title: Uhthoff's phenomena in MS--clinical features and pathophysiology.
abstract: In the late 19(th) century, Wilhelm Uhthoff reported on a series of patients with acute optic neuritis who manifested similar recurrent, stereotyped visual symptoms that were of paroxysmal onset, short in duration, and reversible. These 'Uhthoff's phenomena', which are a feature of multiple sclerosis (MS) and other demyelinating diseases, can be triggered by factors including the perimenstrual period, exercise, infection, fever, exposure to high ambient temperatures, and psychological stress. Here, we characterize the clinical, pathophysiological and neurotherapeutic challenges associated with Uhthoff's phenomena, and discuss the differentiation of these events from other paroxysmal, acute or subacute changes in functional capabilities and neurological symptoms in MS. For instance, whereas MS exacerbations are contingent on immune dysregulation, Uhthoff's phenomena are predicated on ion channel modifications, in conjunction with thermoregulatory derangements that transiently alter the conduction properties of demyelinated axons. An understanding of these pathophysiological underpinnings of Uhthoff's phenomena is germane to their recognition and timely treatment.
authors.affiliation: Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Centre, 5323 Harry Hines Boulevard, Dallas, TX 75235, USA.
authors.forename: Teresa C
authors.initials: TC
authors.lastname: Frohman
authors.forename: Scott L
authors.initials: SL
authors.lastname: Davis
authors.forename: Shin
authors.initials: S
authors.lastname: Beh
authors.forename: Benjamin M
authors.initials: BM
authors.lastname: Greenberg
authors.forename: Gina
authors.initials: G
authors.lastname: Remington
authors.forename: Elliot M
authors.initials: EM
authors.lastname: Frohman
mesh_terms: D049672:History, 19th Century; D006801:Humans; D009103:Multiple Sclerosis / Q000175:diagnosis* / Q000209:etiology* / Q000266:history / Q000628:therapy