title: Pupillary "dilatation lag" in Horner's syndrome.
abstract: 1. Clinical examination will often fail to identify the presence of a unilateral Horner's syndrome. 2. Confirmation and localization of Horner's syndrome is of clinical prognostic value. 3. Cocaine testing provides confirmation of a Horner's syndrome, but it takes 45 min, is sometimes equivocal, and always delays the localizing hydroxyamphetamine test. 4. "Dilatation lag" is a sensitive and physiological sign of Horner's syndrome, and can be demonstrated by simple Polaroid flash photographs.
mesh_terms: D004106:Dilatation; D005132:Eye Manifestations; D006732:Horner Syndrome / Q000175:diagnosis* / Q000503:physiopathology; D006801:Humans; D012025:Reflex, Pupillary; D013997:Time Factors