Idiopathic dural herniation of the thoracic spinal cord.

Symptomatic anterior or anterolateral dural herniation of the spinal cord is rare, and not uncommonly misdiagnosed, both clinically and radiologically. We present four patients with a radiological diagnosis of herniation of the thoracic spinal cord, and review the current literature. All affected patients have been adults, typically presenting with long-standing, unexplained sensory symptoms and eventually developing a Brown-Séquard syndrome, with or without motor changes. Herniation occurs in the upper or midthoracic region, between the T2 and T8 levels.