Department of Neurological Surgery, Nihon University School of Dentistry at Matsudo, Chiba, Japan.
Neuromodulation. 2013 Jul-Aug;16(4):349-54; discussion 354. doi: 10.1111/ner.12019. Epub 2013 Jan 11.
It has been reported that poststroke pain has a complex pharmacologic background and that only about one-half of poststroke pain patients are sensitive to motor cortex stimulation induced by repetitive transcranial magnetic stimulation (rTMS).
The relationship between pharmacologic background and effects of rTMS of the primary motor cortex was investigated to clarify the pharmacologic basis of rTMS-induced analgesia in poststroke pain patients.
Changes in visual analog scale (VAS) score for pain following drug challenge tests using ketamine, morphine, and thiopental were compared with the changes in VAS score following rTMS of the primary motor cortex (frequency 5 Hz, at 100% resting motor threshold, 500 pulses per session) in 20 poststroke pain patients.
In our drug challenge test, 10 of 20 (50%) patients in ketamine test, 7 of 20 (35%) in thiopental test, and 3 of 20 (15%) in morphine test showed more than 40% reduction of VAS score. VAS score decreased immediately after rTMS of motor cortex and persisted for 300 min (p < 0.05, Bonferroni's multiple comparisons). Comparison of the magnitude of VAS score reduction between drug challenge test and rTMS showed significant correlations with ketamine test (r = 0.503, p = 0.012), morphine test (r = 0.526, p = 0.009), and thiopental test (r = 0.609, p = 0.002) by regression analysis.
rTMS-induced VAS score reduction correlated well with morphine, ketamine, and thiopental tests. However, ketamine sensitivity was observed in more cases compared with morphine and thiopental in poststroke pain patients. We speculate that additional pharmacologic therapy using ketamine as determined on the basis of the ketamine test may be useful for enhancing the efficacy of rTMS in poststroke pain patients.
据报道，卒中后疼痛具有复杂的药理学背景，只有约一半的卒中后疼痛患者对重复经颅磁刺激（rTMS）引起的运动皮层刺激敏感。
研究初级运动皮层的药理学背景与 rTMS 效应之间的关系，以阐明 rTMS 诱导卒中后疼痛患者镇痛的药理学基础。
比较 20 例卒中后疼痛患者在接受氯胺酮、吗啡和硫喷妥钠药物挑战试验前后视觉模拟量表（VAS）评分的变化，与接受初级运动皮层 rTMS （频率 5Hz，100%静息运动阈值，每次 500 个脉冲）后的 VAS 评分变化。
在我们的药物挑战试验中，氯胺酮试验中 20 例患者中有 10 例（50%），硫喷妥钠试验中 7 例（35%），吗啡试验中 3 例（15%）的 VAS 评分降低超过 40%。运动皮层 rTMS 后 VAS 评分立即下降，并持续 300 分钟（p<0.05，Bonferroni 多重比较）。药物挑战试验与 rTMS 后 VAS 评分降低幅度的比较显示，与氯胺酮试验（r=0.503，p=0.012）、吗啡试验（r=0.526，p=0.009）和硫喷妥钠试验（r=0.609，p=0.002）呈显著相关，通过回归分析。
rTMS 诱导的 VAS 评分降低与吗啡、氯胺酮和硫喷妥钠试验密切相关。然而，与吗啡和硫喷妥钠相比，在卒中后疼痛患者中观察到氯胺酮的敏感性更高。我们推测，根据氯胺酮试验确定的额外的氯胺酮药理学治疗可能有助于提高 rTMS 在卒中后疼痛患者中的疗效。
