Radiological Patterns and Clinical Features in Adult-onset Subacute Sclerosing Panencephalitis: a Cross-sectional...

Subacute sclerosing panencephalitis (SSPE) is a progressive neurological disorder caused by persistent measles virus infection in the brain. Traditionally a pediatric disorder, adult-onset cases are increasingly reported. Imaging characteristics in adult-onset SSPE remain underexplored. We aimed to characterize radiological abnormalities in adult-onset SSPE and explore clinico-radiological associations.

A cross-sectional study was conducted. Patients with SSPE with symptom onset at age 18 years and above were included. Clinical, demographic, laboratory and MRI brain features were recorded and analyzed.

Fifty-three patients (male: female = 43:10) were included. The median age at presentation was 19 (19-21.5) years and median symptom duration was 10 (10-19) months. The median Jabbour stage was 2 (2-3). Forty-three (81.1%) had MRI abnormalities. Subcortical and periventricular white matter signal change was noted in 28 (65.1%) and 33 (76.7%) patients respectively. The most frequently involved lobes were parietal (39, 90.7%) and frontal (35, 81.4%). Diffusion restriction occurred in 10 (23.3%). Tremor (p = 0.018) and elevated CSF protein (P < 0.001) correlated with overall MRI abnormality. Myoclonus correlated with occipital signal change (p = 0.036). Tremor (p = 0.034) and visual abnormality (p = 0.024) correlated with subcortical involvement. Dysphagia was associated with cortical involvement (p = 0.018), basal ganglia abnormality (p = 0.041), and diffusion restriction (p = 0.008). Symptom duration correlated with periventricular white matter involvement (p = 0.0034), supratentorial atrophy (p < 0.001), and symmetrical involvement (p = 0.027).

MRI abnormalities are frequent in adult-onset SSPE, with diffusion restriction being more prevalent than previously recognized. Our findings highlight the role of neuroimaging in adult-onset SSPE cases, to guide diagnosis and prognostication.