Transverse myelitis (TM) is a potentially disabling neurologic syndrome with a variety of causes; single or recurrent episodes may result in permanent wheelchair dependence.¹ In 1 study, 70% of patients referred to a tertiary referral center with a diagnosis of idiopathic transverse myelitis were found to have a specific etiology for their myelopathy,² highlighting that the causes of transverse myelitis are poorly recognized among the neurology community.² The discovery of the serum diagnostic biomarkers, aquaporin-4 autoantibody (AQP4-IgG) targeting astrocytes, and myelin oligodendrocyte glycoprotein autoantibody (MOG-IgG) targeting oligodendrocytes has aided in the ability to classify patients with idiopathic TM into a specific disease category.^3-6 Accurate diagnosis of these disorders has important treatment and prognostic implications. The clinical, radiologic, and prognostic features of myelitis seropositive for AQP4-IgG have been well characterized,^7-10 but information about the features accompanying myelitis associated with MOG-IgG is much more limited.^11-13 Prior reports suggest that patients with MOG-IgG may have either a monophasic or relapsing course and that the myelitis may occur in isolation, as a component of acute disseminated encephalomyelitis (ADEM), or concurrently with optic neuritis.¹² Accumulating evidence has suggested that detection of MOG-IgG defines a clinical syndrome distinct from both multiple sclerosis (MS) and AQP4-IgG seropositive neuromyelitis optica spectrum disorder.^11,13-16 In this study, we sought to determine the clinical, radiologic, and laboratory characteristics and outcome of myelitis seropositive for MOG-IgG and compare this disease with myelitis associated with AQP4-IgG and MS.

Objective To define the frequency, duration, and severity of intractable nausea, vomiting, or hiccups in aquaporin-4–immunoglobulin G (AQP4-IgG)-positive neuromyelitis optica spectrum disorder (NMOSD) and propose diagnostic criteria and a severity scale for area postrema syndrome (APS). Methods An International NMOSD database was interrogated for frequency of APS. Patients with AQP4-IgG–positive NMOSD completed an APS symptom questionnaire. Nausea and vomiting severity was derived from the Pregnancy-Unique Quantification of Emesis and Nausea (PUQE) score. The diagnostic criteria, severity scale, and immunotherapy response was applied to a prospective validation cohort of patients from multiple centers. Results Analysis of an international database for AQP4-IgG–seropositive NMOSD (n = 430) revealed a high prevalence of isolated APS attacks (onset 7.1%–10.3%; subsequent 9.4%–14.5%) across continents. For 100 patients with 157 episodes of APS, nausea (n = 127, 81%) lasted for a median of 14 days (range 2–365), vomiting (113, 72%) with a median of 5 episodes/d (2–40) lasted 1–20 minutes, and hiccups (102, 65%) lasted a median of 14 days (2–365). Symptoms consistently and completely resolved following immunotherapy. Data were used to propose APS diagnostic criteria and repurpose PUQE score (hiccups severity grade based on symptom duration). The clinical utility was demonstrated in a prospective validation cohort. Conclusion Isolated APS attacks are frequently encountered both at onset and during the NMOSD course. The diagnostic criteria proposed here will assist clinicians in recognizing APS. Diagnosis of an APS attack earlier than 48 hours is possible if a dorsal medulla lesion is detected. Accurate diagnosis and evaluation of APS attack severity will assist in outcome measurement in NMOSD clinical trials.

Background: Cerebrospinal fluid (CSF) used in immunoglobulin gamma (IgG) index testing and oligoclonal bands (OCBs) are common laboratory tests used in the diagnosis of multiple sclerosis. The measurement of CSF free light chains (FLC) could pose as an alternative to the labor-intensive isoelectric-focusing (IEF) gels used for OCBs. Methods: A total of 325 residual paired CSF and serum specimens were obtained after physician-ordered OCB IEF testing. CSF kappa (cKFLC) and lambda FLC (cLFLC), albumin and total IgG were measured. Calculations were performed based on combinations of analytes: CSF sum of kappa and lambda ([cKFLC+cLFLC]), kappa-index (K-index) ([cKFLC/sKFLC]/[CSF albumin/serum albumin]), kappa intrathecal fraction (KFLC_IF) {([cKFLC/sKFLC]–[0.9358×CSF albumin/serum albumin]^[0.6687×sKFLC]/cKFLC)} and IgG-index ([CSF IgG/CSF albumin]/[serum IgG/serum albumin]). Results: Patients were categorized as: demyelination (n=67), autoimmunity (n=53), non-inflammatory (n=50), inflammation (n=38), degeneration (n=28), peripheral neuropathy (n=24), infection (n=13), cancer (n=11), neuromyelitis optica (n=10) and others (n=31). cKFLC measurement used alone at a cutoff of 0.0611 mg/dL showed >90% agreement to OCBs, similar or better performance than all other calculations, reducing the number of analytes and variables. When cases of demyelinating disease were reviewed, cKFLC measurements showed 86% clinical sensitivity/77% specificity. Conclusions: cKFLC alone demonstrates comparable performance to OCBs along with increased sensitivity for demyelinating diseases. Replacing OCB with cKFLC would alleviate the need for serum and CSF IgG and albumin and calculated conversions. cKFLC can overcome challenges associated with performance, interpretation, and cost of traditional OCBs, reducing costs and maintaining sensitivity and specificity supporting MS diagnosis.

Transnasal sphenopalatine ganglion block is emerging as is an attractive and effective treatment modality for acute migraine headaches, cluster headache, trigeminal neuralgia, and several other conditions. We assessed the efficacy and safety of this treatment using the Sphenocath® device. 55 patients with acute migraine headaches underwent this procedure, receiving 2 ml of 2% lidocaine in each nostril. Pain numeric rating scale (baseline, 15 minutes, 2 hours, and 24 hours) and patient global impression of change (2 hours and 24 hours after treatment) were recorded. The majority of patients became headache-free at 15 minutes, 2 hours, and 24 hours after procedure (70.9%, 78.2%, and 70.4%, resp.). The rate of headache relief (50% or more reduction in headache intensity) was 27.3% at 15 minutes, 20% at 2 hours, and 22.2% at 24 hours. The mean pain numeric rating scale decreased significantly at 15 minutes, 2 hours, and 24 hours, respectively. Most patients rated the results as very good or good. The procedure was well-tolerated with few adverse events. This treatment is emerging as an effective and safe option for management of acute migraine attacks.

Objective Diagnostic criteria from 2002 classify transverse myelitis (TM) as idiopathic or disease associated but predate the discovery of aquaporin-4 (AQP4)–immunoglobulin G (IgG) and myelin oligodendrocyte glycoprotein (MOG)-IgG, which associate with TM. Prior incidence estimates of idiopathic TM (ITM) range from 1 to 6.2 per 1 million. We sought to determine whether the population-based incidence and prevalence of ITM were reduced by testing patients with ITM for AQP4/MOG-IgG and reclassifying seropositive cases as having disease-associated TM. Methods For this observational study, we retrospectively identified all cases of incident (January 1, 2003–December 31, 2016) and prevalent (December 31, 2016) ITM in Olmsted County (85% white) by using the Rochester Epidemiology Project medical records linkage system. ITM was defined by the 2002 Transverse MyelitisConsortium Working Group diagnostic criteria. Available sera were tested for AQP4-IgG and MOG-IgG. Results Twenty-four patients (incident 22, prevalent 17) initially met 2002 ITM criteria (longitudinally extensive TM [LETM] 6). Sera were tested for AQP4-IgG in 22 of 24 (92%) and MOG-IgG in 21 of 24 (88%). Three seropositive cases (AQP4-IgG 2, MOG-IgG 1) were identified and reclassified as having disease-associated TM, accounting for 14% of total incident and 12% of total prevalent cases. AQP4-IgG and MOG-IgG seropositive cases represented 50% (3 of 6) of idiopathic LETM. After reclassification of seropositive patients, the final ITM incidence was 8.6 per 1,000,000 and prevalence was 7.9 per 100,000. Three cases of ITM (14%) subsequently fulfilled multiple sclerosis criteria within the study period. Conclusions The availability of AQP4-IgG and MOG-IgG modestly reduced ITM incidence and prevalence, which remained higher than previously reported in this predominantly white population. Incorporation of these biomarkers into future revisions of TM diagnostic criteria should be considered.