A 2.5-year-old, previously healthy, female child presented to the emergency department with cough, fever, lethargy, and a 6-day history of decreased movement in her legs and a lack of facial expression. One week prior to admission, she had symptoms of an upper respiratory tract infection with fever and was seen by the family doctor and prescribed amoxicillin. She was admitted to the pediatric intensive care unit for investigation and because of chest X-ray changes and the persistent fever, she was switched over to intravenous cephalosporin antibiotics for presumed community-acquired pneumonia. Because of the bradykinesia, she had a CT scan of the head completed and a neurology consultation. On examination, the child was somnolent but followed some simple commands. Cranial nerve examination was positive only for a nearly complete lack of facial expression. Motor examination showed normal muscle bulk, generalized bradykinesia, cogwheeling of the arms, and rigidity of the legs with a flexor plantar response. Respiratory examination revealed only coarse upper airway sounds. The CT scan showed bilateral hypodensities in the basal ganglia. Blood cultures were sterile, and sputum grew nonspecific species that were felt to be contamination. A blood sample taken at the time of admission was negative for carbon monoxide. The CSF showed normal glucose, protein, and cell count, and it did not grow any organisms, and common viral testing was normal; however, the CSF lactate was elevated at 4.4. mmol/L (N. <. 2.2. mmol/L). A brain MRI showed a high signal on T2-weighted images in the head of the caudate, globus pallidus, and putamen.