Mapping of Capsular Side Effects by using Intraoperative Motor-Evoked Potentials during Asleep Deep Brain Stimulation Surgery of the Subthalamic Nucleus for Parkinson's Disease.

INTRODUCTION: The aim of this study was to present a novel technique for subthalamic nucleus (STN) deep brain stimulation (DBS) implantation under general anesthesia by using intraoperative motor-evoked potentials (MEPs) through direct lead stimulation and determining their correlation to the thresholds of postoperative stimulation-induced side effects. METHODS: This study included 22 consecutive patients with advanced Parkinson's disease who underwent surgery in our institution between January 2021 and September 2023. All patients underwent bilateral implantation in the STN (44 leads) under general anesthesia without microelectrode recordings (MERs) by using MEPs with electrostimulation directly through the DBS lead. No cortical stimulation was performed during this process. Intraoperative fluoroscopic guidance and immediate postoperative computed tomography were used to verify the electrode's position. The lowest MEP thresholds were recorded and were correlated to the postoperative stimulation-induced side-effect threshold. The predictive values of the MEPs were analyzed. Five DBS leads were repositioned intraoperatively due to the MEP results. RESULTS: A moderately strong positive correlation was found between the MEP threshold and the capsular side-effect threshold (RS = 0.425, 95% CI, 0.17-0.67, p = 0.004). The highest sensitivity and specificity for predicting a side-effect threshold of 5 mA were found to be at 2.4 mA MEP threshold (sensitivity 97%, specificity 87.5%, positive predictive value 97%, and negative predictive value 87.5%). We also found high sensitivity and specificity (100%) at 1.15 mA MEP threshold and 3 mA side-effect threshold. Out of the total 44 leads, 5 (11.3%) leads were repositioned intraoperatively due to MEP thresholds lower than 1 mA (4 leads) or higher than 5 mA (1 lead). The mean accuracy on postoperative CT was 1.05 mm, and there were no postoperative side-effects under 2.8 mA. CONCLUSION: Intraoperative MEPs with electrostimulation directly through the contacts of the DBS lead correlate with the stimulation-induced capsular side effects. The lead reposition based on intraoperative MEP may enlarge the therapeutic window of DBS stimulation.

Outcome measurement in functional neurological disorder: a systematic review and recommendations.

OBJECTIVES: We aimed to identify existing outcome measures for functional neurological disorder (FND), to inform the development of recommendations and to guide future research on FND outcomes. METHODS: A systematic review was conducted to identify existing FND-specific outcome measures and the most common measurement domains and measures in previous treatment studies. Searches of Embase, MEDLINE and PsycINFO were conducted between January 1965 and June 2019. The findings were discussed during two international meetings of the FND-Core Outcome Measures group. RESULTS: Five FND-specific measures were identified-three clinician-rated and two patient-rated-but their measurement properties have not been rigorously evaluated. No single measure was identified for use across the range of FND symptoms in adults. Across randomised controlled trials (k=40) and observational treatment studies (k=40), outcome measures most often assessed core FND symptom change. Other domains measured commonly were additional physical and psychological symptoms, life impact (ie, quality of life, disability and general functioning) and health economics/cost-utility (eg, healthcare resource use and quality-adjusted life years). CONCLUSIONS: There are few well-validated FND-specific outcome measures. Thus, at present, we recommend that existing outcome measures, known to be reliable, valid and responsive in FND or closely related populations, are used to capture key outcome domains. Increased consistency in outcome measurement will facilitate comparison of treatment effects across FND symptom types and treatment modalities. Future work needs to more rigorously validate outcome measures used in this population.

A comparative retrospective exploration of the profiles of patients in South Africa diagnosed with epileptic and psychogenic non-epileptic seizures.

Psychogenic non-epileptic seizures (PNES) have a high prevalence globally but the accurate diagnosis of this condition still remains a challenge. This is particularly the case in countries where there is scarce expertise and insufficient affordable medical facilities to which patients have access. The rate of PNES diagnosis in epilepsy units is typically within the range of 20 to 30%. In the context of developing countries, this rate tends to be higher and increases demand on the existing scarce health care capacities. Although the profiling of patients with different seizure presentations is essential for informing appropriate treatment, to date there has been no comparative analysis of the profiles of patients with PNES and epilepsy in South Africa. The aim of the present study was to explore retrospectively the demographic and medication characteristics of these patients and to compare these characteristics to those reported in patient populations from other countries and regions. The total sample of 246 participants included 85 (35%) male and 161 (65%) female patients who were admitted to the Epilepsy Monitoring Unit (EMU) at Milpark Hospital, South Africa. Following the video-EEG monitoring assessment, 123 patients (50%) were diagnosed with PNES, and for 123 patients (50%) the diagnosis of epilepsy was confirmed. The results indicated that the demographic profiles of the groups of patients with epilepsy and PNES were similar with reference to age and self-ascribed ethnicity. In both groups, the majority of the patients were females, but proportionally their prevalence was higher in the PNES patient group than in the epilepsy patient group, which is compatible with the trends found in the PNES patient populations internationally. Pre-diagnostically, the type and the number of medications prescribed to patients with PNES and epilepsy were comparable. Subsequent to the diagnosis at the EMU, there was a significant reduction of overall medications in each group, but this reducton was more pronounced in the group with PNES. It is concluded that the rate of misdiagnosis of PNES in South Africa surpasses the rates reported for the patient populations in other countries and is one of the highest documented worldwide. Considering that post-diagnostically, there was reduction in central nervous system (CNS) medications as well as anti-epileptic drugs (AEDs) in both patients with epilepsy and those with PNES, it is likely that pre-diagnostically a significant proportion of all patients were over medicated. Compared to the epilepsy diagnosis, the PNES diagnosis resulted in a more substantial reduction of medication. These findings outline important dimensions of the diagnostic and medication treatment practices of epilepsy and PNES and point to the urgent need to improve these practices in South Africa and the African continent.

Is PDQ-39 a reliable measure of quality of life of patients at advanced stages of Parkinson's disease considered for Deep Brain Stimulation.

Purpose: Parkinson's disease (PD) significantly impedes, especially at its advanced stages, the health-related quality of life (QoL) of patients. The Parkinson's disease questionnaire (PDQ-39) is a widely-used measure assessing the impact of the disease on the patients' QoL. To date, the reliability of PDQ-39 has not been selectively evaluated for patients at a particular delineated stage of the PD progression. Against this backdrop, the study aimed firstly to evaluate comprehensively the internal consistency reliability of PDQ-39 and the constituent scales specifically for patients at the advanced stages of PD who were candidates for Deep Brain Stimulation (DBS) surgery, and secondly, to compare the Cronbach's alpha coefficients with those reported in other studies conducted with patients across all stages of the PD progression. Methods: The sample included 36 Bulgarian patients (29 men and 7 women) at advanced stages of PD (Hoehn and Yahr stage 4), PD duration, M = 11.06, SD = 3.50). The internal consistency reliability of the questionnaire and the constituent scales was assessed using three criteria: Cronbach's alpha coefficients, inter-item and item-total correlations. Results: The internal consistency reliability indicators were satisfactory for the entire instrument and for most of the scales and similar to those reported in previous studies. None of the scales had low internal consistency reliability results across the three criteria. Except for the Communication scale, seven of the eight scales had Cronbach's alpha values that were satisfactory or marginally below the cut off score. All scales had acceptable inter-item correlations. Three of the scales (Emotional Well-Being, Cognition and Communication) contained more than one item with non-satisfactory item-total correlations. With minor exceptions, the removal of the items with low item-total correlations either did not improve or improved marginally or even decreased the Cronbach's alpha coefficients of the respective scale. The Communication scale was the only scale with a Cronbach's alpha coefficient that was both low and comparatively different to other studies and had as well low item-total correlations for all constituent items, thus showing non-satisfactory results on two of the three internal consistency reliability estimates. In contrast, the Mobility scale met all three internal consistency reliability criteria. Conclusion: PDQ-39 is a reliable tool for assessing the QoL of patients at advanced stages of PD across multiple health-related domains. The questionnaire can be recommended for inclusion in the best practice guidelines for evaluating DBS candidacy and the efficacy of DBS treatment for patients' QoL.

Neuropsychological and psychological dysfunctions associated with coronavirus disease 2019: a case report.

BACKGROUND: Patient's account of personal experiences of having lived through coronavirus disease 2019 is important for understanding the magnitude of the debilitating impact of the infection. There is increasing recognition that the infection impedes multiple functional domains, but to date the evidence remains scarce. Moreover, to the author's knowledge, there are no documented cases reporting on research data derived from self-reflective first-person experience. CASE PRESENTATION: The patient was a 59-year-old female psychologist of White self-ascribed ethnicity who had coronavirus disease 2019. She had no history of medical, neurological, or psychiatric conditions and works in a neurosurgery clinic at a large hospital as a psychologist, specializing in neuropsychology. Using the introspective method, she captured the occurrence of neuropsychological and psychological dysfunctions she experienced in the acute stage of the illness, which took place in December 2020 and lasted for 17 days. Treatment of coronavirus disease 2019 was conducted in the home environment under medical supervision and followed a standardized protocol adopted at the time in the country. CONCLUSIONS: The data derived from the first-person experience indicated that among the most salient cognitive functions impacted by the disease were: executive control, working memory, attention, concentration, and processing speed. Furthermore, emotional instability; mood swings; racing, repetitive, or intrusive thoughts; uncontrolled associations; dizziness; fatigue; disbalance; and sleep disturbances featured consistently throughout the illness. The overall profile of these dysfunctions suggests disruption in the overall operation of the brain and particularly in the functioning of the frontal lobes. Although less tangible than the physical symptoms, the neuropsychological and psychological dysfunctions associated with coronavirus disease 2019 form a distinct cluster that has a highly debilitating impact on a person's well-being.