title: Parabrachial nucleus involvement in multiple system atrophy.
abstract: Multiple system atrophy (MSA) is associated with respiratory dysfunction, including sleep apnea, respiratory dysrhythmia, and laryngeal stridor. Neurons of the parabrachial nucleus (PBN) control respiratory rhythmogenesis and airway resistance.
  
  
  OBJECTIVE
  The objective of this study is to determine whether there was involvement of putative respiratory regions of the PBN in MSA.
  
  
  METHODS
  We examined the pons at autopsy in 10 cases with neuropathologically confirmed MSA and 8 age-matched controls. Sections obtained throughout the pons were processed for calcitonin-gene related peptide (CGRP) and Nissl staining to identify the lateral crescent of the lateral PBN (LPB) and the Kölliker-Fuse nucleus (K-F), which are involved in respiratory control. Cell counts were performed using stereology.
  
  
  RESULTS
  There was loss of CGRP neurons in the PBN in MSA (total estimated cell counts for the external LPB cluster was 12,584 ± 1146 in controls and 5917 ± 389 in MSA, p<0.0001); for the external medial PBN (MPB) cluster it was 15,081 ± 1758 in controls and 7842 ± 466 in MSA, p<0.001. There was also neuronal loss in putative respiratory regions of the PBN, including the lateral crescent of the LPB (13,039 ± 1326 in controls and 4164 ± 872 in MSA, p<0.0001); and K-F (5120 ± 495 in controls and 999 ± 308 in MSA, p<0.0001).
  
  
  CONCLUSIONS
  There is involvement of both CGRP and putative respiratory cell groups in the PBN in MSA. Whereas the clinical implications of CGRP cell loss are still undetermined, involvement of the LPB and K-F may contribute to respiratory dysfunction in this disorder.
authors.affiliation: Department of Neurology, Mayo Clinic, Rochester, MN, USA. Electronic address: benarroch.eduardo@mayo.edu.
authors.forename: E E
authors.initials: EE
authors.lastname: Benarroch
authors.forename: A M
authors.initials: AM
authors.lastname: Schmeichel
authors.forename: P A
authors.initials: PA
authors.lastname: Low
authors.forename: J E
authors.initials: JE
authors.lastname: Parisi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019578:Multiple System Atrophy / Q000473:pathology*; D009415:Nerve Net / Q000473:pathology / Q000502:physiology; D011149:Pons / Q000473:pathology* / Q000502:physiology; D012125:Respiratory Center / Q000473:pathology* / Q000502:physiology
keywords: CGRP; Lateral parabrachial; MSA; Medial parabrachial; Stridor