15 January 2021 : Review article
Alterations in Cerebral Hemodynamics During Microgravity: A Literature Review
Jichen Du1ADE*, Jiangbo Cui2BC, Jing Yang1D, Peifu Wang1B, Lvming Zhang1D, Bin Luo1BDF, Bailin Han1EDOI: 10.12659/MSM.928108
Med Sci Monit 2021; 27:e928108
Table 2 Impact of simulated or actual microgravity on cerebral blood flow and cerebral blood flow velocity.
| Authors | n | Experimental protocol | Conclusion |
|---|---|---|---|
| Kawai et al. []28 | 8 | 24h, −6° HDBR, TCD, rMCA | CBFv increased at 0.5h of HDBR, during upright seated recovery, CBFv decreased when compared with baseline, and CBFv positively correlated with IAP |
| Sun et al. []29 | 12 | 21 days, −6° HDBR, TCD, rMCA | CBFv decreased since day 1 and dropped further on day 3 until reaching a minimum value on day 21 |
| Arbeille et al. []30 | 24 | 60 days, −6° HDBR, TCD, rMCA | CBFv significantly decreased on day 55 |
| Iwasaki et al. []31 | 6 | 16 days, space mission, TCD, MCA | Resting CBFv did not change significantly from preflight values during or after spaceflight |
| Klein et al. []33 | 17 | 15 bouts of 22s intervals Parabolic flight, TCD, rMCA | With decreased MAP and increased CO, CBFv remained unchanged in the microgravity condition |
| Ogoh et al. []34 | 10 | 3 days, DI, TCD, rICA, rECA, rVA | CBFv in ICA, ECA and VA did not change. A decreased cardiac output associated with CBFv in ICA and VA but not ECA |
| Marshall-Goebel et al. []35 | 9 | 3 h, −6°, −12°, −18° HDBR, MRI, bilateral ICA and VA | CBFv in ICA decreased at each tilt degree, CBFv in VA did not changed |
| Ogoh et al. []36 | 10 | 60 days, −6° HDBR, TCD | CBFv in ICA decreased on day 30, returned to baseline on day 57; CBFv in VA remained unaltered throughout HDBR; CBFv in ECA increased on day 30 and 57, indicating long-term microgravity may induce heterogeneous responses in cerebral circulation |
| CBF – cerebral blood flow; CBFv – cerebral blood flow velocity; HDBR – head-down bed rest; rMCA – right middle cerebral artery; rICA – right internal carotid artery; rECA – right external carotid artery; rVA – right vertebral artery; IAP – intracranial arterial pressure; DI – dry immersion. | |||