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.

Systemic manifestations and symptom burden of facioscapulohumeral muscular dystrophy in a referral cohort.

INTRODUCTION/AIMS: The full spectrum of the clinical phenotype of facioscapulohumeral muscular dystrophy (FSHD), beyond skeletal muscle weakness, remains poorly characterized. In this study, we describe systemic manifestations and symptom burden in a large series of FSHD patients. METHODS: We performed a retrospective chart review of FSHD patients seen at our institution between 2000 and 2017. We reviewed patients' responses to a comprehensive review of symptoms and the results of diagnostic testing for sensorineural hearing loss, cardiac disease, dysphagia, ocular abnormalities, and respiratory insufficiency. We assessed the association between disease manifestations and age of onset, genetic profile, and disease duration. RESULTS: We identified 87 patients with FSHD. The most common reported symptoms included pain (71%), difficulty sleeping (41%), headaches (27%), and altered mood (24%). When tested, 7 of 16 (44%) patients had sensorineural hearing loss, 20 of 60 (33%) had cardiac arrhythmias or conduction defects, 17 of 45 (38%) had echocardiogram abnormalities, 12 of 25 (48%) had reduced forced vital capacity, and 4 of 10 (40%) had oropharyngeal dysphagia. However, patients with these abnormalities represented 8%, 23%, 20%, 14%, and 5% of total number of patients, respectively, as uniform screening was lacking. Ocular pathology attributable to FSHD was not detected. DISCUSSION: FSHD demonstrates a broad clinical phenotype. Increased vigilance among neurologists to screen for systemic manifestations of the disease is warranted. More uniform screening and future population-based studies are needed to compare findings in FSHD patients with the general population.

Autoimmune encephalitis epidemiology and a comparison to infectious encephalitis.

OBJECTIVE: To evaluate the incidence and prevalence of autoimmune encephalitis and compare it to that of infectious encephalitis. METHODS: We performed a population-based comparative study of the incidence and prevalence of autoimmune and infectious encephalitis in Olmsted County, Minnesota. Autoimmune encephalitis diagnosis and subgroups were defined by 2016 diagnostic criteria, and infectious encephalitis diagnosis required a confirmed infectious pathogen. Age- and sex-adjusted prevalence and incidence rates were calculated. Patients with encephalitis of uncertain etiology were excluded. RESULTS: The prevalence of autoimmune encephalitis on January 1, 2014 of 13.7/100,000 was not significantly different from that of all infectious encephalitides (11.6/100,000; p = 0.63) or the viral subcategory (8.3/100,000; p = 0.17). The incidence rates (1995-2015) of autoimmune and infectious encephalitis were 0.8/100,000 and 1.0/100,000 person-years, respectively (p = 0.58). The number of relapses or recurrent hospitalizations was higher for autoimmune than infectious encephalitis (p = 0.03). The incidence of autoimmune encephalitis increased over time from 0.4/100,000 person-years (1995-2005) to 1.2/100,000 person-years (2006-2015; p = 0.02), attributable to increased detection of autoantibody-positive cases. The incidence (2.8 vs 0.7/100,000 person-years, p = 0.01) and prevalence (38.3 vs 13.7/100,000, p = 0.04) of autoimmune encephalitis was higher among African Americans than Caucasians. The prevalence of specific neural autoantibodies was as follows: myelin oligodendrocyte glycoprotein, 1.9/100,000; glutamic acid decarboxylase 65, 1.9/100,000; unclassified neural autoantibody, 1.4/100,000; leucine-rich glioma-inactivated protein 1, 0.7/100,000; collapsin response-mediator protein 5, 0.7/100,000; N-methyl-D-aspartate receptor, 0.6/100,000; antineuronal nuclear antibody type 2, 0.6/100,000; and glial fibrillary acidic protein α, 0.6/100,000. INTERPRETATION: This study shows that the prevalence and incidence of autoimmune encephalitis are comparable to infectious encephalitis, and its detection is increasing over time. Ann Neurol 2018;83:166-177.