Pittock, S J

Background: Optic neuritis (ON) is often the presenting symptom in inflammatory central nervous system demyelinating disorders. Objective: To compare the frequency and pattern of optic chiasm involvement in patients with aquaporin-4-immunoglobulin G (AQP4-IgG)-associated ON to patients with myelin oligodendrocyte glycoprotein-immunoglobulin G (MOG-IgG)-associated ON. Methods: Retrospective review of all patients evaluated at Mayo Clinic, Stanford University and Ramathibodi Hospital who were found to have: (1) ON, (2) either MOG-IgG or AQP4-IgG by cell-based assay, and (3) magnetic resonance imaging (MRI) at the time of ON. MRI was reviewed for contrast enhancement of the optic chiasm and the pattern of involvement. Results: One hundred and fifty-four patients (74 AQP4-IgG and 80 MOG-IgG) were included. Among patients with AQP4-IgG-ON, 20% had chiasmal involvement, compared with 16% of patients with MOG-IgG-ON ( p = 0.66). In patients with chiasmal involvement, longitudinally extensive optic nerve enhancement (from orbit extending to chiasm) was identified in 54% of MOG-IgG-ON patients, compared with 7% of AQP4-IgG-ON patients ( p = 0.01). Conclusion: Chiasmal involvement of MOG-IgG-ON and AQP4-IgG-ON occur at more similar frequencies than previously reported. Furthermore, MOG-IgG-ON chiasmal involvement is more likely to be part of a longitudinally extensive optic nerve lesion.

AbstractThe objective of this study was to describe serological association of musicogenic epilepsy and to evaluate clinical features and outcomes of seropositive cases. Through retrospective chart review, musicogenic epilepsy patients were identified. Among 16 musicogenic epilepsy patients, nine underwent autoantibody evaluations and all had high‐titer glutamic acid decarboxylase 65–immunoglobulin G (GAD65‐IgG; >20 nmol·L–1, serum, normal ≤ .02 nmol·L–1, eight women). Median GAD65‐IgG serum titer was 294 nmol·L–1 (20.3–3005 nmol·L–1), and median cerebrospinal fluid titer (n = 4) was 14.7 nmol·L–1. All patients had temporal lobe epilepsy, and bitemporal epileptiform abnormalities were common. Right temporal lobe seizures were most frequently captured when seizures were induced by music on electroencephalogram (3/4; 75%). Intravenous (IV) methylprednisolone and/or IV Ig (IVIG) was utilized in four patients, with one having greater than 50% reduction. Rituximab (n = 2) and mycophenolate (n = 1) were ineffective. Two patients underwent right temporal lobe resections but continued to have seizures. Vagus nerve stimulation was effective at reducing seizures in one patient by 50%, and an additional patient was seizure‐free by avoiding provoking music. Right temporal lobe epilepsy was more common among patients with musicogenic epilepsy when compared to nonmusicogenic GAD65 epilepsies (n = 71, 89% vs. 47%, p = .03). GAD65‐IgG should be tested in patients with musicogenic epilepsy, given implications for management and screening for comorbid autoimmune conditions.

AbstractParaneoplastic neurological syndrome (PNS) comprises a group of neurological disorders that result from a misguided immune response to the nervous system triggered by a distant tumor. These disorders frequently manifest before the diagnosis of the underlying neoplasm. Since the first reported case in 1888 by Oppenheim, the knowledge in this area has evolved rapidly. Several classic PNS have been described, such as limbic encephalitis, paraneoplastic cerebellar degeneration, encephalomyelitis, opsoclonus-myoclonus, sensory neuronopathy, Lambert-Eaton Myasthenic syndrome, and chronic gastrointestinal dysmotility. It is now recognized that PNS can have varied nonclassical manifestations that extend beyond the traditional syndromic descriptions. Multiple onconeural antibodies with high specificity for certain tumor types and neurological phenotypes have been discovered over the past 3 decades. Increasing use of immune checkpoint inhibitors (ICIs) has led to increased recognition of neurologic ICI-related adverse events. Some of these resemble PNS. In this article, we review the clinical, oncologic, and immunopathogenic associations of PNS.

AbstractObjectiveNeuroinflammation associated with anti‐N‐methyl‐D‐aspartate receptor (NMDAR) encephalitis may facilitate seizures. We previously showed that intraventricular administration of cerebrospinal fluid from patients with anti‐NMDAR encephalitis to mice precipitates seizures, thereby confirming that antibodies are directly pathogenic. To determine whether interleukin (IL)‐1‐mediated inflammation exacerbates autoimmune seizures, we asked whether blocking the effects of IL‐1 by anakinra, a selective IL‐1 receptor antagonist, blunts antibody‐induced seizures.MethodsWe infused C57BL/6 mice intraventricularly with purified serum IgG from patients with anti‐NMDAR encephalitis or monoclonal anti‐NMDAR IgG; subdural electroencephalogram was continuously recorded. After a 6‐day interval, mice received anakinra (25 mg/kg sc, twice daily) or vehicle for 5 days. Following a 4‐day washout period, we performed behavioral tests to assess motor function, anxiety, and memory, followed by hippocampus tissue analysis to assess astrocytic (glial fibrillary acidic protein [GFAP]) and microglial (ionized calcium‐binding adapter molecule [Iba]‐1) activation.ResultsOf 31 mice infused with purified patient NMDAR‐IgG (n = 17) or monoclonal NMDAR‐IgG (n = 14), 81% developed seizures. Median baseline daily seizure count during exposure to antibodies was 3.9; most seizures were electrographic. Median duration of seizures during the baseline was 82.5 s. Anakinra administration attenuated daily seizure frequency by 60% (p = .02). Anakinra reduced seizure duration; however, the effect was delayed and became apparent only after the cessation of treatment (p = .04). Anakinra improved novel object recognition in mice with antibody‐induced seizures (p = .03) but did not alter other behaviors. Anakinra reduced the expression of GFAP and Iba‐1 in the hippocampus of mice with seizures, indicating decreased astrocytic and microglial activation.SignificanceOur evidence supports a role for IL‐1 in the pathogenesis of seizures in anti‐NMDAR encephalitis. These data are consistent with therapeutic effects of anakinra in other severe autoimmune and inflammatory seizure syndromes. Targeting inflammation via blocking IL‐1 receptor‐mediated signaling may be promising for developing novel treatments for refractory autoimmune seizures.

ObjectiveDuring PREVENT (NCT01892345), eculizumab significantly reduced relapse risk versus placebo in patients with aquaporin‐4 immunoglobulin G‐positive neuromyelitis optica spectrum disorder (AQP4‐IgG+ NMOSD). We report an interim analysis of PREVENT's ongoing open‐label extension (OLE; NCT02003144) evaluating eculizumab's long‐term safety and efficacy.MethodsPatients who completed PREVENT could enroll in the OLE to receive eculizumab (maintenance dose = 1,200 mg/2 weeks, after a blinded induction phase). Safety and efficacy data from PREVENT and its OLE (interim data cut, July 31, 2019) were combined for this analysis.ResultsAcross PREVENT and the OLE, 137 patients received eculizumab and were monitored for a median (range) of 133.3 weeks (5.1–276.9 weeks), for a combined total of 362.3 patient‐years (PY). Treatment‐related adverse event (AE) and serious adverse event (SAE) rates were 183.5 in 100 PY and 8.6 in 100 PY, respectively. Serious infection rates were 10.2 in 100 PY in eculizumab‐treated patients versus 15.1 in 100 PY in the PREVENT placebo group. No patient developed a meningococcal infection. At 192 weeks (3.7 years), 94.4% (95% confidence interval [CI], 88.6–97.3) of patients remained adjudicated relapse‐free. The adjudicated annualized relapse rate was 0.025 (95% CI = 0.013–0.048) in all eculizumab‐treated patients versus 0.350 (95% CI = 0.199–0.616) in the PREVENT placebo group. During the OLE, 37% of patients (44 of 119 patients) stopped or decreased background immunosuppressive therapy use.InterpretationThis analysis demonstrates that eculizumab's long‐term safety profile in NMOSD is consistent with its established profile across other indications. This analysis also demonstrated the sustained ability of long‐term eculizumab treatment to reduce relapse risk in patients with AQP4‐IgG+ NMOSD. ANN NEUROL 2021;89:1088–1098