Lhermitte Sign

Lhermitte's sign (also known as Lhermitte's phenomenon or the barber chair phenomenon) is the term used that describes a transient sensation of an electric shock that extends down the spine and extremities upon flexion and/or movement of the neck. It was first described by Marie and Chatelin in 1917, but was erroneously first credited to Babinski and Dubois, and thenafter credited to Jean Jaque Lhermitte through the seminal paper  (1924) by Lhermitte et al. and Gutre. Lhermitte described this phenomenon in patients with multiple sclerosis and other spinal cord diseases. It was then further hypothesized that it resulted from irritation and inflammation of the spinal cord, likely in the posterior and lateral columns. Lhermitte's sign is also classified as one of the paroxysmal pain syndromes of multiple sclerosis, a chronic, predominantly immune-mediated disease of the central nervous system. It is among the most common causes of neurological disability in young adults globally. It can cause many other neurological clinical symptoms, including mononuclear painful visual loss, spinal cord hemiparesis, mono/paraparesis, hypoesthesia, dysesthesia, paraesthesia, urinary and/or sphincter dysfunction, diplopia, oscillopsia, vertigo, gait ataxia, dysmetria, intentional/postural tremor, facial paresis, faciobrachial–crural hemiparesis, and faciobrachial–crural hemihypesthesia. Lhermitte's sign should not be confused with the Uhthoff phenomenon, another finding in multiple sclerosis patients that is defined by heat sensitivity after prolonged heat exposure, saunas, and hot tubs.