[Syringomyelia appearing in a short term after brain abscess].

We describe a rare case of syringomyelia that developed within only 4 months after the cure of the focal cerebritis and abscess. An 18-year-old man who had suffered from meningitis and brain abscess 1.5 years before, presented with pain and sensory disturbance in his left shoulder. Magnetic resonance image (MRI) showed a syrinx formation extending from the upper cervical to the lower thoracic cord. Investigation by MRI during the course of the brain abscess had the appearance of posterior cerebellar arachnoid cyst 3 months after the onset of brain abscess and syrinx developed within 9 months. After posterior fossa decompression and reopening of the Magendie's foramen, his symptom and MRI abnormality improved after one month. In contrast to reported cases of syringomyelia following cerebritis, syrinx formation in our case appeared in relatively a short time. We speculated that basal arachnoiditis and the formation of posterior cerebellar arachnoid cyst caused syrinx formation in a short term after cerebritis.