Positive Romberg test with eyes closed detects defect in:

Romberg Test: The patient is asked to stand with the feet closely approximated, first with his/her eyes open, and then closed. The test is 'positive' when the patient is able to stand with his/her feet together while his/her eyes are open, but sways or falls when they are closed. Any lesion along the proprioceptive pathway can result in a positive Romberg test. Proprioceptive pathway: Proprioception is the ability to sense the position of one's extremities without the aid of vision. The peripheral sense organs are located in the muscle, tendons, and joints. The first cell body is situated in the dorsal root ganglion, going without a synapse to the ipsilateral fasiculi cuneatus and gracilis (dorsal column) to the lower medulla where the synapse occurs. Following a decussation of the internal arcuate fibers, the impulses ascend in the medial lemniscus to the thalmus, terminating in the parietal lobe, posterior to those that convey touch. Conditions commonly causing a positive Romberg test: Posterior column dysfunction Sensory polyneuropathy Intracranial lesions