The purpose of this study is to identify the advancing role of Intraoperative Neurophysiological Monitoring (IONM) in detecting and preventing nerve injuries during shoulder surgery procedures. We performed a retrospect...The purpose of this study is to identify the advancing role of Intraoperative Neurophysiological Monitoring (IONM) in detecting and preventing nerve injuries during shoulder surgery procedures. We performed a retrospective analysis of IONM data from ten shoulder procedures. The patients consisted of nine females and one male with ages ranging from 67 to 81 years (median: 74 years). IONM modalities utilized were bilateral Somatosensory Evoked Potentials (SSEP), Transcranial Motor Evoked Potentials (TCeMEP), ipsilateral Electromyogram (EMG) from upper extremity muscles and Train of four (TOF) recordings. A decrease in signals was noted in three patients (30%). Only upper SSEP amplitude decreased in one patient; both upper extremity SSEP and TCeMEP decreased in two patients. Only one patient had poor baseline radial nerve SSEP that improved during the surgery. We performed spontaneous EMG (s-EMG) in all ten patients and successfully recorded triggered (t-EMG) in seven patients (71.4%). In one patient, SSEP and TCeMEP did not improve, and the patient woke up with deficits. In this small series, we were able to identify real-time impending nerve injury. The use of IONM alerted and may have prevented intraoperative nerve injury in 30% of the patients in this series. In one patient, SSEP and TCeMEP did not recover even after the intervention due to severe blood loss. The patient woke up with sensory and motor deficits. The utilization of multimodality IONM can be helpful due to signal changes, therefore minimizing the frequency of nerve injury and deficits.
A severe and unusual complication found in children with influenza is an acute necrotizing encephalopathy. A 20-month-old female with no significant past medical history was admitted to our facility, presenting with a 4-...A severe and unusual complication found in children with influenza is an acute necrotizing encephalopathy. A 20-month-old female with no significant past medical history was admitted to our facility, presenting with a 4-day history of worsening fever, upper respiratory symptoms, new-onset altered mental status and episodes of extensor posturing. The initial concern was a dystonic reaction secondary to promethazine following a recent diagnosis of influenza A virus. A head computed tomography scan indicated concern for widespread edema, and the video EEG revealed focal slowing in the frontocentral regions with no epileptiform activity during episodes of extensor posturing. The first magnetic resonance imaging results were consistent with acute hemorrhagic encephalitis or severe anoxic brain injury for which there is a broad differential. A second MRI five days later found new areas of restricted diffusion that were consistent with acute necrotizing encephalitis.
Tilt table testing is a common noninvasive diagnostic test performed to reproduce and evaluate syncope in a vulnerable patient and subsequently guide therapy. Electroencephalography (EEG) is typically useful for identify...Tilt table testing is a common noninvasive diagnostic test performed to reproduce and evaluate syncope in a vulnerable patient and subsequently guide therapy. Electroencephalography (EEG) is typically useful for identifying interictal and ictal abnormalities within the context of epilepsy or suspected epilepsy. We report a series of patients who underwent simultaneous tilt table testing with EEG. Diagnostic benefits are not exclusively the verification of EEG correlates secondary to clinical and cardiovascular changes during syncope, but also confirmation of nonphysiological events, including psychogenic nonepileptic seizures and psychogenic pseudosyncope. Fifty tilt table studies were combined with EEG over a six-year period. Seven studies (14%) captured episodes of behavioral unresponsiveness with normal EEG and EKG patterns, diagnostic of psychogenic pseudosyncope. Whereas psychogenic nonepileptic events are well established in the literature, psychogenic pseudosyncope is probably underestimated and rarely evaluated outside of an epilepsy monitoring unit. This novel combined protocol should be considered for any patient with suspected psychogenic unresponsiveness.
Since 1995, ASET has published recommendations for infection prevention. With the aim of keeping our readers current with updates in infection prevention initiatives, this article reviews ASET's past publications by Altm...Since 1995, ASET has published recommendations for infection prevention. With the aim of keeping our readers current with updates in infection prevention initiatives, this article reviews ASET's past publications by Altman 1995, Altman 2000, Scott 2013, and Sullivan & Altman 2008, and incorporates new information from published scientific literature, online resources, print publications, national and international guidelines, OSHA and other regulatory agencies. Knowledge of current infection control practices and recommendations is essential for every Neurodiagnostic technologist, whether working in a hospital, an ambulatory setting, intensive care unit or in the operating room. All technologists who have direct patient contact are responsible for ensuring use of best practices to prevent the spread of infection.
: Ambulatory electroencephalography technology has improved in the last 40 years. Many clinicians believe that some skin injury is an unavoidable complication of prolonged EEG monitoring. In this study, we examined poten...: Ambulatory electroencephalography technology has improved in the last 40 years. Many clinicians believe that some skin injury is an unavoidable complication of prolonged EEG monitoring. In this study, we examined potential risk factors associated with electrode-induced skin injury in adult patients with AEEG monitoring. : A cross-sectional observational study was conducted from December 2017 to October 2018, in the outpatient clinic at a teaching hospital in Sydney, Australia. Patients were included if they were older than 16 years of age and had been referred for AEEG monitoring of two to five days duration. Trained neurophysiology nurses completed a pre-application skin assessment before they applied the EEG electrodes. Daily assessments of the skin condition were conducted. The patients completed a questionnaire to assess comfort levels at the completion of the testing. : A total of 251 patients participated in this study. Two groups were established - those who were monitored for 2-3 days (Group 1; n = 92) and those who were monitored for 4-5 days (Group 2; n = 159). There was a significant acceleration in inflammation which occurred between day 2 and day 4/5. Cross-sectional analyses of patient characteristics showed that increasing age, fair skin color, dry skin texture and fine hair texture were the prevailing risk factors for greater inflammation scores. : The patient discomfort and inflammatory burden associated with this procedure were high. Inflammation was shown to increase with the duration of electrode application.
Paradoxical cortical potential polarity of the upper extremity somatosensory evoked potential (SSEP) has been reported in cases of polymicrogyria (PMG) syndrome. To date, the pathophysiological basis of this electrophysi...Paradoxical cortical potential polarity of the upper extremity somatosensory evoked potential (SSEP) has been reported in cases of polymicrogyria (PMG) syndrome. To date, the pathophysiological basis of this electrophysiological aberration remains under investigation. Here we present a case of mild PMG that showed "layered" microgyri in the left frontoparietal cortices affecting both hand and foot sensorimotor areas. The SSEP recordings revealed an isolated polarity reversal of N20 from the dysplastic cortex. We postulate a central sulcus misfolding theory to explain the "positive" N20 potential recorded in the PMG cortex.
Nonketotic hyperglycinemia (NKH) or glycine encephalopathy is an autosomal recessive disorder of glycine metabolism resulting in an excessive accumulation of glycine in all body tissues, including the central nervous sys...Nonketotic hyperglycinemia (NKH) or glycine encephalopathy is an autosomal recessive disorder of glycine metabolism resulting in an excessive accumulation of glycine in all body tissues, including the central nervous system. It is caused by a biochemical defect in the glycine cleavage system and considered as a rare disorder with an estimated prevalence of 1:60,000. The neonatal form presents in the first few days of life with progressive encephalopathy, hypotonia, myoclonic jerks, hiccups, seizures, rapid progression to coma and often death due to central apnea. Surviving infants often have severe developmental delay and refractory seizures. Atypical forms of NKH present with heterogeneous and nonspecific disease course. Classical glycine encephalopathy usually carries a very poor prognosis. We describe two neonates who presented with neonatal encephalopathy, apnea, and progressive lethargy. Increased CSF glycine level along with an elevated CSF to plasma glycine ratio was suggestive of classic NKH. Burst suppression EEG and agenesis of the corpus callosum were supportive findings. Evolution of the EEG patterns and course of the disease are discussed in detail. Transient phases of clinical stabilization and normalized plasma biochemical results may not necessarily reflect the actual encephalopathic process. Serial EEGs are helpful to assess the efficacy of treatment and to modify the therapeutic approach.
Collodion remover, a solvent blend used to remove collodion glue after long-term video EEG monitoring, was implicated as a potential causative factor in patient safety events at our institution during which damage to pla...Collodion remover, a solvent blend used to remove collodion glue after long-term video EEG monitoring, was implicated as a potential causative factor in patient safety events at our institution during which damage to plastic components of medical devices was noted in the intensive care unit. We sought to determine experimentally whether collodion remover could lead to degradation of multiple plastic-containing medical devices commonly used in the intensive care unit to determine whether workflow changes were needed during electrode removal. We exposed devices to collodion remover for brief, intermediate, and prolonged durations. We report that collodion remover is capable of degrading the hard plastic components of multiple medical devices after prolonged exposure; however, intermediate duration exposure was also capable of producing damage to clave connectors used with intravenous and central lines, which could plausibly lead to adverse events given the widespread use of these devices. These data suggest a pathway-based approach to collodion remover use might be beneficial in minimizing the potential impact of this solvent on plastic-containing medical devices.
Triggered electromyography (t-EMG) is a common technique used during spinal instrumentation in surgery for adolescent idiopathic scoliosis. This study tests the validity of t-EMG values obtained with a standard ball-tipp...Triggered electromyography (t-EMG) is a common technique used during spinal instrumentation in surgery for adolescent idiopathic scoliosis. This study tests the validity of t-EMG values obtained with a standard ball-tipped probe after completion of screw placement versus t-EMG values obtained during screw insertion with a powered screwdriver. t-EMG values were collected for screws spanning T7-L5 using both a standard probe and a powered screwdriver. A power analysis determined that a sample size of 300 screws would provide enough precision to estimate limits of agreement within ±2 mA. A monopolar constant current stimulation technique (0.2 ms duration and 3.11 Hz stimulation rate) was used at each level. EMG was acquired with placement of bipolar pairs of subdermal needle electrodes. A Bland-Altman plot was used to assess agreement between threshold readings from the two techniques. Twenty-nine patients were enrolled in this study with 305 screws. t-EMG values measured using a powered screwdriver were on average 1 mA lower than values from a standard probe. When readings less than or equal to 20 mA were considered, the limits of agreement were approximately 4 and 7 mA overall. In total, 28/305 (9%) screws were removed and reinserted, 9/305 (3%) screws were redirected, and 3/305 (1%) screws were aborted based on t-EMG readings. Despite a small overall difference in t-EMG value between the standard probe and screwdriver, there was still large variability in agreement between the two techniques. t-EMG values obtained with a powered screwdriver during screw insertion are not interchangeable with values measured by a probe.
Awake craniotomy is advocated for the resection of supratentorial low-grade gliomas (LGG). The combination of neurophysiological electrical mapping techniques and performing the craniotomy awake has demonstrated increase...Awake craniotomy is advocated for the resection of supratentorial low-grade gliomas (LGG). The combination of neurophysiological electrical mapping techniques and performing the craniotomy awake has demonstrated increased total and supratotal resection of LGG, as well as increased overall survival rates. We present an illustrative case where the patient's gross motor function deteriorated during the resection of a LGG and mapping techniques using the phase reversal technique and Taniguchi direct cortical stimulation technique while the patient was awake proved to be valuable in determining continuity of the corticospinal tracts.
Aphasia is commonly seen in focal brain lesions. Prolonged aphasia from an ictal state is rarely reported. We report the case of a 62-year-old man with focal motor status epilepticus manifested initially as episodic righ...Aphasia is commonly seen in focal brain lesions. Prolonged aphasia from an ictal state is rarely reported. We report the case of a 62-year-old man with focal motor status epilepticus manifested initially as episodic right cheiro-oral clonic movements with preserved awareness and expressive aphasia for 48 hours. EEG showed left frontal and central lateralized periodic discharges (LPDs) without plus features (rhythmicity, overlying fast) and electrographic seizures that correlated with right clonic movements. Treatment with two seizure medications (levetiracetam and lacosamide) resulted in complete electrographic and clinical resolution of his symptoms, including aphasia. In this case, aphasia was determined to be an ictal semiology, as patient had complete resolution of his symptoms supported by a normal EEG after receiving seizure medications. We suggest keeping high suspicion for an ictal process in patients with sudden-onset aphasia supported by EEG findings of LPDs.
Iatrogenic facial nerve (FN) injury is one of the most feared complications of otologic surgery. Dehiscence of the bony covering of the FN within the temporal bone increases FN vulnerability to accidental injury. High-re...Iatrogenic facial nerve (FN) injury is one of the most feared complications of otologic surgery. Dehiscence of the bony covering of the FN within the temporal bone increases FN vulnerability to accidental injury. High-resolution computed tomography (HRCT) of the temporal bone is used preoperatively to assess middle ear and mastoid anatomy; however, it is unreliable for detecting facial canal dehiscence. In this study, our aim was to determine if preoperative percutaneous FN stimulation could predict middle ear facial canal dehiscence. Between January 2015 and February 2017, we performed preoperative HRCT and percutaneous FN stimulation on adult patients who underwent otologic surgery at our institution. Stimulation was performed with a monopolar probe placed on the skin over the stylomastoid foramen. Electrical stimuli ranged from 0 to 40 milliamperes (mA). Recordings were made from ipsilateral facial muscles. Dependent variables included threshold to compound muscle action potential (CMAP), threshold to maximum amplitude of CMAP, and maximum amplitude of CMAP for each muscle. A retrospective chart review was performed. Seventy patients met inclusion criteria. Of the 24 with an intraoperatively confirmed dehiscence, 10 were identified preoperatively by the attending surgeon on HRCT. Averages of the lowest recorded threshold to CMAP (5.1mA v. 9.1mA), and an average of the threshold to CMAP (8.9 mA. 11.8 mA) of dehiscent versus non-dehiscent nerves were significantly different ( < .05). In conclusion, percutaneous FN stimulation is a simple and cost-effective tool that can give the surgeon important preoperative information about FN anatomy.
When changes occur in neurological responses during a surgical case, it is very important that all staff in the operating room (OR) understand their role in resolving or improving these conditions. Timely interventions a...When changes occur in neurological responses during a surgical case, it is very important that all staff in the operating room (OR) understand their role in resolving or improving these conditions. Timely interventions are needed, and each personnel team is responsible for very specific tasks. Our intent was to cut down on confusion and delay by implementing a checklist that assigns tasks and designates a coordinator, so we incorporated the use of a checklist developed by Vitale et al. into our process for neuromonitoring cases. Staff members who used the checklist were surveyed to assess ease of use, understanding and perceptions about patient safety and case efficiency with the incorporation of the checklist. The post-implementation survey showed an increase in confidence and understanding in team responsibilities and workflow. Results showed ease of use and a perception of increased patient safety with no perceived decrease in surgery case efficiency.