Herniation of spinal cord into nerve root avulsion pseudomeningocele: A rare cause of delayed progressive neurological deficit.

We present a patient with old traumatic right brachial plexus injury, who developed progressive neurological deterioration 4 years after the initial injury. On magnetic resonance imaging (MRI), herniation of the upper dorsal cord was noted into a post-traumatic pseudomeningocele. Though the herniation of cord into a post-traumatic pseudomeningocele is very rare, it should be suspected in cases of delayed progressive myelopathy. A three dimensional (3-D) T2-weighted sequence such as Sampling Perfection with Application optimized Contrasts using different flip angle Evolution (SPACE) or constructive interference in steady state (CISS) provides optimal visualization of the herniated cord and helps in surgical planning.