title: Collapsed Jugular Vein and abnormal cerebral blood flow changes in patients of Panic Disorder.
abstract: OBJECTIVE
  Panic disorder (PD) is characterized by panic attacks accompanied with respiratory symptoms. Internal jugular vein (IJV) alters its hemodynamics in response to respiration and which might cause cerebral blood flow (CBF) changes. In the present study, we compared (1) respiratory-related IJV hemodynamics and (2) CBF changes during Valsalva maneuver (VM) between PD and normal subjects.
  
  
  METHODS
  42 PD patients and age/gender-matched controls (14 men; 52.3 ± 11.4 years) were recruited. Duplex ultrasonography measured time-averaged mean velocity (TAMV) and lumen in IJV at baseline and deep inspiration. Lumen area <0.10 cm(2) at deep inspiration was defined as IJV collapse. CBF changes during VM were recorded by transcranial Doppler (TCD).
  
  
  RESULTS
  Compared with normal group, PD patients had significantly higher frequency of IJV collapse at deep inspiration (Left: 40.0% vs. 7.0%, p = 0.0003, Right: 17.0% vs. 0%, p = 0.0119). IJV collapse was associated with symptoms of respiratory subtype in our PD patients. PD group also had smaller lumen (Left: 0.53 ± 0.29 vs. 0.55 ± 0.26 cm(2), p = 0.8296, Right: 0.63 ± 0.36 vs. 0.93 ± 0.45 cm(2), p = 0.0014) and slower TAMV of IJV at baseline (Left: 11.8 ± 8.43 vs. 20.6 ± 16.5 cm/s, p = 0.0003, Right: 15.9 ± 9.19 vs. 24.1 ± 15.7 cm/s, p = 0.0062). PD patients with inspiration-induced IJV collapse had more decreased CBF during VM compared with the other PD patients and normal individuals respectively.
  
  
  CONCLUSIONS
  We are the first to show that PD have less IJV flow at baseline and more frequent collapse at deep inspiration. Inspiration-induced IJV collapsed was associated with CBF decrement during VM in PD patients. These results suggest that venous drainage impairment might play a role in the pathophysiology of PD by influencing CBF.
authors.affiliation: Department of Internal Medicine, Yonghe Cardinal Tien Hospital, Taipei 234, Taiwan; Department of Neurology, Neurological Institute, Taipei Veterans General Hospital, Taipei 11217, Taiwan; School of Medicine, National Yang-Ming University, Taipei 11217, Taiwan.
authors.forename: Yu-Chien
authors.initials: YC
authors.lastname: Tsao
authors.affiliation: Department of Neurology, Neurological Institute, Taipei Veterans General Hospital, Taipei 11217, Taiwan; School of Medicine, National Yang-Ming University, Taipei 11217, Taiwan. Electronic address: cpchung@vghtpe.gov.tw.
authors.forename: Chih-Ping
authors.initials: CP
authors.lastname: Chung
authors.affiliation: Department of Neurology, Tungs' Taichung Metro Harbor Hospital, Taichung 435, Taiwan; School of Medicine, Chung Shan Medical University, Taichung 40201, Taiwan.
authors.forename: Hung-Yi
authors.initials: HY
authors.lastname: Hsu
authors.affiliation: School of Medicine, National Yang-Ming University, Taipei 11217, Taiwan; Internal Medicine Department, Cheng Hsin General Hospital, Taipei 112, Taiwan.
authors.forename: Chun-Yu
authors.initials: CY
authors.lastname: Cheng
authors.affiliation: Department of Neurology, Kaohsiung Medical University Chung-Ho Memorial Hospital, Kaohsiung 807, Taiwan.
authors.forename: A-Ching
authors.initials: AC
authors.lastname: Chao
authors.affiliation: Department of Neurology, Neurological Institute, Taipei Veterans General Hospital, Taipei 11217, Taiwan.
authors.forename: Wen-Yung
authors.initials: WY
authors.lastname: Sheng
authors.affiliation: Department of Neurology, Neurological Institute, Taipei Veterans General Hospital, Taipei 11217, Taiwan; School of Medicine, National Yang-Ming University, Taipei 11217, Taiwan.
authors.forename: Han-Hwa
authors.initials: HH
authors.lastname: Hu
authors.affiliation: School of Medicine, National Yang-Ming University, Taipei 11217, Taiwan; Department of Psychiatry, Taipei Veterans General Hospital, Taipei 11217, Taiwan.
authors.forename: Chen-Jee
authors.initials: CJ
authors.lastname: Hong
authors.affiliation: School of Medicine, National Yang-Ming University, Taipei 11217, Taiwan; Department of Medical Research and Education, Taipei Veterans General Hospital, Taipei 11217, Taiwan.
authors.forename: Jaw-Ching
authors.initials: JC
authors.lastname: Wu
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D002540:Cerebral Cortex / Q000098:blood supply*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D005260:Female; D006801:Humans; D007601:Jugular Veins / Q000000981:diagnostic imaging / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D020768:Middle Cerebral Artery / Q000503:physiopathology; D016584:Panic Disorder / Q000473:pathology*; D011569:Psychiatric Status Rating Scales; D018709:Statistics, Nonparametric; D018616:Ultrasonography, Doppler, Duplex; D014636:Valsalva Maneuver / Q000502:physiology
keywords: Cerebral blood flow; Jugular vein; Panic disorder