Somnolence syndrome after focal radiation therapy to the pineal region: case report and review of the literature.

Somnolence syndrome classically occurs in children after cranial irradiation for acute lymphocytic leukemia. Symptoms include somnolence, fever, nausea and vomiting, and headache. The authors report a 29 year-old female who developed symptoms compatible with the somnolence syndrome after completing radiation therapy for a benign meningioma near the pineal region. Five weeks after completing conformal radiation therapy (54 Gy), she developed profound fatigue, headaches, and 102-degree fevers. Physical examination and routine laboratory work were unrevealing. Imaging was not performed. Prednisone was prescribed and within 1 week her symptoms had largely resolved. This is the first report of the somnolence syndrome after focal radiation therapy. The possible etiology of the somnolence syndrome is discussed.