title: Anhidrosis: a clue to an underlying autonomic disorder.
abstract: We describe a patient with Ross syndrome who had the classic triad of segmental anhidrosis, tonic pupils and hyporeflexia. Dilute pilocarpine (0.1%) instillation in both eyes revealed parasympathetic denervation hypersensitivity. There was evidence of cardiac dysautonomia in the form of a decrease in heart rate variability with deep breathing and an abnormal Valsalva response. A thermoregulatory sweat test showed the presence of sweating in the right cheek, neck and upper one-third of the left arm and shoulder only. Sympathetic skin responses were absent in the affected segments of the upper limb. Ross syndrome is a degenerative disorder that progressively involves different fibre populations, starting with autonomic fibres and then involving the unmyelinated and myelinated sensory fibres. A careful clinical examination and simple bedside autonomic tests can confirm the diagnosis.
authors.affiliation: Department of Neurology, Christian Medical College, Ludhiana, Punjab, India.
authors.forename: Thomas
authors.initials: T
authors.lastname: Chemmanam
authors.forename: Jeyaraj D
authors.initials: JD
authors.lastname: Pandian
authors.forename: Randhir S
authors.initials: RS
authors.lastname: Kadyan
authors.forename: S M
authors.initials: SM
authors.lastname: Bhatti
mesh_terms: D000328:Adult; D001342:Autonomic Nervous System Diseases / Q000150:complications* / Q000175:diagnosis; D001794:Blood Pressure / Q000187:drug effects; D006801:Humans; D007007:Hypohidrosis / Q000175:diagnosis / Q000209:etiology*; D008297:Male; D008916:Miotics; D009431:Neural Conduction; D010862:Pilocarpine; D011680:Pupil / Q000502:physiology; D012021:Reflex, Abnormal / Q000502:physiology; D013577:Syndrome
chemical_list: D008916:Miotics; D010862:Pilocarpine