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

PURPOSE: 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.

METHODS

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.

RESULTS

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).

CONCLUSION

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.