Clinical Features, Treatment Strategies, and Outcomes in Hospitalized Children With Immune-Mediated Encephalopathies

Evaluation, Treatment, and Outcomes of Viral and Autoimmune Encephalitis in Children

Viral encephalitis and autoimmune encephalitis are currently the most common causes of encephalitis. Determining the causative agent is helpful in initiating medical treatment that may help reduce long-term sequelae. Cerebrospinal fluid, neuroimaging, serologic, and electroencephalogram in combination with clinical manifestations play a role in determining the cause of the encephalitis. Although motor dysfunction tends to improve, there is a significant risk of long-term neurologic and cognitive sequelae. These persistent deficits that occur in childhood indicate the importance for ongoing rehabilitative services to maximize functional skills, improve cognitive deficits, and assist with community integration.

Evidence of neuroinflammation and immunotherapy responsiveness in individuals with down syndrome regression disorder

Background

Down syndrome regression disorder is a symptom cluster consisting of neuropsychiatric regression without cause. This study evaluated the incidence of neurodiagnostic abnormalities in individuals with Down syndrome regression disorder and determined if abnormalities are indicative of responses to therapeutic intervention.

Methods

A retrospective, multi-center, case-control study was performed. Patients were required to have subacute onset and the presence of four of five symptom groups present (cognitive decline, expressive language, sleep derangement, loss of ability to perform activities of daily living, and/or a new movement disorder) and no other explanation for symptoms.

Results

Individuals with Down syndrome regression disorder were comparable to a cohort of individuals with only Down syndrome although had higher rates of autoimmune disease (p = 0.02, 95%CI 1.04–1.75). Neurodiagnostic abnormalities were found on EEG (n = 19, 26%), neuroimaging (n = 16, 22%), and CSF (n = 9, 17%). Pleocytosis was appreciated in five cases, elevated total protein in nine, elevated IgG index in seven, and oligoclonal bands in two. Testing within 2 years of symptom onset was more likely to have neurodiagnostic abnormalities (p = 0.01, 95%CI 1.64–37.06). In individuals with neurodiagnostic abnormalities, immunotherapy was nearly four times more likely to have a therapeutic effect than in those without neurodiagnostic abnormalities (OR 4.11, 95%CI 1.88–9.02). In those with normal neurodiagnostic studies (n = 43), IVIg was effective in 14 of 17 (82%) patients as well although other immunotherapies were uniformly ineffective.

Conclusions

This study reports the novel presence of neurodiagnostic testing abnormalities in individuals with Down syndrome regression disorder, providing credence to this symptom cluster potentially being of neurologic and/or neuroimmunologic etiology.

Supplementary Information

The online version contains supplementary material available at 10.1186/s11689-022-09446-w.

Autoimmune Encephalitis

Autoimmune encephalitis is a common and treatable cause of encephalitis in children and adults. Individuals present with a variety of symptoms, including altered mental status, behavioral changes, irritability, insomnia, developmental regression, seizures, dyskinetic movements, and autonomic instability. Evaluation includes electroencephalography, magnetic resonance imaging, and lumbar puncture. Once infectious and other causes are reasonably ruled out, treatment should be started empirically without waiting for antibody confirmation. Early clinical suspicion is key, as the outcome depends on early initiation of immunotherapy, including corticosteroids, intravenous immunoglobulin, and/or plasmapheresis. Severe or refractory cases require other treatments, such as rituximab, cyclophosphamide, or other immunotherapies using novel monoclonal antibodies. Psychiatry should be involved early for the management of behavioral issues. Additional considerations include management of seizures and dyskinesias. ICU admission may be required for management of hypoventilation necessitating mechanical ventilation (either intrinsic or iatrogenic, eg, from sedatives), refractory seizures, and dysautonomia. Anti-N-methyl-d-aspartate receptor and other forms of autoimmune encephalitis are less often associated with neoplasia (such as ovarian teratoma) in children compared with adults, but screening and removal of tumor if present should be performed.

Diagnosis and Management of Suspected Pediatric Autoimmune Encephalitis: A Comprehensive, Multidisciplinary Approach and Review of Literature

Autoimmune encephalitis is an increasingly recognized entity in children. When treated promptly, favorable outcomes are seen in a majority of pediatric patients. However, recognition of autoimmune encephalitis in young patients is challenging. Once autoimmune encephalitis is suspected, additional difficulties exist regarding timing of treatment initiation and duration of treatment, as evidence to guide management of these patients is emerging. Here, we review available literature regarding pediatric autoimmune encephalitis and present our institution's comprehensive approach to the evaluation and management of the disease. These guidelines were developed through an iterative process involving both pediatric neurologists and rheumatologists.

Post-COVID-19 acute disseminated encephalomyelitis: Case report and review of the literature

Background

Our understanding of the spectrum of neurological manifestations associated with COVID-19 keeps evolving. Reports of life-threatening neurological complications, such as acute disseminated encephalomyelitis (ADEM), are alarmingly growing in number.

Case presentation

We report a 42 years old previously healthy man who presented with left visual loss and cognition deterioration, manifesting at least ten days after infection with SARS-CoV-2. Serological work-up for potential immunological markers (i.e., antibodies against aquaporin-4 and myelin oligodendrocyte glycoprotein) were negative. Magnetic resonance imaging revealed multiple bilateral and asymmetrical lesions in the brainstem, cortical, juxtacortical, and periventricular regions, with surrounding edema. Post-contrast sequences demonstrated punctate, ring, and open ring enhancement patterns. Methylprednisolone pulse therapy was initiated for the patient, and he was placed on rituximab. After one month, his clinical symptoms had resolved, and his cognitive function was normal.

Conclusions

We conducted an extensive literature search, and COVID-19-associated ADEM cases reported thus far were identified and reviewed. ADEM often occurs in a post-infectious fashion; however, it is unclear how SARS-CoV-2 infection can trigger such rapidly progressive episodes of encephalopathy and demyelination. Nevertheless, considering the alarming number of cases of ADEM developing after SARS-CoV-2 infection, neurologists should consider this severe phenotype of COVID-19 neurological complication in mind, enabling prompt therapeutic interventions to be made.

Assessment and Management of Acute Disseminated Encephalomyelitis (ADEM) in the Pediatric Patient

Acute disseminated encephalomyelitis (ADEM) is an inflammatory demyelinating disease of the central nervous system that typically presents in childhood and is associated with encephalopathy and multifocal brain lesions. Although ADEM is thought to be a post-infectious disorder, the etiology is still poorly understood. ADEM is often a monophasic disorder, in contrast to other demyelinating disorders such as multiple sclerosis and neuromyelitis optica spectrum disorder. With increasing awareness, understanding, and testing for myelin oligodendrocyte glycoprotein antibodies, this disease is now known to be a cause of pediatric ADEM and also has the potential to be relapsing. Diagnostic evaluation for ADEM involves neuroimaging and laboratory studies to exclude potential infectious, inflammatory, neoplastic, and genetic mimics of ADEM. Acute treatment modalities include high-dose intravenous corticosteroids, therapeutic plasma exchange, and intravenous immunoglobulin. Long-term outcomes for ADEM are generally favorable, but some children have significant morbidity related to the severity of acute illness and/or manifest ongoing neurocognitive sequelae. Further research related to the optimal management of pediatric ADEM and its impact on prognosis is needed. This review summarizes the current knowledge of the pathogenesis, epidemiology, clinical features, diagnostic evaluation, treatment approaches, and outcomes in pediatric ADEM.