Ozan Hasimoglu

Purpose: Subthalamic nucleus deep brain stimulation (STN-DBS) effectively alleviates motor symptoms in Parkinson’s disease (PD), yet its impact on speech and voice remains inconsistent. This study examined acoustic parameters, perceptual features, and speech intelligibility using a large, methodologically standardized cohort. Methods: A total of 105 PD patients (55 females, 50 males; mean age ≈ 57 years) undergoing STN-DBS were evaluated. All received posterolateral electrode placement, bilateral stimulation, and a postoperative 30–35% reduction in levodopa. Acoustic measures fundamental frequency (F0), jitter, shimmer, harmonic-to-noise ratio (HNR), and maximum phonation time (MPT) were obtained one day preoperatively and at three months postoperatively. Perceptual ratings (GRBAS), Voice Handicap Index-10 (VHI-10), and speech intelligibility (percentage of correctly produced words) were assessed concurrently. Results: Motor symptoms improved in the medication-on state (19.4 → 13.6). Acoustic analysis showed no significant postoperative change in F0, shimmer, HNR, or MPT; however, jitter improved significantly in both sexes. On the GRBAS scale, all parameters improved in females, whereas grade, roughness, and asthenia improved in males. VHI-10 scores improved overall (22.7 → 21.8; p = 0.031), driven primarily by females (27.5 → 25.9; p = 0.004). Speech intelligibility increased in the full cohort (70.1% → 71.7%; p = 0.01) and reached significance in females but not males. Higher age and greater motor severity correlated with reduced intelligibility, while sex, PD subtype, and stimulation parameters showed no associations. Conclusion: STN-DBS yields short-term motor improvement and produces parameter-specific speech effects. Utilizing a highly standardized “pure” cohort enhances interpretability and suggests that, under controlled conditions, STN-DBS can exert a beneficial influence on speech performance despite its multifactorial impact.

Evaluating the Efficacy and Associated Factors of Vagus Nerve Stimulation in Medically Refractory Epilepsy Patients - Medical Journal of Bakirkoy

Speech changes significantly impact the quality of life for Parkinson's disease (PD) patients. Deep Brain Stimulation (DBS) of the Subthalamic Nucleus (STN) is a standard treatment for advanced PD, but its effects on speech remain unclear. This study aimed to investigate the relationship between STN-DBS and speech changes in PD patients using comprehensive clinical assessments and tractography. Forty-seven PD patients underwent STN-DBS, with preoperative and 3-month postoperative assessments. Speech analyses included acoustic measurements, auditory-perceptual evaluations, and fluency-intelligibility tests. On the other hand, structures within the volume tissue activated (VTA) were identified using MRI and DTI. The clinical and demographic data and structures associated with VTA (Corticospinal tract, Internal capsule, Dentato-rubro-thalamic tract, Medial forebrain bundle, Medial lemniscus, Substantia nigra, Red nucleus) were compared with speech analyses. The majority of patients (36.2-55.4% good, 29.7-53.1% same) exhibited either improved or unchanged speech quality following STN-DBS. Only a small percentage (8.5-14.9%) experienced deterioration. Older patients and those with worsened motor symptoms postoperatively were more likely to experience negative speech changes (p < 0.05). Interestingly, stimulation of the right Substantia Nigra correlated with improved speech quality (p < 0.05). No significant relationship was found between other structures affected by VTA and speech changes. This study suggests that STN-DBS does not predominantly negatively impact speech in PD patients, with potential benefits observed, especially in younger patients. These findings underscore the importance of individualized treatment approaches and highlight the need for further long-term studies to optimize therapeutic outcomes and better understand the effects of STN-DBS on speech.

Purpose: To assess whether diffusion tensor imaging (DTI) and generalized q-sampling imaging (GQI) metrics could preoperatively predict the clinical outcome of deep brain stimulation (DBS) in patients with Parkinson’s disease (PD). Methods: In this single-center retrospective study, from September 2021 to March 2023, preoperative DTI and GQI examinations of 44 patients who underwent DBS surgery, were analyzed. To evaluate motor functions, the Unified Parkinson’s Disease Rating Scale (UPDRS) during on- and off-medication and Parkinson’s Disease Questionnaire-39 (PDQ-39) scales were used before and three months after DBS surgery. The study population was divided into two groups according to the improvement rate of scales: ≥ 50% and < 50%. Five target regions, reported to be affected in PD, were investigated. The parameters having statistically significant difference were subjected to a receiver operating characteristic (ROC) analysis. Results: Quantitative anisotropy (qa) values from globus pallidus externus, globus pallidus internus (qa_Gpi), and substantia nigra exhibited significant distributional difference between groups in terms of the improvement rate of UPDRS-3 scale during on-medication (p = 0.003, p = 0.0003, and p = 0.0008, respectively). In ROC analysis, the best parameter in predicting DBS response included qa_Gpi with a cut-off value of 0.01370 achieved an area under the ROC curve, accuracy, sensitivity, and specificity of 0.810, 73%, 62.5%, and 85%, respectively. Optimal cut-off values of ≥ 0.01864 and ≤ 0.01162 yielded a sensitivity and specificity of 100%, respectively. Conclusion: The imaging parameters acquired from GQI, particularly qa_Gpi, may have the ability to non-invasively predict the clinical outcome of DBS surgery.

Objective : Postoperative data on Cushing’s disease (CD) are equivocal in the literature. These discrepancies may be attributed to different series with different criteria for remission and variable follow-up durations. Additional data from experienced centers may address these discrepancies. In this study, we present the results obtained from 96 endoscopic transsphenoidal surgeries (ETSSs) for CD conducted in a well-experienced center.Methods : Pre- and postoperative data of 96 ETSS in 87 patients with CD were included. All cases were handled by the same neurosurgical team between 2014 and 2022. We obtained data on remission status 3−6 months postoperatively (medium-term) and during the latest follow-up (long-term). Additionally, magnetic resonance imaging (MRI) and pathology results were obtained for each case.Results : The mean follow-up duration was 39.5±3.2 months. Medium and long-term remission rates were 77% and 82%, respectively. When only first-time operations were considered, the medium- and long-term remission rates were 78% and 82%, respectively. The recurrence rate in this series was 2.5%. Patients who showed remission between 3−6 months had higher longterm remission rates than did those without initial remission. Tumors >2 cm and extended tumor invasion of the cavernous sinus (Knosp 4) were associated with lower postoperative remission rates.Conclusion : Adenoma size and the presence/absence of cavernous sinus invasion on preopera-tive MRI may predict long-term postoperative remission. A tumor size of 2 cm may be a supporting criterion for predicting remission in Knosp 4 tumors. Further studies with larger patient populations are necessary to support this finding.