Journal of Clinical Neurophysiology最新文献

Purpose: The American Clinical Neurophysiology Society has provided a set of recommendations on the use of critical care EEG monitoring (CEEG). However, these recommendations have not been prospectively validated. We aimed to assess the adherence to the American Clinical Neurophysiology Society recommendations for obtaining CEEG for different indications and the yield of obtained CEEG according to these different indications.

Methods: This was a multicenter prospective observational study of critically ill adult patients between April 01, 2022, and June 22, 2022, in two academic medical centers and a large teaching hospital. Indications for CEEG, according to the American Clinical Neurophysiology Society recommendations, were determined based on clinical data at the time of discharge from the intensive care unit. The use of CEEG and detection of electrographic seizures were retrieved from the EEG databases.

Results: A total of 600 patients were enrolled in this study. The primary admission diagnoses were medical (49%), surgical (30%), or neurologic/neurosurgical (21%). Approximately 60% of patients had an altered mental status. A few (6%) patients had a preceding clinical seizure, and 1% had generalized convulsive status epilepticus. Indications were identified in 226 admissions. Of these patients, 88 (39%) underwent CEEG. In addition, 12 patients underwent CEEG without clear indications. Of the 100 patients, 33 (33%) had electrographic seizures. Adherence to recommendations and yields was highest for refractory status epilepticus, altered mental status after any clinical seizure, and acute brain injury. Adherence and yield varied the most and were inversely correlated in the group of patients without acute brain injury, suggesting that additional clinical factors may have contributed to patient selection.

Conclusions: Patients meeting American Clinical Neurophysiology Society indications and receiving CEEG had a high seizure risk. Emerging CEEG programs should focus on epilepsy-related and neurologic diagnosis. Although recommendations effectively identify groups of patients with a high seizure risk, additional clinical factors might further help select candidates in the low-risk group.

Purpose: Recent research on quantitative EEG in coma has proposed several metrics correlating with consciousness level. However, the heterogeneous nature of coma can challenge the generalizability of these measures. This study investigates alpha-coma, an electroclinical pattern characterized by a widespread, nonreactive alpha rhythm often linked to poor outcomes. The aim was to quantify the electrophysiological features of alpha-coma and compare them to the alpha rhythm in awake controls, seeking clearer insights into quantitative EEG analysis in comatose states.

Methods: Fourteen alpha-coma patients were retrospectively selected from University Hospitals of Geneva and age-matched with 14 healthy control subjects from an open-source dataset. EEG data were preprocessed and analyzed to extract power spectra, spectral decay (aperiodic activity), sample entropy, and functional connectivity.

Results: Alpha-coma patients did not differ in alpha power but exhibited significantly higher levels of spectral decay ( p < 0.001), suggesting a convergence toward an inhibitory state. Sample entropy was significantly higher in alpha-coma patients ( p = 0.01), indicating an increase in the cortical complexity in alpha-coma compared with healthy subjects.

Conclusions: Alpha-coma shows increased aperiodic activity and EEG complexity, despite similar alpha power and clustering coefficient. The increased aperiodic activity aligns with findings in other comatose patients, including those sedated or with subcortical dysfunction. However, the increased entropy contradicts existing literature, suggesting that alpha-coma may represent a state of widespread cortical dysfunction likely resulting from nonhierarchical, turbulent brain activity. This indicates that the loss of consciousness does not guarantee consistent cortical measures across the whole spectrum of EEG patterns.

Purpose: To investigate daytime autonomic dysregulation in patients with obstructive sleep apnea (OSA).

Methods: This retrospective study was conducted at Brigham and Women's Faulkner Hospital Autonomic Laboratory and evaluated adult patients with a history of orthostatic intolerance and sleep disturbances who completed autonomic testing (deep breathing test, Valsalva maneuver, tilt test) and polysomnography between 2018 and 2024. The Quantitative Scale for Grading of Cardiovascular Autonomic Reflex Tests scoring instrument graded autonomic tests and skin biopsies for the assessment of small fibers. The apnea-hypopnea index was used to assess OSA severity.

Results: In total, 138 patients were evaluated in this study. Subjects with OSA (43 with mild and 29 with moderate/severe OSA) were compared with 66 subjects without OSA. Age, body mass index, and the prevalence of hypertension increased with the severity of sleep apnea. At least moderate autonomic failure was identified in 60% of patients without OSA and in 78% of those with OSA. Autonomic failure score was proportional to the severity of OSA (autonomic failure scores: no OSA 4.2 ± 2.54, mild OSA 5.44 ± 3.41, moderate/severe OSA 8.1 ± 4.3, P < 0.001). Small fiber neuropathy was found in 41.8% of patients without OSA and in 70.8% of patients with moderate/severe OSA.

Conclusions: Autonomic failure associated with small fiber autonomic neuropathy is common in patients with OSA, and the degree of autonomic failure is proportional to the severity of sleep apnea. Autonomic failure can be an additional risk factor contributing to the cardiovascular complications observed in OSA.

Purpose: To investigate the prevalence and functional significance of 14 and 6 Hz positive spikes (PS) in children with Self-limited Epilepsy with Centrotemporal spikes and explore their potential correlation with clinical features and neurophysiological mechanisms.

Methods: Our study included 52 pediatric Self-limited Epilepsy with Centrotemporal spikes patients and 52 age-matched controls who underwent ≥48-hour video-EEG monitoring in the epilepsy monitoring unit at Oishei Children's Hospital from 2016 to 2024. EEGs were reviewed by blinded epileptologists to identify the presence, localization, and lateralization of 14 and 6 Hz PS.

Results: Fourteen and 6 Hz PS were detected in 80.8% (n = 42) of SeLECTs patients versus 0% of controls (P < 0.001). No significant lateralization correlation was found between PS and centrotemporal spikes (P = 0.651); only 28.6% of PS cases matched centrotemporal spikes lateralization.

Conclusions: This study demonstrates a significantly higher prevalence of 14 and 6 Hz PS in children with Self-limited Epilepsy with Centro-temporal spikes. Their high prevalence and similar age-dependent expression and sleep-related activation suggest that PS may reflect developmental immaturity in thalamocortical networks, immature corticolimbic circuits, and heightened cortical excitability. These findings challenge the traditional view of PS as benign and support their potential role in thalamocortical dysregulation in self-limited childhood epilepsies.

Purpose: The linked quadripolar montage for transcranial electric motor-evoked potentials (qTceMEP) consists of four stimulation electrodes: two linked anodes and two linked cathodes. This montage has grown in popularity because it can result in a larger compound muscle action potential amplitude compared with the conventional bipolar montage. Despite the increasing number of centers adopting qTceMEP, no studies have investigated patient safety to date. The aim of this study is to evaluate the safety profile of qTceMEP.

Methods: A total of 3,806 spine surgeries performed at a single institution using intraoperative transcranial electrical motor-evoked potentials (TceMEP) were reviewed. Among them, 1,196 were performed using bipolar TceMEP, while the remaining 2,610 cases were performed using qTceMEP. The incidence of intraoperative seizure, unexpected cardiac events, bite/oral injuries, and movement-related injuries was compared between the two groups, bipolar TceMEP and qTceMEP. The statistical analysis was performed using MedCalc.

Results: No seizure activity, cardiac anomalies, or adverse events related to intracranial and cardiac implant devices were reported in either group. The incidence of intraoperative oral injuries was 0.4% in the bipolar TceMEP group and 0.5% in the qTceMEP group. The difference in the incidence of oral injuries between the two groups was not statistically significant.

Conclusions: The use of qTceMEP does not increase or decrease a patient's risk of intraoperative injury. Both bipolar TceMEP and qTceMEP are safe, presenting a small incidence of oral injuries and no other adverse side effects.

Purpose: Magnetospinography provides a noninvasive and detailed visualization of neural currents. We previously reported that magnetospinography can be used to evaluate neural function in the lower lumbar spine in response to tibial, peroneal, and sciatic nerve stimulation. However, evaluating the neural function of the upper and middle lumbar spine is often difficult due to lower current intensity. We aimed to visualize the neural activity of the upper and middle lumbar spine using new stimulation methods and assess the foraminal current.

Methods: Neural magnetic fields in 10 healthy volunteers were recorded after stimulation of the lateral femoral cutaneous nerve, saphenous nerve, femoral nerve, and peroneal nerve. The conduction velocity and current intensity in the spinal canal and intervertebral foramen were calculated and compared for each type of nerve stimulation.

Results: Magnetospinography visualized the evoked magnetic fields in the lumbar region after each nerve stimulation method in all volunteers. The current intensity in the upper lumbar spine was significantly greater after femoral nerve stimulation. Magnetospinography revealed that action current flowed mainly along the L2 nerve root after lateral femoral cutaneous nerve stimulation and the L4 nerve root after saphenous nerve stimulation.

Conclusions: Using a new stimulation method, magnetospinography enabled the noninvasive visualization of neural currents in the upper and middle lumbar spine. Femoral nerve stimulation is suitable for evaluating the spinal canal of the upper lumbar spine, and lateral femoral cutaneous nerve and saphenous nerve stimulations are suitable for evaluating the upper and middle lumbar intervertebral foramina, respectively.

Purpose: This study aimed to develop and validate magnetoencephalography paradigms for presurgical language mapping in patients with drug-resistant epilepsy.

Methods: This prospective observational study of 30 patients with drug-resistant epilepsy included two trials involving visual picture naming and auditory word recognition tasks. Language activation was analyzed using dynamic statistical parametric mapping for beta desynchronization and a fixed time window (350-500 ms). Concordance across trials, analysis methods, and functional MRI comparisons were also assessed.

Results: Primary visual and auditory cortex activation occurred in 66.6 and 80% of the patients, respectively. Language-specific area activation was observed in 56.7% of the picture naming task patients and 70% of the auditory word recognition task patients. Lateralization was predominantly left sided in 41.1% (picture naming) and 61.9% (auditory word recognition) of cases, with some bihemispheric patterns. Beta desynchronization and fixed-time window analyses had comparable detection rates but with limited concordance. Magnetoencephalography-functional MRI lateralization agreement was 56.25% (Cohen kappa = 0.15). No significant correlations were found between the epilepsy parameters and language activation.

Conclusions: Magnetoencephalography provides valuable insights into language localization and functional reorganization in patients with epilepsy. Although task-specific activations highlight their utility, further studies with larger cohorts and gold-standard validations are needed to enhance their clinical applicability in presurgical planning.

Purpose: To report clinical and electrodiagnostic (EDX) findings in ulnar neuropathy at the wrist (UNW).

Methods: This is a monocentric study. We collected demographic and clinical data, history, symptom type, neurologic examination findings, EDX results, as well as causes and risk factors of UNW.

Results: We enrolled 150 consecutive cases. Based on EDX findings, the most common UNW pattern involved the ulnar nerve at the entrance of Guyon canal, prior to its bifurcation into sensory and motor branches (44% of cases). We identified atypical topographic lesions involving the superficial sensory branch and motor fibers innervating the hypothenar (4.7% of cases) or the interossei muscles (12.8% of cases). The most frequent causes were compressive (20.7%) and traumatic (22%), mainly affecting males, blue-collar workers, and individuals aged ≤60 years. Ganglion was prevalent in females (66.7%). Cases of UNW with unknown etiology were significantly associated with age >60 years, the presence of muscle atrophy, and a history of carpal tunnel syndrome (CTS).

Conclusions: Clinical and EDX characteristics of UNW depend on injury site at wrist or hand palm. It is not possible to determine the cause with certainty based solely on the type, although some causes tend to affect specific sites of nerve injury. The coexistence of Guyon canal syndrome and CTS is confirmed to be a fairly frequent finding. The awareness of the ulnar nerve anatomical variations should not lead to the exclusion of UNW if EDX abnormalities do not fall into any of the five classical types according to Wu's classification.