The connection of motor improvement after deep brain stimulation in Parkinson's disease and microstructural integrity of the substantia nigra and subthalamic nucleus.

BACKGROUND: Nigrostriatal microstructural integrity has been suggested as a biomarker for levodopa response in Parkinson's disease (PD), which is a strong predictor for motor response to deep brain stimulation (DBS) of the subthalamic nucleus (STN). This study aimed to explore the impact of microstructural integrity of the substantia nigra (SN), STN, and putamen on motor response to STN-DBS using diffusion microstructure imaging. METHODS: Data was collected from 23 PD patients (mean age 63 ± 7, 6 females) who underwent STN-DBS, had preoperative 3 T diffusion magnetic resonance imaging including multishell diffusion-weighted MRI with b-values of 1000 and 2000 s/mm2 and records of motor improvement available. RESULTS: The association between a poorer DBS-response and increased free interstitial fluid showed notable effect sizes (rho > |0.4|) in SN and STN, but not in putamen. However, this did not reach significance after Bonferroni correction and controlling for sex and age. CONCLUSION: Microstructural integrity of SN and STN are potential biomarkers for the prediction of therapy efficacy following STN-DBS, but further studies are required to confirm these associations.

Technical note: preliminary surgical experience with a new implantable epicranial stimulation device for chronic focal cortex stimulation in drug-resistant epilepsy.

PURPOSE: This study is to report some preliminary surgical considerations and outcomes after the first implantations of a new and commercially available implantable epicranial stimulation device for focal epilepsy. METHODS: We retrospectively analyzed data from clinical notes. Outcome parameters were as follows: wound healing, surgery time, and adverse events. RESULTS: Five patients were included (17-52 y/o; 3 female). Epicranial systems were uneventfully implanted under neuronavigation guidance. Some minor adverse events occurred. Wound healing in primary intention was seen in all patients. Out of these surgeries, certain concepts were developed: Skin incisions had to be significantly larger than expected. S-shaped incisions appeared to be a good choice in typical locations behind the hairline. Preoperative discussions between neurologist and neurosurgeon are mandatory in order to allow for the optimal coverage of the epileptogenic zone with the electrode geometry. CONCLUSION: In this first small series, we were able to show safe implantation of this new epicranial stimulation device. The use of neuronavigation is strongly recommended. The procedure is simple but not trivial and ideally belongs in the hands of a neurosurgeon.

Assessment of postoperative pain, dysesthesia, and weather sensitivity after pterional and temporal neurosurgical approaches.

OBJECTIVE: Many neurosurgical approaches require incision of the temporal muscle (TM). Consequently, patients often report reduced opening of the mouth, facial asymmetry, numbness, and pain after lateral craniotomies. A systematic assessment of these postoperative subjective complaints is lacking in the literature. Therefore, in this study, the authors evaluate subjective complaints after pterional, frontolateral-extended pterional, or temporal craniotomy using a 6-item questionnaire. They examine the association of these subjective complaints with the extent of the mobilization of the TM. METHODS: The questionnaire assessed complaints about limited opening of the mouth, pain in the mastication muscles, facial asymmetry, sensory deficits in the temporal region, weather sensitivity, and headache. Eligible patients with benign intracranial processes operated on using lateral cranial approaches between 2016 and 2019 were included. The questionnaire was answered before surgery (baseline) and 3 and 15 months after surgery. Surgeons documented the extent of TM incision. RESULTS: Among the 55 patients in this study, all complaints apart from headache showed an increase at a statistically significant rate at 3 months postoperatively, that is, limited mouth opening (p < 0.0001), pain in the mastication muscles (p < 0.0001), an impression of asymmetry in the mastication muscles (p = 0.0002), sensory disturbances in the temporal region (p < 0.0001), and weather sensitivity (p < 0.001). Only pain in the mastication muscles showed a relevant decrease at 15 months postsurgery (p = 0.058). The extent of the mobilized TM was associated with pain in the mastication muscles at 3 months (p = 0.0193). CONCLUSIONS: Subjective complaints in patients following lateral craniotomy can be detected. As the extent of the mobilized TM relevantly influenced pain in the mastication muscles, the authors conclude that one should sparsely mobilize the TM. Furthermore, a neurosurgeon should be aware and warn the patient of subjective postoperative complaints and inform the patient about their natural course.

Mastication after craniotomy: pilot assessment of postoperative oral health-related quality of life.

BACKGROUND: Neurosurgical approaches to the brain often require the mobilization of the temporal muscle. Many patients complain of postoperative pain, atrophy, reduced mouth opening, and masticatory problems. Although the pterional, frontolateral-extended-pterional, and temporal craniotomies are the most frequently used approaches in neurosurgery, a systematic assessment of the postoperative oral health-related quality of life has never been performed so far. This study evaluates the oral health-related quality of life of patients after pterional, frontolateral-extended-pterional, or temporal craniotomy using a validated and standardized dental questionnaire, compares the results with the normal values of the general population, and investigates whether this questionnaire is sensitive to changes caused by surgical manipulation of the temporal muscle. METHODS: The "Oral Health Impact Profile" (OHIP14) is a validated questionnaire to assess the oral health-related quality of life. It asks the patients to assess their oral health situation within the past 7 days in 14 questions. Possible answers range from 0 (never) to 4 (very often). Sixty patients with benign intracranial processes operated through a lateral cranial approach were included. The questionnaire was answered before surgery (baseline) and 3 months and 15 months after surgery. RESULTS: Overall, postoperative OHIP scores increase significantly after 3 months and decrease after 15 months, but not to preoperative values. No factors can be identified which show a considerable relationship with the postoperative OHIP score. CONCLUSIONS: Postoperative impairment of mouth opening and pain during mastication can be observed 3 to 15 months after surgery and sometimes cause feedback from patients and their dentists. However, in line with existing literature, these complaints decrease with time. The study shows that the OHIP questionnaire is sensitive to changes caused by surgical manipulation of the temporal muscle and can therefore be used to investigate the influence of surgical techniques on postoperative complaints. Postoperatively, patients show worse OHIP scores than the general population, demonstrating that neurosurgical cranial approaches negatively influence the patient's oral health-related wellbeing. Larger studies using the OHIP questionnaire should evaluate if postoperative physical therapy, speech therapy, or specialized rehabilitation devices can improve the masticatory impairment after craniotomy. TRIAL REGISTRATION: Clinical trial register: DRKS00011096.

Piezosurgery-A Safe Technique to Perform Lateral Suboccipital Craniotomy?

BACKGROUND: Piezosurgery (PS) is a relatively new technique based on microvibrations generated by the piezoelectric effect. It selectively cuts bone tissue and preserves the surrounding soft tissue. OBJECTIVE: To evaluate the use of PS for performing lateral suboccipital craniotomy. METHODS: PS was used to perform a lateral suboccipital craniotomy in 22 patients who underwent surgery for different cerebellopontine angle (CPA) pathologies in the neurosurgical department. The applicability of PS for lateral suboccipital craniotomy was evaluated with respect to safety, preciseness of bone cutting, and in particular the preservation of the adjacent dura and sigmoid and transverse sinuses. RESULTS: Lateral suboccipital craniotomy in 22 patients who underwent surgery for different CPA pathologies (13 vestibular schwannoma, 5 petrous bone meningioma, 1 petroclival meningioma, 2 epidermoid cysts, and 1 petrous bone cholesterol granuloma) was performed with PS without any complications. A burr hole was set before piezosurgical craniotomy in 6 patients, with no prior burr hole in 16 patients. Incidental durotomy during piezosurgical craniotomy occurred in 6 patients, and small lacerations of the sigmoid sinus caused by the piezosurgical device were observed in 3 patients. CONCLUSION: Although PS is a safe and selective bone cutting technique that preserves the surrounding soft tissue, it can still lead to unintended dural tears during lateral suboccipital craniotomy. This must be kept in mind when using PS for craniotomies and relying on the selective bone cutting properties of PS.

Piezosurgery in Modified Pterional Orbital Decompression Surgery in Graves Disease.

OBJECTIVE: Piezosurgery uses microvibrations to selectively cut bone, preserving the adjacent soft tissue. The present study evaluated the use of piezosurgery for bone removal in orbital decompression surgery in Graves disease via a modified pterional approach. METHODS: A piezosurgical device (Piezosurgery medical) was used in 14 patients (20 orbits) with Graves disease who underwent orbital decompression surgery in additional to drills and rongeurs for bone removal of the lateral orbital wall and orbital roof. The practicability, benefits, and drawbacks of this technique in orbital decompression surgery were recorded. Piezosurgery was evaluated with respect to safety, preciseness of bone cutting, and preservation of the adjacent dura and periorbita. Preoperative and postoperative clinical outcome data were assessed. RESULTS: The orbital decompression surgery was successful in all 20 orbits, with good clinical outcomes and no postoperative complications. Piezosurgery proved to be a safe tool, allowing selective bone cutting with no damage to the surrounding soft tissue structures. However, there were disadvantages concerning the intraoperative handling in the narrow space and the efficiency of bone removal was limited in the orbital decompression surgery compared with drills. CONCLUSIONS: Piezosurgery proved to be a useful tool in bone removal for orbital decompression in Graves disease. It is safe and easy to perform, without any danger of damage to adjacent tissue because of its selective bone-cutting properties. Nonetheless, further development of the device is necessary to overcome the disadvantages in intraoperative handling and the reduced bone removal rate.