Journal of Clinical Neurophysiology最新文献

Introduction: Postoperative delirium is common and associated with poor postoperative outcomes. However, the predictive power of intraoperative electroencephalogram (EEG) features for postoperative delirium has not yet been well studied.

Methods: Intraoperative EEG data from 261 patients who underwent major cardiac surgery were analyzed. Cases were identified using the Confusion Assessment Method. Predictive analytics for delirium outcome were performed using (1) only clinical data, (2) only EEG data, and (3) a combined list of important features from the first two stages.

Results: Eleven percentage of participants experienced postoperative delirium. The patients were generally older and had lower physical and cognitive function. EEG models were found to be highly specific but less sensitive in identifying delirium cases. The combined EEG-clinical model performed comparably to the clinical-only model (AUC = 80%) but outperformed the EEG-only model (AUC = 56%). After adjusting for clinical covariates, only interhemispheric mutual information remained significantly associated with delirium (OR = 2.29, p = 0.03), with a positive correlation with delirium severity (ρ = 0.18, P ≤ 0.01).

Conclusions: This study enhances our understanding of delirium neurophysiology by emphasizing the role of intraoperative EEG as a marker of brain vulnerability. Although EEG may not constitute a standalone biomarker of delirium, it holds promise for delirium risk stratification.

Purpose: Maximal safe resection is recommended for intramedullary spinal cord tumors (IMSCT). Tools to minimize surgical morbidity are, therefore, critical. We review intraoperative neurophysiologic monitoring (IONM) in a large series of pediatric IMSCTs, focusing on its relationship with functional outcomes and surgical decision making.

Methods: A single-institution, retrospective review of all IMSCT resections with IONM from 2000 to 2022 was conducted. Univariate analysis evaluated IONM changes with clinical and functional outcomes across an extended follow-up period.

Results: Among the 59 IMSCT cases with IONM that met inclusion, somatosensory evoked potentials were used in 89.8%, motor evoked potentials in 86.4%, and Direct wave monitoring in 18.6%. Almost a third of patients experienced intraoperative changes in motor evoked potentials, somatosensory evoked potentials, and Direct waves, respectively, depending on the modality of IONM used. Monitoring alerts were more common in older patients (≥15 years) and those with larger tumors, and often led to longer hospital/intensive care unit stays and a higher rate of discharge to inpatient rehabilitation. Motor evoked potential and Direct wave alerts significantly affected the surgeon's decision to stop further resection ( p = 0.001 and p = 0.067). Marked somatosensory evoked potential changes were associated with worse immediate postoperative sensory deficits (<6-weeks, p < 0.05). At 1-year follow-up, most patients experienced improved functional outcomes, with favorable motor and sensory recovery.

Conclusions: Multiple IONM modalities are technically feasible in pediatric IMSCTs and help guide surgical decision making. Intraoperative neurophysiologic monitoring alerts were more common in patients with larger tumors and older ages, significantly affecting the surgeon's decision to stop further resection. Although associated with longer hospital/intensive care unit stays and increased discharge rates to rehabilitation, IONM changes did not significantly affect long-term functional outcomes.

Summary: Dravet syndrome is an intractable developmental and epileptic encephalopathy caused primarily by SCN1A haploinsufficiency, leading to impaired NaV1.1 sodium channel function and reduced inhibitory signaling. Despite treatment with antiseizure medications, many patients remain drug resistant, necessitating alternative approaches such as neuromodulation. Responsive neurostimulation (RNS), which detects and responds to abnormal brain activity in real time, has shown promise in generalized epilepsy by targeting the thalamus. Thalamic stimulation can disrupt abnormal oscillatory activity, potentially reducing seizure frequency and severity. This report presents a 7-year-old girl with Dravet syndrome in the setting of a pathogenic SCN1A variant and drug-resistant epilepsy, who experienced numerous generalized seizures daily. After extensive testing and multiple antiseizure medication trials, RNS was implanted with bilateral centromedian nucleus of the thalamus depth electrodes. At her most recent clinic visit, she exhibited a 50% to 75% reduction in seizure frequency, with resolution of myoclonic and myoclonic-atonic seizures. Her family reported significant reductions in rescue medication use, seizure duration, and seizure severity after RNS implantation. This case adds to the growing evidence supporting the use and safety of RNS in pediatric patients with drug-resistant generalized epilepsy and is the first reported instance of RNS treatment in a patient with Dravet syndrome. Although the initial results are promising, further research is needed to explore the long-term efficacy, safety, and neurodevelopmental impacts of RNS in this population. This case highlights the importance of continued research and clinical innovation in neuromodulation therapies for Dravet syndrome.

Purpose: This study aimed to establish reference values for laryngeal adductor reflex latency and amplitude under general anesthesia using a noninvasive technique with commercially available electromyographic endotracheal tubes.

Methods: This retrospective observational study included 380 patients undergoing head and neck surgery. The inclusion criteria were recording the laryngeal adductor reflex from the nonsurgical side and the absence of pathology in the recurrent laryngeal nerve. Measurements were taken before incision and surgical completion.

Results: The R1 component medians for the latency and amplitude were 20 ms and 448 µV for the right and 22 ms and 425 µV for the left LARs, respectively. There were significant differences in the R1 latencies between the sides. Quantile regression models revealed that 95th percentile amplitudes exceeded 400 µV, whereas 5% of our data set surpassed 600 µV. The R2 component was present in 26% of patients initially but decreased to 8% at surgical conclusion. The percentage difference between the median R1 value at the end of the surgery, compared with the opening value, was up to 4% for latency and 10% for amplitude.

Conclusions: The R1 component of the laryngeal adductor reflex remains a reliable tool for intraoperative neuromonitoring. This is the largest study to provide reference values for laryngeal adductor reflex, aiding future diagnostic applications in head and neck surgeries.

Purpose: Repetitive head impact exposure, from contact and collision sports, are increasingly being attributed to increased risk of neurodegenerative disease in aging athletes. This exploratory study investigated the association of playing career in retired professional contact sport athletes with cortical neurophysiology via transcranial magnetic stimulation (TMS).

Methods: This study used a cross-correlation design without a control group. Male athletes between the ages of 28 and 68 years ( n = 113; mean age [SD] 48.8 [9.7]) who had been retired from professional sport for a minimum of 5 years were recruited. Cortical excitability was measured using single pulse TMS for motor evoked potentials and paired pulse for short-interval intracortical inhibition and long-interval intracortical inhibition. Associations were assessed between TMS measures and concussion history, clinical symptom scores, total career length (including junior to complete retirement), and professional career length (elite competition only).

Results: Correlations showed significant associations between motor evoked potentials and clinical symptom reporting ( rho : -0.21 to -0.38; P < 0.01) and motor evoked potentials and short-interval intracortical inhibition with total career length ( rho : 0.26 to -0.33; P < 0.01). No significant correlations were observed between single and paired-pulse TMS and professional career length ( rho : 0.16 to -0.15), nor the number of concussions ( rho : 0.17 to -0.17).

Conclusions: This exploratory study is the first to report pathophysiologic outcomes in a cohort of retired professional athletes associated with total career exposure, rather than professional career exposure or concussion history. Without a control group comparison and cross-correlational design, these preliminary results should be viewed with caution; however, TMS assessment could be considered a viable biomarker in future studies of retired athletes classified with traumatic encephalopathy syndrome.

Purpose: The surgical resection of cerebral arteriovenous malformations (AVMs) presents a significant neurosurgical challenge, particularly because of the need to achieve complete obliteration of the nidus while preserving neurologic function. AVMs located within or adjacent to eloquent regions such as the motor or language cortex carry a high risk of postoperative deficits. To mitigate these risks, a variety of intraoperative tools have been developed to enhance surgical safety and decision making.

Methods: Cortical and subcortical mapping is a dynamic technique that helps identify and preserve critical functional areas by applying targeted electrical stimulation to the cortex or subcortical white matter and observing motor or sensory responses. Additional neuromonitoring modalities include electrocorticography (ECoG), somatosensory evoked potentials, and motor evoked potentials, each contributing distinct insights into neural pathway integrity during resection.

Results: A systematic review was performed using 2 databases (PubMed/MEDLINE and Scopus), yielding 892 initial results. After applying inclusion and exclusion criteria, six studies were selected for final analysis. These studies collectively included 63 patients who underwent AVM resection with the aid of intraoperative neurophysiologic monitoring or mapping.

Conclusions: Intraoperative neurophysiologic monitoring plays a critical role in the safe resection of high-grade or eloquently located AVMs. Although its routine use in low-grade lesions remains debatable, intraoperative neurophysiologic monitoring offers significant intraoperative value by helping surgeons recognize functional limits in real time. In select cases, it enables a strategic shift toward subtotal resection with planned adjuvant radiosurgery, reducing the risk of permanent neurologic deficits.

Purpose: To understand the current state of epilepsy surgery education delivered to epilepsy fellows in the United States.

Methods: An online survey focused on characteristics of epilepsy surgery education was distributed to all 93 epilepsy fellowship program directors listed on the ACGME website (accessed in May 2022). Programs were stratified per the number of fellows currently enrolled: 0 to 3 (group A) and ≥4 (group B).

Results: Forty-one of 93 (44%) epilepsy fellowship programs were included in the study. The average number of resective surgeries, ablations, or corpus callosotomies per year was mostly 0 to 30 (54%) in group A and mostly >30 (80%) in group B ( P = 0.05). The average number of intracranial implantations per year was mostly 0 to 20 (58%) in group A and mostly >20 (80%) in group B ( P < 0.05). The average number of neurostimulation implantations per year was 15 (range 0-90; vagal nerve stimulation), 7 (range 0-25; responsive neurostimulation), and 4 (range 0-10; deep brain stimulation). In 78% of programs, fellows are not required to present a minimum number of epilepsy surgery cases in multidisciplinary conference before graduation. Roughly half of programs (51%) reported not using objective measures to assess fellow competency in epilepsy surgery.

Conclusions: Our results suggest significant variability in epilepsy surgery volume and, consequently, fellow exposure to surgical cases and lack of standardized, objective measures in fellow teaching and assessment in the field of epilepsy surgery across programs in the United States. We advocate development of a core epilepsy surgery curriculum including minimum standards at the national level.

Purpose: Electroencephalography (EEG) remains underutilized for stroke characterization. We sought to assess the performance of the EEG Correlate Of Injury to the Nervous system (COIN) index, a quantitative metric designed for stroke recognition in children, in discriminating large from small ischemic strokes in adults.

Methods: Retrospective, single-center cohort of adults with acute (within 7 days) ischemic stroke who underwent at least 8 hours of continuous EEG monitoring in hospital. Stroke size was categorized as large or small based on a threshold of 100 mL using the ABC/2 approach. EEG data were processed on MATLAB. COIN was independently calculated from consecutive 4-second EEG epochs. Student t-test and logistic regression were used to assess COIN performance in stroke size discrimination across the entire recording; random forest classification was used to determine COIN performance in limited EEG time windows ranging from 5 to 30 minutes in duration.

Results: Thirty-five patients with mean age 67 (SD ± 17) years were analyzed with mean 4.5 ± 1.3 hours of clean EEG per patient. Ten patients had large stroke and 25 had small stroke. Participants with large strokes had larger COIN values than those with small strokes (-53 vs. -16, P = 0.0001). Logistic regression for stroke size classification model showed accuracy 83% ± 8%, sensitivity 70%±15%, specificity 88%±8%, and area under the receiver operator curve 0.75±0.10. Random Forest Classification performance was similar using 5 or 30 minutes of EEG data with accuracy 81% to 82%, specificity 91% to 92%, and sensitivity 55% to 58%, respectively.

Conclusions: COIN differentiated large from small acute ischemic strokes in this single-center cohort. Prospective evaluation in larger multicenter data sets is necessary to determine COIN utility as an aid for bedside detection of large ischemic strokes in contexts where neuroimaging cannot be easily obtained or when neurologic examination is limited by sedation or neuromuscular blockade.