title: Muscle and skin sympathetic activities in Ross syndrome.
abstract: OBJECTIVE
  Ross syndrome (RS) is a rare degenerative disorder characterized by tonic pupil, areflexia and anhydrosis. The underlying lesion affects postganglionic skin sympathetic nerve fibers whereas the postganglionic muscle sympathetic branch is thought to be spared. Microneurography explores both skin and muscle peripheral sympathetic branches and it does not usually detect peripheral sympathetic outflow in either branch in chronic autonomic failure syndromes. The aim of this study was to record sympathetic activity by microneurography for the first time in RS patients to confirm the selective involvement of skin sympathetic nerve activity (SSNA) with spared muscle sympathetic nerve activity (MSNA).
  
  
  METHODS
  We studied seven patients (49 ± 14 years, four males) with a typical clinical picture and skin biopsy findings. Patients underwent cardiovascular reflexes and microneurography from the peroneal nerve (anhydrotic skin) to record MSNA, SSNA and the corresponding organ effector responses (skin sympathetic response-SSR and skin vasomotor response-SVR) in the same innervation field. The absence of sympathetic bursts was established after exploring at least three different corresponding nerve fascicles. Twenty age-matched healthy subjects served as controls.
  
  
  RESULTS
  RS patients complained of diffuse anhydrosis and they showed tonic pupil and areflexia. Cardiovascular reflexes were normal. All patients displayed absent SSNA, SSR and SVR whereas MSNA was always recorded showing normal characteristics.
  
  
  CONCLUSIONS
  Microneurographic study of sympathetic activity from affected skin confirmed the selective involvement of skin sympathetic activity with spared muscle sympathetic activity and it may represent the neurophysiological hallmark of the disease.
  
  
  CONCLUSIONS
  Microneurography together with clinical and skin biopsy findings may contribute to RS diagnosis. Our data also suggest that autonomic damage in RS does not involve cardiovascular activity.
authors.affiliation: IRCSS, Istituto delle Scienze Neurologiche di Bologna, Department of Neurological Sciences, Bolgna University, Italy. vincenzo.donadio@unibo.it
authors.forename: V
authors.initials: V
authors.lastname: Donadio
authors.forename: P
authors.initials: P
authors.lastname: Cortelli
authors.forename: M P
authors.initials: MP
authors.lastname: Giannoccaro
authors.forename: M
authors.initials: M
authors.lastname: Nolano
authors.forename: V
authors.initials: V
authors.lastname: Di Stasi
authors.forename: A
authors.initials: A
authors.lastname: Baruzzi
authors.forename: R
authors.initials: R
authors.lastname: Liguori
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D007007:Hypohidrosis / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000503:physiopathology*; D012021:Reflex, Abnormal / Q000502:physiology*; D012867:Skin / Q000294:innervation* / Q000503:physiopathology; D013543:Sweat Gland Diseases / Q000503:physiopathology; D013564:Sympathetic Nervous System / Q000503:physiopathology*; D013577:Syndrome; D015845:Tonic Pupil / Q000503:physiopathology*