title: Sensorimotor gating deficits in multiple system atrophy: comparison with Parkinson's disease and idiopathic REM sleep behavior disorder.
abstract: BACKGROUND
  Prepulse inhibition (PPI) of the auditory blink reflex is a measure of sensorimotor gating, which reflects an organism's ability to filter out irrelevant sensory information. PPI has never been studied in patients with multiple system atrophy (MSA), although sensorimotor deficits are frequently associated with synucleinopathies. We investigated whether alterations in PPI were more pronounced in MSA compared with Parkinson's disease (PD), idiopathic rapid eye movement sleep behavior disorder (iRBD) and healthy controls.
  
  
  METHODS
  10 patients with MSA, 12 patients with iRBD, 40 patients with PD, and 20 healthy controls completed the study. A passive acoustic prepulse inhibition paradigm was applied with prepulses 5 dB and 15 dB above background noise at 30-, 60-, 120- and 300-ms intervals.
  
  
  RESULTS
  Non-parametric analyses showed that MSA patients had significantly lower prepulse inhibition, as measured with max-amplitude, than PD patients and iRBD patients on the 60 ms-85 dB and 120 ms-85 dB inter-stimulus intervals. The same relation was found when using area under the curve. No differences were found between groups for the 30 ms-85 dB and 300 ms-85 dB. Furthermore, blink reflex characteristics such as habituation did not differ between patients and controls.
  
  
  CONCLUSIONS
  The present study showed that sensorimotor gating, as measured with PPI, is markedly reduced in MSA. This may be due to the pronounced severity of striatal and brainstem dysfunction, as well as the degeneration of other structures related to the PPI modulating pathways in MSA. PPI may be a non-invasive neurophysiological measure that can aid in the differential diagnosis between PD and MSA.
authors.affiliation: Department of Neurology, Bispebjerg Hospital, Copenhagen, Denmark; Danish Center for Sleep Medicine, Department of Clinical Neurophysiology, Glostrup Hospital, Copenhagen, Denmark; Center for Healthy Aging, University of Copenhagen, Copenhagen, Denmark. Electronic address: m.e.a.zoetmulder.assenholt@regionh.dk.
authors.forename: Marielle
authors.initials: M
authors.lastname: Zoetmulder
authors.affiliation: Department of Neurology, Bispebjerg Hospital, Copenhagen, Denmark.
authors.forename: Heidi Bryde
authors.initials: HB
authors.lastname: Biernat
authors.affiliation: Department of Clinical Neurophysiology, Glostrup Hospital, Copenhagen, Denmark.
authors.forename: Miki
authors.initials: M
authors.lastname: Nikolic
authors.affiliation: Department of Neurology, Bispebjerg Hospital, Copenhagen, Denmark.
authors.forename: Lise
authors.initials: L
authors.lastname: Korbo
authors.affiliation: Danish Center for Sleep Medicine, Department of Clinical Neurophysiology, Glostrup Hospital, Copenhagen, Denmark; Center for Healthy Aging, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Poul Jørgen
authors.initials: PJ
authors.lastname: Jennum
mesh_terms: D000161:Acoustic Stimulation / Q000379:methods; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019578:Multiple System Atrophy / Q000175:diagnosis / Q000503:physiopathology*; D010300:Parkinson Disease / Q000175:diagnosis / Q000503:physiopathology*; D017286:Polysomnography / Q000379:methods; D020187:REM Sleep Behavior Disorder / Q000175:diagnosis / Q000503:physiopathology*; D055139:Sensory Gating / Q000502:physiology*
keywords: Auditory blink reflex; Idiopathic REM sleep behavior disorder; Multiple systems atrophy; Parkinson's disease; Prepulse inhibition