Background: Ventral cord
herniation from dura defect is a rare cause of focal progressive myelopathy due
to the thoracic cord herniation through the dural defect. In the majority of
cases it is spontaneous, and could be congenital or idiopathic. In some
patients there could be a history of previous trauma or surgery in the thoracic
region. The dura defect usually need repair to prevent the progression of myelopathy.

Case
report: A
33-year-old man presented with an insidious onset and progressive numbness over
right lower chest for about 2 years. He had a history of traffic accident and
underwent a repair of right knee tendon rupture 4 years before. In the past two
years, He also experienced intermittent mild to severe upper back pain,
sometimes radiating to the neck. The pain was aggravated by cough and on
raising up from bed suddenly. He got a scald burn over right calf due to a
reduction of thermal sensation on his right lower leg. The neurological examination
revealed right leg weakness with muscle strength of 4/5 and reduced pain and
temperature sensation below right chest (about T5 level). The vibration was
also decreased on right lower limb. The spinal magnetic resonance imaging study
showed a dura ventral herniation of spinal cord at the T3,4 level. Due to the
symptomatic myelopathy, he underwent an operation of total laminectomy of T2-5
with repair of ventral dura defect. After the surgical treatment, his back pain
relieved and the numbness ameliorated as well.

Conclusion: Symptomatic myelopathy is usually
caused by compression from degenerative disease, tumor, injury, circulatory or
inflammatory diseases, idiopathic ventral spinal cord herniation is a rare cause of thoracic myelopathy. Most patients experience
progressive myelopathy for many years before the exact
diagnosis is achieved. The awareness and early
diagnosis are essential to prevent irreversible neurological dysfunction.