Margherita Nosadini

Radiological differentiation of optic neuritis with myelin oligodendrocyte glycoprotein antibodies, aquaporin-4 antibodies, and multiple sclerosis.

Background: Recognizing the cause of optic neuritis (ON) affects treatment decisions and visual outcomes. Objective: We aimed to define radiological features of first-episode demyelinating ON. Methods: We performed blinded radiological assessment of 50 patients presenting with first-episode myelin oligodendrocyte glycoprotein (MOG) antibody-associated ON (MOG-ON; n=19), aquaporin-4 (AQP4) antibody-associated ON (AQP4-ON; n=11), multiple sclerosis (MS)-associated ON (MS-ON; n=13), and unclassified ON (n=7). Results: Bilateral involvement was more common in MOG-ON and AQP4-ON than MS-ON (84% vs. 82% vs. 23%), optic nerve head swelling was more common in MOG-ON (53% vs. 9% vs. 0%), chiasmal involvement was more common in AQP4-ON (5% vs. 64% vs. 15%), and bilateral optic tract involvement was more common in AQP4-ON (0% vs. 45% vs. 0%). Retrobulbar involvement was more common in MOG-ON, whereas intracranial involvement was more common in AQP4-ON. MOG-ON and AQP4-ON had longer lesion lengths than MS-ON. The combination of two predictors, the absence of magnetic resonance imaging brain abnormalities and a higher lesion extent score, showed a good ability to discriminate between an autoantibody-associated ON (MOG or AQP4) and MS. AQP4-ON more frequently had severe and sustained visual impairment. Conclusion: MOG-ON and AQP4-ON are more commonly bilateral and longitudinally extensive. MOG-ON tends to involve the anterior optic pathway, whereas AQP4-ON the posterior optic pathway.

Immune therapy in autoimmune encephalitis: a systematic review

We have reviewed the literature of immune therapy in autoimmune encephalitis associated with antibodies to cell surface antigens including N-methyl-D-aspartate receptor (NMDAR), leucine-rich, glioma-inactivated protein-1 (LGI1), contactin-associated protein-2 (Caspr2), the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR), γ-aminobutyric acid-A receptor (GABAAR), γ-aminobutyric acid-B receptor (GABABR), Glycine R and other rarer antigens. Most studies are retrospective cohorts, and there are no randomised controlled trials. Most clinicians use first-line therapy (steroids, intravenous immunoglobulin, plasma exchange), and if severe or refractory, second-line therapy (rituximab, cyclophosphamide). When present, tumours should be removed. There are common therapeutic themes emerging. Firstly, patients given immune therapy do better and relapse less than patients given no treatment. Secondly, patients given early treatment do better. And thirdly, when patients fail first-line therapy, second-line therapy improves outcomes and reduces relapses. Given the retrospective uncontrolled data, the literature has inherent bias, including severity and reporting bias.

Longitudinal Electroencephalographic (EEG) Findings in Pediatric Anti-N-Methyl-d-Aspartate (Anti-NMDA) Receptor Encephalitis The Padua Experience

To contribute to characterize electroencephalographic (EEG) activity in pediatric anti-N-methyl-d-aspartate (anti-NMDA) receptor encephalitis, we reviewed electroclinical data of 5 children with anti-NMDA receptor encephalitis diagnosed in our department. We identified 4 longitudinal electroencephalographic phases: in the early phase, background activity was normal, with intermixed nonreactive slow waves; in the florid phase, background activity deteriorated with appearance of sequences of peculiar rhythmic theta and/or delta activity unrelated to clinical changes, unresponsive to stimuli and antiepileptic medications; in the recovery phase, these sequences decreased and reactive posterior rhythm re-emerged; electroencephalogram normalized 2 to 5 months after onset. In conclusion, in the presence of evocative clinical history, recognizing a characteristic longitudinal electroencephalographic activity could provide ancillary aspects addressing the diagnosis and the overall management of children with anti-N-methyl-d-aspartate receptor encephalitis; in particular, knowing that peculiar and recurrent paroxysmal nonepileptic rhythmic theta-delta patterns can occur in these patients could help distinguish paroxysmal epileptic and nonepileptic electroencephalographic activity.

Rituximab monitoring and redosing in pediatric neuromyelitis optica spectrum disorder

Objective: To study rituximab in pediatric neuromyelitis optica (NMO)/NMO spectrum disorders (NMOSD) and the relationship between rituximab, B cell repopulation, and relapses in order to improve rituximab monitoring and redosing. Methods: Multicenter retrospective study of 16 children with NMO/NMOSD receiving ≥2 rituximab courses. According to CD19 counts, events during rituximab were categorized as “repopulation,” “depletion,” or “depletion failure” relapses (repopulation threshold CD19 ≥10 × 106 cells/L). Results: The 16 patients (14 girls; mean age 9.6 years, range 1.8–15.3) had a mean of 6.1 events (range 1–11) during a mean follow-up of 6.1 years (range 1.6–13.6) and received a total of 76 rituximab courses (mean 4.7, range 2–9) in 42.6-year cohort treatment. Before rituximab, 62.5% had received azathioprine, mycophenolate mofetil, or cyclophosphamide. Mean time from rituximab to last documented B cell depletion and first repopulation was 4.5 and 6.8 months, respectively, with large interpatient variability. Earliest repopulations occurred with the lowest doses. Significant reduction between pre- and post-rituximab annualized relapse rate (ARR) was observed (p = 0.003). During rituximab, 6 patients were relapse-free, although 21 relapses occurred in 10 patients, including 13 “repopulation,” 3 “depletion,” and 4 “depletion failure” relapses. Of the 13 “repopulation” relapses, 4 had CD19 10–50 × 106 cells/L, 10 had inadequate monitoring (≤1 CD19 in the 4 months before relapses), and 5 had delayed redosing after repopulation detection. Conclusion: Rituximab is effective in relapse prevention, but B cell repopulation creates a risk of relapse. Redosing before B cell repopulation could reduce the relapse risk further. Classification of evidence: This study provides Class IV evidence that rituximab significantly reduces ARR in pediatric NMO/NMOSD. This study also demonstrates a relationship between B cell repopulation and relapses.

Symptomatic treatment of children with anti-NMDAR encephalitis

We performed the first study on the perceived benefit and adverse effects of symptomatic management in children with anti‐N‐methyl‐d‐aspartate receptor (NMDAR) encephalitis.

Paediatric anti-N-methyl-d-aspartate receptor encephalitis: The first Italian multicenter case series

BACKGROUND Given the rarity of this condition, especially in children, there is a paucity of large reported paediatric case series of anti-N-methyl-d-aspartate receptor encephalitis. METHODS To contribute to define the features of this condition, we describe retrospectively a new nationwide case series of 20 children (50% females), referred by 13 Italian centres. RESULTS Mean age at onset was 8 years (range 3-17). Prodromal symptoms were reported in 31.6%; onset was with neurological symptoms in 70%, and with behavioural/psychiatric disturbances in 30%. Most patients developed a severe clinical picture (90%), and 41% experienced medical complications; children 12-18 years old seemed to be more severe and symptomatic than younger patients. All children received first-line immune therapy; second-line treatment was administered to 45%. Relapses occurred in 15%. At last follow-up (mean 23.9 months, range 5-82), 85% patients had mRS 0-1; this rate was higher among older patients, and in those receiving first immune therapy within 1 month. CONCLUSIONS Our case series confirms a symptomatologic core of paediatric anti-N-methyl-d-aspartate receptor encephalitis, even though displaying some distinctive features that may be explained by a specific genetic background or by the limited number of patients. The growing incidence of this condition, the relative age-dependent variability of its manifestations, the availability of immunotherapy and the possible better outcome with early treatment impose a high index of clinical suspicion be maintained. In the absence of data suggesting other specific etiologies, paediatricians should consider this diagnosis for children presenting with neurological and/or behavioural or psychiatric disturbances, regardless of age and gender.

Plasma exchange in pediatric anti-NMDAR encephalitis: A systematic review

OBJECTIVE To clarify the most frequent modalities of use of plasma exchange (PE) in pediatric anti-N-methyl-d-aspartate receptor (anti-NMDAR) encephalitis and to establish the most effective association with other immunotherapies. METHODS Systematic literature review on PE in pediatric anti-NMDAR encephalitis (2007-2015). RESULTS Seventy-one articles were included (mostly retrospective), reporting a total of 242 subjects (73.2%, 93/127 females; median age at onset 12years, range 1-18). Median time to immunotherapy was 21days (range 0-190). In most cases, PE was given with steroids and IVIG (69.5%, 89/128), or steroids only (18%, 23/128); in a minority, it was associated with IVIG only (7%, 9/128), or was the only first-line treatment (5.5%, 7/128). In 54.5% (65/119), PE was the third treatment after steroids and IVIG, in 31.1% (37/119) the second after steroids or IVIG; only in 14.3% (17/119) was it the first treatment. Second-line immunotherapies were administered in 71.9% (100/139). Higher rates of full/substantial recovery at follow-up were observed with immunotherapy given ⩽30days from onset (69.4%, 25/36) compared to later (59.2%, 16/27), and when PE was associated with steroids (66.7%, 70/105) rather than not (46.7%, 7/15). Significant adverse reactions to PE were reported in 6 patients. CONCLUSION Our review disclosed a paucity of quality data on PE in pediatric anti-NMDAR encephalitis. PE use in this condition has been increasingly reported, most often with steroids and IVIG. Despite the limited number of patients, our data seem to confirm the trend towards a better outcome when PE was administered early, and when given with steroids.

Herpes simplex virus-induced anti-N-methyl-D-aspartate receptor encephalitis: a systematic literature review with analysis of 43 cases.

To conduct a systematic literature review on patients with biphasic disease with herpes simplex virus (HSV) encephalitis followed by anti‐N‐methyl‐D‐aspartate receptor (NMDAR) encephalitis.

Long-Term Neurocognitive Outcome and Quality of Life in Pediatric Acute Disseminated Encephalomyelitis

BACKGROUND Acute disseminated encephalomyelitis is an inflammatory-demyelinating disorder of the central nervous system usually with a monophasic course and a favorable neurological outcome. Long-term neurocognitive sequelae and quality of life have not yet been fully investigated. AIM To examine neurocognitive outcome and quality of life in pediatric monophasic acute disseminated encephalomyelitis. METHODS Of the 36 patients diagnosed with acute disseminated encephalomyelitis at our institution, six were lost to follow-up and eight relapsed (two with multiphasic forms and six with multiple sclerosis). The outcome of the 22 remaining patients was evaluated using four subscales of the Wechsler Intelligence Scales for estimation of IQ, a battery of neuropsychological tests, and semistructured and PedsQL questionnaires for quality of life. The effect of age at onset, neuroradiological recovery, and time elapsed from the acute event on outcome was also investigated. RESULTS Estimated IQ, neuropsychological mean group scores, and quality of life at follow-up were within the normal range, but 23% of the patients had pathological scores in various neuropsychological functions, among which attention was the most clearly affected. The neuroradiological recovery was not correlated with the result of the neuropsychological tests. Age at onset correlated with linguistic skills, whereas the time elapsed from the acute event had a significant effect on attention tasks: scores were worse in the group of patients with a follow-up shorter than 7 years. CONCLUSION Our results suggest that pediatric monophasic acute disseminated encephalomyelitis has a favorable neurocognitive outcome. Patients with longer follow-up had a better outcome, suggesting a neurocognitive course that is different from that of multiple sclerosis and a potential for long-term recovery of affected functions.

Delayed myelination is not a constant feature of Allan–Herndon–Dudley syndrome: Report of a new case and review of the literature

INTRODUCTION Allan-Herndon-Dudley syndrome is an X-linked condition caused by mutations of the monocarboxylate transporter 8 gene. This syndrome is characterized by axial hypotonia, severe mental retardation, dysarthria, athetoid movements, spastic paraplegia, and a typical thyroid hormone profile. In most of the cases reported so far, brain magnetic resonance imaging showed delayed myelination of the central white matter and this finding greatly affects the diagnosis of the syndrome. CASE REPORT We present a new case studied with magnetic resonance imaging and spectroscopy and we reviewed all the articles published between 2004 and 2012 containing information on brain neuroimaging in this syndrome. An Italian boy, showing a classical phenotype of the syndrome, was diagnosed at 17months of age. Genetic analysis revealed a new frameshift mutation of the monocarboxylate transporter 8 gene. His brain magnetic resonance imaging and spectroscopy, performed at the age of 14months, were normal. DISCUSSION Among the 33 cases reported in the literature, 3 cases had normal neuroimaging and in 7 of 14 cases, having a longitudinal follow-up, the initial finding of delayed myelination gradually improved. Our case and the review of the pertinent literature suggest that Allan-Herndon-Dudley syndrome should be suspected in males with the typical neurological and thyroid profile, even in cases with normal brain myelination.