Which type of sensory information is impaired in a DCML lesion?

In a lesion of the dorsal column-medial lemniscus (DCML) pathway, the type of sensory information that is primarily impaired is proprioception and discriminative touch, which includes the sense of vibration. The DCML pathway is responsible for transmitting fine touch, proprioception, and vibration sensations from the periphery to the brain.

The vibration sensation is particularly affected because it is carried by the large myelinated fibers that travel through the DCML system. When there is a lesion in this pathway, the individual may experience a decreased ability to perceive vibrations, often observed using tuning forks during clinical assessments.

This pathway contrasts with the spinothalamic tract, which carries sensations such as pain and crude touch. Therefore, impairments resulting from a DCML lesion would not typically affect pain perception or crude touch. Such distinctions are crucial in clinical settings for diagnosing the type of sensory deficits a patient may present with based on their neurological examination.