僵直迟缓型帕金森病患者内苍白球放电活动的特点

Neuronal activity in the globus pallidus internus in parkinsonian patients with rigidity and bradykinesia

目的探讨与帕金森病（PD）僵直迟缓相关的内苍白球（GPi）细胞电活动特点。方法26例以僵直迟缓为主征PD患者（僵直〉／5分，迟缓≥9分）接受了立体定向GPi毁损术。术中应用微电极和肌电（EMG）记录技术采集细胞电活动和肢体EMG。应用单细胞和峰间隔（ISI）分析方法分析细胞放电模式和频率。采用帕金森病统一评分量表运动部分（UPDRS Ⅲ）对患者进行疗效评估。结果在记录到的237个GPi神经元中，除10．1％（n=24）为与震颤相关的细胞放电活动外，57．4％（n=136）为紧张性放电活动，32．5％（n=77）为不规则放电活动。进一步分析发现，75．7％（n,=103）的紧张性放电活动的平均放电频率为（124．1±39．2）Hz，平均峰间隔（ISI）为（8．7±6．9）ms，而其余24．3％（n=33）的神经元显示出相对正常的紧张性放电活动：平均放电频率为（69．5±5．9）Hz，平均ISI间期为（14．4±13．2）ms。同时发现这些不规则的放电活动平均放电频率为（30．2±9．8）Hz，平均ISI间期为（35．6±36．8）ms。方差分析显示高频紧张性放电活动、相对正常的紧张性放电活动、不规则放电活动三者两两比较其放电频率、ISI及ISI系数差异均有统计学意义（均P〈0．01）。术后UPDRS显示僵直和迟缓的改善率分别为71．9％和61．8％。结论GPi存在大量高频紧张性和不规则放电活动提示放电频率和模式的改变可能与PD僵直迟缓的病理生理相关。

Objective To investigate the neuronal activities in the globus pallidus internus （GPi） related to parkinsonian rigidity and bradykenisa. Methods Twenty-six patients （ M： 13 and F： 13 ） with parkinsonian syndromes of rigidity and bradykinesia, aged （58 ± 11 ） with the duration of disease of （5.5 ± 3.4） years, underwent pallidotomy. Their unified Parkinson＇s disease rating scale （UPDRS） motor score of rigidity was ≥5 （total score： 8） and the UPDRS score of bradykinesia was ≥9 （total score：16） at ＂off＂ medication state pre-operationally. During operation, microelectrode recording in the GPi and electromyography （EMG） on the contralateral limbs to the surgery were performed. Single tmite analysis and coefficient of variation （CV） of the interspike interval （ISI） were performed. The UPDRS motor score was assessed pre- and post-operationally. One-way ANOVA was carried out to study the firing rate as well as the ISI and CV of the ISI among different types of neuronal activity. Bonferroni test was conducted for means comparison. Results 10. 1% （ n = 24） of the total 237 GPi neurons （ 26 trajectories） showed discharge activity related to tremor （4 - 6 Hz ） , 57.4% （ n = 136 ） of the neurons discharged tonic activity, and 32. 5% （n = 77 ） neurons discharged irregular activity. Further analysis focused on 136 tonic active neurons and found that 75.7% （n = 103） of the neurons were characterized by a mean firing rate of （ 124. 1 ±39. 2） Hz with an ISI of （ 8.7 ± 6.9 ） ms, and 24. 3% （ n = 33 ） of the neurons were characterized by a relative normal mean firing rate of （69. 5 ±5.9） Hz with an ISI of （ 14. 4 ± 13.2） ms. The neurons with irregular neuronal activity had a mean firing rate of （ 30. 2 ±9. 8 ） Hz with an ISI of （ 35.6 ± 36. 8 ） ms. ANOVA revealed that there were statistically differences in the mean firing rate, ISI, and CV of the ISI for these neurons with relative normal tonic activity, high frequency tonic activity, and irregular activity （ P 〈 0. 01 ）. UPDRS showed that the improvement of rigidity and bradykesia were 71.9% and 61.8% respectively. Conclusion High percent neurons with high frequency tonic activity and irregular neuronal activity observed in GPi suggest that the neuronal activity with altered rate and pattern may play an important role in parkinsonian symptoms such as rigidity and bradykinesia.