scholarly journals Long‐duration spaceflight alters estimated intracranial pressure and cerebral blood velocity

2020 ◽  
Author(s):  
Ken‐ichi Iwasaki ◽  
Yojiro Ogawa ◽  
Takuya Kurazumi ◽  
Syed M. Imaduddin ◽  
Chiaki Mukai ◽  
...  
Keyword(s):  
Intracranial Pressure ◽  
Blood Velocity ◽  
Long Duration ◽  
Cerebral Blood Velocity

Which Neurological Examinations can be used to Predict Outcome During the Neonatal Period?

1991 ◽  
Vol 7 (S1) ◽  
pp. 118-124
Author(s):  
Frances Cowan
Keyword(s):  
Neurological Examination ◽  
Prognostic Value ◽  
Neonatal Period ◽  
Diagnostic Value ◽  
Blood Velocity ◽  
Evoked Responses ◽  
Clinical Neurological Examination ◽  
Velocity Imaging ◽  
Ultrasound Measurements ◽  
Cerebral Blood Velocity

In this review I shall discuss the prognostic value of the clinical neurological examination, the EEG (and the various methods of recording it), evoked responses, and Doppler ultrasound measurements of cerebral blood velocity. Imaging modalities (ultrasound, CT, MRI) will be dealt with elsewhere under discussion of their diagnostic value.

Global REACH 2018: Regional differences in cerebral blood velocity control during normoxic and hypoxic cold pressor tests

2020 ◽  
Vol 229 ◽  
pp. 102740
Author(s):  
Michael M. Tymko ◽  
Ryan L. Hoiland ◽  
Philip N. Ainslie
Keyword(s):  
Regional Differences ◽  
Cold Pressor ◽  
Blood Velocity ◽  
Velocity Control ◽  
Cerebral Blood Velocity ◽  
Global Reach

scholarly journals Spaceflight-Induced Intracranial Hypertension and Visual Impairment: Pathophysiology and Countermeasures

2018 ◽  
Vol 98 (1) ◽  
pp. 59-87 ◽  
Author(s):  
Li-Fan Zhang ◽  
Alan R. Hargens
Keyword(s):  
Optic Nerve ◽  
Intracranial Pressure ◽  
Visual Impairment ◽  
Elevated Pressure ◽  
Lamina Cribrosa ◽  
Fluid System ◽  
Fluid Systems ◽  
Long Duration ◽  
Multiple Structures ◽  
Intracranial Circulation

Visual impairment intracranial pressure (VIIP) syndrome is considered an unexplained major risk for future long-duration spaceflight. NASA recently redefined this syndrome as Spaceflight-Associated Neuro-ocular Syndrome (SANS). Evidence thus reviewed supports that chronic, mildly elevated intracranial pressure (ICP) in space (as opposed to more variable ICP with posture and activity on Earth) is largely accounted for by loss of hydrostatic pressures and altered hemodynamics in the intracranial circulation and the cerebrospinal fluid system. In space, an elevated pressure gradient across the lamina cribrosa, caused by a chronic but mildly elevated ICP, likely elicits adaptations of multiple structures and fluid systems in the eye which manifest themselves as the VIIP syndrome. A chronic mismatch between ICP and intraocular pressure (IOP) in space may acclimate the optic nerve head, lamina cribrosa, and optic nerve subarachnoid space to a condition that is maladaptive to Earth, all contributing to the pathogenesis of space VIIP syndrome. Relevant findings help to evaluate whether artificial gravity is an appropriate countermeasure to prevent this seemingly adverse effect of long-duration spaceflight.

Inspiratory Resistance Increases Cerebral Blood Velocity Oscillations During Standing After Exercise

2008 ◽  
Vol 40 (Supplement) ◽  
pp. S286
Author(s):  
Christine N. Freeman ◽  
Steven A. Romero ◽  
Caroline A. Rickards ◽  
Kathy L. Ryan ◽  
Keith G. Lurie ◽  
...  
Keyword(s):  
Blood Velocity ◽  
Inspiratory Resistance ◽  
Cerebral Blood Velocity

scholarly journals Regional Cerebral Blood Flow, Cerebral Blood Velocity, and Pulsatility Index in Newborn Dogs

1983 ◽  
Vol 17 (11) ◽  
pp. 908-912 ◽  
Author(s):  
Daniel G Batton ◽  
Jonathan Hellmann ◽  
Milton J Hernandez ◽  
M Jeffrey Maisels
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Pulsatility Index ◽  
Regional Cerebral Blood Flow ◽  
Blood Velocity ◽  
Regional Cerebral Blood ◽  
Cerebral Blood Velocity

scholarly journals Augmented cerebral blood velocity in response to isometric handgrip exercise in women with a history of preeclampsia

2019 ◽  
Vol 317 (6) ◽  
pp. R834-R839
Author(s):  
Kathleen B. Miller ◽  
Virginia M. Miller ◽  
Ronée E. Harvey ◽  
Sushant M. Ranadive ◽  
Michael J. Joyner ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Recovery Period ◽  
Blood Velocity ◽  
Hypertensive Disorder ◽  
Isometric Handgrip ◽  
Arterial Blood ◽  
Increased Risk ◽  
Cerebral Blood Velocity ◽  
History Of ◽  
Isometric Handgrip Exercise

Preeclampsia (PE) is a hypertensive disorder of pregnancy described as a condition of excessive sympathoexcitation. PE places a woman at increased risk for lifelong hypertension and cognitive impairment. Cerebral blood velocity is blunted in response to a vasoactive stimulus in women with a history of PE. This study investigated how a sympathoexcitatory stimulus affects cerebral blood velocity in women with a history of PE. Middle cerebral artery blood velocity (MCAv) and beat-to-beat mean arterial blood pressure (MAP) were measured in postmenopausal women with a history of PE ( n = 21; age = 59 ± 5 yr) and a history of a normotensive pregnancy (NP; n = 27; age = 58 ± 4 yr), at baseline, during isometric handgrip to fatigue (IHG) followed by postexercise ischemia (PEI), and a recovery period (REC). Baseline MAP and MAP responses to IHG and PEI did not differ between groups. MCAv at baseline and throughout the stimulus was lower in PE women compared with NP women ( P < 0.05 for all). MCAv increased during IHG in both groups ( P < 0.05). This increase in MCAv was greater in PE compared with NP women during IHG and REC (IHG: PE 13 ± 2% vs. NP 9 ± 2%; REC: PE 3 ± 2% vs. NP −2 ± 2%; P < 0.05 for both). Thus, a history of PE is associated with low baseline cerebral blood velocity but an augmented response to a sympathoexcitatory stimulus. These changes in cerebral blood flow regulation may lead to an increased risk for cognitive impairment in women with a history of PE.

Doppler ultrasound measurements of superior sagittal sinus blood velocity

1972 ◽  
Vol 37 (3) ◽  
pp. 312-315 ◽  
Author(s):  
Ronald Brisman ◽  
Sadek K. Hilal ◽  
Michael Tenner
Keyword(s):  
Intracranial Pressure ◽  
Superior Sagittal Sinus ◽  
Mass Effect ◽  
Blood Velocity ◽  
Doppler Measurement ◽  
Content Type ◽  
Sagittal Sinus ◽  
The Mean ◽  
Sagittal Sinus Occlusion ◽  
The Relationship

✓ Transcutaneous Doppler recordings from the patent anterior fontanel were used to measure superior sagittal sinus blood velocity (SSSV). In 15 cases it ranged from 4.5 to 18.1 cm/sec. In five of these patients with no mass effect and normal intracranial pressure, the mean SSSV was 13.6 cm/sec. An independent arteriographic measurement of SSSV was 4.5 cm/sec in a hydrocephalic patient with elevated intracranial pressure whose Doppler measurement of SSSV was 6.6 cm/ sec. The Doppler technique may be used to diagnose sagittal sinus occlusion. SSSV tended to be low when CSF pressure was elevated, but the relationship was not constant.

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