What is Lhermittes sign?
Lhermittes sign (also known as Lhermitte’s phenomenon) is present when the patient reports an electric shock-like sensation down the spine with neck flexion. It is most commonly associated with multiple sclerosis.
In patients with multiple sclerosis, the prevalence is thought to be approximately 15%.
The symptom is produced by stretching or irritating damaged fibers in the dorsal columns of the cervical cord.
In addition to multiple sclerosis, it may also occur in cervical spondylogenic myelopathy, intramedullary lesions, or as part of subacute combined degeneration from vitamin B12 deficiency.
Lhermitte’s sign is the reported sensation of an electric-like shock propagating down the spine as a result of brisk neck flexion. This maneuver may also induce limb paresthesias and weakness. Lhermitte’s sign is not only observed in some patients with spinal cord compression but also in patients with multiple sclerosis.