AIm: Subthalamic nucleus (STN) deep brain stimulation (DBS) has become a well-accepted treatment for patients with advanced Parkinson's disease (PD). During surgical planning for DBS, the length of the STN is taken into account and verified during microelectrode recording (MER) intraoperatively. Here, we addressed the question to which extent the length of the STN measured with the T2 weighted MRI in the probe's eye view corresponded with the intraoperatively determined length of the STN with MER. BulGulAR: Analizimiz T2 ağırlıklı probe eye görüntüdeki STN uzunluğu ile MER arasında istatistiksel açıdan anlamlı fark olmadığını gösterdi. sonuÇ: STN'nin giriş ve çıkış noktaları preoperatif probe eye görüntüsü kullanılarak doğru bir şekilde belirlenebilir.

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AIM: To investigate the effect of using microelectrode recording (MER) on the length of time required to carry out a deep brain stimulation (DBS) procedure of the subthalamic nucleus in patients with Parkinson's disease (PD). MATERIAL and METHODS: The time required to include MER in the DBS operation was calculated for the first and second sides in 24 patients with PD. The number of microelectrodes used on each trajectory for the first and second sides, and the percentage of permanent electrodes implanted on each trajectory for the first and second sides, were quantified. RESULTS: The average times taken to use MER were 23.4 ± 6.2 minutes, 17.4 ± 6.5 minutes, and 41.2 ± 6.3 minutes for the first side, second side and total procedure, respectively. In 75% of patients, the permanent electrode was implanted at the planned target site for the first side, and in 61% of patients for the second side. CONCLUSION: MER extends the time required to carry out the DBS procedure. However, during surgery, it provides real-time information on the electrodes' neurophysiological locations and helps the surgical team choose an alternative target if the planned target does not produce satisfying results.

Background: Frame mounting is considered one of the most critical steps in stereotactic neurosurgery. In routine clinical practice, the aim is to mount the frame as symmetrical as possible, parallel to Reid’s line. However, sometimes, the frame is mounted asymmetrically often due to patient-related reasons. Methods: In this study, we addressed the question whether an asymmetrically mounted frame influences the accuracy of stereotactic electrode implantation. A Citrullus lanatus was used for this study. After a magnetic resonance imaging scan, symmetric and asymmetric mounting of the frame, which could occur in clinical scenarios, was performed with computed tomography (CT). Three different stereotactic software packages were used to analyze the results. In addition, manual calculations were performed by two different observers. Results: Our results show that an asymmetrically mounted frame (deviated, tilted, or rotated) does not affect the accuracy in the mediolateral axis (X-coordinate) or the anteroposterior axis (Y-coordinate). However, it can lead to a clinically relevant error in the superoinferior axis (Z-coordinate). This error was largest with manual calculations. Conclusion: These results suggest that asymmetrical frame mounting can lead to stereotactic inaccuracy in the superoinferior axis (Z coordinate).

Background:Tremor is an important cause of disability in patients with multiple sclerosis (MS). It is an ongoing debate as to which brain region should be targeted in MS patients with complex tremors.Case Description:Here, we describe our experience with targeting thalamic tremor cells in the ventro-intermediate/ventro-oralis posterior (Vim/Vop) region in a patient with MS related complex tremor. Intraoperative multiple-microelectrode recordings showed the existence of tremor cells. Test stimulation produced the best effect when performed at the regions where tremor cells were recorded. Postoperative examination revealed a substantial improvement of the tremor.Conclusion:Our case observation reveals the existence of a neurophysiological target for deep brain stimulation (DBS) in MS related tremor.