title: The value of the bulbocavernosus reflex and pudendal nerve somatosensory evoked potentials in distinguishing between multiple system atrophy and Parkinson's disease at an early stage.
abstract: OBJECTIVE
  This study was designed to investigate the clinical value of the bulbocavernosus reflex (BCR) and pudendal nerve somatosensory evoked potentials (PSEPs) in the differential diagnosis between multiple system atrophy (MSA) and Parkinson's disease (PD) in early stage.
  
  
  METHODS
  A total of 31 patients with MSA, 45 patients with PD, and 60 healthy participants were included in this study. A Keypoint EMG/EP system was used for BCR and PSEP measurements. Electrophysiological parameters were collected for statistical analysis.
  
  
  RESULTS
  The BCR elicitation rates were significantly lower in the patients with MSA than in the patients with PD (P<.05). Prolonged BCR latencies were found in the MSA group compared to the PD and control groups (P<.05). Bulbocavernosus reflex latencies were significantly prolonged in patients with MSA compared with PD patients showing early urogenital symptoms (P<.05). There was no significant difference in PSEP P41 latencies among the three groups (P=.434 in males, P=.948 in females). Both BCR and PSEP amplitudes were significantly lower in the MSA/PD group than in the control group (P<.001).
  
  
  CONCLUSIONS
  Pudendal nerve damage is more severe in MSA than in PD. Prolonged BCR latency may be valuable for distinguishing between MSA and PD in the early stages. BCR and PSEP testing may also contribute to localized and qualitative diagnosis of the distribution of neurodegenerative pathologies in these two disorders.
authors.affiliation: Department of Neurology, First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China.
authors.forename: Z-Y
authors.initials: ZY
authors.lastname: Cai
authors.affiliation: Department of Neurology, First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China.
authors.forename: X-T
authors.initials: XT
authors.lastname: Niu
authors.affiliation: Department of Neurology, First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China.
authors.forename: J
authors.initials: J
authors.lastname: Pan
authors.affiliation: Department of Neurology, First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China.
authors.forename: P-Q
authors.initials: PQ
authors.lastname: Ni
authors.affiliation: Department of Neurology, First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China.
authors.forename: X
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Neurology, First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China.
authors.forename: B
authors.initials: B
authors.lastname: Shao
mesh_terms: D000368:Aged; D003937:Diagnosis, Differential; D005073:Evoked Potentials, Somatosensory; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019578:Multiple System Atrophy / Q000175:diagnosis*; D010300:Parkinson Disease / Q000175:diagnosis*; D060525:Pudendal Nerve / Q000502:physiology; D012018:Reflex
keywords: Parkinson's disease; bulbocavernosus reflex; differential diagnosis; multiple system atrophy; pudendal nerve somatosensory evoked potentials