Application of microelectrode mapping in surgery of deep brain stimulation of subthalamic nucleus in ameliorating the symptoms of Parkinson¬ðs disease

    WANG Xueª²Lian,GAO Guoª²Dong,HE Shiª²Ming ,LI Weiª²Xin,WANG Juª²Lei,GUAN Dingª²Guo,Chen Ling

    Department of Neurosurgery , Tangdu Hospital, Fourth Military Medical University, Xi¬ðan 710038,China

    ¡¾Abstract¡¿ AIM: To improve the precision of targeting in surgery of the deep brain stimulation of subthalamic nucleus (STN) to ameliorate the symptoms of Parkinson¬ðs disease by recording neurophysiological characteristics of encountered cells along microelectrode trajectories and mapping motor and nonmotor territory of STN using microelectrode recording techniques. METHODS: From November 1999 to April 2004, 30 patients with Parkinson¬ðs disease underwent the surgery of deep brain stimulation and 45 electrodes were implanted into the STN. Indirected spiral CT scan imagingª²based anatomic targeting was used. Microelectrode recording mapping techniques were employed and the cellular activity was analyzed for various neurophysiologcal parameters, including firing patterns, firing rate, interspike intervals, background noise, evoked potential and reactions to microstimulation. Imagings of CT/MRI preoperative and Schaltenbrand and Wahren atlas were overlapped, so as to identify the motor and nonmotor territory of STN and line out the boundary with adjacent nucleus. Thus, the functional targeting of STN and the optimal place of electrode implant were precisely located. RESULTS: One hundred and thirty one microelectrode recording trajectories and mappings were accomplished. The average microelectrode recording time for each trajectory was 20 min, with a mean of 2ª±91 trajectories/electrode. Recordings from the STN exhibited an increase in the background activity and an irregular firing pattern, with a mean rate of (49¡À13) Hz. The mean cell density was (5ª±8¡À1ª±4) cells /mm, with an average length from upper bounder to lower bounder of (5ª±8¡À0ª±8) mm. The movementª²related cells were located primarily in the dorsolateral sector of the STN, with the leg area located medial along the mediolateral axis and centrally along the anteroposterior axis, compared with the arm area. Tremorª²synchronized cells can also be recorded and identified. The target change rate was 89%. CONCLUSION: Application of microelectrode recording mapping techniques can precisely locate the motor and nonmotor territory of STN and line out the boundary with adjacent nucleus, thus enhancing the precise pinpoint of the target. Microelectrode recording and mapping can help us better understand the physiological features of basal ganglion. ......