Pulsation of brain tissue increases in response to caffeine: a pilot healthy volunteer study
Pulsation of brain tissue increases in response to caffeine: a pilot healthy volunteer study
Objective: caffeine is known to induce cerebral vasoconstriction. We used this effect in a pilot ultrasound-based healthy volunteer study to investigate the directionality of response of brain tissue pulsations (BTPs) with changing middle cerebral artery velocity (MCAv) following caffeine ingestion.
Approach: BTPs were measured in healthy volunteers using transcranial tissue Doppler (TCTD) ultrasound and MCAv was measured using conventional transcranial Doppler ultrasound. Measurements of blood pressure, heart rate, and end-tidal carbon dioxide (EtCO2) were also recorded. Data were collected at rest and at multiple timepoints over a 60 min period following ingestion of 250 mg of caffeine.
Main results: a multivariate multilevel model identified significant decreases in mean MCAv of -0.17 (-0.21, -0.14) (cm s-1) min-1, ΔMCAv of -0.06 (-0.1, -0.04) (cm s-1) min-1, and EtCO2of -0.02 (-0.04, -0.01) mmHg min-1. Significant increases in mean arterial pressure of 0.21 (0.15, 0.28) mmHg min-1and bulk BTP amplitude of 0.08 (0.02, 0.14)μm min-1were observed. These changes confirm the expected physiological effects of caffeine and provide novel evidence of an inverse relationship between MCAv and BTP amplitude, suggesting that these variables respond in opposite directions following a vasoconstrictive challenge.
Significance: we hypothesise that increased bulk BTP amplitude reflects a reduction in intracranial pressure (ICP), driven by caffeine-induced cerebral vasoconstriction, allowing greater brain tissue mobility. This interpretation is supported by magnetic resonance imaging studies, which show increased brain tissue motion with lowered ICP. Measurement of BTPs may provide real-time information on intracranial haemodynamics.
brain tissue pulsations, cerebral blood velocity, transcranial Doppler, transcranial tissue Doppler, ultrasound
Nicholls, Jennifer K.
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Lecchini-Visintini, Andrea
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Almudayni, Alanoud
3859384e-3ae3-434f-99ca-064295402f08
Ince, Jonathan
55157657-56bb-45ef-b67c-1ff1c23ab4dd
Minhas, Jatinder S.
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Chung, Emma M.L.
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23 December 2025
Nicholls, Jennifer K.
0ab4fda3-e36e-4fa1-869a-232cb141568a
Lecchini-Visintini, Andrea
23cc1428-c307-4fba-b171-cb3f53ba8c80
Almudayni, Alanoud
3859384e-3ae3-434f-99ca-064295402f08
Ince, Jonathan
55157657-56bb-45ef-b67c-1ff1c23ab4dd
Minhas, Jatinder S.
30fb32c8-5c1a-4ea5-9e1c-5df576bab99b
Chung, Emma M.L.
2a4bf9d7-6ed4-4726-94aa-a57d6fd78b3e
Nicholls, Jennifer K., Lecchini-Visintini, Andrea, Almudayni, Alanoud, Ince, Jonathan, Minhas, Jatinder S. and Chung, Emma M.L.
(2025)
Pulsation of brain tissue increases in response to caffeine: a pilot healthy volunteer study.
Physiological Measurement, 46 (12), [125005].
(doi:10.1088/1361-6579/ae29e4).
Abstract
Objective: caffeine is known to induce cerebral vasoconstriction. We used this effect in a pilot ultrasound-based healthy volunteer study to investigate the directionality of response of brain tissue pulsations (BTPs) with changing middle cerebral artery velocity (MCAv) following caffeine ingestion.
Approach: BTPs were measured in healthy volunteers using transcranial tissue Doppler (TCTD) ultrasound and MCAv was measured using conventional transcranial Doppler ultrasound. Measurements of blood pressure, heart rate, and end-tidal carbon dioxide (EtCO2) were also recorded. Data were collected at rest and at multiple timepoints over a 60 min period following ingestion of 250 mg of caffeine.
Main results: a multivariate multilevel model identified significant decreases in mean MCAv of -0.17 (-0.21, -0.14) (cm s-1) min-1, ΔMCAv of -0.06 (-0.1, -0.04) (cm s-1) min-1, and EtCO2of -0.02 (-0.04, -0.01) mmHg min-1. Significant increases in mean arterial pressure of 0.21 (0.15, 0.28) mmHg min-1and bulk BTP amplitude of 0.08 (0.02, 0.14)μm min-1were observed. These changes confirm the expected physiological effects of caffeine and provide novel evidence of an inverse relationship between MCAv and BTP amplitude, suggesting that these variables respond in opposite directions following a vasoconstrictive challenge.
Significance: we hypothesise that increased bulk BTP amplitude reflects a reduction in intracranial pressure (ICP), driven by caffeine-induced cerebral vasoconstriction, allowing greater brain tissue mobility. This interpretation is supported by magnetic resonance imaging studies, which show increased brain tissue motion with lowered ICP. Measurement of BTPs may provide real-time information on intracranial haemodynamics.
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Nicholls_2025_Physiol._Meas._46_125005
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Accepted/In Press date: 8 December 2025
Published date: 23 December 2025
Keywords:
brain tissue pulsations, cerebral blood velocity, transcranial Doppler, transcranial tissue Doppler, ultrasound
Identifiers
Local EPrints ID: 508633
URI: http://eprints.soton.ac.uk/id/eprint/508633
ISSN: 0967-3334
PURE UUID: 33aa4c5c-64cb-4075-a035-a959fb42a42a
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Date deposited: 28 Jan 2026 17:55
Last modified: 28 Jan 2026 17:55
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Contributors
Author:
Jennifer K. Nicholls
Author:
Andrea Lecchini-Visintini
Author:
Alanoud Almudayni
Author:
Jonathan Ince
Author:
Jatinder S. Minhas
Author:
Emma M.L. Chung
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