The Neurodiagnostic Journal最新文献

Entrapment neuropathy of the ulnar nerve at the elbow, the so-called cubital tunnel syndrome, is the second most frequent focal mononeuropathy after carpal tunnel syndrome in adults. Currently, there is a pressing need to identify cost-effective biomarkers and procedures capable of accurately detecting alterations in ulnar nerve structural and functional integrity. Established electrophysiological techniques, such as motor and sensory nerve conduction studies, along with needle electromyography of specific muscles, represent the gold standard for ulnar nerve electrodiagnosis. Concurrently, the introduction of neuromuscular ultrasound and its integration into electromyographic laboratories has significantly impacted structural diagnosis and the precise localization of ulnar nerve pathology over the past two decades. In this review, our objective is to summarize the current knowledge on both classical and advanced diagnostic methods utilized in clinical neurophysiology laboratories. We aim to provide a synthesis of modern electrodiagnostic and neurosonographic techniques, with a particular emphasis on easily attainable, clinically relevant parameters.

Recurrent laryngeal nerve (RLN) injury during neck surgery can cause significant morbidity related to vocal cord (VC) dysfunction. VC electromyography (EMG) is used to aid in the identification of the RLN and can reduce the probability of inadvertent surgical injury. Errors in the placement of specialized EMG endotracheal tubes (ETT) can result in unreliable signals, false-negative responses, or no response when stimulating the RLN. We describe a novel educational protocol developed to optimize uniformity in the placement of ETTs to improve the reliability of RLN monitoring. An intraoperative neuromonitoring database was queried for all neck surgeries requiring RLN monitoring. Data points extracted for all cases requiring EMG monitoring for neck procedures. Free running and stimulated EMG were monitored and continuously recorded by a certified technologist. Alerts were compared between 2013-14 and 2015-18 using a two-sample test of proportions. Significant reductions in alerts were demonstrated after protocol implementation (7.5% pre-implementation to 2.1% post). Alerts were compared between 2013-14 (overall alert rate of 1.8%, pre-implementation period) and 2015-18 (overall alert rate of 2.8%, post-implementation period). Protocolization for placement of EMG-ETT improved accuracy in EMG monitoring. In the follow-up cohort of 1,080 patients, use of this protocol continued to reduce the rate of alerts related to ETT malposition, confirming the sustainability of this intervention through routine education. The risk of nerve injury is reduced when the rate of alerts is minimized. Scheduled or continuous protocol education of anesthesia personnel should continue to ensure compliance with protocol.

Epileptiform abnormalities that arise over the midline can sometimes be confused with normal sleep transients, such as vertex sharp waves, because of their location and their activation during sleep. However, epileptiform transients can be distinguished from sleep architecture by their waveform and their occurrence during wakefulness. Here, we report a 24-year-old man with drug-resistant epilepsy whose seizures began with tonic posturing of the left leg before progressing to bilateral tonic-clonic activity. During presurgical scalp video-EEG monitoring, his interictal background showed focal spike-wave discharges maximal over the vertex (phase reversal at Cz), with a more-well-defined field over the right parasagittal region (C4/F4), that were present during both sleep and awake states. The discharges met the IFCN criteria for focal interictal epileptiform discharges (spiky morphology, duration shorter than background activity, asymmetric waveform, after-going slow wave, and physiologic distribution) and appeared to be distinct from the patient's vertex sharp waves. Prior to electroclinical seizures, these discharges would increase in prevalence and appear as repetitive spike-wave discharges. When distinguishing epileptiform from nonepileptiform transients, it is critical to consider both their morphology, especially the degree of background disruption and presence of an after-going slow wave, and their variability with state changes.

Brain-computer interface (BCI) is a term used to describe systems that translate biological information into commands that can control external devices such as computers, prosthetics, and other machinery. While BCI is used in military applications, home control systems, and a wide array of entertainment, much of its modern interest and funding can be attributed to its utility in the medical community, where it has rapidly propelled advancements in the restoration or replacement of critical functions robbed from victims of disease, stroke, and traumatic injury. BCI devices can allow patients to move prosthetic limbs, operate devices such as wheelchairs or computers, and communicate through writing and speech-generating devices. In this article, we aim to provide an introductory summary of the historical context and modern growing utility of BCI, with specific interest in igniting the conversation of where and how the neurodiagnostics community and its associated parties can embrace and contribute to the world of BCI.

A craniotomy with cortical and subcortical mapping was planned for a 64-year-old male with a large right frontotemporal brain mass. Total intravenous anesthesia was performed, and 200 milligrams of succinylcholine was administered at induction. A train of four prior to head pinning (52 minutes after succinylcholine administration) revealed zero of four twitches in the left hand and foot. The patient did not regain spontaneous breathing despite discontinuation of infusions and the surgeon canceled the case at 108 minutes from induction. The patient was safely extubated at 270 minutes. Pseudocholinesterase deficiency was suspected, and labs revealed that the patient was outside of the normal range for pseudocholinesterase enzyme at 698 units/L with a dibucaine inhibition number of 40. The patient's procedure was rescheduled 2 days later, and neuromuscular blockade was avoided. The procedure went ahead as planned with successful mapping and monitoring. This case highlights the effect of pseudocholinesterase deficiency on neuromonitoring and the importance of running train of four early on to detect neuromuscular junction issues in high-risk procedures. In this case, the surgeon was able to avoid pinning and positioning the patient and rescheduled the procedure so that motor mapping, direct cortical motor evoked potentials, and transcranial motor evoked potentials could be successfully performed.

Intraoperative neurophysiological monitoring (IONM) is shown to be useful in surgeries when the nervous system is at risk. Its success in part relies upon proper setup of often dozens of electrodes correctly placed and secured upon patients and inserted in specific stimulating and recording receptacles. Given the complicated setups and the demanding operating room environment, errors in setup are bound to occur. These have led to false negatives associated with new patient morbidities including, at times, paralysis. No studies quantify the prevalence of these types of setup errors. Approximately 800,000 operations annually utilize intraoperative neuromonitoring in the US alone, so even a small percentage of errors suggests clinical significance. In addition, these types of errors hinder the overall effectiveness of IONM and may result in lower reported sensitivities and lower cost-effectiveness of this important service. We sought to discover through a prospective study and verification through chart review the prevalence of "electrode-swap" errors (when recording and/or stimulating electrodes are incorrectly placed on the patient or in the IONM equipment during setup) across all procedures monitored. We found recording and/or stimulating electrode set up errors in 24 of 454 cases (5.3%). These data and examples of how errors were discovered intraoperatively are reported. We also offer techniques to help reduce this error rate. This study demonstrates a significant potential avoidable error in IONM diagnostic utility, patient outcome, and sensitivity/specificity of alert criteria. The value of identifying and correcting these errors is consequential, multifaceted, and far-reaching.