 recurrent cases, resulting in the failure of pain relief. In one of these cases, internal capsular (posterior limb) stimulation was performed, obtaining encouraging result. In cases of localized thalamic pain, epidural spinal cord stimulation proved to be an effective treatment. Thalamic surgery achieved pain relief in those cases with diffuse type pain, limited to preserving sensory function on the sensory thalamocortical system. Precentral electrical cortical stimulation, internal capsular (posterior limb) stimulation or Gamma thalamotomy may be an alternative treatment for central (thalamic) pain.