A case of subdural empyema with transient cerebral white matter lesions

We reported a fourteen years old male with subdural empyema followed by consecutive magnetic resonance imaging (MRI) examination. He was admitted to our hospital, complaining incomplete paresis of the left upper extremities, headache and high fever. The first MRI T2-weighted image at admission revealed an abnormal high intensity in the right frontal subdural space, indicating an abscess. Antibiotics therapy and a burr hole operation were effective and he made a remarkable recovery. One month later, the third MRI T2-weighted image showed an abnormal high intensity in the deep white matter of the right frontal lobe, which had not been detected in the subsequent MRI after the operation. On the other hand, the meningeal enhancement on the second Gd-DTPA enhanced MRI was more thickened than the previous meningeal enhancement. This abnormal high intensity on MRI had disappeared two month later, when the meningeal enhancement had grown thin. These data suggested the meningeal enhancement was relative to the transient high intensity which was considered to represent brain edema. We concluded that careful observation and serial MRI examination might be necessary in patient with subdural empyema even after disappearance of all symptoms.