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Updated: Feb 16, 2026

Double Direct Injection of Blood into the Cisterna Magna as a Model of Subarachnoid Hemorrhage
Published on: August 30, 2020
The Link Between Cerebrovascular Hemodynamics and Rehabilitation Outcomes After Aneurysmal Subarachnoid Hemorrhage
Forrest A Brooks1, Uvieoghene Ughwanogho, Galen V Henderson
1From the New York University School of Medicine, New York City, New York (FAB); Spaulding Rehabilitation Hospital, Charlestown, Massachusetts (UU, RB-S, COT); Department of Physical Medicine and Rehabilitation, Harvard Medical School, Boston, Massachusetts (UU, RB-S, COT); Neurocritical Care and Neuroscience Intensive Care Unit, Brigham and Women's Hospital, Boston, Massachusetts (GVH, FAS); Department of Neurology, Harvard Medical School, Boston, Massachusetts (GVH, FAS); and Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, Illinois (FAS).
Objective:
The aim of the study was to assess the relation between cerebrovascular function early after aneurysmal subarachnoid hemorrhage onset and functional and rehabilitation outcomes.
Design:
Observational cohort study of subarachnoid hemorrhage patients (n = 133) admitted to rehabilitation (n = 49), discharged home (n = 52), or died before discharge (n = 10). We obtained hemodynamic markers of cerebral autoregulatory function from blood flow velocities in the middle cerebral artery and arterial pressure waveforms, recorded daily on days 2-4 after symptom onset, and functional independence measure (FIM) scores and FIM efficiency for those admitted to acute rehabilitation.
Results:
Compared to those discharged home, the range of pressures within which autoregulation is effective was lower in patients admitted to rehabilitation (4.6 [0.2] vs. 3.9 [0.2] mm Hg) and those who died (2.7 [0.4], P = 0.04). For those admitted to rehabilitation, autoregulatory range and the ability of cerebrovasculature to increase flow were related to discharge FIM score (R = 0.33 and 0.43, P < 0.01) and efficiency (R = 0.33 and 0.47 P < 0.01). The latter marker, along with subarachnoid hemorrhage severity and admission FIM, explained 84% and 69% of the variability in discharge FIM score and efficiency, respectively, even after accounting for age.
Conclusions:
Early cerebrovascular function is a major contributor to functional outcomes after subarachnoid hemorrhage and may represent a modifiable target to develop therapeutic approaches.
To Claim Cme Credits:
Complete the self-assessment activity and evaluation online at http://www.physiatry.org/JournalCME CME OBJECTIVES: Upon completion of this article, the reader should be able to: (1) Define cerebral autoregulation; (2) Explain the importance of the integrity of cerebral autoregulation for longer-term functional and rehabilitation outcomes after aneurysmal subarachnoid hemorrhage; and (3) Theorize why treatment strategies that may be effective in reducing large-vessel vasospasms after an aneurysmal subarachnoid hemorrhage might not always translate into improved functional outcomes.
Level:
Advanced ACCREDITATION: The Association of Academic Physiatrists is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.The Association of Academic Physiatrists designates this Journal-based CME activity for a maximum of 0.5 AMA PRA Category 1 Credit(s)™. Physicians should only claim credit commensurate with the extent of their participation in the activity.
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