[Enhancing Neuromuscular Disease Diagnosis through Electrophysiology].

Electrophysiologic testing plays an important role in evaluating peripheral nerve, muscle, and neuromuscular junction diseases, aiding in diagnosis and treatment strategies by offering real-time assessment. Demyelination of peripheral nerves results in increased conduction delay, temporal dispersion, conduction block, and stimulation threshold. The localization or diffusion of these changes is crucial in understanding disease pathogenesis, necessitating stimulation at multiple points along nerve pathways. When axonal degeneration occurs, the amplitude is reduced, with mild conduction delay. Acute axonal degeneration may require 1 week to develop into Wallerian degeneration. During this time, conductivity was preserved in the nerve peripheral to the lesion. When MG or LEMS is suspected, repetitive nerve stimulation tests and single-fiber EMG are valuable for the diagnosis and pathophysiological evaluation. Notably, the latter is highly sensitive but not specific. Needle electromyography (EMG) assists in differentiating between myopathies and neurogenic diseases, and in determining whether the patient is in an acute or chronic stage. Integration of these tests contribute to an accurate diagnosis when considering the presenting symptoms.

Subacute Progressive Severe Ataxic Sensory Neuropathy with Sjögren's Syndrome.

We herein report a 79-year-old woman with subacute progressive ataxic sensory neuropathy. The patient's symptoms began with numbness in the lower extremities, which rapidly deteriorated, resulting in gait disturbance and abnormal sensations in the extremities, reaching a peak over a period of approximately two months. Nerve conduction studies revealed pure axonal-type sensory polyneuropathy. The expeditious progression of the disease initially prompted suspicion of Guillain-Barré syndrome or paraneoplastic syndrome. Nevertheless, after comprehensive evaluations, the conclusive diagnosis was confirmed as ataxic sensory neuropathy with Sjögren's syndrome. Intensive immunotherapy was administered; however, it was ineffective in halting disease progression. Consequently, this case underscores the significance of an early comprehensive diagnosis and prompt immunotherapy for ataxic sensory neuropathy associated with Sjögren's.

[Efficacy of FilmArray® ME panel for the rapid diagnosis of meningitis and encephalitis].

Microbial tests are essential for appropriate management for acute meningitis and encephalitis, but it often takes several days to identify the results of culture tests or PCR. BioFire FilmArray® meningitis/encephalitis panel (ME panel) is a rapid multiplex PCR assay that targets 14 bacteria, viruses, and yeast in 1 hour. In this single-center retrospective study, we reviewed adult patients who underwent ME panel test in parallel with conventional microbial tests from January to August 2021. Eighteen of 70 patients (26%) tested positive by ME panel, of which 8 patients (11%) were helpful in altering treatment strategy. Fifty-two patients (74%) could stop empirical treatment such as acyclovir or antibiotics due to negative results on ME panel. All results of ME panel were same as traditional assays. Use of ME panel can contribute to early diagnosis and treatment.

Visualization of axonal and volume currents in median nerve compound action potential using magnetoneurography.

OBJECTIVE: Reconstruct compound median nerve action currents using magnetoneurography to clarify the physiological characteristics of axonal and volume currents and their relationship to potentials. METHODS: The median nerves of both upper arms of five healthy individuals were investigated. The propagating magnetic field of the action potential was recorded using magnetoneurography, reconstructed into a current, and analyzed. The currents were compared with the potentials recorded from multipolar surface electrodes. RESULTS: Reconstructed currents could be clearly visualized. Axonal currents flowed forward or backward in the axon, arcing away from the depolarization zone, turning about the subcutaneous volume conductor, and returning to the depolarization zone. The zero-crossing latency of the axonal current was approximately the same as the peak of its volume current and the negative peak of the surface electrode potential. Volume current waveforms were proportional to the derivative of axonal ones. CONCLUSIONS: Magnetoneurography allows the visualization and quantitative evaluation of action currents. The currents in axons and in volume conductors could be clearly discriminated with good quality. Their properties were consistent with previous neurophysiological findings. SIGNIFICANCE: Magnetoneurography could be a novel tool for elucidating nerve physiology and pathophysiology.

Predictive factors and clinical impact of ICU-acquired weakness on functional disability in mechanically ventilated patients with COVID-19.

BACKGROUND: Patients with critical COVID-19 often require invasive mechanical ventilation (IMV) and admission to the intensive care unit (ICU), resulting in a higher incidence of ICU-acquired weakness (ICU-AW) and functional decline. OBJECTIVE: This study aimed to examine the causes of ICU-AW and functional outcomes in critically ill patients with COVID-19 who required IMV. METHODS: This prospective, single-center, observational study included COVID-19 patients who required IMV for ≥48 h in the ICU between July 2020 and July 2021. ICU-AW was defined as a Medical Research Council sum score <48 points. The primary outcome was functional independence during hospitalization, defined as an ICU mobility score ≥9 points. RESULTS: A total of 157 patients (age: 68 [59-73] years, men: 72.6%) were divided into two groups (ICU-AW group; n = 80 versus non-ICU-AW; n = 77). Older age (adjusted odds ratio [95% confidence interval]: 1.05 [1.01-1.11], p = 0.036), administration of neuromuscular blocking agents (7.79 [2.87-23.3], p < 0.001), pulse steroid therapy (3.78 [1.49-10.1], p = 0.006), and sepsis (7.79 [2.87-24.0], p < 0.001) were significantly associated with ICU-AW development. In addition, patients with ICU-AW had significantly longer time to functional independence than those without ICU-AW (41 [30-54] vs 19 [17-23] days, p < 0.001). The development of ICU-AW was associated with delayed time to functional independence (adjusted hazard ratio: 6.08; 95% CI: 3.05-12.1; p < 0.001). CONCLUSIONS: Approximately half of the patients with COVID-19 requiring IMV developed ICU-AW, which was associated with delayed functional independence during hospitalization.

Magnetoneurography to investigate the mechanisms underlying the P9 far-field potential.

OBJECTIVE: The mechanism underlying the generation of P9 far-field somatosensory evoked potentials (SEPs) is unresolved. Accordingly, we used magnetoneurography to visualize the current distribution in the body at the P9 peak latency and elucidate the origin of P9 generation. METHODS: We studied five healthy male volunteers without neurological abnormalities. We recorded far-field SEPs after median nerve stimulation at the wrist to identify the P9 peak latency. Using magnetoneurography, we recorded the evoked magnetic fields in the whole body under the same stimulus conditions as the SEP recording. We analyzed the reconstructed current distribution at the P9 peak latency. RESULTS: At the P9 peak latency, we observed the reconstructed current distribution dividing the thorax into two parts, upper and lower. Anatomically, the depolarization site at the P9 peak latency was distal to the interclavicular space and at the level of the second intercostal space. CONCLUSIONS: By visualizing the current distribution, we proved that P9 peak latency originates in the change in volume conductor size between the upper and lower thorax. SIGNIFICANCE: We clarified that magnetoneurography analysis is affected by the current distribution due to the junction potential.

Discrepancy between distribution of alpha-synuclein oligomers and Lewy-related pathology in Parkinson's disease.

The pathological hallmarks of Parkinson's disease (PD) are α-synuclein (αSYN)-positive inclusions referred to as Lewy bodies and Lewy neurites, collectively referred to as Lewy-related pathology (LRP). LRP is thought to propagate in an ascending manner throughout the brain as the disease progresses. LRP is visible with histologic methods and is thought to represent a later stage of the disease process, while αSYN oligomers, which are not visible with routine histologic methods, are considered earlier. There is increasing evidence to suggest that αSYN oligomers may be more toxic than visible LRP. Detecting αSYN oligomers requires special techniques, and their distribution and association with clinical features are important research objectives. In this report, we describe the distribution of αSYN oligomers in multiple cortical and subcortical regions of PD using a proximity ligation assay (PLA). We observe widespread distribution of αSYN oligomers with PLA and more restricted distribution of LRP with αSYN immunohistochemistry. The distribution of αSYN oligomers differed from LRP in that αSYN oligomer burden was significantly greater in the neocortex, while LRP was greater in vulnerable subcortical regions, including the brainstem. We also found that cognitive impairment was associated with αSYN oligomers in the hippocampus. These results suggest that αSYN oligomers may be widely distributed in PD early in the disease process and that they may contribute to cognitive impairment in PD.

Convulsive-like symptoms as initial indications of basilar artery occlusion: A case series study.

BACKGROUND: There is little evidence regarding relevant clinical findings for the early diagnosis of basilar artery occlusion (BAO) in the prehospital setting. We focused on "convulsive-like symptoms", including convulsive seizures and other convulsive-like movements, and examined the frequency and clinical characteristics of patients with BAO having these symptoms as an initial symptom. METHODS: In this single-center case series from 2015 to 2020, we identified patients who underwent endovascular therapy (EVT) for BAO and presented with convulsive-like symptoms between the stroke onset and initiation of emergency medical care. The clinical course and neurological findings were evaluated by reviewing the run sheets of emergency medical services and medical records. RESULTS: Among a total of 32 patients with BAO, 7 (21.9%) developed convulsive-like symptoms before EVT, of whom 6 were men and whose median age was 72 (interquartile range, 69-78) years. These 7 patients had no history of epilepsy or stroke, and the semiology of convulsive-like symptoms was generalized in 6 of them. In only 3 of the 7 cases, emergency medical services could consider the possibility of stroke on scene, and time from hospital arrival to groin puncture was longer in those who were transported without suspicion of stroke. CONCLUSIONS: 21.9% of our patients who underwent EVT for BAO experienced convulsive-like symptoms initially. We should be vigilant in the possibility of BAO when managing the first-time generalized convulsive-like symptoms occurring in older patients, which may enable to adequate triage and better management for patients with acute BAO.

Prehospital stroke notification and endovascular therapy for large vessel occlusion: a retrospective cohort study.

The impact of prehospital notification by emergency medical services (EMS) on outcomes of endovascular therapy (EVT) for large vessel occlusion (LVO) remains unclear. We therefore explored the association between prehospital notification and clinical outcomes after EVT. In this single-center retrospective study from 2016 through 2020, we identified all LVO patients who received EVT. Based on the EMS's usage of a prehospital stroke notification system, we categorized patients into two groups, Hotline and Non-hotline. The primary outcome was good neurological outcome at 90 days; other time metrics were also evaluated. Of all 312 LVO patients, the proportion of good neurological outcomes was 94/218 (43.1%) in the Hotline group and 8/34 (23.5%) in the Non-hotline group (adjusted odds ratio 2.86; 95% confidence interval 1.12 to 7.33). Time from hospital arrival to both tissue plasminogen activator and to groin puncture were shorter in the Hotline group (30 (24 to 38) min vs 48(37 to 65) min, p < 0.001; 40 (32 to 54) min vs 76 (50 to 97) min, p < 0.001), respectively. In conclusion, prehospital notification was associated with a reduction in time from hospital arrival to intervention and improved clinical outcomes in LVO patients treated with EVT.

High-dose immunoglobulin-dependent chronic demyelinating inflammatory polyneuropathy successfully managed with subcutaneous immunoglobulin using pharmacokinetic analysis.

Immunoglobulin G therapy for chronic inflammatory demyelinating polyneuropathy (CIDP) often requires individual dose adjustments because of the heterogeneity of pathogenesis and varying catabolic rates. However, currently available pharmacokinetic studies of immunoglobulin G therapy do not consider individual differences. We conducted a pharmacokinetic study of both intravenous immunoglobulin and subcutaneous immunoglobulin in a single patient with CIDP who was dependent on high-dose immunoglobulin treatment. This patient-a 77-year-old man with symmetrical limb weakness, diffuse demyelination determined by a nerve conduction study, and lacking autoantibodies-was treated with intravenous immunoglobulin and experienced severe fluctuations in symptoms. We transitioned him to subcutaneous immunoglobulin: his serum immunoglobulin G levels stabilised and he experienced symptomatic relief. Monitoring of serum immunoglobulin G concentrations revealed volatile changes following intravenous immunoglobulin administration which stabilised following subcutaneous immunoglobulin treatment. This suggests that subcutaneous immunoglobulin is a preferable long-term treatment option, especially for high-dose immunoglobulin-dependent patients with CIDP.

Efficacy and Safety of Ultrahigh-Dose Methylcobalamin in Early-Stage Amyotrophic Lateral Sclerosis: A Randomized Clinical Trial.

Importance: The effectiveness of currently approved drugs for amyotrophic lateral sclerosis (ALS) is restricted; there is a need to develop further treatments. Initial studies have shown ultrahigh-dose methylcobalamin to be a promising agent. Objective: To validate the efficacy and safety of ultrahigh-dose methylcobalamin for patients with ALS enrolled within 1 year of onset. Design, Setting, and Participants: This was a multicenter, placebo-controlled, double-blind, randomized phase 3 clinical trial with a 12-week observation and 16-week randomized period, conducted from October 17, 2017, to September 30, 2019. Patients were recruited from 25 neurology centers in Japan; those with ALS diagnosed within 1 year of onset by the updated Awaji criteria were initially enrolled. Of those, patients fulfilling the following criteria after 12-week observation were eligible for randomization: 1- or 2-point decrease in the Revised Amyotrophic Lateral Sclerosis Functional Rating Scale (ALSFRS-R) total score, a percent forced vital capacity greater than 60%, no history of noninvasive respiratory support and tracheostomy, and being ambulatory. The target participant number was 64 in both the methylcobalamin and placebo groups. Patients were randomly assigned through an electronic web-response system to methylcobalamin or placebo. Interventions: Intramuscular injection of methylcobalamin (50-mg dose) or placebo twice weekly for 16 weeks. Main Outcomes and Measures: The primary end point was change in ALSFRS-R total score from baseline to week 16 in the full analysis set. Results: A total of 130 patients (mean [SD] age, 61.0 [11.7] years; 74 men [56.9%]) were randomly assigned to methylcobalamin or placebo (65 each). A total of 129 patients were eligible for the full analysis set, and 126 completed the double-blind stage. Of these, 124 patients proceeded to the open-label extended period. The least square means difference in ALSFRS-R total score at week 16 of the randomized period was 1.97 points greater with methylcobalamin than placebo (-2.66 vs -4.63; 95% CI, 0.44-3.50; P = .01). The incidence of adverse events was similar between the 2 groups. Conclusions and Relevance: Results of this randomized clinical trial showed that ultrahigh-dose methylcobalamin was efficacious in slowing functional decline in patients with early-stage ALS and with moderate progression rate and was safe to use during the 16-week treatment period. Trial Registration: ClinicalTrials.gov Identifier: NCT03548311.

Threshold-based Monitoring of Compound Muscle Action Potentials for Percutaneous Pedicle Screw Placement in the Lumbosacral Spine: Can We Rely on Stimulation of the Uninsulated Screw to Provide a Valid Safety Warning?

STUDY DESIGN: A prospective analysis. OBJECTIVE: To test if threshold-based monitoring of compound muscle action potentials (CMAPs) by stimulating the screw loaded to uninsulated extender sleeve provides a valid safety warning for percutaneous pedicle screw (PPS) placements in the lumbosacral spine. SUMMARY OF BACKGROUND DATA: Utility of the CMAP monitoring to PPS procedures remains controversial. METHODS: A series of 202 patients underwent a total of 1664 lumbosacral PPS placements under CMAP monitoring without fluoroscopic guidance. The monitoring consisted of stimulating the PPS assembled to uninsulated extender sleeve and recording CMAPs from the vastus medialis, biceps femoris, tibialis anterior, and medial gastrocnemius. Automated steps of a threshold hunting algorithm using 0.2-ms duration pulses of increasing intensities delivered at 2/s allowed quick determination of a minimum stimulation current to evoke >100-µV amplitude CMAPs. RESULTS: At L2 through S1 spines, postoperative CT scans identified 51 medial or inferior pedicle wall breaches of 1536 screws (3.3%) without neurologic complications. The receiver operating characteristic curve analysis determined the critical cutoff threshold value of 27 mA (74% sensitivity and 95% specificity) for predicting 35 breaches of 627 screws (5.6%) at L2 and L3, and of 17 mA (100% sensitivity and 98% specificity) for 16 of 909 (1.8%) at L4 through S1. While advancing the screw, three breaches (5.9%) showed a particularly low threshold of ≤6-mA, allowing the surgeon to immediately redirect the screw and retest the new trajectory as safe. CONCLUSION: Screw stimulation with threshold hunting algorithm has a distinct advantage over the time-consuming insulated pilot hole stimulation, allowing an uninterrupted flow of the surgery. The present findings have documented practical usefulness and reliability of CMAP monitoring using direct stimulation of the PPS assembled to uninsulated extender sleeve.

Two Lambert-Eaton Myasthenic Syndrome Patients with Ameliorated Activities of Daily Living Due to Cholinesterase Inhibitors.

We herein report two P/Q-type voltage-gated calcium channel (VGCC) antibody-positive Lambert-Eaton myasthenic syndrome (LEMS) patients who responded dramatically to cholinesterase inhibitors. Patient 1, a 76-year-old man, had small-cell lung cancer and developed LEMS during chemotherapy. When symptomatic treatment was started with pyridostigmine, gait disturbance was ameliorated, and his modified Rankin scale decreased from 4 points to 3 points. Patient 2, a 68-year-old man, had cancer-free LEMS. Distigmine bromide was very effective and ameliorated not only his gait disturbance but also autonomic symptoms, and his modified Rankin scale decreased from 2 points to 1 point. Cholinesterase inhibitors alone may be effective in a small portion of LEMS patients.

Post COVID-19 Bilateral Facial Nerve Palsy.

Coronavirus disease 2019 (COVID-19) patients have been increasingly reported to develop various neurological manifestations. We herein present a rare case of bilateral facial nerve palsy in a patient that occurred 5 weeks after the onset of COVID-19. The patient had no motor or sensory deficits in his extremities, and there were no other diseases that may have resulted in bilateral facial palsy. Based on these findings, we concluded that the facial palsy in this case may have been triggered by COVID-19.

Isolated progression of miliary brain metastasis in a patient with stable lung adenocarcinoma successfully treated with whole-brain radiotherapy: A case report.

Miliary brain metastasis is a rare form of metastasis commonly associated with advanced stages of cancer. In this article, we report a case of a 38-year-old male with solitary progression of miliary brain metastasis originating from stage 4 EML-ALK-positive lung adenocarcinoma. Multiple brain lesions were first detected upon the patient's inclusion in a brigatinib clinical trial. The brain lesions dissipated, and the lung and bone lesions decreased in size after starting the brigatinib therapy; however, the brain lesions later increased in number. A biopsy revealed miliary brain metastasis of lung adenocarcinoma. The patient was successfully treated with whole brain therapy, in addition to brigatinib. This case suggests that it is possible for an isolated miliary brain metastasis to occur during the effective suppression of systemic cancer progression. Whole brain radiotherapy while continuing effective systemic therapy is a good strategy for such patients.

Neurological Manifestations and Long-term Sequelae in Hospitalized Patients with COVID-19.

Objective Various neurological manifestations have been increasingly reported in coronavirus disease 2019 (COVID-19). We determined the neurological features and long-term sequelae in hospitalized COVID-19 patients. Methods We retrospectively studied 95 consecutive hospitalized patients with COVID-19 between March 1 and May 13, 2020. Acute neurological presentations (within two weeks of the symptom onset of COVID-19) were compared between 60 non-severe and 35 severely infected patients who required high-flow oxygen. In the 12 ventilated patients (the most severe group), we evaluated neurological complications during admission, subacute neurological presentations, and neurological sequelae (51 and 137 days from the onset [median], respectively). Results Of the 95 patients (mean age 53 years old; 40% women), 63% had acute neurological presentations, with an increased prevalence in cases of severe infections (83% vs. 52%, p<0.001). Impaired consciousness and limb weakness were more frequent in severe patients than in non-severe ones (0% vs. 49%; p<0.001, and 0% vs. 54%; p<0.001, respectively). In the most severe group (mean age 72 years old; 42% women), 83% of patients had neurological complications [cerebrovascular disease (17%), encephalopathy (82%), and neuropathy (55%)], and 92% had subacute neurological presentations [impaired consciousness (17%), higher brain dysfunction (82%), limb weakness (75%), and tremor (58%)]. Neurological sequelae were found in 83% of cases, including higher brain dysfunction (73%), limb weakness (50%), and tremor (58%). Conclusions Neurological manifestations are common in COVID-19, with the possibility of long-lasting sequelae.

Impact of physical frailty on the clinical outcomes of older patients hospitalized for pneumonia.

AIM: This study aimed to assess the association between physical frailty and clinical outcomes among older patients hospitalized for pneumonia. METHODS: This study examined 852 consecutive patients hospitalized for pneumonia between October 2018 and September 2020. Patients who were <65 years old, scheduled for admission, did not receive inpatient rehabilitation, or died during admission were excluded. A short physical performance battery (SPPB) test was performed by physical therapists upon discharge. The primary outcome measure was a composite endpoint of readmission or mortality due to any cause within 6 months of discharge. RESULTS: In total, 521 patients (median age, 80 years; interquartile range, 74-86 years) were included in the analyses, and were divided into the following two groups: robust group with SPPB scores >9 (n = 150), and physical frailty group with SPPB scores ≤9 (n = 371). Of these, 346 (66.4%) patients were men; and the median SPPB score was 6 (interquartile range, 1-10). During the median follow-up period of 53 days (interquartile range, 4-180 days), 92 (17.6%) patients were readmitted and 25 (4.8%) patients died. Patients with physical frailty were at an increased risk for the primary endpoint (hazard ratio, 2.21; 95% confidence interval, 1.44-3.41; P < 0.001); the risk remained significant after adjusting for multiple variables (adjusted hazard ratio, 1.70; 95% confidence interval, 1.05-2.74; P = 0.028). CONCLUSIONS: Among older patients with pneumonia, physical frailty status at discharge was an independent risk factor for readmission and mortality within 6 months after initial discharge. Geriatr Gerontol Int 2021; 21: 926-931.

[Bacterial Meningitis and Suppurative Thrombophlebitis after Trigger Point Injections: A Case Report].

A 73-year-old woman with untreated diabetes mellitus visited our emergency department with a 4-day history of progressive headache, fever, and chills. She received trigger point injections (TPI) into the right sternocleidomastoid for exercise-induced ipsilateral shoulder pain, 13 days before admission and into the right trapezius, 6 days before admission. Cerebrospinal fluid (CSF) evaluation revealed pleocytosis with a predominance of neutrophils, as well as elevated protein and reduced glucose levels. Magnetic resonance imaging of the cervical spine revealed inflammatory changes of the right-sided posterior cervical muscles and the right vertebral arch of the C5-C6 vertebrae without contrast enhancement of the right posterior cervical veins. She was diagnosed with bacterial meningitis and suppurative thrombophlebitis, and empiric broad-spectrum antibiotic therapy was administered intravenously. The initial blood culture yielded Streptococcus intermedius; however, CSF culture showed no growth. She recovered completely after a 4-week course of intravenously administered ampicillin and was discharged with oral clindamycin to complete a total 6-week antibiotic course. TPI are widely used as a safe therapeutic strategy associated with few complications, and serious infections are rare. However, clinicians must remain mindful of the possibility of these complications in immunocompromised patients, such as those with diabetes mellitus who undergo TPI. (Received September 18, 2020; Accepted December 21, 2020; Published June 1, 2021).