Retrospective Pediatric Cohort Study Validates NEOS Score and Demonstrates Applicability in Children With Anti-NMDAR Encephalitis.

BACKGROUND AND OBJECTIVES: Anti-N-methyl-D-aspartate receptor encephalitis (NMDARE) is the most common form of autoimmune encephalitis in children and adults. Although our understanding of the disease mechanisms has progressed, little is known about estimating patient outcomes. Therefore, the NEOS (anti-NMDAR Encephalitis One-Year Functional Status) score was introduced as a tool to predict disease progression in NMDARE. Developed in a mixed-age cohort, it currently remains unclear whether NEOS can be optimized for pediatric NMDARE. METHODS: This retrospective observational study aimed to validate NEOS in a large pediatric-only cohort of 59 patients (median age of 8 years). We reconstructed the original score, adapted it, evaluated additional variables, and assessed its predictive power (median follow-up of 20 months). Generalized linear regression models were used to examine predictability of binary outcomes based on the modified Rankin Scale (mRS). In addition, neuropsychological test results were investigated as alternative cognitive outcome. RESULTS: The NEOS score reliably predicted poor clinical outcome (mRS ≥3) in children in the first year after diagnosis (p = 0.0014) and beyond (p = 0.036, 16 months after diagnosis). A score adapted to the pediatric cohort by adjusting the cutoffs of the 5 NEOS components did not improve predictive power. In addition to these 5 variables, further patient characteristics such as the "Herpes simplex virus encephalitis (HSE) status" and "age at disease onset" influenced predictability and could potentially be useful to define risk groups. NEOS also predicted cognitive outcome with higher scores associated with deficits of executive function (p = 0.048) and memory (p = 0.043). DISCUSSION: Our data support the applicability of the NEOS score in children with NMDARE. Although not yet validated in prospective studies, NEOS also predicted cognitive impairment in our cohort. Consequently, the score could help identify patients at risk of poor overall clinical outcome and poor cognitive outcome and thus aid in selecting not only optimized initial therapies for these patients but also cognitive rehabilitation to improve long-term outcomes.

Autoimmune Encephalitis with Autoantibodies to NMDAR1 following Herpes Encephalitis in Children and Adolescents.

Herpes simplex virus (HSV) type 1 is a frequent pathogen causing infectious encephalitis (HSVE). Early treatment with intravenous acyclovir has led to a significant decrease in mortality. However, especially in children, deterioration during or after HSVE may occur without any evidence of HSV reactivation or improvement following repeated antiviral therapy. Here, we report 15 patients (age range 3 months to 15 years) who suffered from autoimmune encephalitis with autoantibodies to NMDAR1 following Herpes encephalitis, presenting with movement abnormalities (young children) or neuropsychiatric symptoms (older children) as major complaints, respectively. The diagnosis was based on positive cerebrospinal fluid (CSF) and/or serum anti-NMDAR-antibodies with two children showing only positive CSF antibody findings. The time lag between first symptoms and diagnosis of autoimmune encephalitis was significantly longer than between first symptoms and diagnosis of HSVE (p <0.01). All patients improved during immunosuppressive treatment, during which plasmapheresis or rituximab treatments were applied in 11 patients, irrespective of their age. Despite immunotherapy, no patients relapsed with HSVE. Early diagnosis and treatment of autoimmune encephalitis after HSVE may be associated with a better outcome so that high clinical awareness and routine testing for anti-NMDAR-antibodies after HSVE seems advisable. If autoimmune encephalitis is suspected, antibody testing should also be performed on CSF if negative in serum.

Paroxysmal tonic upgaze: A heterogeneous clinical condition responsive to carbonic anhydrase inhibition.

BACKGROUND: Paroxysmal tonic upgaze (PTU), defined as an involuntary upward movement of the eyes, has been considered as a benign phenomenon but may also be associated with ataxia and developmental delay. METHODS: We report eight children with PTU; six of them also exhibiting symptoms of ataxia and/or developmental delay. Treatment with carbonic anhydrase inhibition was offered to children with persisting and/or severe forms. RESULTS: Whole-exome sequencing and genome-wide array analysis (n = 7) did not reveal mutations in the three known genes associated with PTU (CACNA1A, GRID2, SEPSECS), whereas by MLPA a heterozygous deletion of exon 31 of the CACNA1A gene could be detected in one patient, her mother and two further family members. Further exome and array analysis showed no recurrent variants in potentially novel PTU-related genes in more than one patient. A de novo variant at a highly conserved position in the SIM1 gene was detected in one patient, for which a pathogenic effect could be speculated. Carbonic anhydrase inhibition was started in five children and proved at least partially effective in all of them. CONCLUSION: Irrespective of the clinical background and the molecular basic mechanism of PTU, therapeutic carbonic anhydrase inhibition was effective in all five children (acetazolamide, n = 3; sultiame, n = 2) who received this treatment.

Microangiopathy and mild mixed neuromyopathic alterations in a patient with homozygous PIEZO-2 mutation.

We report a 9-year-old girl homozygous for a loss-of-function mutation in the PIEZO-2 gene. She showed generalized muscular hypotonia with severe scoliosis, joint deformities, deficient proprioceptive function and selective atrophy and signal alterations of both gastrocnemii on whole body MRI scan. Light microscopic and ultrastructural examination showed few atrophic fibres, abnormal mitochondria, focal myofibrillar disruption and endomysial capillary microangiopathy.

Stroke in Ehlers-Danlos Syndrome Kyphoscoliotic Type: Dissection or Vasculitis?

BACKGROUND: Patients with the kyphoscoliotic type of Ehlers-Danlos syndrome have an increased risk of vascular complications such as aortic dissection and perforation. Cerebral ischemia has only rarely been documented. PATIENT DESCRIPTION: This 13-year-old girl with the kyphoscoliotic type of Ehlers-Danlos syndrome experienced a large right middle cerebral artery distribution infarction. Full intravenous heparinization was started in response to presumed arterial dissection. Magnetic resonance imaging studies including magnetic resonance angiography and digital subtraction angiography, however, did not confirm dissection but suggested with cerebral vasculitis extending from the intradural right internal carotid artery to the M2 branches of the middle cerebral artery. Combined steroid and cyclophosphamide therapy was associated with clinical improvement. Two months later she died from hemorrhagic shock caused by a two-sided spontaneous rupture of the aortic artery. CONCLUSIONS: Cerebral vasculitis should be included in the differential diagnosis of vascular complications in kyphoscoliotic type of Ehlers-Danlos syndrome.