Reduction in Posterior Cerebral Artery Blood Flow Velocity during Caloric Vestibular Stimulation

Transcranial Doppler (TCD) sonography was performed to assess the differential effects of caloric vestibular stimulation on cerebral blood flow (CBF) to the vestibular [middle cerebral artery (MCA)] and the visual [posterior cerebral artery (PCA)] cortices in 15 healthy volunteers with eyes closed. Caloric irrigation caused a sensation of rotation and nystagmus and not only increased velocity in the MCA (2.7 ± 3.3%) but also, simultaneously, decreased velocity in the PCA (4.2 ± 6.2%, p < 0.001 vs. MCA). CBF changes indicated by changes in velocity through the MCA and PCA may reflect functional deactivation of the visual cortex together with activation of the vestibular cortex: this beneficial multisensory interaction suppresses distressing oscillopsia.

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Posterior cerebral artery blood flow response to visual stimulation during exercise

The FASEB Journal ◽

10.1096/fasebj.26.1_supplement.1138.41 ◽

2012 ◽

Vol 26 (S1) ◽

Author(s):

Yuji Yamaguchi ◽

Tsukasa Ikemura ◽

Hideaki Kashima ◽

Naoyuki Hayashi

Keyword(s):

Blood Flow ◽

Cerebral Artery ◽

Visual Stimulation ◽

Posterior Cerebral Artery ◽

Artery Blood Flow ◽

Blood Flow Response ◽

Flow Response

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Transcranial Doppler-determined change in posterior cerebral artery blood flow velocity does not reflect vertebral artery blood flow during exercise

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00676.2016 ◽

2017 ◽

Vol 312 (4) ◽

pp. H827-H831 ◽

Cited By ~ 6

Author(s):

Takuro Washio ◽

Hiroyuki Sasaki ◽

Shigehiko Ogoh

Keyword(s):

Blood Flow ◽

Cerebral Blood Flow ◽

Vertebral Artery ◽

Flow Velocity ◽

Cerebral Artery ◽

Transcranial Doppler ◽

Posterior Cerebral Artery ◽

Dynamic Exercise ◽

Artery Blood Flow ◽

Artery Flow

We examined whether a change in posterior cerebral artery flow velocity (PCAv) reflected the posterior cerebral blood flow in healthy subjects during both static and dynamic exercise. PCAv and vertebral artery (VA) blood flow, as an index of posterior cerebral blood flow, were continuously measured during an exercise trial using transcranial Doppler (TCD) ultrasonography and Doppler ultrasound, respectively. Static handgrip exercise significantly increased both PCAv and VA blood flow. Increasing intensity of dynamic exercise further increased VA blood flow from moderate exercise, while PCAv decreased to almost resting level. During both static and dynamic exercise, the PCA cerebrovascular conductance (CVC) index significantly decreased from rest (static and high-intensity dynamic exercise, −11.5 ± 12.2% and −18.0 ± 16.8%, means ± SD, respectively) despite no change in the CVC of VA. These results indicate that vasoconstriction occurred at PCA but not VA during exercise-induced hypertension. This discrepancy in vascular response to exercise between PCA and VA may be due to different cerebral arterial characteristics. Therefore, to determine the effect of exercise on posterior cerebral circulation, at least, we need to carefully consider which cerebral artery to measure, regardless of exercise mode. NEW & NOTEWORTHY We examined whether transcranial Doppler-determined flow velocity in the posterior cerebral artery can be used as an index of cerebral blood flow during exercise. However, the changes in posterior cerebral artery flow velocity during exercise do not reflect vertebral artery blood flow.

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Increase of posterior cerebral artery blood flow velocity during threshold repetitive magnetic stimulation of the human visual cortex: hints for neuronal activation without cortical phosphenes

Electroencephalography and Clinical Neurophysiology ◽

10.1016/s0013-4694(96)95651-5 ◽

1996 ◽

Vol 99 (5) ◽

pp. 473-478 ◽

Cited By ~ 9

Author(s):

Dirk Sander ◽

Bernd-U. Meyer ◽

Simone Röricht ◽

Gernot Matzander ◽

Jürgen Klingelhöfer

Keyword(s):

Blood Flow ◽

Visual Cortex ◽

Flow Velocity ◽

Cerebral Artery ◽

Blood Flow Velocity ◽

Magnetic Stimulation ◽

Posterior Cerebral Artery ◽

Artery Blood Flow ◽

Repetitive Magnetic Stimulation ◽

Stimulation Of

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Neurovascular coupling is not influenced by lower body negative pressure in humans

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00076.2020 ◽

2020 ◽

Vol 319 (1) ◽

pp. H22-H31

Author(s):

Milena Samora ◽

Lauro C. Vianna ◽

Jake C. Carmo ◽

Victor Macedo ◽

Matthew Dawes ◽

...

Keyword(s):

Blood Flow ◽

Vertebral Artery ◽

Cerebral Artery ◽

Negative Pressure ◽

Visual Stimulation ◽

Posterior Cerebral Artery ◽

Lower Body Negative Pressure ◽

Neurovascular Coupling ◽

Lower Body ◽

Artery Blood Flow

Visual stimulation evoked a robust increase in posterior cerebral artery velocity and a modest increase in vertebral artery blood flow, i.e., neurovascular coupling (NVC), which was unaffected by lower body negative pressure in humans (LBNP). In addition, although LBNP induced a mild hypocapnia, this degree of hypocapnia in the absence of LBNP failed to modify the NVC response.

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