Physical examination showed an irritable infant with macrocephaly (head circumference, 42.5 cm; 97th percentile, 42 cm) and gray, poorly perfused skin. The anterior fontanel was bulging and his eyes demonstrated a sunset sign. He lay spontaneously with his neck extended. The peripheral blood showed a white blood cell count of 24.9× 109/L. The blood culture was sterile. Results of a lumbar puncture and analysis of the cerebrospinal fluid showed a white blood cell count of 4.3×109/L, a protein concentration of 226 g/L, and a glucose concentration of less than 0.5 µmol/L (<10 mg/dL). No bacteria were detected microscopically. The cerebrospinal fluid culture was sterile.