Perception of emotionally incongruent cues: evidence for overreliance on body vs. face expressions in Parkinson's disease

Individuals with Parkinson's disease (PD) may exhibit impaired emotion perception. However, research demonstrating this decline has been based almost entirely on the recognition of isolated emotional cues. In real life, emotional cues such as expressive faces are typically encountered alongside expressive bodies. The current study investigated emotion perception in individuals with PD (n = 37) using emotionally incongruent composite displays of facial and body expressions, as well as isolated face and body expressions, and congruent composite displays as a baseline. In addition to a group of healthy controls (HC) (n = 50), we also included control individuals with schizophrenia (SZ) (n = 30), who display, as in PD, similar motor symptomology and decreased emotion perception abilities. The results show that individuals with PD showed an increased tendency to categorize incongruent face-body combinations in line with the body emotion, whereas those with HC showed a tendency to classify them in line with the facial emotion. No consistent pattern for prioritizing the face or body was found in individuals with SZ. These results were not explained by the emotional recognition of the isolated cues, cognitive status, depression, or motor symptoms of individuals with PD and SZ. As real-life expressions may include inconsistent cues in the body and face, these findings may have implications for the way individuals with PD and SZ interpret the emotions of others.

Bridging language barriers in developing valid health policy research tools: insights from the translation and validation process of the SHEMESH questionnaire

BACKGROUND

The use of research tools developed and validated in one cultural and linguistic context to another often faces challenges. One major challenge is poor performance of the tool in the new context. This potentially impact the legitimacy of health policy research conducted with informal adaptations of existing tools which have not been subjected to formal validation. Best practices exist to guide researchers in adapting and validating research tools effectively. We present here, as an extended example, our validation of the SHEMESH questionnaire ('Organizational Readiness to Change Assessment'; In Hebrew: 'SHE'elon Muchanut Ergunit le'SHinuy'), a Hebrew-language version of the Organizational Readiness to Change Assessment (ORCA). SHEMESH is tailored to support implementation science projects, whose aim is to promote a more rapid and complete adoption of evidence-based health policies and practices.

METHODS

The SHEMESH included originally eleven questions from the Evidence (item 1-4) and Context (items 5-11) domains. We validated SHEMESH through the following steps: 1. Professional translation to Hebrew and discussion of the translation by multidisciplinary committee; 2. Back-translation into English by a different translator to detect discrepancies; 3. Eleven cognitive interviews with psychiatric emergency department physicians and nurses; and 4. Pilot testing and psychometric analyses, including Cronbach's alpha for subscales and factor analyses.

RESULTS

Following translation and cognitive interviews, SHEMESH was administered to 222 psychiatrists and nurses. Pearson correlation showed significant and strong correlations of items 1-4 to the Evidence construct and items 6-11 to the Context construct. Item 5 did not correlate with the other items, and therefore was removed from the other psychometric procedures and eventually from the SHEMESH. Factor analysis with the remaining 10 items yielded two factors, which together explained a total of 69.7% of variance. Cronbach's Alpha scores for the two subscales were high (Evidence, 0.887, and Context, 0.852).

CONCLUSIONS

This multi-step validation process of the SHEMESH questionnaire may serve as a comprehensive guideline for others who are willing to adapt research tools that were developed in other languages. Practically, SHEMESH has been validated for use in implementation science research projects in Israel.

Tuned to Tremor: Increased Sensitivity of Cortico-Basal Ganglia Neurons to Tremor Frequency in the MPTP Nonhuman Primate Model of Parkinson's Disease

Rest tremor is one of the most prominent clinical features of Parkinson's disease (PD). Here, we hypothesized that cortico-basal ganglia neurons tend to fire in a pattern that matches PD tremor frequency, suggesting a resonance phenomenon. We recorded spiking activity in the primary motor cortex (M1) and globus pallidus external segment of 2 female nonhuman primates, before and after parkinsonian state induction with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine. The arm of nonhuman primates was passively rotated at seven different frequencies surrounding and overlapping PD tremor frequency. We found entrainment of the spiking activity to arm rotation and a significant sharpening of the tuning curves in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine state, with a peak response at frequencies that matched the frequency of PD tremor. These results reveal increased sensitivity of the cortico-basal ganglia network to tremor frequency and could indicate that this network acts not only as a tremor switch but is involved in setting its frequency.SIGNIFICANCE STATEMENT Tremor is a prominent clinical feature of Parkinson's disease; however, its underlying pathophysiology is still poorly understood. Using electrophysiological recordings of single cortico-basal ganglia neurons before and after the induction of a parkinsonian state, and in response to passive arm rotation, this study reports increased sensitivity to tremor frequency in Parkinson's disease. We found sharpening of the population tuning to the midrange of the tested frequencies (1-13.3 Hz) in the healthy state that further increased in the parkinsonian state. These results hint at the increased frequency-tuned sensitivity of cortico-basal ganglia neurons and suggest that they tend to resonate with the tremor.

Enabling Expedited Disposition of Emergencies Using Telepsychiatry in Israel: Protocol for a Hybrid Implementation Study

BACKGROUND

Telepsychiatry is the use of virtual communication, such as a video link, to deliver mental health assessment, treatment, and follow-up. Previous studies have shown telepsychiatry to be feasible, accurate compared with in-person practice, and satisfying for psychiatrists and patients. Telepsychiatry has also been associated with reduced waiting times for evaluation and, in some studies, lower admission rates. However, most previous studies focused on using telepsychiatry in community settings and not on involuntary admission.

OBJECTIVE

The aim of this study is to examine the effectiveness and implementation process of patient assessment for involuntary admissions in the psychiatric emergency department (ED) using a video link.

METHODS

This type 1 hybrid implementation study will examine telepsychiatry effectiveness and the implementation process, by comparing telepsychiatry (n=240) with historical controls who had a face-to-face evaluation (n=240) during the previous, usual care period in 5 psychiatric EDs in Israel. A temporary waiver of the standing policy requiring in-person evaluations only, for the purpose of research, was obtained from the Israeli Ministry of Health. During the telepsychiatry phase, clinical staff and patients will join a video call from the ED, while the attending physician will log in elsewhere. The Promoting Action on Research Implementation in Health Services (PARIHS) framework will guide the evaluation of the telepsychiatry implementation process in the ED. PARIHS has the following 3 constructs: (1) evidence: staff's opinions regarding the innovation's viability and practicality, their satisfaction levels with its use, and patients' perceptions of the change; (2) context: level of approval of new strategies in the ED, decision-making processes, and the manner in which clinical teams converse and work together; (3) facilitation: adequacy of the facilitation efforts using champions reports. Primary clinical outcomes include ED length of stay and violent incidents obtained from medical records.

RESULTS

This study received Helsinki approval from the Ethics Committee of Abarbanel Mental Health Center (174; March 13, 2023), Jerusalem Mental Health Center (22-21; November 6, 2022), Lev-Hasharon Mental Health Medical Center (LH12023; February 12, 2023), Tel-Aviv Medical Center (TLV-22-0656; January 3, 2023), and Sha'ar Menashe (1-4-23; April 18, 2023). Data collection began in July 2023 in 2 study sites and will begin soon at the others.

CONCLUSIONS

Telepsychiatry could have significant benefits for patients in the psychiatric ED. Examining telepsychiatry effectiveness in the ED, in addition to identifying the facilitators and barriers of implementing it in different emergency settings, will facilitate better policy decisions regarding its implementation.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05771545; https://clinicaltrials.gov/study/NCT05771545.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/49405.

When radical uncertainty is too much: Clinical aspects of Conviction Narrative Theory

We propose extrapolating Conviction Narrative Theory (CNT) to clinical psychology and psychiatry. We demonstrate how CNT principles may benefit assessment, therapy, and possibly even modify public health views of neuropsychiatric disorders. Our commentary focuses on hoarding disorder as a model, elaborates on discrepancies in the scientific literature and suggests how the CNT may resolve them.

Comparable reliability and acceptability of telepsychiatry and face-to-face psychiatric assessments in the emergency room setting

OBJECTIVE

This study aims to compare the reliability and acceptability of psychiatric interviews using telepsychiatry and face-to-face modalities in the emergency room setting.

METHODS

In this prospective observational feasibility study, psychiatric patients (n = 38) who presented in emergency rooms between April and June 2020, went through face-to-face and videoconference telepsychiatry interviews in a non-randomised varying order. Interviewers and a senior psychiatry resident who observed both interviews determined diagnosis, recommended disposition and indication for involuntary admission. Patients and psychiatrists completed acceptability post-assessment surveys.

RESULTS

Agreement between raters on recommended disposition and indication for involuntary admission as measured by Cohen's kappa was 'strong' to 'almost perfect' (0.84/0.81, 0.95/0.87 and 0.89/0.94 for face-to-face vs. telepsychiatry, observer vs. face-to-face and observer vs. telepsychiatry, respectively). Partial agreement between the raters on diagnosis was 'strong' (Cohen's kappa of 0.81, 0.85 and 0.85 for face-to-face vs. telepsychiatry, observer vs. face-to-face and observer vs. telepsychiatry, respectively).Psychiatrists' and patients' satisfaction rates, and psychiatrists' perceived certainty rates, were comparably high in both face-to-face and telepsychiatry groups.

CONCLUSIONS

Telepsychiatry is a reliable and acceptable alternative to face-to-face psychiatric assessments in the emergency room setting. Implementing telepsychiatry may improve the quality and accessibility of mental health services.Key pointsTelepsychiatry and face-to-face psychiatric assessments in the emergency room setting have comparable reliability.Patients and providers report a comparable high level of satisfaction with telepsychiatry and face-to-face modalities in the emergency room setting.Providers report a comparable level of perceived certainty in their clinical decisions based on telepsychiatry and face-to-face psychiatric assessments in the emergency room setting.

Modulation of dopamine tone induces frequency shifts in cortico-basal ganglia beta oscillations

Βeta oscillatory activity (human: 13-35 Hz; primate: 8-24 Hz) is pervasive within the cortex and basal ganglia. Studies in Parkinson's disease patients and animal models suggest that beta-power increases with dopamine depletion. However, the exact relationship between oscillatory power, frequency and dopamine tone remains unclear. We recorded neural activity in the cortex and basal ganglia of healthy non-human primates while acutely and chronically up- and down-modulating dopamine levels. We assessed changes in beta oscillations in patients with Parkinson's following acute and chronic changes in dopamine tone. Here we show beta oscillation frequency is strongly coupled with dopamine tone in both monkeys and humans. Power, coherence between single-units and local field potentials (LFP), spike-LFP phase-locking, and phase-amplitude coupling are not systematically regulated by dopamine levels. These results demonstrate that beta frequency is a key property of pathological oscillations in cortical and basal ganglia networks.

Deep Brain Stimulation Can Differentiate Subregions of the Human Subthalamic Nucleus Area by EEG Biomarkers

Introduction: Precise lead localization is crucial for an optimal clinical outcome of subthalamic nucleus (STN) deep brain stimulation (DBS) treatment in patients with Parkinson's disease (PD). Currently, anatomical measures, as well as invasive intraoperative electrophysiological recordings, are used to locate DBS electrodes. The objective of this study was to find an alternative electrophysiology tool for STN DBS lead localization.

Methods: Sixty-one postoperative electrophysiology recording sessions were obtained from 17 DBS-treated patients with PD. An intraoperative physiological method automatically detected STN borders and subregions. Postoperative EEG cortical activity was measured, while STN low frequency stimulation (LFS) was applied to different areas inside and outside the STN. Machine learning models were used to differentiate stimulation locations, based on EEG analysis of engineered features.

Results: A machine learning algorithm identified the top 25 evoked response potentials (ERPs), engineered features that can differentiate inside and outside STN stimulation locations as well as within STN stimulation locations. Evoked responses in the medial and ipsilateral fronto-central areas were found to be most significant for predicting the location of STN stimulation. Two-class linear support vector machine (SVM) predicted the inside (dorso-lateral region, DLR, and ventro-medial region, VMR) vs. outside [zona incerta, ZI, STN stimulation classification with an accuracy of 0.98 and 0.82 for ZI vs. VMR and ZI vs. DLR, respectively, and an accuracy of 0.77 for the within STN (DLR vs. VMR)]. Multiclass linear SVM predicted all areas with an accuracy of 0.82 for the outside and within STN stimulation locations (ZI vs. DLR vs. VMR).

Conclusions: Electroencephalogram biomarkers can use low-frequency STN stimulation to localize STN DBS electrodes to ZI, DLR, and VMR STN subregions. These models can be used for both intraoperative electrode localization and postoperative stimulation programming sessions, and have a potential to improve STN DBS clinical outcomes.

A comparative study reveals a similar validity of telepsychiatry and face-to-face psychiatric assessment in emergency room setting

Introduction

Telepsychiatry (TP) can provide an alternative to traditional face-to-face (FTF) assessments. However, TP in the emergency room setting is much less prevalent, probably due to lack of solid evidence about its effectiveness and acceptability.

Objectives

To directly compare traditional FTF and TP modalities in the emergency room setting.

Methods

Psychiatric patients (n=38) presented to the emergency room went through traditional in-person and videoconference TP interviews in varying order. Both FTF and TP interviewers that examined the patients as well as a third psychiatrist, acting as an observer for both modalities, determined the diagnosis, disposition recommendation and indication for involuntary admission.

Results

Rater decisions had a high matching on disposition and indication for involuntary admission (Cohen’s Kappa (CK) of 0.84/0.81, 0.95/0.87 and 0.89/0.94 for FTF-TP, Observer-FTF and Observer-TP, respectively). Although identical diagnosis matching between the raters was relatively low, the partial diagnosis matching was high (CK of 0.52/0.81, 0.52/0.85 and 0.56/0.85 for FTF-TP, Observer-FTF and Observer-TP, respectively). Telepsychiatry assessments had comparable acceptability in items such as psychiatrists’ certainty and interviewers’ and patients’ satisfaction.

Conclusions

TP and FTF psychiatric assessments in the emergency room settings have similar validity and acceptability. Implementation of TP in emergency room settings might improve the mental health services’ quality and access especially for remote populations. TP is especially important during the COVID-19 pandemic to enable treatment for epidemiologically isolated patients and to protect the medical personnel.

Machine learning-based personalized subthalamic biomarkers predict ON-OFF levodopa states in Parkinson patients

Objective.Adaptive deep brain stimulation (aDBS) based on subthalamic nucleus (STN) electrophysiology has recently been proposed to improve clinical outcomes of DBS for Parkinson's disease (PD) patients. Many current models for aDBS are based on one or two electrophysiological features of STN activity, such as beta or gamma activity. Although these models have shown interesting results, we hypothesized that an aDBS model that includes many STN activity parameters will yield better clinical results. The objective of this study was to investigate the most appropriate STN neurophysiological biomarkers, detectable over long periods of time, that can predict OFF and ON levodopa states in PD patients.Approach.Long-term local field potentials (LFPs) were recorded from eight STNs (four PD patients) during 92 recording sessions (44 OFF and 48 ON levodopa states), over a period of 3-12 months. Electrophysiological analysis included the power of frequency bands, band power ratio and burst features. A total of 140 engineered features was extracted for 20 040 epochs (each epoch lasting 5 s). Based on these engineered features, machine learning (ML) models classified LFPs as OFF vs ON levodopa states.Main results.Beta and gamma band activity alone poorly predicts OFF vs ON levodopa states, with an accuracy of 0.66 and 0.64, respectively. Group ML analysis slightly improved prediction rates, but personalized ML analysis, based on individualized engineered electrophysiological features, were markedly better, predicting OFF vs ON levodopa states with an accuracy of 0.8 for support vector machine learning models.Significance.We showed that individual patients have unique sets of STN neurophysiological biomarkers that can be detected over long periods of time. ML models revealed that personally classified engineered features most accurately predict OFF vs ON levodopa states. Future development of aDBS for PD patients might include personalized ML algorithms.

Perceiving dynamic emotions expressed simultaneously in the face and body minimizes perceptual differences between young and older adults

OBJECTIVES

It is commonly argued that older adults show difficulties in standardized tasks of emotional expression perception, yet most previous works relied on classic sets of static, decontextualized, and stereotypical facial expressions. In real-life, facial expressions are dynamic and embedded in a rich context, two key factors that may aid emotion perception. Specifically, body language provides important affective cues that may disambiguate facial movements.

METHOD

We compared emotion perception of dynamic faces, bodies, and their combination, in a sample of older (age 60-83, n=126) and young (age 18-30, n=124) adults. We used the Geneva Multimodal Emotion Portrayals (GEMEP) set, which includes a full view of expressers' faces and bodies, displaying a diverse range of positive and negative emotions, portrayed dynamically and holistically in a non-stereotypical, unconstrained manner. Critically, we digitally manipulated the dynamic cue such that perceivers viewed isolated faces (without bodies), isolated bodies (without faces), or faces with bodies.

RESULTS

Older adults showed better perception of positive and negative dynamic facial expressions, while young adults showed better perception of positive isolated dynamic bodily expressions. Importantly, emotion perception of faces with bodies was comparable across ages.

DISCUSSION

Dynamic emotion perception in young and older adults may be more similar than previously assumed, especially when the task is more realistic and ecological. Our results emphasize the importance of contextualized and ecological tasks in emotion perception across ages.

A prospective international multi-center study on safety and efficacy of deep brain stimulation for resistant obsessive-compulsive disorder

Deep brain stimulation (DBS) has been proposed for severe, chronic, treatment-refractory obsessive-compulsive disorder (OCD) patients. Although serious adverse events can occur, only a few studies report on the safety profile of DBS for psychiatric disorders. In a prospective, open-label, interventional multi-center study, we examined the safety and efficacy of electrical stimulation in 30 patients with DBS electrodes bilaterally implanted in the anterior limb of the internal capsule. Safety, efficacy, and functionality assessments were performed at 3, 6, and 12 months post implant. An independent Clinical Events Committee classified and coded all adverse events (AEs) according to EN ISO14155:2011. All patients experienced AEs (195 in total), with the majority of these being mild (52% of all AEs) or moderate (37%). Median time to resolution was 22 days for all AEs and the etiology with the highest AE incidence was 'programming/stimulation' (in 26 patients), followed by 'New illness, injury, condition' (13 patients) and 'pre-existing condition, worsening or exacerbation' (11 patients). Sixteen patients reported a total of 36 serious AEs (eight of them in one single patient), mainly transient anxiety and affective symptoms worsening (20 SAEs). Regarding efficacy measures, Y-BOCS reduction was 42% at 12 months and the responder rate was 60%. Improvements in GAF, CGI, and EuroQol-5D index scores were also observed. In sum, although some severe AEs occurred, most AEs were mild or moderate, transient and related to programming/stimulation and tended to resolve by adjustment of stimulation. In a severely treatment-resistant population, this open-label study supports that the potential benefits outweigh the potential risks of DBS.

Interrupting traumatic memories in the emergency department: a randomized controlled pilot study

BACKGROUND

The hours immediately following a traumatic event may present a window of opportunity to interrupt the consolidation of memories of the traumatic event, and this may prevent PTSD development. This theory has been validated in a series of analogue studies, showing that a visuo-spatial task reduces intrusive memories, however clinical studies are scarce.

OBJECTIVE

This pilot RCT examined the use of a semi-immersive Virtual Reality visuospatial task, as an intervention to interrupt memory consolidation, in the Emergency Department (ED) in the immediate hours following a traumatic event. We hypothesised that participants who had received the intervention would present with lower levels of PTSD symptoms than the control group who received no intervention.

METHOD

Seventy-seven adult survivors of traumatic events, meeting study criteria, were recruited in the ED of a Level III Trauma Centre. Survivors arrived at the ED less than one hour, on average, after the trauma. After signing informed consent, participants were randomized to the SnowWorld intervention or control group. Both groups completed self-report questionnaires, and the intervention group used SnowWorld for up to 10 minutes.

RESULTS

No significant differences between the intervention and control groups were found regarding PTSD symptom levels two weeks and six months following the traumatic event.

CONCLUSIONS

These results add to the growing literature examining the use of a concurrent task to reduce intrusions following a traumatic event. In contrast to previous clinical studies, this study did not show significant group differences; however, it replicates an analogue study that used a specifically developed app. Further studies are needed to elucidate possible reasons for these conflicting results.

Independently together: subthalamic theta and beta opposite roles in predicting Parkinson's tremor

Tremor is a core feature of Parkinson’s disease and the most easily recognized Parkinsonian sign. Nonetheless, its pathophysiology remains poorly understood. Here, we show that multispectral spiking activity in the posterior-dorso-lateral oscillatory (motor) region of the subthalamic nucleus distinguishes resting tremor from the other Parkinsonian motor signs and strongly correlates with its severity. We evaluated microelectrode-spiking activity from the subthalamic dorsolateral oscillatory region of 70 Parkinson’s disease patients who underwent deep brain stimulation surgery (114 subthalamic nuclei, 166 electrode trajectories). We then investigated the relationship between patients’ clinical Unified Parkinson’s Disease Rating Scale score and their peak theta (4–7 Hz) and beta (13–30 Hz) powers. We found a positive correlation between resting tremor and theta activity (r = 0.41, P < 0.01) and a non-significant negative correlation with beta activity (r = −0.2, P = 0.5). Hypothesizing that the two neuronal frequencies mask each other’s relationship with resting tremor, we created a non-linear model of their proportional spectral powers and investigated its relationship with resting tremor. As hypothesized, patients’ proportional scores correlated better than either theta or beta alone (r = 0.54, P < 0.001). However, theta and beta oscillations were frequently temporally correlated (38/70 patients manifested significant positive temporal correlations and 1/70 exhibited significant negative correlation between the two frequency bands). When comparing theta and beta temporal relationship (r θ β) to patients’ resting tremor scores, we found a significant negative correlation between the two (r = −0.38, P < 0.01). Patients manifesting a positive correlation between the two bands (i.e. theta and beta were likely to appear simultaneously) were found to have lower resting tremor scores than those with near-zero correlation values (i.e. theta and beta were likely to appear separately). We therefore created a new model incorporating patients’ proportional theta–beta power and r θ βscores to obtain an improved neural correlate of resting tremor (r = 0.62, P < 0.001). We then used the Akaike and Bayesian information criteria for model selection and found the multispectral model, incorporating theta–beta proportional power and their correlation, to be the best fitting model, with 0.96 and 0.89 probabilities, respectively. Here we found that as theta increases, beta decreases and the two appear separately—resting tremor is worsened. Our results therefore show that theta and beta convey information about resting tremor in opposite ways. Furthermore, the finding that theta and beta coactivity is negatively correlated with resting tremor suggests that theta–beta non-linear scale may be a valuable biomarker for Parkinson’s resting tremor in future adaptive deep brain stimulation techniques.

A Novel Integrative Psychotherapy for Psychogenic Nonepileptic Seizures Based on the Biopsychosocial Model: A Retrospective Pilot Outcome Study

BACKGROUND

Psychogenic nonepileptic seizures (PNES) represent one of the most sizable treatment challenges in neuropsychiatry. Although the underlying mechanism is far from being understood, several interventions have been suggested. However, patients with comorbid psychiatric diagnoses and epilepsy are excluded from most intervention studies.

OBJECTIVE

To To present a within-group posttreatment vs pretreatment study representing the retrospective clinical results of an integrative psychotherapy model.

METHODS

We present the clinical results of 22 patients with PNES diagnosed in an epilepsy center and treated in our neuropsychiatry clinic using an integrative rehabilitative psychotherapy. Therapy included presenting the diagnosis, psychoeducation, seizure reduction behavioral techniques, and coping with past and present stressors. Insomuch as integrative biopsychosocial psychotherapy is based on an individualized treatment protocol for each patient, treatment was individualized and case specific.

RESULTS

By the end of treatment, 36% of patients had become seizure free and a further 54% achieved a major seizure reduction (reduction of more than 70%). Seventy-two percent of patients kept at least 70% seizure reduction at follow-up. Global Assessment of Functioning scores improved from a mean of 43.09 to a mean of 72.81 at the end of treatment and 69.72 at follow-up. In addition, we present 3 case descriptions that emphasize the individualized nature of psychotherapeutic decisions.

CONCLUSIONS

Our results support the feasibility and effectiveness of biopsychosocial based integrative psychotherapy for PNES and set principles for future treatment and prospective clinical trials in the field of individualized psychotherapy.

Real-time machine learning classification of pallidal borders during deep brain stimulation surgery

OBJECTIVE

Deep brain stimulation (DBS) of the internal segment of the globus pallidus (GPi) in patients with Parkinson's disease and dystonia improves motor symptoms and quality of life. Traditionally, pallidal borders have been demarcated by electrophysiological microelectrode recordings (MERs) during DBS surgery. However, detection of pallidal borders can be challenging due to the variability of the firing characteristics of neurons encountered along the trajectory. MER can also be time-consuming and therefore costly. Here we show the feasibility of real-time machine learning classification of striato-pallidal borders to assist neurosurgeons during DBS surgery.

APPROACH

An electrophysiological dataset from 116 trajectories of 42 patients consisting of 11 774 MER segments of background spiking activity in five classes of disease was used to train the classification algorithm. The five classes included awake Parkinson's disease patients, as well as awake and lightly anesthetized genetic and non-genetic dystonia patients. A machine learning algorithm was designed to provide prediction of the striato-pallidal borders, based on hidden Markov models (HMMs) and the L₁-distance measure in normalized root mean square (NRMS) and power spectra of the MER. We tested its performance prospectively against the judgment of three electrophysiologists in the operating rooms of three hospitals using newly collected data.

MAIN RESULTS

The awake and the light anesthesia dystonia classes could be merged. Using MER NRMS and spectra, the machine learning algorithm was on par with the performance of the three electrophysiologists across the striatum-GPe, GPe-GPi, and GPi-exit transitions for all disease classes.

SIGNIFICANCE

Machine learning algorithms enable real-time GPi navigation systems to potentially shorten the duration of electrophysiological mapping of pallidal borders, while ensuring correct pallidal border detection.

Microelectrode Recordings Validate the Clinical Visualization of Subthalamic-Nucleus Based on 7T Magnetic Resonance Imaging and Machine Learning for Deep Brain Stimulation Surgery

BACKGROUND

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is a proven and effective therapy for the management of the motor symptoms of Parkinson's disease (PD). While accurate positioning of the stimulating electrode is critical for success of this therapy, precise identification of the STN based on imaging can be challenging. We developed a method to accurately visualize the STN on a standard clinical magnetic resonance imaging (MRI). The method incorporates a database of 7-Tesla (T) MRIs of PD patients together with machine-learning methods (hereafter 7 T-ML).

OBJECTIVE

To validate the clinical application accuracy of the 7 T-ML method by comparing it with identification of the STN based on intraoperative microelectrode recordings.

METHODS

Sixteen PD patients who underwent microelectrode-recordings guided STN DBS were included in this study (30 implanted leads and electrode trajectories). The length of the STN along the electrode trajectory and the position of its contacts to dorsal, inside, or ventral to the STN were compared using microelectrode-recordings and the 7 T-ML method computed based on the patient's clinical 3T MRI.

RESULTS

All 30 electrode trajectories that intersected the STN based on microelectrode-recordings, also intersected it when visualized with the 7 T-ML method. STN trajectory average length was 6.2 ± 0.7 mm based on microelectrode recordings and 5.8 ± 0.9 mm for the 7 T-ML method. We observed a 93% agreement regarding contact location between the microelectrode-recordings and the 7 T-ML method.

CONCLUSION

The 7 T-ML method is highly consistent with microelectrode-recordings data. This method provides a reliable and accurate patient-specific prediction for targeting the STN.

A Real-Life Search for the Optimal Set of Conversion Factors to Levodopa-Equivalent-Dose in Parkinson's Disease Patients on Polytherapy

BACKGROUND

A wide variety of conversion factors for a levodopa-equivalent-dose (LED) have been proposed for each Parkinson's disease (PD) medication. The currently-used set of conversion factors is based on studies that relied on subjective experience or theoretical assumptions. This set was never validated in patients receiving polytherapy.

OBJECTIVES

To use real-life data to identify an optimal set of conversion factors independent of prior assumptions regarding clinical efficacy of different medications.

METHODS

Retrospective analysis of data from 206 cognitively-preserved patients with advanced PD receiving polytherapy before deep brain stimulation (DBS) surgery. A nonlinear automated problem solver was used to find a set of conversion factors that, when applied, minimized the coefficient of variation of LEDs in a relatively homogenous cohort of patients.

RESULTS

Independent and model-free evaluation of a wide range of possible sets of conversion factors to LED suggested a set of normalized conversion factors for immediate release levodopa (1.00), controlled release levodopa (0.88), and amantadine (1.23). A minimal clinical benefit of entacapone was observed for patients with motor fluctuations. Our analysis could not detect conversion factors for dopamine agonists and MAO-B inhibitors, possibly because their clinical contribution when added to levodopa is limited.

CONCLUSIONS

Independent from previous studies and prior assumptions we show that the currently-used LED conversion factors for immediate release levodopa, controlled release levodopa and amantadine are largely correct and that dopamine agonists, MAO-B inhibitors and entacapone, given in addition to levodopa, have little additional clinical value for PD patients with motor fluctuations.

[DEEP BRAIN STIMULATION FOR OBSESSIVE COMPULSIVE DISORDER: CASE REPORT OF THE FIRST OCD PATIENT IN ISRAEL]

Treatment-resistant obsessive-compulsive disorder (OCD) is considered a severe psychiatric disorder that causes severe functional decline. In the past, these patients were treated by selective ablation of neuronal pathways related to the pathophysiology of OCD. Deep brain stimulation is an effective and safe treatment alternative that enables reversible changes in neural circuits and reduces OCD symptoms. In this paper we present the outcome of a treatment-resistant OCD patient who underwent deep brain stimulation procedure for the first time in Israel. The patient has achieved a significant decline in OCD symptoms as well as improvement in personal and social functioning. The discussion focuses on methods to implement deep brain stimulation for OCD patients in Israel.

Subthalamic theta activity: a novel human subcortical biomarker for obsessive compulsive disorder

Obsessive-compulsive disorder (OCD) is a common and serious psychiatric disorder. Although subthalamic nucleus deep brain stimulation (DBS) has been studied as a treatment for OCD patients the underlying mechanism of this treatment and the optimal method of stimulation are unknown. To study the neural basis of subthalamic nucleus DBS in OCD patients we used a novel, implantable DBS system with long-term local field potential sensing capability. We focus our analysis on two patients with OCD who experienced severe treatment-resistant symptoms and were implanted with subthalamic nucleus DBS systems. We studied them for a year at rest and during provocation of OCD symptoms (46 recording sessions) and compared them to four Parkinson's disease (PD) patients implanted with subthalamic nucleus DBS systems (69 recording sessions). We show that the dorsal (motor) area of the subthalamic nucleus in OCD patients displays a beta (25-35 Hz) oscillatory activity similar to PD patients whereas the ventral (limbic-cognitive) area of the subthalamic nucleus displays distinct theta (6.5-8 Hz) oscillatory activity only in OCD patients. The subthalamic nucleus theta oscillatory activity decreases with provocation of OCD symptoms and is inversely correlated with symptoms severity over time. We conclude that beta oscillations at the dorsal subthalamic nucleus in OCD patients challenge their pathophysiologic association with movement disorders. Furthermore, theta oscillations at the ventral subthalamic nucleus in OCD patients suggest a new physiological target for OCD therapy as well as a promising input signal for future emotional-cognitive closed-loop DBS.

One year double blind study of high vs low frequency subcallosal cingulate stimulation for depression

Subcallosal Brodmann's Area 25 (Cg25) Deep Brain Stimulation (DBS) is a new promising therapy for treatment resistant major depressive disorder (TR-MDD). While different DBS stimulating parameters may have an impact on the efficacy and safety of the therapy, there is no data to support a protocol for optimal stimulation parameters for depression. Here we present a prospective multi-center double-blind randomized crossed-over 13-month study that evaluated the effects of High (130 Hz) vs Low (20 Hz) frequency Cg25 stimulation for nine patients with TR-MDD. Four out of nine patients achieved response criteria (≥40% reduction of symptom score) compared to mean baseline values at the end of the study. The mean percent change of MADRS score showed a similar improvement in the high and low frequency stimulation groups after 6 months of stimulation (-15.4 ± 21.1 and -14.7 ± 21.1 respectively). The mean effect at the end of the second period (6 months after cross-over) was higher than the first period (first 6 months of stimulation) in all patients (-23.4 ± 19.9 (n = 6 periods) and -13.0 ± 22 (n = 9 periods) respectively). At the end of the second period, the mean percent change of the MADRS scores improved more in the high than low frequency groups (-31.3 ± 19.3 (n = 4 patients) and -7.7 ± 10.9 (n = 2 patients) respectively). Given the small numbers, detailed statistical analysis is challenging. Nonetheless the results of this study suggest that long term high frequency stimulation might confer the best results. Larger scale, randomized double blind trials are needed in order to evaluate the most effective stimulation parameters.

Ketamine induced converged synchronous gamma oscillations in the cortico-basal ganglia network of nonhuman primates

N-methyl-d-aspartate (NMDA) antagonists are widely used in anesthesia, pain management, and schizophrenia animal model studies, and recently as potential antidepressants. However, the mechanisms underlying their anesthetic, psychotic, cognitive, and emotional effects are still elusive. The basal ganglia (BG) integrate input from different cortical domains through their dopamine-modulated connections to achieve optimal behavior control. NMDA antagonists have been shown to induce gamma oscillations in human EEG recordings and in rodent cortical and BG networks. However, network relations and implications to the primate brain are still unclear. We recorded local field potentials (LFPs) simultaneously from the primary motor cortex (M1) and the external globus pallidus (GPe) of four vervet monkeys (26 sessions, 97 and 76 cortical and pallidal LFPs, respectively) before and after administration of ketamine (NMDA antagonist, 10 mg/kg im). Ketamine induced robust, spontaneous gamma (30-50 Hz) oscillations in M1 and GPe. These oscillations were initially modulated by ultraslow oscillations (~0.3 Hz) and were highly synchronized within and between M1 and the GPe (mean coherence magnitude = 0.76, 0.88, and 0.41 for M1-M1, GPe-GPe, and M1-GPe pairs). Phase differences were distributed evenly around zero with broad and very narrow distribution for the M1-M1 and GPe-GPe pairs (-3.5 ± 31.8° and -0.4 ± 6.0°), respectively. The distribution of M1-GPe phase shift was skewed to the left with a mean of -18.4 ± 20.9°. The increased gamma coherence between M1 and GPe, two central stages in the cortico-BG loops, suggests a global abnormal network phenomenon with a unique spectral signature, which is enabled by the BG funneling architecture.NEW & NOTEWORTHY This study is the first to show spontaneous gamma oscillations under NMDA antagonist in nonhuman primates. These oscillations appear in synchrony in the cortex and the basal ganglia. Phase analysis refutes the confounding effects of volume conduction and supports the funneling and amplifying architecture of the cortico-basal ganglia loops. These results suggest an abnormal network phenomenon with a unique spectral signature that could account for pathological mental and neurological states.

Local vs. volume conductance activity of field potentials in the human subthalamic nucleus

Subthalamic nucleus field potentials have attracted growing research and clinical interest over the last few decades. However, it is unclear whether subthalamic field potentials represent locally generated neuronal subthreshold activity or volume conductance of the organized neuronal activity generated in the cortex. This study aimed at understanding of the physiological origin of subthalamic field potentials and determining the most accurate method for recording them. We compared different methods of recordings in the human subthalamic nucleus: spikes (300-9,000 Hz) and field potentials (3-100 Hz) recorded by monopolar micro- and macroelectrodes, as well as by differential-bipolar macroelectrodes. The recordings were done outside and inside the subthalamic nucleus during electrophysiological navigation for deep brain stimulation procedures (150 electrode trajectories) in 41 Parkinson's disease patients. We modeled the signal and estimated the contribution of nearby/independent vs. remote/common activity in each recording configuration and area. Monopolar micro- and macroelectrode recordings detect field potentials that are considerably affected by common (probably cortical) activity. However, bipolar macroelectrode recordings inside the subthalamic nucleus can detect locally generated potentials. These results are confirmed by high correspondence between the model predictions and actual correlation of neuronal activity recorded by electrode pairs. Differential bipolar macroelectrode subthalamic field potentials can overcome volume conductance effects and reflect locally generated neuronal activity. Bipolar macroelectrode local field potential recordings might be used as a biological marker of normal and pathological brain functions for future electrophysiological studies and navigation systems as well as for closed-loop deep brain stimulation paradigms.NEW & NOTEWORTHY Our results integrate a new method for human subthalamic recordings with a development of an advanced mathematical model. We found that while monopolar microelectrode and macroelectrode recordings detect field potentials that are considerably affected by common (probably cortical) activity, bipolar macroelectrode recordings inside the subthalamic nucleus (STN) detect locally generated potentials that are significantly different than those recorded outside the STN. Differential bipolar subthalamic field potentials can be used in navigation and closed-loop deep brain stimulation paradigms.

Stop! border ahead: Automatic detection of subthalamic exit during deep brain stimulation surgery

BACKGROUND

Microelectrode recordings along preplanned trajectories are often used for accurate definition of the subthalamic nucleus (STN) borders during deep brain stimulation (DBS) surgery for Parkinson's disease. Usually, the demarcation of the STN borders is performed manually by a neurophysiologist. The exact detection of the borders is difficult, especially detecting the transition between the STN and the substantia nigra pars reticulata. Consequently, demarcation may be inaccurate, leading to suboptimal location of the DBS lead and inadequate clinical outcomes.

METHODS

We present machine-learning classification procedures that use microelectrode recording power spectra and allow for real-time, high-accuracy discrimination between the STN and substantia nigra pars reticulata.

RESULTS

A support vector machine procedure was tested on microelectrode recordings from 58 trajectories that included both STN and substantia nigra pars reticulata that achieved a 97.6% consistency with human expert classification (evaluated by 10-fold cross-validation). We used the same data set as a training set to find the optimal parameters for a hidden Markov model using both microelectrode recording features and trajectory history to enable real-time classification of the ventral STN border (STN exit). Seventy-three additional trajectories were used to test the reliability of the learned statistical model in identifying the exit from the STN. The hidden Markov model procedure identified the STN exit with an error of 0.04 ± 0.18 mm and detection reliability (error < 1 mm) of 94%.

CONCLUSIONS

The results indicate that robust, accurate, and automatic real-time electrophysiological detection of the ventral STN border is feasible. © 2016 International Parkinson and Movement Disorder Society.

Robotic blue-dye sentinel lymph node detection for endometrial cancer - Factors predicting successful mapping

OBJECTIVE

Sentinel lymph node (SLN) mapping has emerged as a viable option for the treatment of patients with endometrial cancer. We report our initial experience with SLN mapping algorithm, and examine the factors predicting successful SLN mapping.

METHODS

We analyzed all data recorded in our institute on robotic blue-dye SLN detection mapping from the time it was first introduced to our department in January 2012-December 2014. Data included patient demographics, SLN allocation, operating room times, and pathology results.

RESULTS

During the study period, 74 patients had robotic assisted surgery for endometrial cancer with attempted SLN mapping. SLN was found overall in 46 patients (62.1%). At first, SLN was detected in only 50% of cases, but after performing 30 cases, detection rates rose to 84.6% (OR = 3.34, CI 1.28-8.71; p = 0.003). Univariate analysis showed a higher detection rate with methylene blue than patent blue dye, 74.3% vs. 52.3% (OR = 2.744, 95% CI 1.026-7.344; p = 0.042). In multivariate analysis, high body mass index (BMI) was associated with failed mapping (OR = 0.899; 95% CI 0.808-1.00), as was the presence of lymph-vascular space invasion (LVSI) (OR = 0.126; 95% CI 0.24-0.658) and few cases per surgeon (OR = 1.083, 95% CI 1.032-1.118). Factors related to uterine pathology itself, including tumor histology, grade, method of diagnosis, the presence of an endometrial polyp, and lower uterine segment involvement were not found to be associated with successful mapping.

CONCLUSIONS

Surgeon experience, BMI and LVSI may affect the success rate of SLN mapping for endometrial cancer. These factors should be investigated further in future studies.

Early intervention for preventing posttraumatic stress disorder: an Internet-based virtual reality treatment

BACKGROUND

Posttraumatic stress disorder (PTSD) develops in approximately 20% of people exposed to a traumatic event, and studies have shown that cognitive-behavioral therapy (CBT) is effective as a treatment for chronic PTSD. It has also been shown to prevent PTSD when delivered early after a traumatic event. However, studies have shown that uptake of early treatment is generally low, and therefore, the need to provide interventions through other mediums has been identified. The use of technology may overcome barriers to treatment.

OBJECTIVE

This paper describes a randomized controlled trial that will examine an early CBT intervention for PTSD. The treatment incorporates virtual reality (VR) as a method for delivering exposure-based elements of the treatment. The intervention is Internet based, such that the therapist and patient will "meet" in a secure online site. This site will also include multi-media components of the treatment (such as videos, audios, VR) that can be accessed by the patient between sessions.

METHOD

Two hundred patients arriving to a Level 1 emergency department following a motor vehicle accident will be randomly assigned to either treatment or control groups. Inclusion criteria are age 18-65, PTSD symptoms 2 weeks posttrauma related to current trauma, no suicidality, no psychosis. Patients will be assessed by telephone by a team blind to the study group, on four occasions: before and after treatment, and 6 and 12 months posttreatment. The primary outcome is PTSD symptoms at follow up. Secondary outcomes include depression and cost effectiveness. Analyses will be on an intention-to-treat basis.

DISCUSSION

The results will provide more insight into the effects of preventive interventions, in general, and Internet-based early interventions, in particular, on PTSD, in an injured population, during the acute phase after trauma. We will discuss possible strengths and limitations.

Subthalamic nucleus long-range synchronization-an independent hallmark of human Parkinson's disease

Beta-band synchronous oscillations in the dorsolateral region of the subthalamic nucleus (STN) of human patients with Parkinson's disease (PD) have been frequently reported. However, the correlation between STN oscillations and synchronization has not been thoroughly explored. The simultaneous recordings of 2390 multi-unit pairs recorded by two parallel microelectrodes (separated by fixed distance of 2 mm, n = 72 trajectories with two electrode tracks >4 mm STN span) in 57 PD patients undergoing STN deep brain stimulation surgery were analyzed. Automatic procedures were utilized to divide the STN into dorsolateral oscillatory and ventromedial non-oscillatory regions, and to quantify the intensity of STN oscillations and synchronicity. Finally, the synchronicity of simultaneously vs. non-simultaneously recorded pairs were compared using a shuffling procedure. Synchronization was observed predominately in the beta range and only between multi-unit pairs in the dorsolateral oscillatory region (n = 615). In paired recordings between sites in the dorsolateral and ventromedial (n = 548) and ventromedial-ventromedial region pairs (n = 1227), no synchronization was observed. Oscillation and synchronicity intensity decline along the STN dorsolateral-ventromedial axis suggesting a fuzzy border between the STN regions. Synchronization strength was significantly correlated to the oscillation power, but synchronization was no longer observed following shuffling. We conclude that STN long-range beta oscillatory synchronization is due to increased neuronal coupling in the Parkinsonian brain and does not merely reflect the outcome of oscillations at similar frequency. The neural synchronization in the dorsolateral (probably the motor domain) STN probably augments the pathological changes in firing rate and patterns of subthalamic neurons in PD patients.

Asymmetric right/left encoding of emotions in the human subthalamic nucleus

Emotional processing is lateralized to the non-dominant brain hemisphere. However, there is no clear spatial model for lateralization of emotional domains in the basal ganglia. The subthalamic nucleus (STN), an input structure in the basal ganglia network, plays a major role in the pathophysiology of Parkinson's disease (PD). This role is probably not limited only to the motor deficits of PD, but may also span the emotional and cognitive deficits commonly observed in PD patients. Beta oscillations (12–30 Hz), the electrophysiological signature of PD, are restricted to the dorsolateral part of the STN that corresponds to the anatomically defined sensorimotor STN. The more medial, more anterior and more ventral parts of the STN are thought to correspond to the anatomically defined limbic and associative territories of the STN. Surprisingly, little is known about the electrophysiological properties of the non-motor domains of the STN, nor about electrophysiological differences between right and left STNs. In this study, microelectrodes were utilized to record the STN spontaneous spiking activity and responses to vocal non-verbal emotional stimuli during deep brain stimulation (DBS) surgeries in human PD patients. The oscillation properties of the STN neurons were used to map the dorsal oscillatory and the ventral non-oscillatory regions of the STN. Emotive auditory stimulation evoked activity in the ventral non-oscillatory region of the right STN. These responses were not observed in the left ventral STN or in the dorsal regions of either the right or left STN. Therefore, our results suggest that the ventral non-oscillatory regions are asymmetrically associated with non-motor functions, with the right ventral STN associated with emotional processing. These results suggest that DBS of the right ventral STN may be associated with beneficial or adverse emotional effects observed in PD patients and may relieve mental symptoms in other neurological and psychiatric diseases.

Disrupted abdominal laparotomy wounds in gynaecologic oncology patients: benefits of active surgical re-closure

OBJECTIVE

To assess the outcome of active management of disrupted wounds through surgical approximation and re-closure.

METHOD

A prospective, non-comparative study, on all consecutive patients with disrupted laparotomy wounds treated at a tertiary medical centre, from November 2009 to December 2011. Data on patient demographics, diagnosis, type of abdominal incision, initial closure technique, infections and results of secondary re-closure were collected from the medical files. All patients underwent bedside closure with an en bloc mass suture mattress technique, performed by two attending gynaecologic oncologists.

RESULTS

Of 197 patients who underwent abdominal laparotomy during the study period, 31 (16%) had a disrupted wound. Following surgical re-closure, 26 wounds (84%) were completely healed or needed only minor additional care by follow up on day 10. Five wounds (16%) failed primary management and required re-suturing; all subsequently healed. There were no long-term complications.

CONCLUSION

Active surgical re-closure of disrupted abdominal laparotomy wounds is safe and effective in patients after treatment surgically for Müllerian malignancies.