Beyond Myelin Oligodendrocyte Glycoprotein and Aquaporin-4 Antibodies: Alternative Causes of Optic Neuritis.

Optic neuritis (ON) is the most common cause of vision loss in young adults. It manifests as acute or subacute vision loss, often accompanied by retrobulbar discomfort or pain during eye movements. Typical ON is associated with Multiple Sclerosis (MS) and is generally mild and steroid-responsive. Atypical forms are characterized by unusual features, such as prominent optic disc edema, poor treatment response, and bilateral involvement, and they are often associated with autoantibodies against aquaporin-4 (AQP4) or Myelin Oligodendrocyte Glycoprotein (MOG). However, in some cases, AQP4 and MOG antibodies will return as negative, plunging the clinician into a diagnostic conundrum. AQP4- and MOG-seronegative ON warrants a broad differential diagnosis, including autoantibody-associated, granulomatous, and systemic disorders. These rare forms need to be identified promptly, as their management and prognosis are greatly different. The aim of this review is to describe the possible rarer etiologies of non-MS-related and AQP4- and MOG-IgG-seronegative inflammatory ON and discuss their diagnoses and treatments.

A score that predicts aquaporin-4 IgG positivity in patients with longitudinally extensive transverse myelitis.

BACKGROUND AND PURPOSE: Longitudinally extensive transverse myelitis (LETM) associated with aquaporin-4 autoantibodies (AQP4-IgG) can cause severe disability. Early diagnosis and prompt treatment are critical to prevent relapses. A novel score is described based on clinical and neuroimaging characteristics that predicts AQP4-IgG positivity in patients with LETM. METHODS: Patients were enrolled both retrospectively and prospectively from multiple Italian centers. Clinical and neuroimaging characteristics of AQP4-IgG positive and negative patients were compared through univariate and multivariate analysis. RESULTS: Sixty-six patients were included. Twenty-seven (41%) were AQP4-IgG positive and median age at onset was 45.5 years (range 19-81, interquartile range 24). Female sex (odds ratio [OR] 17.9, 95% confidence interval [CI] 2.6-381.9; p = 0.014), tonic spasms (OR 45.6, 95% CI 3.1-2197; p = 0.017) and lesion hypointensity on T1-weighted images (OR 52.9, 95% CI 6.8-1375; p = 0.002) were independently associated with AQP4-IgG positivity. The AQP4-IgG positivity in myelitis (AIM) score predicted AQP4-IgG positivity with 85% sensitivity and 95% specificity. Positive and negative likelihood ratios were 16.6 and 0.2 respectively. The inter-rater and intra-rater agreement in the score application were both excellent. CONCLUSIONS: The AIM score predicts AQP4-IgG positivity with good sensitivity and specificity in patients with a first episode of LETM. The score may assist clinicians in early diagnosis and treatment of AQP4-IgG positive LETM.

Does MIDAS reduction at 3 months predict the outcome of erenumab treatment? A real-world, open-label trial.

BACKGROUND: In Italy, monoclonal antibodies targeting the CGRP pathway are subsidized for the preventive treatment of high frequency and chronic migraine (CM) in patients with a MIgraine Disability ASsessment (MIDAS) score ≥ 11. Eligibility to treatment continuation requires a ≥ 50% MIDAS score reduction at three months (T3). In this study, we evaluate whether a ≥ 50% MIDAS score reduction at T3 is a reliable predictor of response to one-year erenumab treatment. METHODS: In this prospective, open-label, real-world study, 77 CM patients were treated with erenumab 70-140 mg s.c. every 28 days for one year (T13). We collected the following variables: monthly migraine days (MMDs), monthly headache days (MHDs), days of acute medication intake, MIDAS, HIT-6, anxiety, depression, quality of life and allodynia. Response to erenumab was evaluated as: i) average reduction in MMDs during the 1-year treatment period; and ii) percentage of patients with ≥ 50% reduction in MMDs during the last 4 weeks after the 13th injection (RespondersT13). RESULTS: Erenumab induced a sustained reduction in MMDs, MHDs and intake of acute medications across the 12-month treatment period, with 64.9% of patients qualifying as RespondersT13. At T3, 55.8% of patients reported a ≥ 50% reduction in MIDAS score (MIDASRes) and 55.4% of patients reported a ≥ 50% reduction in MMDs (MMDRes). MIDASRes and MMDRes patients showed a more pronounced reduction in MMDs during the 1-year treatment as compared to NON-MIDASRes (MIDASRes: T0: 23.5 ± 4.9 vs. T13: 7.7 ± 6.2; NON- MIDASRes: T0: 21.6 ± 5.4 vs. T13: 11.3 ± 8.8, p = 0.045) and NON-MMDRes (MMDRes: T0: 23.0 ± 4.5 vs. T13: 6.6 ± 4.8; NON-MMDRes: T0: 22.3 ± 6.0 vs. T13: 12.7 ± 9.2, p < 0.001) groups. The percentage of RespondersT13 did not differ between MIDASRes (74.4%) and NON-MIDASRes (52.9%) patients (p = 0.058), while the percentage of RespondersT13 was higher in the MMDRes group (83.3%) when compared to NON-MMDRes (42.9%) (p = 0.001). MMDRes predicted the long-term outcome according to a multivariate analysis (Exp(B) = 7.128; p = 0.001), while MIDASRes did not. Treatment discontinuation based on MIDASRes would have early excluded 36.0% of RespondersT13. Discontinuation based on "either MIDASRes or MMDRes" would have excluded a lower percentage (16%) of RespondersT13. CONCLUSION: MIDASRes only partly reflects the 12-month outcome of erenumab treatment in CM, as it excludes more than one third of responders. A criterion based on the alternative consideration of ≥ 50% reduction in MIDAS score or MMDs in the first three months of treatment represents a more precise and inclusive option. TRIAL REGISTRATION: The trial was retrospectively registered at www. CLINICALTRIALS: gov (NCT05442008). CGRP: Calcitonin Gene Related Peptide. MIDAS: MIgraine Disability Assessment. MMDs: monthly migraine days. MIDASRes: Patients with a MIDAS score reduction of at least 50% at T3. MMDRes: Patients with a MMDs reduction of at least 50% at T3. ResponderT13: Patients with a MMDs reduction from baseline of at least 50% in the last 4 weeks of observation period (after 13 erenumab administrations). T0: First erenumab administration. T3, T6, T9, T12: Follow-up visits at three, six, nine, and twelve months after first erenumab administration. T13: Last visit of the protocol.

COVID-19 and Guillain-Barré syndrome: A single-center prospective case series with a 1-year follow-up.

Single reports of Guillain-Barré syndrome (GBS) have been reported worldwide during the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. While case reports are likely to be biased toward uncommon clinical presentations, systematic assessment of prospective series can highlight the true clinical features and spectrum. In this prospective, observational study, we included all consecutive patients who developed GBS. In patients with SARS-CoV-2 infection as antecedent, the time-gap between the infection and GBS onset had to be ≤30 days. The referral was a neurological University Research Hospital, in the Italian Region more severely involved by the pandemic, and hospitalizing both COVID+ and non-COVID neurological diseases. Clinical, laboratory, cerebrospinal fluid, and electromyographic features of GBS diagnosed between March 2020 and March 2021 were compared to a retrospective series of GBS diagnosed between February 2019 and February 2020 (control population). Nasopharyngeal swab was still positive at GBS onset in 50% of patients. Mild-to-moderate COVID-related pneumonia, as assessed by X-ray (6 patients) or X-ray plus computerized tomography (2 patients) co-occurred in 6 of 10 patients. GBS diagnosed during the pandemic period, including 10 COVID-GBS and 10 non-COVID-GBS, had higher disability on admission (P = .032) compared to the GBS diagnosed between February 2019 and 2020, possibly related to later hospital referral in the pandemic context. Compared to non-COVID-GBS (n = 10) prospectively diagnosed in the same period (March 2020-2021), post-COVID-GBS (n = 10) had a higher disability score on admission (P = .028), lower sum Medical Research Council score (P = .022) and lymphopenia (P = .025), while there were no differences in GBS subtype/variant, severity of peripheral involvement, prognosis and response to treatment. Cerebrospinal fluid search for SARS-CoV-2 RNA and antiganglioside antibodies were negative in all COVID+ patients. Temporal clustering of cases, coinciding with the waves of the pandemic, and concomitant reduction of the incidence of COVID-negative GBSs may indicate a role for SARS-CoV-2 infection in the development of GBS, although the association may simply be related to a bystander effect of systemic inflammation; lack of prevalence of specific GBS subtypes in post-COVID-GBS also support this view. GBS features and prognosis are not substantially different compared to non-COVID-GBS.

Bioimpedance Phase Angle as a Prognostic Tool in Late-Onset Pompe Disease: A Single-Centre Prospective Study With a 15-year Follow-Up.

Background: Late-onset Pompe disease (LOPD) is an autosomal-recessive metabolic myopathy caused by deficiency of the lysosomal enzyme Acid Alpha-Glucosidase (GAA), leading to glycogen accumulation in proximal and axial muscles, and in the diaphragm. Enzyme Replacement Therapy (ERT) with recombinant GAA became available in 2006. Since then, several outcome measures have been investigated for the adequate follow-up of disease progression and treatment response, usually focusing on respiratory and motor function. Prognostic factors predicting outcome have not been identified till now. Methods: In this single Centre, prospective study, we evaluate the response to enzyme replacement therapy in 15 patients (7 males) with LOPD in different stages of disease, aged 49.4 ± 16.1, followed-up for 15 years. Treatment response was measured by the 6-min walking test, vital capacity in supine and upright position, respiratory muscle strength, muscle MRI, manual muscle testing. We investigated the usefulness of Body Impedance Vectorial Analysis for serial body composition assessment. Results: Although most patients with LOPD benefit from long-term treatment, some secondary decline may occur after the first 3-5 years. Some nutritional (lower body mass index, higher fat free mass, higher phase angle) and disease parameters (higher creatinine and shorter disease duration at the beginning of treatment) seem to predict a better motor outcome. Lower Phase Angle, possibly reflecting loss of integrity of skeletal muscle membranes and thus treatment mis-targeting, seems to correlate with worse treatment response on long-term follow-up. Conclusion: Body Impedance Vectorial Analysis is a fast, easily performed and cheap tool that may be able to predict long-term treatment response in patients with LOPD. Low Phase angle may serve as a marker of muscle quality and may be used to predict the response to a muscle-targeted intervention such as ERT, thus improving the identification of patients needing a closer follow-up due to higher fragility and risk of deterioration.

The endocannabinoid system and related lipids as potential targets for the treatment of migraine-related pain.

BACKGROUND: Migraine is a complex and highly disabling neurological disease whose treatment remains challenging in many patients, even after the recent advent of the first specific-preventive drugs, namely monoclonal antibodies that target calcitonin gene-related peptide. For this reason, headache researchers are actively searching for new therapeutic targets. Cannabis has been proposed for migraine treatment, but controlled clinical studies are lacking. A major advance in cannabinoid research has been the discovery of the endocannabinoid system (ECS), which consists of receptors CB1 and CB2; their endogenous ligands, such as N-arachidonoylethanolamine; and the enzymes that catalyze endocannabinoid biosynthesis or degradation. Preclinical and clinical findings suggest a possible role for endocannabinoids and related lipids, such as palmitoylethanolamide (PEA), in migraine-related pain treatment. In animal models of migraine-related pain, endocannabinoid tone modulation via inhibition of endocannabinoid-catabolizing enzymes has been a particular focus of research. METHODS: To conduct a narrative review of available data on the possible effects of cannabis, endocannabinoids, and other lipids in migraine-related pain, relevant key words were used to search the PubMed/MEDLINE database for basic and clinical studies. RESULTS: Endocannabinoids and PEA seem to reduce trigeminal nociception by interacting with many pathways associated with migraine, suggesting a potential synergistic or similar effect. CONCLUSIONS: Modulation of the metabolic pathways of the ECS may be a basis for new migraine treatments. The multiplicity of options and the wealth of data already obtained in animal models underscore the importance of further advancing research in this area. Multiple molecules related to the ECS or to allosteric modulation of CB1 receptors have emerged as potential therapeutic targets in migraine-related pain. The complexity of the ECS calls for accurate biochemical and pharmacological characterization of any new compounds undergoing testing and development.

How to forget a "traumatic" experience: a case report of transient global amnesia after nasopharyngeal swab for Coronavirus disease 19.

BACKGROUND: Transient global amnesia (TGA) is a clinical syndrome characterized by a temporary short-term memory loss with inability to retain new memories, usually lasting 2 to 8 h. TGA may be related to several medical procedures, including angiography, general anesthesia, gastroscopy. CASE PRESENTATION: We report a 58-year-old woman who experiencing TGA one hour after the execution of her first-time nasopharyngeal swab for COVID-19. Brain MRI showed a typical punctate Diffusion Weight Image (DWI) hippocampal lesion. CONCLUSIONS: This is the first report of TGA after the execution of nasopharyngeal swab for COVID-19. This association lengthen the list of medical procedures associated with TGA, and we discuss the possible plausible mechanisms by which a nasopharyngeal swab could trigger TGA.

Gender Differences in the Clinical Presentation of Cluster Headache: A Role for Sexual Hormones?

Introduction: Cluster Headache (CH) is a well-characterized primary headache that mostly affects men, although a progressive decrease in the male-to-female ratio has occurred over time. Available, but partly discordant, data on gender-related differences in CH suggest a more marked overlapping with migraine features in female subjects. The aim of this study is to carefully evaluate the female/male distribution of the typical migraine-associated symptoms and of other features of the disease in a large and well-characterized clinical population of CH subjects. Materials and Methods: We enrolled consecutive CH patients regularly followed at the tertiary Headache Science Center of the IRCCS Mondino Foundation of Pavia (Italy) who attended the Center for a CH bout between September 2016 and October 2018. The subjects were requested to fill in a semi-structured questionnaire focused on the presence of migraine-associated symptoms, familiarity for migraine and, for women, the relationship of CH onset with the reproductive events of their life. These data were compared and integrated with those recorded over time in our clinical database, including demographics and clinical characteristics. The primary outcome was the gender distribution of subjects who satisfied ICHD-III criterion D for migraine-associated symptoms. The secondary outcomes were represented by the gender distribution of individual migraine-associated symptoms and of other disease features included in the questionnaire and/or in the clinical database. Results: Data from 163 males (mean age 41.46 ± 10.37) and 87 females suffering of CH (mean age 42.24 ± 11.95) were analyzed. We did not find a different distribution between sexes as regards the primary outcome measure (F 73.6%, M 65.6%, p = 0.200). However, when we analyzed the occurrence of individual symptoms, nausea and osmophobia were reported more frequently by women (p = 0.048, p = 0.037, respectively). Ptosis and nasal congestion were predominant in females (p = 0.017 and p = 0.01, respectively), while enlarged temporal artery was more frequently reported by men (p = 0.001). Distribution of pain across the head tended to be larger in women, extending more frequently to the zygomatic (p = 0.050), parietal (p = 0.049), and frontal (p = 0.037) regions. Women had a longer mean attack duration (p = 0.004) than men. In CH women the onset of disease often corresponded with moments of important changes in the levels of sexual hormones (menarche, post-partum, menopause). Concomitant thyroid diseases and psychiatric disorders were observed more frequently in women than in men, while snoring and smoking habit was reported by a higher percentage of men than women. Conclusion: We confirmed the presence of distinct gender-related differences in CH and added some novel information that lends credibility to the hypothesis of a closer phenotypical similarity between CH and migraine in the female sex. These observations are relevant for advancing our knowledge on CH pathophysiology, as well as for a more refined diagnostic framing and improved management of the disease.