These authors contributed equally to this work.
Short-duration hypothermia after ischemic stroke prevents delayed intracranial pressure rise
Article first published online: 12 SEP 2013
© 2013 The Authors. International Journal of Stroke © 2013 World Stroke Organization
International Journal of Stroke
Volume 9, Issue 5, pages 553–559, July 2014
How to Cite
Murtha, L. A., McLeod, D. D., McCann, S. K., Pepperall, D., Chung, S., Levi, C. R., Calford, M. B. and Spratt, N. J. (2014), Short-duration hypothermia after ischemic stroke prevents delayed intracranial pressure rise. International Journal of Stroke, 9: 553–559. doi: 10.1111/ijs.12181
Conflict of interest: The authors declare no potential conflict of interest.
Funding: This work was supported by a NHMRC Program Grant #454417 and research support from the Hunter Medical Research Institute from funds donated by the Greater Building Society. N. Spratt received a NHMRC training fellowship, #455632. L. Murtha received a student grant from the National Stroke Foundation (Australia). D. McLeod and N. Spratt received a project grant from the National Stroke Foundation (Australia).
- Issue published online: 9 JUN 2014
- Article first published online: 12 SEP 2013
- Manuscript Accepted: 22 JUL 2013
- Manuscript Received: 27 MAY 2013
- NHMRC Program Grant. Grant Numbers: 454417, 455632
- Hunter Medical Research Institute
- National Stroke Foundation (Australia)
- intracranial pressure;
- ischemic stroke
Intracranial pressure elevation, peaking three to seven post-stroke is well recognized following large strokes. Data following small–moderate stroke are limited. Therapeutic hypothermia improves outcome after cardiac arrest, is strongly neuroprotective in experimental stroke, and is under clinical trial in stroke. Hypothermia lowers elevated intracranial pressure; however, rebound intracranial pressure elevation and neurological deterioration may occur during rewarming.
(1) Intracranial pressure increases 24 h after moderate and small strokes. (2) Short-duration hypothermia-rewarming, instituted before intracranial pressure elevation, prevents this 24 h intracranial pressure elevation.
Long-Evans rats with two hour middle cerebral artery occlusion or outbred Wistar rats with three hour middle cerebral artery occlusion had intracranial pressure measured at baseline and 24 h. Wistars were randomized to 2·5 h hypothermia (32·5°C) or normothermia, commencing 1 h after stroke.
In Long-Evans rats (n = 5), intracranial pressure increased from 10·9 ± 4·6 mmHg at baseline to 32·4 ± 11·4 mmHg at 24 h, infarct volume was 84·3 ± 15·9 mm3. In normothermic Wistars (n = 10), intracranial pressure increased from 6·7 ± 2·3 mmHg to 31·6 ± 9·3 mmHg, infarct volume was 31·3 ± 18·4 mm3. In hypothermia-treated Wistars (n = 10), 24 h intracranial pressure did not increase (7·0 ± 2·8 mmHg, P < 0·001 vs. normothermia), and infarct volume was smaller (15·4 ± 11·8 mm3, P < 0·05).
We saw major intracranial pressure elevation 24 h after stroke in two rat strains, even after small strokes. Short-duration hypothermia prevented the intracranial pressure rise, an effect sustained for at least 18 h after rewarming. The findings have potentially important implications for design of future clinical trials.