<b>Electrical spinal, internal capsular or cortical stimulation </b><b>treatment for central (thalamic) pain </b>

Abstract

We studied the effectiveness of electrical stimulation treatment in 10 cases with central (thalamic) pain. Pain was caused by thalamic hemorrhage in 6 cases. There was one case each of putaminothalamic, putaminal, pontine hemorrhage and thalamic infarct. We were able to achieve sufficient and long-term pain control by epidural spinal cord stimulation in all 4 cases in which pain was localized on the distal part of the upper or lower extremity. Pain control extended for a mean of 3.8 years in these cases. Precentral cortical stimulation treatment was carried out in 6 cases with diffuse pain (hemibody). Three cases were new, while 3 others were recurrent cases after thalamotomy. Sufficient pain relief was achieved in 3 cases. However, it was not obtained in the other 3 cases. In the former 3 cases, two were new with one recurrent case after thalamotomy. Pain was controlled during a mean of one year and 9 months. In all these cases, spontaneous pain was severe but hypesthesia mild. Electrical stimulation on the presumed precentral cortical area evoked a sensori-motor effect on the painful part of the body with low voltage stimulation. Regional CBF or rCMRglu decreased slightly and was localized in the affected thalamus. A MEG study demonstrated preservation of spino-thalamo-cortical function in one case. In the latter 3 cases in which we failed to obtain pain relief, one was new and the other two were recurrent cases after thalamotomy. In the 2 recurrent cases, we frequently encountered irregular burst discharges and positive spikes, but seldom found sensory responses of the sensory thalamus to peripheral natural stimulation during the operation. In one of these 3 cases, internal capsular (posterior limb) stimulation was performed, resulting in sufficient but short-term pain relief. In cases of localized thalamic pain, epidural spinal cord stimulation proved to be an effective treatment. In cases with diffuse pain, precentral cortical stimulation could be expected to ameliorate the intractable pain in those limited cases in which CVD had caused mild destruction of the pain conducting system and the spino-thalamo-cortical function was mostly preserved.

<b>Spinal cord stimulation therapy for localized central pain </b>

“…我々は脳，脊髄に病変を有し，難治性の局所 性疼痛を生じた中枢性疼痛例に対し脊髄刺激術 を施行している 7, 9,10) ．中枢性疼痛のうちでも 脳血管障害に起因する視床痛に対しては，視床 正中中心核，髄板内核，枕核など視床を中心と した神経破壊術 21) ，視床後腹側核，内包後脚 など脳深部 12) や大脳皮質中心前回 19) を中心 とする神経刺激術が用いられてきたが，その治 療結果は侵襲性が高い割には必ずしも満足すべ きものでなく，一方，中枢性疼痛例の中には後 述のごとく脊髄刺激術が奏功する例が存在する からである．中枢性疼痛の成因としては様々な 仮説が提唱されているが 18) ，これまでの視床 痛例に対する電気生理学的手法，機能画像的手 法を用いた病態解析 6,8,11) ，治療結果 5,7, 9,10) から，視床感覚中継核病変，および病変周囲疼 痛伝達系の機能構築の再編 15,19) ，およびその 大脳皮質中心溝付近への影響…”

<b>Spinal cord stimulation and thalamic surgery for the treatment of central post-stroke pain </b>

“…Though many hypo theses concerning the factors which cause this intractable pain have been proposed 1,20) , the real mechanism of CPSP remains problematic 13,17) and systematic studies have been lacking. We carried out epidural spinal cord, thalamic, internal capsule (posterior limb), or precentral cortical stimulation 21) for the treatment of CPSP 6,8,9) . We examined the pathophysiological mechanism of CPSP using neuroimaging and depth microrecording.…”

<b>Study on neural activity of thalamic sensory nucleus </b><b>and microstimulation effect in patients </b><b>with central post-stroke pain </b>

“…Recently, neuromodulation therapy has been applied for intractable functional disorders of the brain or spinal cord 21) . We carried out epidural spinal cord, thalamic, internal capsule (posterior limb), or precentral cortical stimulation 20) for the treatment of CPSP 8,10,11) , based on the preoperative or intraoperative neurophysiological data and a hypothesis in the genesis of CPSP.…”