title: Obstruction of Venous Drainage Linked to Transient Global Amnesia.
abstract: Abnormal extracranial venous drainage modality has been considered an etiology of transient global amnesia (TGA). Evidence suggests that the transmission of the intrathoracic/intraabdominal pressure during a Valsalva maneuver (VM) is mainly through the vertebral venous system, and patency of internal jugular vein (IJV) is essential for venous drainage and pressure releasing. We hypothesize that obstruction of IJV venous drainage is a contributing factor in TGA pathogenesis. A magnetic resonance (MR) imaging protocol was used in 45 TGA patients and 45 age- and sex-matched controls to assess the morphologies of IJV, brachiocephalic vein (BCV) and asymmetry of transverse sinus (TS). The IJV was divided into the upper- and middle-IJV segments. Compared to the controls, TGA patients had significantly higher rates of moderate and severe compression/stenosis at the bilateral upper-IJV segment (left: 37.8% vs. 17.8%, P = 0.0393; right: 57.8% vs.15.6%, P<0.0012), in left BCV (60% vs. 8.9%, P<0.0004), and in TS hypoplasia (53.3%% vs. 31.1%, P = 0.0405). The prevalence of at least one site of venous compression/stenosis in IJV or BCV was significantly higher in patients than in controls (91.1% vs. 33.3%, P<0.0004). The diameter of the left TS in MRV, but not in T1 contrast imaging, was significantly smaller in TGA patients than in controls (0.31 ± 0.21 vs. 0.41 ± 0.19, P = 0.0290), which was compatible with downstream venous stenosis/obstruction. TGA patients have a higher prevalence of compression/stenosis of the bilateral IJV and the left BCV and TS hypoplasia, which is new evidence that supports the role of extracranial veins in TGA pathogenesis.
authors.affiliation: Department of Neurology, First Hospital of Jilin University, Changchun, Jilin Province, China.
authors.forename: Ke
authors.initials: K
authors.lastname: Han
authors.affiliation: Department of Neurology, College of Medicine, Kaohsiung Medical University and Department of Neurology, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.
authors.forename: A-Ching
authors.initials: AC
authors.lastname: Chao
authors.affiliation: Department of Radiology, Taipei Veterans General Hospital and National Yang Ming University, Taipei, Taiwan.
authors.forename: Feng-Chi
authors.initials: FC
authors.lastname: Chang
authors.affiliation: Department of Neurology, Taipei Veterans General Hospital and National Yang-Ming University, Taipei, Taiwan.
authors.forename: Chih-Ping
authors.initials: CP
authors.lastname: Chung
authors.affiliation: Department of Neurology, Tungs' Taichung Metro Harbor Hospital and Department of Neurology, School of Medicine, Chung Shan Medical University, Taichung, Taiwan.
authors.forename: Hung-Yi
authors.initials: HY
authors.lastname: Hsu
authors.affiliation: Department of Neurology, Taipei Veterans General Hospital and National Yang-Ming University, Taipei, Taiwan.
authors.forename: Wen-Yung
authors.initials: WY
authors.lastname: Sheng
authors.affiliation: Department of Neurology, First Hospital of Jilin University, Changchun, Jilin Province, China.
authors.forename: Jiang
authors.initials: J
authors.lastname: Wu
authors.affiliation: Graduate Institute of Clinical Medicine and Department of Neurology, College of Medicine, Taipei Medical University and Hospital, Taipei, Taiwan.
authors.forename: Han-Hwa
authors.initials: HH
authors.lastname: Hu
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D020236:Amnesia, Transient Global / Q000209:etiology* / Q000473:pathology*; D016022:Case-Control Studies; D002560:Cerebrovascular Circulation / Q000502:physiology; D003251:Constriction, Pathologic / Q000473:pathology; D004322:Drainage / Q000009:adverse effects*; D005260:Female; D006801:Humans; D007601:Jugular Veins / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D014636:Valsalva Maneuver / Q000502:physiology; D014680:Veins / Q000473:pathology; D014689:Venous Insufficiency / Q000150:complications* / Q000473:pathology*