Lhermitte’s sign, also known as Lhermitte’s phenomenon or the "barber chair phenomenon," is a distinctive neurological symptom often associated with multiple sclerosis (MS). It manifests as a sudden, brief, and intense electric shock-like sensation that travels down the spine and into the limbs when the neck is flexed forward. This symptom is relatively common in MS, affecting approximately 33% to 40% of individuals with the condition​ (MS Focus)​​ (BMJ Journals)​. Understanding Lhermitte’s sign is crucial for individuals with MS, as it provides insight into the underlying neurological disruptions caused by the disease and offers pathways for effective management.

What Causes Lhermitte’s Sign?

1. Demyelination: In MS, Lhermitte’s sign is caused by demyelination, which is the loss of the protective myelin sheath around nerves in the spinal cord. This demyelination disrupts normal nerve function, leading to the characteristic shock-like sensations. Demyelination in MS can result from the immune system mistakenly attacking the myelin sheath, causing…