Femoral neuropathy: A clinical and electrodiagnostic review.

INTRODUCTION/AIMS: Femoral neuropathies can cause severe, prolonged debility, yet there have been few clinical and electrodiagnostic (EDx) studies addressing this condition. The aim of this study was to better understand the etiologies, EDx features, and clinical course of femoral neuropathy. METHODS: We identified patients evaluated at Mayo Clinic Rochester between January 1, 1999 and July 31, 2019, with possible new femoral neuropathy ascertained via International Classification of Diseases-versions 9 and 10 diagnosis codes presenting within 6 months of symptom onset. RESULTS: A retrospective review of 1084 records was performed and we ultimately identified 159 patients with isolated femoral neuropathy for inclusion. The most common femoral neuropathy etiologies were compressive (40%), perioperative stretch (35%), and inflammatory (6%). Presenting symptoms included weakness (96%), sensory loss (73%), and pain (53%). Presenting motor physical exam findings demonstrated moderate weakness (34%) or no activation (25%) of knee extension and mild (32%) or moderate (35%) weakness of hip flexion. Seventy-two percent of patients underwent EDx testing, including 22 with femoral motor nerve conduction studies. Treatment often involved physical therapy (89%) and was otherwise etiology-specific. In patients with follow-up data available (n = 154), 83% had subjective clinical improvement at follow-up with a mean time to initial improvement of 3.3 months and mean time to recovery at final follow-up of 14.8 months. Only 48% of patients had nearly complete or complete recovery. DISCUSSION: In our cohort, the most common etiologies of femoral neuropathy were compression or perioperative stretch with high initial morbidity. Although motor recovery is common, improvement is often prolonged and incomplete.

Clinical and electrophysiological findings in C9ORF72 ALS.

INTRODUCTION/AIMS: Amyotrophic lateral sclerosis (ALS) is a progressive, fatal, neurodegenerative disorder of motor neurons in which the cause is mostly unknown. Early identification of genetic ALS cases, of which C9ORF72 (C9ALS) is the most frequent, can have important implications for evaluation, prognosis, and therapeutics. Here, we aimed to characterize the clinical and electrophysiological hallmarks of C9ALS and investigate differences from C9ORF72 negative ALS (non-C9ALS). METHODS: We retrospectively reviewed clinical and electrodiagnostic (EDX) data for all genetically confirmed C9ALS cases seen between 1/1/2012 and 10/1/2020 who met Gold Coast criteria and compared them 1:1 with non-C9ALS patients within the same time frame. RESULTS: A total of 99 C9ALS and 99 non-C9ALS cases were identified. Compared to non-C9ALS, C9ALS demonstrated higher prevalence in women, lesser racial variability, stronger family history of ALS, and higher frequency of upper motor neuron signs. EDX testing of C9ALS showed higher median sensory nerve and lower fibular compound muscle action potential amplitudes. DISCUSSION: Although the differences between C9ALS and non-C9ALS reached statistical significance in certain nerve conduction parameters, they were not sufficient to discriminate between groups on a case-by-case basis. Genetic testing is required to identify C9ALS patients.

Rapid Antigen Screening of Students and Staff for SARS-CoV-2 in Rural School Districts, Pierce County, WA, 2020.

During fall 2020 in rural Pierce County, Washington, school districts and the county health department offered weekly rapid antigen screening to students and staff. Asymptomatic screening identified 42.5% of confirmed cases from the population. Parents reported it was a positive experience for their children. The program supported decisions to return to in-person learning, but screening ended because of resource and technical limitations. When planning in-school screening, stakeholder engagement and resource sustainability are important factors to consider. (Am J Public Health. 2022;112(8):1134-1137. https://doi.org/10.2105/AJPH.2022.306875).

Streptococcal Pharyngitis: Compliance With National Testing Guidelines in a Pediatric Emergency Department.

OBJECTIVES: The Infectious Diseases Society of America (IDSA) guidelines regarding group A streptococcal (GAS) pharyngitis advise against routine testing for patients younger than 3 years, patients without pharyngitis, and patients with symptoms suggesting a viral infection. Group A streptococcal testing may be overused in some clinical settings; thus, we conducted this study to evaluate compliance with the IDSA guidelines in a pediatric emergency department (ED) setting. METHODS: This retrospective cohort study describes patients younger than 18 years presenting to 2 urban pediatric EDs in 2016 who underwent rapid antigen detection testing for GAS pharyngitis. Testing was classified as noncompliant with the IDSA guidelines if the chief complaint was not indicative of GAS infection and/or the patient age was younger than 3 years. Appropriate nonparametric tests compared groups by IDSA testing compliance status. RESULTS: A total of 13,585 patient encounters met inclusion criteria; 5255 (39%) were noncompliant with the IDSA testing guidelines, the majority due to a chief complaint inconsistent with GAS pharyngitis (67%) and secondarily due to the age of younger than 3 years (48%). Among the patients with noncompliant testing, 51% were prescribed an antibiotic, and return encounters were more likely to occur (13% vs 10%, P < 0.001). Return encounters more commonly resulted in respiratory diagnoses in those with noncompliant GAS testing (60% vs 45%, P < 0.001). CONCLUSIONS: Nearly 40% of all pediatric ED encounters with GAS testing were noncompliant with the IDSA guidelines and were associated with greater return encounter rates. Potential negative outcomes from noncompliant GAS testing include misdiagnosis, inappropriate use of antibiotics, allergic reactions, and loss of school days. Informed interventions to reduce unnecessary GAS testing are warranted.

Autosomal dominant calpainopathy due to heterozygous CAPN3 C.643_663del21.

INTRODUCTION: A calpain-3 (CAPN3) gene heterozygous deletion (c.643_663del21) was recently linked to autosomal dominant (AD) limb-girdle muscular dystrophy. However, the possibility of digenic disease was raised. We describe 3 families with AD calpainopathy carrying this isolated mutation. METHODS: Probands heterozygous for CAPN3 c.643_663del21 were identified by targeted next generation or whole exome sequencing. Clinical findings were collected for probands and families. Calpain-3 muscle Western blots were performed in 3 unrelated individuals. RESULTS: Probands reported variable weakness in their 40s or 50s, with myalgia, back pain, or hyperlordosis. Pelvic girdle muscles were affected with adductor and hamstring sparing. Creatine kinase was normal to 1,800 U/L, independent of weakness severity. Imaging demonstrated lumbar paraspinal muscle atrophy. Electromyographic findings and muscle biopsies were normal to mildly myopathic. Muscle calpain-3 expression was reduced. DISCUSSION: This study provides further evidence for AD calpainopathy associated with CAPN3 c.643_663del21. No pathogenic variants in other genes known to cause myopathy were detected. Muscle Nerve 57: 679-683, 2018.

Composite ganglioside autoantibodies and immune treatment response in MMN and MADSAM.

INTRODUCTION: Multifocal motor neuropathy (MMN) is a motor only, asymmetric onset neuropathy that is relatively treatment-refractory compared with classic chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and multifocal acquired demyelinating sensory and motor (MADSAM) neuropathy. METHODS: We reviewed 35 patients seropositive for GM1 (monosialo-asialo [immunoglobulin M, IgM; immunoglobulin G, IgG]) and/or GD1b (disialo [IgG, IgM]) autoantibodies having MMN, classic CIDP, or MADSAM. Immune-treatment responsiveness and clinical course was compared with antibody negative disease controls. RESULTS: Seventy-nine percent of seropositives with an initial diagnosis of MMN were immunotherapy responsive compared with 46% of seronegatives (P = 0.045). Eight ganglioside antibody positive MMN patients of 19 (42%) developed sensory findings consistent with MADSAM compared with 3 of 41 (7%) seronegative MMN patients (P = 0.003). MMN and MADSAM patients with ganglioside antibody positivity had more sustained treatment responses (P = 0.03). DISCUSSION: Patients initially diagnosed with MMN seropositive for diverse GM1 autoantibodies appear more likely to have sustained treatment response and evolution to MADSAM. Muscle Nerve 57: 1000-1005, 2018.

Steak and Stupor: seizures and E. coli O157 infection.

Neurological complications of haemolytic uraemic syndrome (HUS) include altered states of consciousness, seizures, ischaemic stroke and encephalopathy. Adult-onset HUS is uncommon, and there is only a limited literature reporting neurological complications in this population. We report an adult with Shiga toxin-associated HUS complicated by focal-onset non-convulsive status epilepticus, who made a full neurological recovery.

Incidence, types, and lifetime risk of adult-onset strabismus.

OBJECTIVE: To describe the incidence and types of adult-onset strabismus in a geographically defined population. DESIGN: Retrospectively reviewed population-based cohort. PARTICIPANTS: All adult (≥19 years of age) residents of Olmsted County, Minnesota, diagnosed with new-onset adult strabismus from January 1, 1985, through December 31, 2004. METHODS: The medical records of all potential cases identified by the resources of the Rochester Epidemiology Project were reviewed. MAIN OUTCOME MEASURES: Incidence rates for adult-onset strabismus and its types. RESULTS: Seven hundred fifty-three cases of new-onset adult strabismus were identified during the 20-year period, yielding an annual age- and gender-adjusted incidence rate of 54.1 cases (95% confidence interval, 50.2-58.0) per 100 000 individuals 19 years of age and older. The 4 most common types of new-onset strabismus were paralytic (44.2% of cases), convergence insufficiency (15.7%), small-angle hypertropia (13.3%), and divergence insufficiency (10.6%). The incidence of adult-onset strabismus overall and its 4 most common forms significantly increased with age (P <0.001 for all), with a peak incidence in the eighth decade of life. The lifetime risk of being diagnosed with adult-onset strabismus was 4.0% in women and 3.9% in men. CONCLUSIONS: Paralytic strabismus was the most common subtype of new-onset adult strabismus in this population-based cohort. All of the most common forms of adult-onset strabismus increased with age, especially after the sixth decade of life. Further characterization of strabismus types found in this study is warranted to better define this disorder.

Antineutrophilic Cytoplasmic Antibody-Related Spinal Pachymeningitis.

Isolated spinal pachymeningitis is rarely encountered in clinical practice. Narrowing down the specific cause in individual patients is challenging as the possible etiologies are broad, there is substantial overlap in clinical presentation, and obtaining adequate data is complex, often affected by prior empiric treatments, including steroids. Here, we describe a rare patient with spinal pachymeningitis resulting in subacute to chronic progressive lower extremity weakness and eventually paraplegia. We discuss how we obtained the final diagnosis, provide our diagnostic framework, and offer practical advice in evaluating these patients.

Radiologically Inserted Gastrostomy Tube Placement Guided by the Assessment and Primary Palliative Care Provided by an Amyotrophic Lateral Sclerosis Multidisciplinary Clinic: A Single-Arm Retrospective Clinical Study.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease with a median survival of about 3 years. An ALS multidisciplinary team can provide primary palliative care and improve outcomes and quality of life for patients. Feeding tube insertion may be considered for patients with significant weight loss, or respiratory insufficiency. While radiologically inserted gastrostomy (RIG) tube placement may be an option, further studies are required to determine its best timing and appropriateness. This study's objectives were to evaluate the feasibility and outcomes of RIG tube placement in ALS patients over a 90-day follow-up period through the assessment and primary palliative care provided by the multidisciplinary team. This retrospective study reviewed the placement of 16 or 18 French RIG-tube without intubation or endoscopy for 36 ALS patients at a single center between April 2019 and December 2021. Measures included ALS Functional Rating Scale-Revised (ALSFRS-R) scores to determine the ALS stage. Demographic, clinical, procedural, and follow-up data were reviewed. Results showed that the RIG tube placement had a low rate of minor adverse events (11%) and no major procedure-related adverse events. The mean ALSFRS-R score at the time of procedure in subjects who died within 90 days was lower than of those alive beyond 90 days (P = .04). This study found that RIG-tube placement is a safe and effective way to manage dysphagia in ALS patients and highlights the importance of educating members of the multidisciplinary clinic in palliative care principles to determine the appropriateness of RIG tube placement.

Neurologic Clinical, Electrophysiologic, and Pathologic Characteristics of Primary vs Secondary Neurolymphomatosis.

BACKGROUND AND OBJECTIVES: Neurolymphomatosis (NL) is characterized by lymphomatous infiltration of the peripheral nervous system presenting as the initial manifestation of a lymphoma (primary NL [PNL]) or in relapse of a known lymphoma (secondary NL [SNL]). This report details and compares the neurologic clinicopathologic characteristics of these 2 groups. METHODS: This retrospective study was performed on patients diagnosed with pathologically confirmed NL in nerve between January 1, 1992, and June 31, 2020. Patient clinical characteristics, neurologic examination, imaging studies, EMG, and nerve biopsy data were collected, analyzed, and compared between PNL and SNL. RESULTS: A total of 58 patients were identified (34 PNL and 24 SNL). Time from neurologic symptom onset to diagnosis was longer in PNL at 18.5 months compared with 5.5 months in SNL (p = 0.01). Neurologic symptoms were similar in both patient groups and included primarily sensory loss (98%), severe pain (76%), and asymmetric weakness (76%). A wide spectrum of EMG-confirmed different neuropathy patterns were observed, but patients with SNL had increased numbers of mononeuropathies (n = 8) compared with PNL (n = 1, p = 0.01). MRI studies detected NL more frequently (86%) compared with fluorodeoxyglucose (FDG)-PET CT imaging studies (60%) (p = 0.007). Nerve biopsies revealed B-cell lymphoma (PNL n = 32, SNL n = 22), followed by T-cell lymphoma (PNL n = 2, SNL n = 2), with increased demyelination in both groups and increased axonal degeneration (p = 0.01) and multifocal myelinated fiber loss (p = 0.04) significant in SNL vs PNL. Identifying SNL resulted in patient treatment modifications but a worse prognosis compared with PNL (p = 0.025). DISCUSSION: While PNL and SNL are both primarily painful and asymmetric neuropathies with axonal and demyelinating features on EMG and nerve biopsy, SNL presents somewhat differently than PNL with fulminant, asymmetric often mononeuropathies better detected on MRI than FDG-PET/CT. The focal pattern of SNL is likely a result of residual cancer cells that evaded initial chemotherapy, which does not cross the blood-nerve barrier, and these cells can later recur and result in fulminant disease. Although still resulting in a poorer prognosis, identifying SNL is important because this changed treatment and management in every SNL case.

Multisystem proteinopathies (MSPs) and MSP-like disorders: Clinical-pathological-molecular spectrum.

OBJECTIVES: Mutations in VCP, HNRNPA2B1, HNRNPA1, and SQSTM1, encoding RNA-binding proteins or proteins in quality-control pathways, cause multisystem proteinopathies (MSP). They share pathological findings of protein aggregation and clinical combinations of inclusion body myopathy (IBM), neurodegeneration [motor neuron disorder (MND)/frontotemporal dementia (FTD)], and Paget disease of bone (PDB). Subsequently, additional genes were linked to similar but not full clinical-pathological spectrum (MSP-like disorders). We aimed to define the phenotypic-genotypic spectrum of MSP and MSP-like disorders at our institution, including long-term follow-up features. METHODS: We searched the Mayo Clinic database (January 2010-June 2022) to identify patients with mutations in MSP and MSP-like disorders causative genes. Medical records were reviewed. RESULTS: Thirty-one individuals (27 families) had pathogenic mutations in: VCP (n = 17), SQSTM1 + TIA1 (n = 5), TIA1 (n = 5), MATR3, HNRNPA1, HSPB8, and TFG (n = 1, each). Myopathy occurred in all but 2 VCP-MSP patients with disease onset at age 52 (median). Weakness pattern was limb-girdle in 12/15 VCP-MSP and HSPB8 patient, and distal-predominant in other MSP and MSP-like disorders. Twenty/24 muscle biopsies showed rimmed vacuolar myopathy. MND and FTD occurred in 5 (4 VCP, 1 TFG) and 4 (3 VCP, 1 SQSTM1 + TIA1) patients, respectively. PDB manifested in 4 VCP-MSP. Diastolic dysfunction occurred in 2 VCP-MSP. After 11.5 years (median) from symptom onset, 15 patients ambulated without gait-aids; loss of ambulation (n = 5) and death (n = 3) were recorded only in VCP-MSP. INTERPRETATION: VCP-MSP was the most common disorder; rimmed vacuolar myopathy was the most frequent manifestation; distal-predominant weakness occurred frequently in non-VCP-MSP; and cardiac involvement was observed only in VCP-MSP.

Comparative Performance of Different Respiratory Test Parameters for Detection of Early Respiratory Insufficiency in Patients With ALS.

BACKGROUND AND OBJECTIVES: To compare the performance of different respiratory function testing parameters in a multidisciplinary amyotrophic lateral sclerosis (ALS) clinic. METHODS: Demographics, clinical data, and respiratory testing parameters were abstracted from the medical records of patients who attended a multidisciplinary ALS clinic from 2008 to 2016. We compared the performance of the 3 primary respiratory test parameters used by Medicare for the initiation of noninvasive ventilation (NIV) (forced vital capacity [FVC] < 50% predicted, maximum inspiratory pressure [MIP] < 60 cm H2O, and abnormal overnight pulse oximetry [OvOx]) on how they related to several clinically relevant attributes. RESULTS: Four hundred seventy-six patients were identified who underwent at least 1 respiratory test. Abnormalities of OvOx, MIP, and FVC occurred at a median of 1.6, 1.5, and 3.8 years from disease onset, respectively (p < 0.00001). Patients with bulbar-onset ALS exhibited earlier abnormalities in MIP and FVC than in spinal-onset ALS (p < 0.005). The median survival after an abnormal OvOx, MIP, or FVC test was 1.4, 1.4, and 0.9 years, respectively (p < 0.0001). Using the ALS Functional Rating Score respiratory subscales, at the time of reported respiratory symptoms there were abnormalities in OvOx (60%), MIP (69%), and FVC (19%). Conversely, when respiratory parameter abnormalities preceded reported respiratory symptoms, this occurred with frequencies in OvOx (79%), MIP (42%), or FVC (24%). Four hundred forty-three patients (93.1%) developed at least 1 abnormal respiratory measure meeting Medicare criteria for NIV consideration, but fewer than 50% in our cohort demonstrated NIV use. Improved survival in subjects using NIV was statistically significant in patients with bulbar-onset ALS. DISCUSSION: Abnormalities in OvOx and MIP perform better than FVC at early detection of neuromuscular respiratory weakness in ALS. Initiation of NIV in patients with respiratory insufficiency may improve the overall survival in ALS. In the setting of the COVID-19 pandemic, FVC and MIP have not been routinely performed because of infectious aerosol generation. OvOx, which we now routinely mail to patients' homes, has been used exclusively during the COVID-19 pandemic and allows for continued remote monitoring of the respiratory status of patients with ALS. CLASSIFICATION OF EVIDENCE: This cohort study provides Class III evidence that in people with ALS, OvOx and MIP are valuable respiratory parameters for the detection of early respiratory insufficiency.

Electrodiagnostic Assessment of Myopathy.

Electrodiagnostic testing is a useful tool in the evaluation of suspected myopathy and helps to confirm the presence of a myopathy and exclude disease mimickers. The electrodiagnostic pattern of findings during testing guides subsequent laboratory evaluation, genetic testing, and in identifying potential muscle biopsy targets. It also provides a baseline for subsequent assessment of disease progression or response to therapy. This article summarizes the approach to electrodiagnostic assessment in various myopathic disorders.

Primer on the In-home Teleneurologic Examination: A COVID-19 Pandemic Imperative.

It is imperative in the coronavirus disease 2019 (COVID-19) pandemic that we serve our patients by implementing teleneurology visits for those who require neurologic advice but do not need to be seen face to face. The authors propose a thorough, practical, in-home, teleneurologic examination that can be completed without the assistance of an on-the-scene medical professional and can be tailored to the clinical question. We hope to assist trainees and practicing neurologists doing patient video visits for the first time during the COVID-19 pandemic, focusing on what can, rather than what cannot, be easily examined.

Pure Motor Onset and IgM-Gammopathy Occurrence in Multifocal Acquired Demyelinating Sensory and Motor Neuropathy.

OBJECTIVES: To longitudinally investigate patients with multifocal acquired demyelinating sensory and motor (MADSAM) neuropathy, quantifying timing and location of sensory involvements in motor-onset patients, along with clinico-histopathological and electrophysiological findings to ascertain differences in patients with and without monoclonal gammopathy of uncertain significance (MGUS). METHODS: Patients with MADSAM neuropathy seen at Mayo Clinic and tested for monoclonal gammopathy and ganglioside antibodies, were retrospectively reviewed (January 1st, 2007-December 31st, 2018). RESULTS: Of 76 patients with MADSAM, 53% had pure motor, 16% pure sensory, 30% sensorimotor and 1% cranial nerve onsets. Motor-onset patients were initially diagnosed as multifocal motor neuropathy (MMN). MGUS occurred in 25% (89% IgM subtype), associating with ganglioside autoantibodies (p<0.001) and higher IgM titers (p<0.04). Median time to sensory involvements (confirmed by electrophysiology) in motor-onset patients was 18 months (range: 6-180). Compared to initial motor nerve involvements, subsequent sensory findings were within the same territory 35% (14/40), outside 20% (8/40), or both 45% (18/40). Brachial and lumbosacral plexus MRI was abnormal in 87% (34/39) and 84% (21/25), respectively, identifying hypertrophy and increased T2 signal predominantly in brachial plexus trunks (64%), divisions (69%), and cords (69%), and intrapelvic sciatic (64%) and femoral (44%) nerves. Proximal fascicular nerve biopsies (n=9) more frequently demonstrated onion-bulb pathology (p=0.001) and endoneurial inflammation (p=0.01) than distal biopsies (n=17). MRI and biopsy findings were similar amongst patient subgroups. Initial Inflammatory Neuropathy Cause and Treatment (INCAT) disability scores were higher in patients with MGUS relative to without (p=0.02). Long-term treatment responsiveness by INCAT score reduction ≥1 or motor Neuropathy Impairment Score (mNIS) >8 point reduction occurred in 75% (49/65) irrespective of MGUS or motor-onsets. Most required ongoing immunotherapy (86%). Patients with MGUS more commonly required dual-agent immunotherapy for stability (p=0.02). DISCUSSION: Pure motor-onsets are the most common MADSAM presentation. Long-term follow-up, repeat electrophysiology and nerve pathology help distinguish motor-onset MADSAM from MMN. Better long-term immunotherapy responsiveness occurs in motor-onset MADSAM compared to MMN reports. Patients having MGUS commonly require dual immunotherapy. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that most clinical, electrophysiological, and histopathological findings were similar between patients with MADSAM with and without monoclonal gammopathy of unknown significance.

The Mary Walker effect: Mary Broadfoot Walker.

Mary Broadfoot Walker (1888-1974) was the first to demonstrate the 'Mary Walker effect' describing the weakness of other muscle groups following release of the arteriovenous occlusion of an unrelated exercising muscle group in patients with myasthenia gravis, which led to the search for a circulating causative agent for myasthenia gravis. She was the first to clearly demonstrate that strength temporarily improved in patients with myasthenia gravis with physostigmine or Prostigmin (neostigmine). This dramatic treatment response has been erroneously termed the 'Mary Walker effect'. Further, she noted hypokalaemia during attacks of weakness in familial periodic paralysis, pioneering treatment with potassium chloride. Although Mary Walker practiced in a nonacademic setting and trained at a time when women were not allowed to train alongside men, she was the first to convincingly demonstrate three life-changing treatments in the field of neuromuscular medicine, a feat that few physicians of any era can claim.