Stereotactic Frame-Based Electrode Insertion: The Accuracy of Increasingly Oblique Insertion Angles.

AIM: To investigate the relationship between planned drill approach angle and angular deviation of the stereotactically placed intracranial electrode tips. MATERIAL AND METHODS: Stereotactic electrode implantation was performed in 13 patients with drug resistant epilepsy. A total of 136 electrodes were included in our analysis. Stereotactic targets were planned on pre-operative magnetic resonance imaging (MRI) scans and implantation was carried out using a Cosman-Roberts-Wells stereotactic frame with the Ad-Tech drill guide and electrodes. Post implant electrode angles in the axial, coronal, and sagittal planes were determined from post-operative computerized tomography (CT) scans and compared with planned angles using Bland-Altman plots and linear regression. RESULTS: Qualitative assessment of correlation plots between planned and actual angles demonstrated a linear relationship for axial, coronal, and sagittal planes, with no overt angular deflection for any magnitude of the planned angle. CONCLUSION: The accuracy of CRW frame-based electrode placement using the Ad-Tech drill guide and electrodes is not significantly affected by the magnitude of the planning angle. Based on our results, oblique electrode insertion is a safe and accurate procedure.

The majority of patients with resectable incidental lung cancers are ineligible for lung cancer screening.

Objective: The study objective was to determine what proportion of asymptomatic patients had resectable lung cancer detected through lung cancer screening versus incidentally. Methods: We performed a retrospective study of patients who underwent resection for lung cancer between January 2015 and December 2020. We then assessed whether asymptomatic patients with incidentally found lung cancers were eligible for lung cancer screening using the National Comprehensive Cancer Network, United States Preventive Services Task Force, Centers for Medicare & Medicaid Services, American College of Chest Physicians, American Cancer Society, and American Society of Clinical Oncology guidelines. Results: Of 539 patients who underwent resection for primary lung cancer, 437 (81%) were asymptomatic and 355 (66%) of these patients had lung cancer found discovered incidentally. Of the 355 patients with incidentally detected lung cancer, 10 were excluded for insufficient data. Of the remaining 345 patients, 110 (32%) would have been eligible for screening using National Comprehensive Cancer Network guidelines, 65 (19%) using 2021 United States Preventive Services Task Force guidelines, 53 (15%) using 2013 United States Preventive Services Task Force guidelines, 64 (19%) using 2022 Centers for Medicare & Medicaid Services guidelines, 52 (15%) using 2015 Centers for Medicare & Medicaid Services/American College of Chest Physicians guidelines, and 45 (13%) using American Cancer Society/American Society of Clinical Oncology guidelines. Of the 280 patients who were screen ineligible by 2021 United States Preventive Services Task Force criteria, 143 patients (51%) never smoked, 112 patients (40%) quit smoking more than 15 years ago, 89 patients (32%) did not smoke at least 20 pack-years, and 44 patients (16%) were ineligible due to age. Conclusions: The majority of asymptomatic patients with resectable lung cancers had lung cancer identified incidentally and not through lung cancer screening. Most of these patients were not eligible for screening under current guidelines. This study suggests a need for improved lung cancer screening implementation and further investigation in the identification and assessment of risk factors for lung cancer.

Surgical decision-making in advanced-stage non-small cell lung cancer is influenced by more than just guidelines.

Objective: This qualitative study sought to uncover factors that influence decisions to offer curative-intent surgery for patients with advanced-stage (stage IIIB/IV) non-small cell lung cancer. Methods: A trained interviewer conducted open-ended, semistructured telephone interviews with cardiothoracic surgeons in the United States. Participants were recruited from the Thoracic Surgery Outcomes Research Network, with subsequent diversification through snowball sampling. Four hypothetical clinical scenarios were presented, each demonstrating varying levels of ambiguity with respect to international guideline recommendations. Interviews continued until thematic saturation was reached. Interview transcripts were coded using inductive reasoning and conventional content analysis. Results: Of the 27 participants, most had been in practice for ≤20 years (n = 23) and were in academic practice (n = 18). When considering nonguideline-concordant surgeries, participants were aware of relevant guidelines but acknowledged their limitations for unique scenarios. Surgeons perceived that a common barrier to offering surgery is incomplete nonsurgeon physician understanding of surgical capabilities or expected morbidity; and that improved education is necessary to correct these misperceptions. Surgeons expressed concern that undertaking a controversial resection for an individual patient could fracture trust built in long-term professional relationships. Surgeons may face pressure from patients to operate despite a low expectation of clinical benefit, leading to emotional turmoil for the patient and surgeon. Conclusions: This qualitative study generates the hypothesis that the scope of current guidelines, availability of clinical trial protocols, perceived surgical knowledge among nonsurgeon colleagues, interprofessional relationships, and emotional pressure all influence a surgeon's willingness to offer curative-intent surgery for patients with advanced-stage non-small cell lung cancer.

Lobectomy offers improved survival outcomes relative to segmentectomy for >2 but ≤4 cm non-small cell lung cancer tumors.

Objective: The objective was to compare overall survival (OS) between lobectomy and segmentectomy for patients with non-small cell lung cancers (NSCLCs) > 2 but ≤4 cm. Methods: The National Cancer Database was queried to identify treatment-naïve patients with NSCLC tumors >2 but ≤4 cm. Eligible patients were diagnosed with pT1 or T2 N0 M0 disease, underwent lobectomy or segmentectomy, and received no adjuvant therapy. OS was compared using the Kaplan-Meier method, and the Cox proportional-hazards model was used to identify prognostic factors for death. Propensity score matching was performed to minimize the effects of potential confounders. Results: Included were 32,792 patients: lobectomy (n = 31,353) and segmentectomy (n = 1439). Five-year OS was improved following lobectomy over segmentectomy for patients with >2 but ≤4 cm NSCLCs (62.3% vs 52.6%; P < .0001). Further stratification demonstrated improved 5-year OS following lobectomy over segmentectomy: >2 but ≤3 cm (64.9% vs 54.3%; P < .0001) and >3 but ≤4 cm (56.9% vs 47.6%; P = .0003). In patients with a Charlson-Deyo comorbidity index of 0, 5-year OS was greater following lobectomy for >2 but ≤4 cm tumors (67.1% vs 62.1%; P = .03). Further stratification demonstrated improved 5-year OS following lobectomy for patients with Charlson-Deyo comorbidity index of 0 and > 3 but ≤4 cm tumors (61.8% vs 54.6%; P = .02). Segmentectomy was prognostic for increased risk of death in the year 1 through 5 postoperative period (hazard ratio, 1.35; P < .0001). Five-year OS remained greater following lobectomy after propensity score matching (59.6% vs 52.7%; P = .02). Conclusions: Lobectomy is associated with superior 5-year OS compared with segmentectomy and may be preferred for NSCLC tumors >2 but ≤4 cm when feasible.

Primary signet ring cell histology does not portend worse survival for early stage lung cancer following lobectomy.

INTRODUCTION: Signet ring cell (SRC) histology is considered a poor prognostic factor in various cancers. However, primary SRC lung adenocarcinoma is rare and poorly understood. METHODS: The National Cancer Database was queried to identify treatment-naïve patients who received lobectomy for primary SRC or non-SRC pT1-2N0 lung adenocarcinoma <4 cm within four months of diagnosis. SRC lung adenocarcinoma was defined by ICD-O-3 code 8490, while non-SRC lung adenocarcinoma was defined by ICD-O-3 codes 8140, 8141, 8143, 8147, 8255, 8260, 8310, 8481, 8560, and 8570-8574. The Kaplan-Meier curve and log-rank test was used to compare five-year OS between SRC versus non-SRC lung adenocarcinoma cohorts. The impact of SRC histology on risk of death was assessed using the Cox proportional hazards regression model. RESULTS: 48,399 patients were included in this study: 62 with primary SRC lung adenocarcinoma and 48,337 with non-SRC lung adenocarcinoma. The mean age of the overall cohort was 67.0 ± 9.6 years. Five-year OS following lobectomy did not differ significantly between SRC lung adenocarcinoma and non-SRC lung adenocarcinoma cohorts (SRC 73.9% vs. non-SRC 69.3%, p = 0.64). SRC histology did not significantly impact risk of death within five years after lobectomy (HR 0.89, p = 0.66). CONCLUSIONS: Following lobectomy for pT1-2N0 tumors <4 cm, patients with primary SRC lung adenocarcinoma do not experience worse five-year OS or increased risk of death within five years relative to those with non-SRC lung adenocarcinoma. Additional study, including exploration of emerging molecular profiling data, may serve to better define optimal treatment for this histopathologic group of lung adenocarcinomas.

Exploring the Potential Different Outcomes Associated With the Different Phenotypes Under the Shared Pathologic T3N0 Designation.

INTRODUCTION: The objective of this study was to compare overall survival (OS) between patients with pT1-2N1 versus pT3N0 NSCLC and various subtypes of pT3N0 NSCLC. METHODS: The National Cancer Database was queried to identify treatment-naive patients with pathologic stage IIB primary NSCLC. Patients were included if they were diagnosed with pT3N0 or pT1-2N1 NSCLC and received definitive surgery within 4 months of diagnosis. The pT3N0 cohort was subdivided by single versus multiple concurrent T3 descriptors and single-T3 subtypes. The 5-year OS was compared using the Kaplan-Meier method, and the Cox proportional-hazards model was used to identify prognostic factors for death. RESULTS: A total of 16,770 patients were included (pT3N0: 7179; pT1-2N1: 9591). pT3N0 NSCLC was associated with greater 5-year OS than pT1-2N1 NSCLC (52.4% versus 47.8%, p < 0.0001). Among patients receiving adjuvant chemotherapy after surgery, multiple-T3 pT3N0 NSCLC was associated with lower 5-year OS than single-T3 pT3N0 NSCLC (49.0% versus 63.3%, p < 0.0001), and chest wall-only pT3N0 NSCLC was associated with the lowest 5-year OS across single-T3 subtypes (additional nodule: 68.3%; size: 64.5%; chest wall: 52.2%, p < 0.0001). Adjuvant chemotherapy was associated with decreased risk of death in the pT3N0 cohort (hazard ratio = 0.65, confidence interval: 0.59-0.71, p < 0.0001). CONCLUSIONS: Patients with pT3N0 NSCLC experience greater 5-year OS after surgery compared with those with pT1-2N1 NSCLC. Multiple-T3 and chest wall-only pT3N0 NSCLC are associated with worse 5-year OS and increased risk of death relative to other T3 subtypes. Future staging systems should consider including notation distinguishing multiple T3 descriptors in pT3N0 NSCLC.

Enhanced Recovery After Surgery Protocol Minimizes Intensive Care Unit Utilization and Improves Outcomes Following Pulmonary Resection.

BACKGROUND: Enhanced recovery after surgery (ERAS) protocols have been associated with improved postoperative outcomes but require further validation in thoracic surgery. This study evaluated outcomes of patients undergoing pulmonary resection before and after implementation of an ERAS protocol. METHODS: Electronic medical records were queried for all patients undergoing pulmonary resection between April 2017 and April 2019. Patients were grouped into pre- and post-ERAS cohorts based on dates of operation. The ERAS protocol prioritized early mobilization, limited invasive monitoring, euvolemia, and non-narcotic analgesia. Primary outcome measures included intensive care unit (ICU) utilization, postoperative pain metrics, and perioperative morbidity. Regression analyses were performed to identify predictors of morbidity. Subgroup analyses were performed by pulmonary risk profile and surgical approach. RESULTS: A total of 64 pre- and 67 post-ERAS patients were included in the study. ERAS implementation was associated with reduced postoperative ICU admission (pre: 65.6% vs. post: 19.4%, p < 0.0001), shorter ICU median length of stay (LOS) (pre: 1 vs. post: 0, p < 0.0001), and decreased opioid usage measured by median morphine milligram equivalents (pre: 40.5 vs. post: 20.0, p < 0.0001). Post-ERAS patients also reported lower visual analog scale (VAS) pain scores on postoperative days (POD) 1 and 2 (pre: 6.3/5.6 vs. post: 5.3/4.2, p = 0.04/0.01) as well as average VAS pain score over POD0-2 (pre: 6.2 vs. post: 5.2, p = 0.005). CONCLUSIONS: Implementation of an ERAS protocol for pulmonary resection, which dictated reduced ICU admissions, did not increase major postoperative morbidity. Additionally, ERAS-enrolled patients reported improved postoperative pain control despite decreased opioid utilization.

Mapping of primary somatosensory cortex of the hand area using a high-density electrocorticography grid for closed-loop brain computer interface.

Objective.The ideal modality for generating sensation in sensorimotor brain computer interfaces (BCI) has not been determined. Here we report the feasibility of using a high-density 'mini'-electrocorticography (mECoG) grid in a somatosensory BCI system.Approach.Thirteen subjects with intractable epilepsy underwent standard clinical implantation of subdural electrodes for the purpose of seizure localization. An additional high-density mECoG grid was placed (Adtech, 8 by 8, 1.2 mm exposed, 3 mm center-to-center spacing) over the hand area of primary somatosensory cortex. Following implantation, cortical mapping was performed with stimulation parameters of frequency: 50 Hz, pulse-width: 250µs, pulse duration: 4 s, polarity: alternating, and current that ranged from 0.5 mA to 12 mA at the discretion of the epileptologist. Location of the evoked sensory percepts was recorded along with a description of the sensation. The hand was partitioned into 48 distinct boxes. A box was included if sensation was felt anywhere within the box.Main results.The percentage of the hand covered was 63.9% (± 34.4%) (mean ± s.d.). Mean redundancy, measured as electrode pairs stimulating the same box, was 1.9 (± 2.2) electrodes per box; and mean resolution, measured as boxes included per electrode pair stimulation, was 11.4 (± 13.7) boxes with 8.1 (± 10.7) boxes in the digits and 3.4 (± 6.0) boxes in the palm. Functional utility of the system was assessed by quantifying usable percepts. Under the strictest classification, 'dermatomally exclusive' percepts, the mean was 2.8 usable percepts per grid. Allowing 'perceptually unique' percepts at the same anatomical location, the mean was 5.5 usable percepts per grid.Significance.Compared to the small area of coverage and redundancy of a microelectrode system, or the poor resolution of a standard ECoG grid, a mECoG is likely the best modality for a somatosensory BCI system with good coverage of the hand and minimal redundancy.

Beta-band power modulation in the human hippocampus during a reaching task.

OBJECTIVE: Characterize the role of the beta-band (13-30 Hz) in the human hippocampus during the execution of voluntary movement. APPROACH: We recorded electrophysiological activity in human hippocampus during a reach task using stereotactic electroencephalography (SEEG). SEEG has previously been utilized to study the theta band (3-8 Hz) in conflict processing and spatial navigation, but most studies of hippocampal activity during movement have used noninvasive measures such as fMRI. We analyzed modulation in the beta band (13-30 Hz), which is known to play a prominent role throughout the motor system including the cerebral cortex and basal ganglia. We conducted the classic 'center-out' direct-reach experiment with nine patients undergoing surgical treatment for medically refractory epilepsy. MAIN RESULTS: In seven of the nine patients, power spectral analysis showed a statistically significant decrease in power within the beta band (13-30 Hz) during the response phase, compared to the fixation phase, of the center-out direct-reach task using the Wilcoxon signed-rank hypothesis test (p < 0.05). SIGNIFICANCE: This finding is consistent with previous literature suggesting that the hippocampus may be involved in the execution of movement, and it is the first time that changes in beta-band power have been demonstrated in the hippocampus using human electrophysiology. Our findings suggest that beta-band modulation in the human hippocampus may play a role in the execution of voluntary movement.

A Phantom Study of the Spatial Precision and Accuracy of Stereotactic Localization Using Computed Tomography Imaging with the Leksell Stereotactic System.

BACKGROUND: Stereotactic localization of neurosurgical targets traditionally relies on computed tomography (CT), which is considered the optimal imaging modality for geometric accuracy. However, in-depth investigations that characterize the precision and accuracy of CT images are lacking. We used a CT phantom to examine interscanner precision and interprotocol accuracy in coordinate localization. METHODS: A polymethylacrylate phantom was scanned with Toshiba Aquilion 64 and GE Healthcare LightSpeed 16 CT scanners, using both helical and incremental single-slice (SS) image acquisition protocols. The X, Y, and Z coordinates of 94 points across 6 surfaces of the phantom were physically measured. The CT scan-derived coordinates were compared with the phantom coordinates and with each other to determine accuracy and precision, respectively. RESULTS: Using the SS imaging protocol, the mean (SD) interscanner disparity in localization was 0.93 (0.39) mm, given by the average Euclidean distance between the coordinates of the 2 scanners. This discrepancy significantly varied by axis and surface, with the greatest discrepancy in the Z-axis of 0.30 mm (95% confidence interval, 0.25-0.35; P = 0.05) and on the superior surface of 1.30 mm (95% confidence interval, 1.15-1.45; P = 0.05). SS acquisition was significantly more accurate than the helical protocol. CONCLUSIONS: We found evidence of clinically relevant inconsistency between 2 CT scanners used for stereotactic localization. SS image acquisition was superior to helical scanning with respect to localization accuracy. Interscanner consistency cannot be assumed. Institutions would benefit from identifying the errors inherent in their CT scanners.

Utility and lower limits of frequency detection in surface electrode stimulation for somatosensory brain-computer interface in humans.

OBJECTIVE: Stimulation of the primary somatosensory cortex (S1) has been successful in evoking artificial somatosensation in both humans and animals, but much is unknown about the optimal stimulation parameters needed to generate robust percepts of somatosensation. In this study, the authors investigated frequency as an adjustable stimulation parameter for artificial somatosensation in a closed-loop brain-computer interface (BCI) system. METHODS: Three epilepsy patients with subdural mini-electrocorticography grids over the hand area of S1 were asked to compare the percepts elicited with different stimulation frequencies. Amplitude, pulse width, and duration were held constant across all trials. In each trial, subjects experienced 2 stimuli and reported which they thought was given at a higher stimulation frequency. Two paradigms were used: first, 50 versus 100 Hz to establish the utility of comparing frequencies, and then 2, 5, 10, 20, 50, or 100 Hz were pseudorandomly compared. RESULTS: As the magnitude of the stimulation frequency was increased, subjects described percepts that were "more intense" or "faster." Cumulatively, the participants achieved 98.0% accuracy when comparing stimulation at 50 and 100 Hz. In the second paradigm, the corresponding overall accuracy was 73.3%. If both tested frequencies were less than or equal to 10 Hz, accuracy was 41.7% and increased to 79.4% when one frequency was greater than 10 Hz (p = 0.01). When both stimulation frequencies were 20 Hz or less, accuracy was 40.7% compared with 91.7% when one frequency was greater than 20 Hz (p < 0.001). Accuracy was 85% in trials in which 50 Hz was the higher stimulation frequency. Therefore, the lower limit of detection occurred at 20 Hz, and accuracy decreased significantly when lower frequencies were tested. In trials testing 10 Hz versus 20 Hz, accuracy was 16.7% compared with 85.7% in trials testing 20 Hz versus 50 Hz (p < 0.05). Accuracy was greater than chance at frequency differences greater than or equal to 30 Hz. CONCLUSIONS: Frequencies greater than 20 Hz may be used as an adjustable parameter to elicit distinguishable percepts. These findings may be useful in informing the settings and the degrees of freedom achievable in future BCI systems.

Comparison of Intraoperative 3-Dimensional Fluoroscopy With Standard Computed Tomography for Stereotactic Frame Registration.

BACKGROUND: Three-dimensional fluoroscopy via the O-arm (Medtronic, Dublin, Ireland) has been validated for intraoperative confirmation of successful lead placement in stereotactic electrode implantation. However, its role in registration and targeting has not yet been studied. After frame placement, many stereotactic neurosurgeons obtain a computed tomography (CT) scan and merge it with a preoperative magnetic resonance imaging (MRI) scan to generate planning coordinates; potential disadvantages of this practice include increased procedure time and limited scanner availability. OBJECTIVE: To evaluate whether the second-generation O-arm (O2) can be used in lieu of a traditional CT scan to obtain accurate frame-registration scans. METHODS: In 7 patients, a postframe placement CT scan was merged with preoperative MRI and used to generate lead implantation coordinates. After implantation, the fiducial box was again placed on the patient to obtain an O2 confirmation scan. Vector, scalar, and Euclidean differences between analogous X, Y, and Z coordinates from fused O2/MRI and CT/MRI scans were calculated for 33 electrode target coordinates across 7 patients. RESULTS: Marginal means of difference for vector (X = -0.079 ± 0.099 mm; Y = -0.076 ± 0.134 mm; Z = -0.267 ± 0.318 mm), scalar (X = -0.146 ± 0.160 mm; Y = -0.306 ± 0.106 mm; Z = 0.339 ± 0.407 mm), and Euclidean differences (0.886 ± 0.190 mm) remained within the predefined equivalence margin differences of -2 mm and 2 mm. CONCLUSION: This study demonstrates that O2 may emerge as a viable alternative to the traditional CT scanner for generating planning coordinates. Adopting the O2 as a perioperative tool may offer reduced transport risks, decreased anesthesia time, and greater surgical efficiency.

Functional Frequency Discrimination From Cortical Somatosensory Stimulation in Humans.

Recently, efforts to produce artificial sensation through cortical stimulation of primary somatosensory cortex (PSC) in humans have proven safe and reliable. Changes in stimulation parameters like frequency and amplitude have been shown to elicit different percepts, but without clearly defined psychometric profiles. This study investigates the functionally useful limits of frequency changes on the percepts felt by three epilepsy patients with subdural electrocorticography (ECoG) grids. Subjects performing a hidden target task were stimulated with parameters of constant amplitude, pulse-width, and pulse-duration, and a randomly selected set of two frequencies (20, 30, 40, 50, 60, and 100 Hz). They were asked to decide which target had the "higher" frequency. Objectively, an increase in frequency differences was associated with an increase in perceived intensity. Reliable detection of stimulation occurred at and above 40 Hz with a lower limit of detection around 20 Hz and a just-noticeable difference estimated at less than 10 Hz. These findings suggest that frequency can be used as a reliable, adjustable parameter and may be useful in establishing settings and thresholds of functionality in future BCI systems.

Clinical neuroprosthetics: Today and tomorrow.

Implantable neurostimulation devices provide a direct therapeutic link to the nervous system and can be considered brain-computer interfaces (BCI). Under this definition, BCI are not simply science fiction, they are part of existing neurosurgical practice. Clinical BCI are standard of care for historically difficult to treat neurological disorders. These systems target the central and peripheral nervous system and include Vagus Nerve Stimulation, Responsive Neurostimulation, and Deep Brain Stimulation. Recent advances in clinical BCI have focused on creating "closed-loop" systems. These systems rely on biomarker feedback and promise individualized therapy with optimal stimulation delivery and minimal side effects. Success of clinical BCI has paralleled research efforts to create BCI that restore upper extremity motor and sensory function to patients. Efforts to develop closed loop motor/sensory BCI is linked to the successes of today's clinical BCI.

Directional tuning during reach planning in the supramarginal gyrus using local field potentials.

Previous work in directional tuning for brain machine interfaces has primarily relied on algorithm sorted neuronal action potentials in primary motor cortex. However, local field potential has been utilized to show directional tuning in macaque studies, and inferior parietal cortex has shown increased neuronal activity in reaching tasks that relied on MRI imaging. In this study we utilized local field potential recordings from a human subject performing a delayed reach task and show that high frequency band (76-100 Hz) spectral power is directionally tuned to different reaching target locations during an active reach. We also show that during the delay phase of the task, directional tuning is present in areas of the inferior parietal cortex, in particular, the supramarginal gyrus.

Brain-Computer Interfaces in Quadriplegic Patients.

Brain-computer interfaces (BCI) are implantable devices that interface directly with the nervous system. BCI for quadriplegic patients restore function by reading motor intent from the brain and use the signal to control physical, virtual, and native prosthetic effectors. Future closed-loop motor BCI will incorporate sensory feedback to provide patients with an effective and intuitive experience. Development of widely available BCI for patients with neurologic injury will depend on the successes of today's clinical BCI. BCI are an exciting next step in the frontier of neuromodulation.

Electrocorticographic changes in field potentials following natural somatosensory percepts in humans.

OBJECTIVE: Restoration of somatosensory deficits in humans requires a clear understanding of the neural representations of percepts. To characterize the cortical response to naturalistic somatosensation, we examined field potentials in the primary somatosensory cortex of humans. METHODS: Four patients with intractable epilepsy were implanted with subdural electrocorticography (ECoG) electrodes over the hand area of S1. Three types of stimuli were applied, soft-repetitive touch, light touch, and deep touch. Power in the alpha (8-15 Hz), beta (15-30 Hz), low-gamma (30-50 Hz), and high-gamma (50-125 Hz) frequency bands were evaluated for significance. RESULTS: Seventy-seven percent of electrodes over the hand area of somatosensory cortex exhibited changes in these bands. High-gamma band power increased for all stimuli, with concurrent alpha and beta band power decreases. Earlier activity was seen in these bands in deep touch and light touch compared to soft touch. CONCLUSIONS: These findings are consistent with prior literature and suggest a widespread response to focal touch, and a different encoding of deeper pressure touch than soft touch.

Dual responsive neurostimulation implants for epilepsy.

Closed-loop brain-responsive neurostimulation via the RNS System is a treatment option for adults with medically refractory focal epilepsy. Using a novel technique, 2 RNS Systems (2 neurostimulators and 4 leads) were successfully implanted in a single patient with bilateral parietal epileptogenic zones. In patients with multiple epileptogenic zones, this technique allows for additional treatment options. Implantation can be done successfully, without telemetry interference, using proper surgical planning and neurostimulator positioning.Trajectories for the depth leads were planned using neuronavigation with CT and MR imaging. Stereotactic frames were used for coordinate targeting. Each neurostimulator was positioned with maximal spacing to avoid telemetry interference while minimizing patient discomfort. A separate J-shaped incision was used for each neurostimulator to allow for compartmentalization in case of infection. In order to minimize surgical time and risk of infection, the neurostimulators were implanted in 2 separate surgeries, approximately 3 weeks apart.The neurostimulators and leads were successfully implanted without adverse surgical outcomes. The patient recovered uneventfully, and the early therapy settings over several months resulted in preliminary decreases in aura and seizure frequency. Stimulation by one of the neurostimulators did not result in stimulation artifacts detected by the contralateral neurostimulator.

Therapeutic Relationship and Study Adherence in a Community Health Worker-Led Intervention.

Community health workers (CHWs) are increasingly utilized to reach low-resource communities. A critical domain influencing success is the CHWs' ability to create and maintain a therapeutic relationship with the participants they serve. A limited evidence base exists detailing this construct, and evaluating CHW-participant relationships in the context of CHW-led programs. In a longitudinal study design, data on this therapeutic relationship were collected [as captured using The Scale to Assess the Therapeutic Relationship in Community Mental Health Care (STAR)] on 141 participants who had been assigned to a CHW during their perinatal period. Results indicate that therapeutic relationship was associated with the participant's psychosocial health, and independently predicted study adherence in the longitudinal intervention. Changes in therapeutic relationship over the months following birth were strongly associated with changes in anxiety and depression symptoms. A trustful relationship is critical in ensuring CHWs can effectively reach the population they serve. The findings offer additional psychometric evidence of the uses and benefits of STAR outside of the traditional clinical setting in the context of public health research.