Multiple sclerosis (MS) is an autoimmune disorder that affects the central nervous system. Lhermitte’s sign, also called Lhermitte’s phenomenon or the barber chair phenomenon, is often associated with MS. It is a sudden, uncomfortable sensation that travels from your neck down to your spine. Lhermitte’s is often described as feeling like an electrical shock or buzzing sensation.
Lhermitte’s sign is caused by nerves that are no longer coated with myelin. These damaged nerves respond to the movement of the neck, which causes sensations from the neck to the spine.
Lhermitte’s sign is common in MS, but it’s not exclusive to the disease. People with spinal cord injuries or inflammation, such as cervical spondylitis or disc impingement, might also feel symptoms of the condition. Severe vitamin B-12 deficiency can also cause symptoms of Lhermitte’s sign.
The main symptom of Lhermitte’s sign is an electric sensation that travels down your neck and back and also feels present in the arms, legs, fingers, and toes. The pain is usually strongest when you bend your neck forward. The shock-like feeling is often short and intermittent. However, it can feel quite powerful while it lasts.