Case Report: Focal Myoclonus with a Striatal Lesion as a Presentation of Subacute Sclerosing Panencephalitis

Adult-onset subacute sclerosing panencephalitis (SSPE) is rare, and focal myoclonus as a presenting feature poses a diagnostic dilemma. We report an adult SSPE patient with unusual clinical and radiological features. A 20-year-old girl had jerky neck movement 9 months earlier, which progressed to left hemimyoclonus in 2 months and generalized frequent myoclonus and fall at 4 months. By 6 months, she was bedbound. On examination, her Mini-Mental State Examination score was 10, and patchy retinitis was observed around the macula. Magnetic resonance imaging revealed corpus striatal involvement and electroencephalography showed periodic discharges. Measles cerebrospinal fluid/serum immunoglobulin G index was 3.3 (normal < 1.3), confirming the diagnosis of SSPE. SSPE should also be considered in adults having focal myoclonus with corpus striatal lesion. EEG is helpful in the diagnosis.

Automated summary

We report an adult patient with subacute sclerosing panencephalitis (SSPE) who presented with unusual clinical and radiological features, including myoclonus and focal neurologic deficits. The diagnosis of SSPE was confirmed through magnetic resonance imaging and electroencephalography.