A 12-year-old boy presents with progressive myoclonus, seizures, and cognitive decline over 2 years. He had measles infection at age 18 months. EEG shows periodic complexes. Brain biopsy reveals intranuclear eosinophilic inclusions in neurons and glial cells. These inclusions are composed of which viral antigen?
- A Herpes simplex virus type 1
- B Measles virus ✓
- C JC polyomavirus
- D Cytomegalovirus
Correct answer: B. Measles virus
Explanation
Subacute sclerosing panencephalitis (SSPE) is a rare, late complication of measles infection caused by persistent defective measles virus. It presents years after initial infection with myoclonus, seizures, and cognitive decline. Histology shows intranuclear Cowdry type A inclusions in neurons and oligodendrocytes, with neurofibrillary tangles and gliosis. HSV causes acute necrotizing encephalitis. JC virus causes PML. CMV causes periventricular necrosis in neonates and immunocompromised patients.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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