Frasson Emma, Priori Alberto, Ruzzante Barbara, Didonè Giuseppe, Bertolasi Laura
Divisione di Neurologia, Ospedale Civile, Cittadella, Padua, Italy.
Mov Disord. 2005 May;20(5):624-9. doi: 10.1002/mds.20395.
Spasticity leads to functional and structural changes in nerves and muscles, which alter skeletal muscle function. To evaluate whether short-term electrical nerve stimulation (NS) improves the effect of botulinum toxin in spastic skeletal muscle, we studied changes in the amplitude of the compound muscle action potential (CMAP) recorded from the extensor digitorum brevis (EDB) muscle in response to peroneal nerve stimulation at the ankle after injection of botulinum toxin type A (BTXA) alone or combined with short-term NS. In paraparetic patients, both EDB muscles were injected with BTXA; and NS was applied to one EDB muscle alone. All patients received a 30-minute session of electrical NS once a day for 5 consecutive days after BTXA injection. We used two different stimulation frequencies (low-frequency, 4 Hz; and high-frequency, 25 Hz). EDB-CMAP amplitudes were evaluated before BTXA injection (day 0) and changes in CMAP amplitude, expressed as a percentage (CMAP%), were measured at various time points over a 30-day period after BTXA injection. We compared changes in the CMAP% amplitude on the stimulated and contralateral nonstimulated sides. We also studied the electromyographic activity recorded from EDB muscles over a 30-day period. CMAP% amplitudes measured at all time points after BTXA injections were significantly reduced in both EDB muscles. On days 4, 10, and 15, the CMAP% amplitude reduction was significantly greater for the low-frequency stimulated EDB than for the contralateral nonstimulated EDB. No significant differences in CMAP% were observed for the high-frequency stimulated and nonstimulated EDB. After BTXA injection, spontaneous activity appeared in both EDB muscles; but it appeared earlier and involved larger areas in the stimulated than in the nonstimulated EDB. In conclusion, short-term NS accelerates the effectiveness of intramuscular BTXA injections on the neuromuscular blockade in patients with spastic paraparesis and could induce a rapid and persistent improvement in spasticity. Its action probably arises mainly from low-frequency NS.
痉挛会导致神经和肌肉发生功能及结构变化，进而改变骨骼肌功能。为评估短期电神经刺激（NS）是否能增强肉毒毒素对痉挛性骨骼肌的作用，我们研究了在单独注射A型肉毒毒素（BTXA）或联合短期NS后，刺激踝关节处的腓总神经时，从趾短伸肌（EDB）记录的复合肌肉动作电位（CMAP）幅度的变化。在截瘫患者中，双侧EDB肌肉均注射了BTXA；NS仅应用于一侧EDB肌肉。所有患者在注射BTXA后连续5天每天接受一次30分钟的电NS治疗。我们使用了两种不同的刺激频率（低频，4Hz；高频，25Hz）。在注射BTXA前（第0天）评估EDB-CMAP幅度，并在注射BTXA后的30天内的不同时间点测量CMAP幅度的变化，以百分比（CMAP%）表示。我们比较了刺激侧和对侧未刺激侧CMAP%幅度的变化。我们还研究了30天内从EDB肌肉记录的肌电图活动。注射BTXA后所有时间点测量的CMAP%幅度在双侧EDB肌肉中均显著降低。在第4、10和15天，低频刺激的EDB的CMAP%幅度降低显著大于对侧未刺激的EDB。高频刺激和未刺激的EDB之间未观察到CMAP%的显著差异。注射BTXA后，双侧EDB肌肉均出现自发活动；但刺激侧比未刺激侧出现得更早且涉及更大区域。总之，短期NS可加速肌肉内注射BTXA对痉挛性截瘫患者神经肌肉阻滞的效果，并可诱导痉挛迅速且持续改善。其作用可能主要源于低频NS。
