title: Internal jugular vein valve incompetence and intracranial venous anatomy in transient global amnesia.
abstract: BACKGROUND
  Recently a causal relation between internal jugular vein valve incompetence (IJVVI) and transient global amnesia (TGA) has been suggested. IJVVI is postulated to provoke a transient mesiotemporal ischaemia by venous congestion. This mechanism requires a patent venous pathway from the affected IJV through the transverse sinus, confluens, straight sinus (SS), vein of Galen into the basal vein of Rosenthal and the internal cerebral veins.
  
  
  OBJECTIVE
  To study IJVVI in TGA patients in relation to the intracranial venous anatomy.
  
  
  METHODS
  IJVVI was defined if a repeated Valsalva manoeuvre (VM) led to a retrograde jugular flow detected by extracranial duplex ultrasound. Non-contrast venous MR angiography (MRA) was performed to analyse intracranial drainage patterns of the SS in relation to the side of the IJVVI. SS drainage was differentiated into three groups: predominantly right, left, and bilateral drainage. Ultrasound studies were performed in 25 TGA patients and 85 age matched controls. Twenty patients underwent venous MRA.
  
  
  RESULTS
  Sixty eight per cent of patients and 33% of controls showed unilateral or bilateral IJVVI (p = 0.0025). In 36% of patients a TGA preceding VM was reported. Drainage pattern of SS and side of IJVVI corresponded in five of eight patients (63%) with VM and four of 12 patients without VM (33%, p = 0.0994).
  
  
  CONCLUSIONS
  Our study confirms the significantly higher prevalence of IJVVI in TGA patients. However, no specific IJVVI related intracranial venous drainage patterns could be found to further support the hypothesis of a direct causal relation between IJVVI and TGA.
authors.affiliation: Department of Neurology, University Hospital Charité, Schumannstrasse 20/21, 10117 Berlin, Germany. Stephan.Schreiber@charite.de
authors.forename: S J
authors.initials: SJ
authors.lastname: Schreiber
authors.forename: F
authors.initials: F
authors.lastname: Doepp
authors.forename: R
authors.initials: R
authors.lastname: Klingebiel
authors.forename: J M
authors.initials: JM
authors.lastname: Valdueza
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D020236:Amnesia, Transient Global / Q000209:etiology* / Q000503:physiopathology*; D001921:Brain / Q000098:blood supply / Q000000981:diagnostic imaging / Q000503:physiopathology; D002545:Brain Ischemia / Q000209:etiology / Q000503:physiopathology; D002560:Cerebrovascular Circulation; D005260:Female; D006801:Humans; D007601:Jugular Veins / Q000033:anatomy & histology* / Q000000981:diagnostic imaging / Q000503:physiopathology*; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011859:Radiography; D012720:Severity of Illness Index; D018616:Ultrasonography, Doppler, Duplex; D014636:Valsalva Maneuver / Q000502:physiology; D014689:Venous Insufficiency / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology*