Clinical Reasoning: Left hemiparesis, ataxia, and optic neuritis in a child previously treated for pineoblastoma

Abstract

A 13-year-old girl presented acutely with an episode of headache and signs of elevated intracranial pressure from a pineal gland tumor causing obstructive hydrocephalus. After an endoscopic third ventriculostomy and pineal gland biopsy, she was diagnosed with pineoblastoma. She was treated with surgical resection, craniospinal radiotherapy, and subsequent chemotherapy. Brain MRIs were performed every 3 months after surgery and remained stable with no new lesions or signs of residual tumor. However, a follow-up brain MRI performed 6 months after chemotherapy showed some small white matter nonenhancing lesions in supratentorial subcortical areas and within the cord at C7. She had no neurologic symptoms at that time and the white matter lesions improved over the next 3 months.However, 10 months later, she developed acute weakness of her left arm and leg and blurry vision. Her neurologic examination confirmed left optic neuritis and moderate left hemiparesis. Routine laboratories did not show any abnormalities. A new brain MRI showed new and enhancing lesions in the brain and spinal cord, including cerebellar hemispheres, left cerebellar peduncle, subcortical white matter, left optic nerve, and multilevel (thoracic and lumbar) intramedullary spinal cord lesions ( figure, A and B). Some of them were round and had a complete ring-enhancing pattern. Additional MRI sequences such as diffusionweighted imaging and perfusion-weighted imaging did not clarify the nature of the lesions (normal apparent diffusion coefficient [ADC] values and slightly increased perfusion in enhancing areas). Spectroscopy was normal. Magnetic resonance angiography demonstrated no flow-limiting stenosis. The patient and her family declined a lumbar puncture. She was empirically treated with high-dose IV steroids and her examination results returned to normal after 6-8 weeks.Question for consideration:1. What is your differential diagnosis regarding her second neurologic presentation?GO TO SECTION 2