J of Neurophysiological Monitoring

Multimodality Intraoperative Neurophysiological Monitoring (IONM) with Selective Dorsal Root Rhizotomy For patients with Cerebral Palsy

2024-10-14T08:18:44+03:00

Selective Dorsal Root Rhizotomy (SDR) is a neurosurgical procedure aimed at alleviating spasticity in cerebral palsy patients by selectively severing sensory nerve rootlets in the spinal cord. This process helps reduce spastic muscle activity while preserving motor function. The use of multimodal intraoperative neurophysiological monitoring (IONM) techniques—such as Somatosensory Evoked Potentials (SSEP), Transcranial Motor Evoked Potentials (TCeMEP), and Electromyography (EMG)—has significantly enhanced surgical precision, leading to improved outcomes. Long-term studies report enhanced motor function and quality of life, with reduced reliance on further treatments, positioning SDR as a valuable option for managing spastic cerebral palsy. This literature review explores the evolution of SDR, its clinical effectiveness, patient selection criteria, and long-term outcomes for spasticity management in CP. The review consolidates findings from various studies to assess the impact of SDR on motor function, complications, and quality of life while comparing it with alternative spasticity management options. By synthesizing the current literature, this review aims to offer a comprehensive perspective on the role of SDR in enhancing functional outcomes for children and adults with CP.

Down Syndrome: Neurophysiological Concepts

2024-07-29T15:45:24+03:00

Introduction.

Down syndrome arises from a trisomy of chromosome 21. Neurophysiological aspects of Down syndrome have not been well studied. Subjects often have delayed motor milestones, an increased risk of epilepsy, and an early onset form of Alzheimer’s disease.
Methods.

This report describes differences between Down syndrome individuals and neurologically normal control subjects using standard neurophysiological tests, such as motor and somatosensory evoked potentials and coherence between pairs of neurophysiological signals.

Results.

Subjects with Down Syndrome required a smaller voltage to elicit an equivalent motor evoked potential compared to control subjects (174V vs. 650V) and had larger cortical, but not spinal, somatosensory evoked potentials (52mV vs. 4.2mV). Both EEG-EEG and EMG-EMG coherence was higher in Down Syndrome than in control subjects.

Conclusions.

Because the sensory input to the nervous system is controlled between subjects, as evidenced by the consistent spinal amplitude, we believe that the increased amplitude results from supraspinal (thalamic or cortical) differences rather than spinal gating. We hypothesize that these findings represent a novel set of neurophysiological findings and may be due to an altered pattern of cortical excitability, possibly due to an increased presence of gap junctions in cortical cells.

The Impact of Neurophysiological Monitoring on Patient Outcomes in Carotid Endarterectomy: A Meta-Analysis

2024-06-29T01:44:50+03:00

The 30-day stroke rate following a Carotid Endarterectomy (CEA) ranges between 2-6% and is associated with a three-fold increase in mortality. Various types of Intraoperative Neurological Monitoring (IONM) modalities are available to help detect changes in cerebral blood flow during this procedure. The primary aim of this meta-analysis was to evaluate the efficacy of the different (IONM) techniques used for this surgery and compare them to multiple modality studies. We identified relevant articles on PubMed (2000-2024), EBSCOhost (2000-2024), and Science Direct (2000-2024) to identify studies to include in this meta-analysis. We included literature that consisted of adult patients who underwent a CEA procedure under general anesthesia and were monitored with the specified IONM modalities. We calculated the mean specificities and sensitivities for each IONM Modality studied and are as follows: mean EEG sensitivity 41% and specificity 90%; mean TCD sensitivity 99% and specificity 83%; mean SSEP sensitivity 64% and specificity 88%; combined SSEP+EEG sensitivity 59% and specificity 99%. Each IONM modality presents its own unique set of challenges to determine severe deficits in cerebral blood flow. Given the high specificity or sensitivity observed across virtually all modalities, additional studies are needed to assess the effectiveness of combining the strengths of two modalities to enhance their capabilities.

Sensitivity and Specificity of Intraoperative Neurophysiological Monitoring in Lumbar Spinal Surgery: A Meta-Analysis

2024-10-11T04:49:30+03:00

Our meta-analysis aimed to evaluate the specificity and sensitivity of various intraoperative neurophysiological monitoring (IONM) modalities during lumbar spinal surgeries, with a focus on their practical implications. Sensitivity and specificity are essential measures for assessing the effectiveness of IONM. Sensitivity refers to a test's ability to accurately detect patients with a neurological deficit, ensuring that no impairment is overlooked. Specificity represents the test’s ability to correctly identify patients without a deficit, minimizing the occurrence of false positives and unnecessary concerns. The modalities examined included Somatosensory Evoked Potentials (SSEPs), Electromyography (EMG), and Motor-Evoked Potentials (MEPs).

Our findings suggest that utilizing a multimodal approach significantly enhances the accuracy of neurological monitoring, providing practical benefits for surgeons and patients alike. By employing two or more modalities simultaneously, comprehensive observation is achieved, where the strengths of one modality complement the limitations of another, ultimately improving the detection of potential complications. For instance, SSEPs monitor sensory pathways, while MEPs assess motor pathways, and together, they provide a more complete picture of spinal cord function. EMG further assists by detecting muscle responses, indicating nerve function. Thus, multimodal IONM is the most effective way to reduce the risk of neurological injury, improve surgical outcomes, and ensure optimal patient health during lumbar spine surgery.

Efficacy of Sugammadex as a Reversal with an Optimized Train of Four Stimulation Parameters

2024-10-18T21:19:05+03:00

Residual neuromuscular blockades are a potentially dangerous complication after surgery due to administering neuromuscular blocking agents. Sugammadex is a novel neuromuscular blocking agent reversal drug that combats faster reversal times. However, it still needs to be determined how efficient it is compared to neostigmine, particularly with optimal Train of Four monitoring. Sugammadex and neostigmine were analyzed through 11 studies to determine the speed of recovery and postoperative complications. Sugammadex was found to have a quicker recovery time and fewer complications after surgery compared to neostigmine. A train of four stimulation analyses determined that higher voltages do not create as adequate 4/4 responses as at a lower, more reliable voltage. Therefore, our results determine that Sugammadex is a faster, safer drug choice, and the train of four stimulations is most reliable at 30mA. Still, it may be adequate up to 50mA without supramaximal stimulation. Further research should investigate how Sugammadex may differentiate depending on the patient's sex and how muscle relaxant dosages may change recovery time even with adequate training of four responses.

The Indispensable Role of Intraoperative Neurophysiological Monitoring in Tethered Cord Release Surgeries

2024-10-18T23:25:51+03:00

Untethering of the spinal cord is performed to surgically treat abnormal spinal cord fixation, which tends to arise from conditions such as spina bifida, spinal dysmorphisms (including diastematomyelia, lipomyelomeningocele, and myelomeningocele), trauma, or tumors. This fixation often leads to complications known as Tethered Cord Syndrome (TCS), where the spinal cord becomes abnormally anchored, resulting in restricted mobility and progressive neurological deficits [1]. Surgical untethering aims to prevent further damage or potentially reverse symptoms, with intraoperative neuromonitoring (IONM) playing a vital role in distinguishing functional neural tissue from fibrous tissue to reduce the risk of nerve damage.