What is fasciculus posterior?

The fasciculus posterior, also called the dorsal column or the posterior column, is a structure in the spinal cord that carries sensory information from the skin, joints, and muscles to the brain. It is composed of two distinct tracts, the fasciculus gracilis and the fasciculus cuneatus.

The fasciculus gracilis carries information from the lower extremities and the lower trunk, while the fasciculus cuneatus carries information from the upper extremities and the upper trunk. Both tracts ascend up the spinal cord, crossing over at the medulla oblongata and continuing to the thalamus where they synapse with secondary sensory neurons. From there, the sensory information is relayed to the appropriate areas of the brain for processing.

Damage to the fasciculus posterior can lead to sensory deficits such as loss of vibration sensation, proprioception, and discriminative touch. Additionally, damage to this structure can also result in a positive Romberg test, which is a clinical test used to evaluate balance.