Background Childhood primary angiitis of the CNS (cPACNS) is an increasingly recognized, reversible cause of severe neurological and psychiatric deficit such as stroke, refractory seizures and hallucination in previously healthy children. Aggressive immunosuppression has significantly decreased the mortality, however little is known about the long-term neurocognitive burden of cPACNS.

Objectives To describe the neuropsychological outcome of children with cPACNS, compare the cognitive burden between distinct disease subtypes and identify risk factors for poor neurocognitive outcome.

Methods A single-centre cohort study of children with cPACNS based on Calabrese criteria was performed. Children had to have completed a standard neurocognitive evaluation. Demographic characteristics, disease subtypes, clinical features, laboratory markers, neuroimaging studies, brain biopsy findings and treatment regimens were captured. Neurocognitive function was evaluated with a previously reported comprehensive battery of neuropsychological tests including domains of cognitive, social, emotional and adaptive function. The primary study outcome was the Full Scale IQ (FSIQ). Secondary outcomes included neurological function as defined by the Paediatric Stroke Outcome Measure PSOM, Health-related Quality of Life (PedsQL), disease activity and disease damage (VAS). Analysis: Univariate analysis compared variables between distinct disease subtypes; a multivariate prediction model for adverse cognitive outcome was developed.

Results A total of 111 children were diagnosed with primary CNS vasculitis in the study interval, of whom 70 (63%) completed the neuropsychological assessment. Of these 21 had small vessel CNS vasculitis (SVcPACNS) and 49 angiography-positive CNS vasculitis (APcPACNS). The cohort included 31 girls (17 SVcPACNS, 14 APcPACNS) and 39 boys (4 SVcPACNS, 35 APcPACNS), median age at diagnosis was 8.1 years; SVcPACNS patients were significantly older (9.3 vs. 7.6 years, p=0.04)). At diagnosis, SVcPACNS patients present significantly more commonly with seizures (67%, p=0.003) and diffuse deficits, (90%, p=0.05), while stroke features were more frequently seen in APcPACNS (94%, p=0.01). Outcome: The mean FSIQ was significantly lower at 82 (54-119) in SVcPACNS compared to 97 (52-132) in APcPACNS (p=0.04). Abnormal FSIQ scores (<85) were seen in 52% of the SVcPACNS and 25% of APcPACNS patients. Children with SVcPACNS had lower scores in the domains of verbal comprehension (p=0.04), perceptual reasoning (p=0.007), working memory (p=0.06) and processing speed (p=0.03). Prediction model: Children presenting with seizures were at the highest risk of cognitive deficits (p=0.005).

Conclusions Children with cPACNS carry significant disease burden. The inflammation causes drastically impaired cognitive functioning including comprehension, processing speed and memory deficits. Children with SVcPACNS and in particular those presenting with seizures are at the highest risk for adverse cognitive outcome. Early rehabilitation interventions have to be tailored to this high risk group.

Disclosure of Interest None Declared