丘脑腹外侧核和基底节核团细胞电活动与帕金森病的关系

Neuronal activities in the ventrolateral thalamus and basal ganglia in relation to Parkinson′s disease

目的探讨帕金森病患者丘脑腹外侧核(VL)、内侧苍白球(GPi)和丘脑底核(STN)神经元电活动特点与帕金森症状的关系。方法27例帕金森病患者(男17例,女10例)接受了立体定向毁损术治疗,手术靶点分别为:VL(10例)、GPi(10例)和STN(7例)。术中应用微电极和肌电(EMG)记录技术同时记录神经元电活动和手术对侧肢体EMG。术前和术后采用帕金森综合评分表(UPDRS)对患者“关”状态的运动功能进行比较。通过单细胞分析方法甄别细胞电活动特点,相关性检验探讨细胞电活动与肢体EMG的关系,同时运用方差分析比较3个核团不同放电模式神经元的数量和帕金森病三大主症的改善。结果从27个针道中甄别出361个神经元,其主要放电模式是:与震颤相关的放电活动(159个)、高频紧张性放电活动(134个)和不规则放电活动(68个)。其中与震颤相关的簇状放电节律和肢体震颤有相关性(P<0·01)。方差分析显示VL中与震颤相关的细胞数量与其他两个核团相比差异有统计学意义(VL:9·0个/针道、GPi:4·9个/针道和STN:3·0个/针道)(均P<0·05),STN中不规则放电神经元的数量与其他两个核团相比差异有统计学意义(VL:1·4个/针道、GPi:2·8个/针道和STN:3·7个/针道)(均P<0·05),而紧张性放电神经元的数量(VL:4·2个/针道、GPi:6·2个/针道和STN:4·3个/针道)差异无统计学意义(均P>0·05)。术后手术对侧肢体的UPDRS评分显示VL、GPi和STN对震颤的改善率分别为91·7%、84·8%和62·7%,对行动迟缓的改善率为36·9%、62·3%和70·8%,对僵直的改善率为56·2%、71·3%和68·8%。方差分析结果显示震颤和行动迟缓的改善率比较差异有统计学意义(P<0·01),其中VL对震颤的改善效果最好,而STN对行动迟缓的改善最明显;但是3个核团对僵直的改善差异无统计学意义(均P>0·05)。结论VL、GPi和STN中不同的神经元放电模式可能与帕金森病临床症状有内在联系,这为不同症状为主的帕金森病患者选择最佳手术靶点提供了依据。

Objective To investigate the neuronal activities in the ventrolateral thalamus （VL）, internal globus pallidus （GPi）, and subthalamic nucleus （STN） in relation to parkinsonian symptoms. Methods Twenty-seven patients with Parkinson＇s disease, 17 males and 10 females, aged 59 ± 8, received stereotactic surgical treatment on the VL （ n = 10 ）, GPi （ n = 10 ）, or STN （ n = 7 ） respectively. Micreelectrede recording in the three nuclei and electromyography （EMG） on the limbs contralateral to the surgical side were performed intraoperatively. All patients were evaluated with the unified Parkinson＇s disease rating scale （UPDRS） in ＂off＂ medication state pre-and past-operatively. Single unit analysis and cross-correlation analysis were carried out to explore the relationship among the neuronal activities and limb EMG. One-way ANOVA was performed to study the numbers of neuron in these 3 nuclei in different discharge patterns and the improvement of the 3 main symptoms of Parkinson＇s disease. Results Three hundred and sixty-one neurons were obtained from 27 microrecording trajectories （ 146 for VL, 139 for GPi, and 76 for STN）. Three patterns of neuronal activities were identified ： tremor-related activities （ ＂ tremorceils＂, n = 159） ; tonic neuronal activities （n = 134 ）, and irregular neuronal activities （n = 68 ）. Therhythm of the tremor-related activities was correlated with the frequency of limb tremor in VL （ γ^2 = 0.8, P 〈0.01）, GPi （γ^2 =0.7, P〈0.01）, and STN （γ^2 =0.5, P〈0.01）. The average number of cells in eachtract of VL, GPi, and STN were 9.0, 4.9, and 3.0 for tremor-related activities （ANOVA, P〈0.05） ; 4.2, 6.2 and 4.3 for tonic neuronal activities （ ANOVA, P 〉 0.05） and 1.4, 2.8 and 3.7 for irregularneuronal activities （ ANOVA, P 〈 0.05 ）. The UPDRS revealed that VL had the highest effect on tremorimprovement （91.7%） as compared to GPi （84.8%） and STN （62.7%）, whereas STN and GPi hadsignificant effects on brandykinesia improvement （70.8% and 62.3% respectively） as compared to VL（36.9%）. However there was no significant difference in the improvement of rigidity among VL, GPi, andSTN （56.2%, 71.3%, and 68.8% respectively, all P 〉 0.05 ）. Conclusion Different patterns ofneuronal activities in VL, GPi and STN are likely to associate with parkinsonian symptoms. The results areimportant not only for the target selection, but also for understanding of neurophysiological basis underlying Parkinson＇s disease.