Analysis of alpha-synuclein harvested from intracranial instruments used in deep brain stimulation surgery for Parkinson's disease.

Alpha-synuclein (αSyn) forms pathologic aggregates in Parkinson's disease (PD) and is implicated in mechanisms underlying neurodegeneration. While pathologic αSyn has been extensively studied, there is currently no method to evaluate αSyn within the brains of living patients. Patients with PD are often treated with deep brain stimulation (DBS) surgery in which surgical instruments are in direct contact with neuronal tissue; herein, we describe a method by which tissue is purified from DBS surgical instruments in PD and essential tremor (ET) patients and demonstrate that αSyn is robustly detected. 24 patients undergoing DBS surgery for PD (17 patients) or ET (7 patients) were enrolled; from patient samples, 81.2 ± 44.8 µg protein (n=15) is able to be purified, with immunoblot assays specific for αSyn reactive in all tested samples. Light microscopy revealed axons and capillaries as the primary components of purified tissue (n=3). Further analysis was conducted using western blot, demonstrating that truncated αSyn (1-125 αSyn) was significantly increased in PD (n=5) compared to ET (n=3), in which αSyn misfolding is not expected (0.64 ± 0.25 vs. 0.25 ± 0.12, P = 0.046), thus showing that pathologic αSyn can be reliably purified from living PD patients with this method.

Active recharge biphasic stimulation for the intraoperative monopolar review in deep brain stimulation.

Introduction: Charge balancing is used in deep brain stimulation (DBS) to avoid net charge accumulation at the tissue-electrode interface that can result in neural damage. Charge balancing paradigms include passive recharge and active recharge. In passive recharge, each cathodic pulse is accompanied by a waiting period before the next stimulation, whereas active recharge uses energy to deliver symmetric anodic and cathodic stimulation pulses sequentially, producing a net zero charge. We sought to determine differences in stimulation induced side effect thresholds between active vs. passive recharge during the intraoperative monopolar review. Methods: Sixty-five consecutive patients undergoing DBS from 2021 to 2022 were retrospectively reviewed. Intraoperative monopolar review was performed with both active recharge and passive recharge for all included patients to determine side effect stimulation thresholds. Sixteen patients with 64 total DBS contacts met inclusion criteria for further analysis. Intraoperative monopolar review results were compared with the monopolar review from the first DBS programming visit. Results: The mean intraoperative active recharge stimulation threshold was 4.1 mA, while the mean intraoperative passive recharge stimulation threshold was 3.9 mA, though this difference was not statistically significant on t-test (p = 0.442). Mean stimulation threshold at clinic follow-up was 3.2 mA. In Pearson correlation, intraoperative passive recharge thresholds had stronger correlation with follow-up stimulation thresholds (Pearson r = 0.5281, p < 0.001) than intraoperative active recharge (Pearson r = 0.340, p = 0.018), however the difference between these correlations was not statistically significant on Fisher Z correlation test (p = 0.294). The mean difference between intraoperative passive recharge stimulation threshold and follow-up stimulation threshold was 0.8 mA, while the mean difference between intraoperative active recharge threshold and follow-up threshold was 1.2 mA. This difference was not statistically significant on a t-test (p = 0.134). Conclusions: Both intraoperative active recharge and passive recharge stimulation were well-correlated with the monopolar review at the first programming visit. No statistically significant differences were observed suggesting that either passive or active recharge may be utilized intraoperatively.

Risk factors for postoperative urinary retention after deep brain stimulation surgery: the role of the subthalamic nucleus.

OBJECTIVE: Deep brain stimulation (DBS) is a common procedure in neurosurgery used for the treatment of Parkinson's disease (PD) and essential tremor (ET) among other disorders. Lower urinary tract dysfunction is a common complication in PD, and this study aimed to evaluate the risk factors of postoperative urinary retention (POUR) after DBS surgery in patients with PD compared with patients with ET. Understanding the risk factors associated with this complication may help in the development of strategies to minimize its occurrence and improve patient outcomes. METHODS: The study was a retrospective analysis of patients who underwent DBS surgery for PD and ET at the University of Florida between 2010 and 2021. The surgical technique used has been described in previous articles and included a two-stage procedure, with stage 1 involving burr hole placement, microelectrode recording, and electrode implantation and stage 2 involving the placement of an implantable pulse generator (IPG). Data were collected on patient characteristics and surgical details and analyzed using univariate and mixed-linear models. Post hoc propensity score matching was used to confirm the association between subthalamic nucleus (STN)-DBS and POUR. RESULTS: The study included 350 patients (153 with PD and 197 with ET) who underwent 1086 DBS surgeries (lead implantations, IPG placement, and IPG replacements). The POUR rates were 16.6% (79/477), 5.2% (19/363), and 0.4% (1/246) for stage 1, stage 2, and IPG replacement procedures, respectively. Optimal mixed-effects logistic modeling revealed history of urinary retention (OR 9.3, p = 0.004), male sex (OR 2.7, p = 0.011), having an electrode placed or connected for the first time (OR 2.2, p = 0.014), anesthesia time (OR 1.5 for each 30-minute increase, p < 0.0001), preoperative opioid use (OR 1.4 for each additional 10 morphine milligram equivalents, p = 0.032), and Charlson Comorbidity Index (OR 1.4 per comorbidity, p = 0.017) to be significant risk factors for POUR. Having an electrode in the STN was found to be protective of POUR (propensity score-matched analysis: OR 0.2, p = 0.010). CONCLUSIONS: Most risk factors found to increase the risk of POUR in DBS are not modifiable but are still important to consider in preoperative planning. Opioid use reduction and shorter anesthesia time may be modifiable risk factors to weigh against their alternative. Targeting the STN during DBS may result in decreased rates of POUR. This highlights the potential for STN-targeted DBS in reducing POUR risk in PD and ET patients.

Neural Bypasses: Literature Review and Future Directions in Developing Artificial Neural Connections.

Reported neuro-modulation schemes in the literature are typically classified as closed-loop or open-loop. A novel group of recently developed neuro-modulation devices may be better described as a neural bypass, which attempts to transmit neural data from one location of the nervous system to another. The most common form of neural bypasses in the literature utilize EEG recordings of cortical information paired with functional electrical stimulation for effector muscle output, most commonly for assistive applications and rehabilitation in spinal cord injury or stroke. Other neural bypass locations that have also been described, or may soon be in development, include cortical-spinal bypasses, cortical-cortical bypasses, autonomic bypasses, peripheral-central bypasses, and inter-subject bypasses. The most common recording devices include EEG, ECoG, and microelectrode arrays, while stimulation devices include both invasive and noninvasive electrodes. Several devices are in development to improve the temporal and spatial resolution and biocompatibility for neuronal recording and stimulation. A major barrier to entry includes neuroplasticity and current decoding mechanisms that regularly require retraining. Neural bypasses are a unique class of neuro-modulation. Continued advancement of neural recording and stimulating devices with high spatial and temporal resolution, combined with decoding mechanisms uninhibited by neuroplasticity, can expand the therapeutic capability of neural bypassing. Overall, neural bypasses are a promising modality to improve the treatment of common neurologic disorders, including stroke, spinal cord injury, peripheral nerve injury, brain injury and more.

Institutional review of predictors of in-hospital and 30-day discharge mortality in neurosurgical patients.

OBJECTIVE: Risk of adverse events from neurosurgical diagnoses is high. It is not well described whether there are any demographic, admission, or discharge factors that are associated with inpatient or post-discharge mortality outcomes in neurosurgical patients. The aim of this study is to identify the differences in predictors of mortality during inpatient stay and within 30 days of discharge. METHODS: This was a single-institution, retrospective cohort analysis of mortality. Our patient cohort of 11,477 was defined as all adult patients who were discharged (dead or alive) from an inpatient stay between January 1, 2014, and December 31, 2018, and were either admitted to a neurosurgical service or underwent a neurosurgical procedure during that admission. RESULTS: Out of 11,477 patients, 224 (1.95 %) and 290 (2.53 %) died inpatient and within 30 days of discharge, respectively. In multivariate analysis, the independent predictors of inpatient mortality were older age, female gender, diagnostic group, high present on admission severity of illness (POA-SOI) and present on admission risk of mortality (POA-ROM), intensive care unit (ICU) care, and palliative care consult (all p < 0.05). The predictors of mortality within 30-day discharge were older age, admission urgency, admission specialty type, palliative care consult, and discharge disposition (all p < 0.01). CONCLUSION: Older age and palliative care consult were significant predictors of both inpatient and within 30 days of discharge mortality. Admission SOI (>3) and ROM (>3) and ICU care were significant predictors for inpatient mortality while discharge disposition (home health, skilled nursing facility) was important for 30-day mortality.

The limited influence of neurosurgeons' behavior on inpatient satisfaction: a retrospective multihospital analysis.

OBJECTIVE: The Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) is a survey that assesses patient satisfaction, which is an important measure of the quality of hospital care and ultimately the overall hospital rating (OHR). However, the survey covers several elements of patient satisfaction beyond the patient-surgeon interaction. In this study, authors investigated which admission and experience factors had the highest impact on the OHR. METHODS: This was a retrospective cohort analysis of HCAHPS surveys from patients who, in the period between August 1, 2016, and January 31, 2018, had been discharged from the neurosurgical or orthopedic service at three hospitals serving a single metropolitan area. The top-box score was defined as the highest rating obtainable for each survey question. Baseline admission attributes were obtained, and multivariate logistic regression was used to determine predictors of the top-box OHR. RESULTS: After application of the inclusion and exclusion criteria, 1470 patients remained in the analysis. Categories on the HCAHPS included OHR, communication, education, environment, pain management, and responsiveness. After excluding identifying questions from the survey and adjusting for subspecialty and hospital, 7 of 17 HCAHPS survey items were significant predictors of OHR. Only 2 of these were related to the surgeon: 1) discharge, "Did you get information in writing about what symptoms or health problems to look out for after you left the hospital?" (OR 5.93, 95% CI 2.52-13.94); and 2) doctor, "Did doctors explain things in a way you could understand?" (OR 2.78, 95% CI 1.73-4.46). The top three strongest correlating items were 1) discharge; 2) nursing, "Did nurses treat you with courtesy and respect?" (OR 3.86, 95% CI 2.28-6.52); and 3) hospital environment, "Were your room and bathroom kept clean?" (OR 2.86, 95% CI 1.96-4.17). CONCLUSIONS: The study findings demonstrated that there are several nonmodifiable factors (i.e., specialty, experience) and items that are not under the direct purview of the neurosurgeon (e.g., nursing communication, hospital environment) that are significant influences on overall inpatient satisfaction on the HCAHPS survey. Furthermore, components of the survey that ultimately influence the OHR vary across different hospitals. Hence, HCAHPS survey results should be broadly interpreted as a way to make health systems more aware of the overall hospital factors that can improve quality of care and patient experience.

The true penalty of the waiting room: the role of wait time in patient satisfaction in a busy spine practice.

OBJECTIVE: Most clinics collect routine data on performance metrics on physicians for outpatient visits. However, the relationship of these metrics with patient experience is unclear. The goal of this study was to investigate the relationships between the Consumer Assessment of Healthcare Providers and Systems Clinician and Group Survey (CG-CAHPS), the standard patient experience survey, and clinic performance metrics to understand the determinants of patient satisfaction and identify targets for improving patient experience. METHODS: The authors performed a retrospective single-institution cohort review of spine surgeon metrics over 15 months including demographics, waiting-room times, in-room times, lead times, timely note closure, timely MyChart responses, and monthly patient volume. Kruskal-Wallis tests and mixed-model regression were used to determine the predictors of 3 domains of patient satisfaction-Global, Access, and Communication. RESULTS: Over 15 months, 22 surgeons conducted 27,090 visits. The average clinic visit total time was 85.17 ± 25.75 minutes. Increased wait times were associated with poor Global (p = 0.008), Access (p < 0.001), and Communication scores (p = 0.003) in univariate analysis. Every 10-minute increase in waiting time was associated with a 3%, 9.8%, and 2.4% decrease in Global, Access, and Communication scores, respectively. Increased in-room time was also an independent predictor of poor Access scores (p < 0.001). In multivariate analysis, increased wait times were negative predictors of Global (p = 0.005), Access (p < 0.001), and Communication (p = 0.002) scores. CONCLUSIONS: Excessive waiting-room time significantly impacts unexpected dimensions of the patient experience and impacts communication with patients. Understanding the complex relationship between the factors that inform the patient experience will help target effective interventions to improve clinic efficiency and patient satisfaction.

Chief complaints and feedback from clinic satisfaction tool: Thematic analysis of a new outpatient communication tool.

OBJECTIVES: Up to half of all patients leave their outpatient clinic visit with an uncommunicated need. We designed the clinic satisfaction tool (CST) as a low-cost, highly utilised assessment of the spine clinic experience that improved communication in our multidisciplinary spine practice. The purpose of this study was to qualitatively analyse chief complaints and feedback from the CSTs to determine how spine clinic patients used the form, identify the most prevalent concerns and mark areas for improvement. METHODS: Institutional retrospective review of CSTs. Chief complaints and feedback were inductively coded to create a framework for patient complaints. RESULTS: 832 patients presented to clinic, and 100 sets of chief complaints coded before reaching thematic saturation. Patients used the chief complaint section of CST to canvas four themes: symptoms, questions about their disease, management and treatment. Twenty-nine patients left mostly positive feedback but also wrote additional concerns about care. CONCLUSION: Spine patients have a predictable pattern of chief complaints and with the CST were able to have all these complaints addressed. The CST efficiently collects practice-specific chief complaints that can be used to guide physician behaviour and design educational clinical tools that are useful for patients.

Clinic Satisfaction Tool Improves Communication and Provides Real-Time Feedback.

BACKGROUND: Patient-reported assessments of the clinic experience are increasingly important for improving the delivery of care. The Clinician and Group Consumer Assessment of Healthcare Providers and Systems (CG-CAHPS) survey is the current standard for evaluating patients' clinic experience, but its format gives 2-mo delayed feedback on a small proportion of patients in clinic. Furthermore, it fails to give specific actionable results on individual encounters. OBJECTIVE: To develop and assess the impact of a single-page Clinic Satisfaction Tool (CST) to demonstrate real-time feedback, individualized responses, interpretable and actionable feedback, improved patient satisfaction and communication scores, increased physician buy-in, and overall feasibility. METHODS: We assessed CST use for 12 mo and compared patient-reported outcomes to the year prior. We assessed all clinic encounters for patient satisfaction, all physicians for CG-CAHPS global rating, and physician communication scores, and evaluated the physician experience 1 yr after implementation. RESULTS: During implementation, 14 690 patients were seen by 12 physicians, with a 96% overall CST utilization rate. Physicians considered the CST superior to CG-CAHPS in providing immediate feedback. CG-CAHPS global scores trended toward improvement and were predicted by CST satisfaction scores (P < .05). CG-CAHPS physician communication scores were also predicted by CST satisfaction scores (P < .01). High CST satisfaction scores were predicted by high utilization (P < .05). Negative feedback dropped significantly over the course of the study (P < .05). CONCLUSION: The CST is a low-cost, high-yield improvement to the current method of capturing the clinic experience, improves communication and satisfaction between physicians and patients, and provides real-time feedback to physicians.

Impact of Gender Disparities on Short-Term and Long-Term Patient Reported Outcomes and Satisfaction Measures After Elective Lumbar Spine Surgery: A Single Institutional Study of 384 Patients.

BACKGROUND: There is a paucity of data determining the impact that gender disparities have on spine outcomes, particularly perception of health and satisfaction. The aim of this study was to determine whether there is a difference in 3-month and 1-year patient-reported outcomes and satisfaction after elective lumbar spine surgery. METHODS: This was a retrospectively analyzed study from a maintained prospective database of 384 patients who underwent elective lumbar spine surgery. Patients were categorized by gender (men, n = 199; women, n = 185). Patient-reported outcome instruments (Oswestry disability index, visual analogue scale-back pain/leg pain, EuroQol visual analogue scale, and EuroQol 5 dimensions questionnaire) were completed before surgery, then at 3 and 12 months after surgery along with patient satisfaction measures. RESULTS: Baseline patient demographics, comorbidities, and operative variables were similar between both cohorts. The female cohort had a slightly longer hospital stay than male cohort (P = 0.007). Baseline patient-reported outcome measures were different between both cohorts, with female patients having more Oswestry disability index (23.8 vs. 20.4; P ≤ 0.0001) and visual analogue scale-back pain (7.2 vs. 6.2; P = 0.0004), and a lower EuroQol 5 dimensions questionnaire (0.34 vs. 0.49; P = 0.0001) compared with the male cohort. At 1-year follow-up, the male cohort had a significantly more mean change in visual analogue scale-leg pain (-3.9 vs. -2.8; P = 0.04) and trended to have more mean change in visual analogue scale-back pain (-3.4 vs. -2.5; P = 0.06) and EuroQol visual analogue scale (8.6 vs. 3.4; P = 0.054) scores compared with the female cohort. At 1-year a significantly more portion in the male cohort found that surgery met their expectations compared with the female cohort (65.0% vs. 49.5%; P = 0.02). CONCLUSIONS: Our study suggests that there may be differences in perception of health, pain, and disability between men and women at baseline, short-term and long-term follow-up that may influence overall patient satisfaction.

Impact of Affective Disorders on Recovery of Baseline Function in Patients Undergoing Spinal Surgery: A Single Institution Study of 275 Patients.

BACKGROUND: Decompressive spinal surgery patients have high expectations of recovering functionally, both at work and with leisurely activities. Affective disorders, such as depression or anxiety, are increasingly prevalent in this population and are associated with poorer baseline quality-of-life measures and worse postoperative outcomes. The study examined the results of affective disorders on self-reported recovery of baseline function (RBF) following decompressive spinal surgery. METHODS: Medical records of 275 patients undergoing elective decompressive spinal surgery at a major academic institution were reviewed. There were 101 (36.7%) patients (with diagnosed anxiety or depression) in the affective disorder cohort (ADC) and 174 (63.6%) patients in the control cohort. The main outcome measure was self-reported RBF 3 months after surgery. Multivariate regression analysis was also used to determine whether affective disorders were a risk factor for poor RBF. RESULTS: Baseline demographics, comorbidities, and perioperative variables between the two cohorts were similar, except for a higher proportion of females, more smokers, and longer length of stay in the ADC. On patient-reported outcome measures, the ADC had significantly decreased baseline scores and decreased improvement in scores over time. On univariate analysis, the ADC had significantly lower rates of RBF at 3 months after surgery. On regression analysis, affective disorders were an independent risk factors for poor RBF. CONCLUSIONS: This study suggests that affective disorders are an independent risk factor for decreased recovery of baseline functionality after decompressive spinal surgery. Preoperatively identifying these patients could improve management of postoperative expectations and thereby improve surgical outcome.