What is the term for the shock-like sensation experienced in the neck and back upon neck flexion, commonly seen in multiple sclerosis patients?

The term for the shock-like sensation experienced in the neck and back upon neck flexion, commonly seen in multiple sclerosis patients, is known as Lhermitte's sign. This neurological phenomenon occurs due to the demyelination of cervical spinal cord pathways, which disrupts normal conduction of sensory impulses.

When the neck is flexed, it can create a stretch or tension that induces this uncomfortable, electric shock-like sensation radiating down the spine and into the limbs. This sign is particularly pertinent in diagnosing multiple sclerosis as it reflects underlying spinal cord involvement, helping clinicians assess the extent of the disease's impact on neurological function.

Other terms listed, such as paraperesis, refer to weakness in the lower limbs, while monoparesis describes weakness affecting a single limb. Sensory ataxia is related to a lack of coordination arising from sensory input loss. These conditions do not specifically characterize the shock-like sensation linked with neck flexion as aptly as Lhermitte's sign does.