Late onset of syringomyelia after traumatic brain injury: association with Chiari 1 malformation.

Syringomyelia should be suspected when progressive weakness or sensory loss develops. It most commonly occurs as a congenital malformation but has also been associated with spinal cord injury and the Chiari malformation. Symptomatic Chiari malformation after head injury is rare and usually presents with signs of acutely increased intracranial pressure. This article describes syringomyelia as a late onset complication of head injury in the presence of an underlying Chiari malformation. A possible causal relationship between head injury, the brain malformation, and an extensive syrinx is postulated.