Lhermitte's sign
Meaning of Lhermitte's sign: Lhermitte's sign is an electric shock like sensation down the spine triggered by bending the neck forward, pointing to spinal cord irritation.
Definition of Lhermitte's sign
Lhermitte's sign is a brief, electric shock like sensation that radiates from the back of the neck down the spine, and sometimes into the arms or legs, when the neck is bent forward. The sensation typically lasts only a moment and resolves once the neck returns to a neutral position.
This sign reflects irritation or damage affecting the dorsal columns of the spinal cord, the pathways that carry certain sensory information toward the brain, within the cervical portion of the spine. Bending the neck forward stretches and mechanically stimulates these already irritated pathways, producing the characteristic shock like sensation.
Lhermitte's sign is most often associated with multiple sclerosis, though it can also occur with cervical spinal cord compression, certain vitamin deficiencies, and past radiation treatment to the neck, so its presence points toward a problem within the cervical spinal cord without identifying a single specific cause.
Used in a sentence
The patient described a Lhermitte's sign occurring when bending the neck forward to look down.
Good to know
Lhermitte's sign is often associated specifically with multiple sclerosis, but it is not specific to that condition and can arise from any process irritating the cervical spinal cord's dorsal columns.