Position of Stroke Patient’s Head Before Surgery May Improve Neurological Function

Research Highlights:

• Hospital beds for stroke patients are typically elevated at the head, however, a flat head position before surgical removal of a blood clot in the brain (thrombectomy) may lead to better outcomes.
• Results from a multicenter trial in the U.S. found significant improvements in clinical stability and neurological function for patients with 0-degree head positioning compared to patients with head positioning at a 30-degree angle, suggesting that 0-degree positioning may be an appropriate change to the standard of care for stroke patients before thrombectomy.
• Head positioning is considered a maneuver to maintain blood flow for patients awaiting surgical intervention, not a stroke treatment itself.

Embargoed until 11:50 a.m. MT/1:50p.m. ET Wednesday, Feb. 7, 2024

PHOENIX, Feb. 7, 2024 — Positioning patients with large vessel ischemic (clot-caused) stroke with their heads flat (0-degrees) before surgery to remove the blood clot resulted in significant improvements in neurological function, compared to patients whose heads were elevated (at a 30-degree angle), according to preliminary late-breaking science presented today at the American Stroke Association’s International Stroke Conference 2024. The meeting, held in person in Phoenix, Feb. 7 - 9, 2024, is a world premier meeting for researchers and clinicians dedicated to the science of stroke and brain health.

Large vessel occlusion is a type of ischemic stroke involving blockage of a major artery in the brain. A surgical procedure called thrombectomy removes the blood clot to restore blood flow and reduce the risk of death or permanent injury to the brain including a potential loss of neurological function.

“Many thrombectomy patients have delays until the procedure can be started, whether due to slow internal hospital processes, multiple patients arriving at the same time or if the patient needs to be transferred to another hospital,” said lead study researcher Anne W. Alexandrov, Ph.D., a professor of nursing and neurology at the University of Tennessee Health Science Center in Memphis. “Optimizing blood flow to the brain while patients are waiting for surgery, is essential to minimize the risk of neurological deficits and ultimately disability.” 

Currently, hospital beds for stroke patients awaiting thrombectomy surgery are typically set with the head of the bed at a 30-degree angle, or a slight incline, Alexandrov said. However, pilot studies conducted by Alexandrov’s team have shown that when the head of the bed is flat at 0-degrees, thrombectomy patients benefit from increased gravitational blood flow through the narrowed/blocked artery and more open collateral arteries for the procedure. 

In this randomized clinical trial called Zero Degree Head Positioning in Acute Large Vessel Ischemic Stroke or ZODIAC, researchers used the National Institutes of Health Stroke Scale (NIHSS) — which assesses consciousness, vision, speech, motor strength and sensory loss —  to evaluate stroke patients with large vessel occlusion acute ischemic stroke. They compared if patients’ conditions remained stable or worsened depending on whether they were set with 0-degree head positioning vs. 30-degree head positioning before thrombectomy surgery.

Stroke patients’ baseline NIHSS scores were measured at 0-degrees immediately after neuroimaging, then they were randomly positioned to head positioning at either 0-degrees or 30-degrees. Patients underwent repeat NIHSS scoring every 10 minutes until the thrombectomy was performed, with a final NIHSS score assessed immediately before they were positioned on the surgical table.

An interim analysis found that 0-degree head positioning before thrombectomy surgery resulted in greater stability and/or clinical improvement prior to surgery based on repeated NIHSS scores in stroke patients compared to patients with 30-degree head positioning.

The investigators also explored whether there would be differences in the NIHSS score at 24 hours following surgery and at 7 days or discharge (whichever came first), however, they didn’t expect to find a difference because thrombectomy itself dramatically improves patient outcomes. They were surprised to find that at both 24 hours after surgery and at 7 days after discharge, the 0-degree-head-position patients had less neurological deficits on the NIHSS compared to patients with head-positioning at a 30-degree incline before surgery.

“By three months following surgery, there was no difference in outcomes for patients in either group, however, it’s exciting to see that we were able to discharge patients from the hospital with less disability requiring rehabilitation,” Alexandrov said.

Due to the efficacy of 0-degree head positioning for stroke patients awaiting thrombectomy, the study’s Data and Safety Monitoring Board stopped enrollment in this trial on November 1, 2023.

“Our findings suggest that gravitational force can play an important role in improving blood flow temporarily while patients are waiting for surgery,” Alexandrov said. “Zero-degree head positioning is a safe and effective strategy to optimize blood flow to the brain until the thrombectomy can be performed, and it should be considered the standard of care for stroke patients prior to thrombectomy.”

Study background and details:

• The study included 92 patients from 12 stroke centers in the U.S.
• Demographic information on the patients will be provided at presentation.
• Alexandrov noted that 0-degree head positioning is NOT a treatment for stroke; it is a way to preserve brain function by optimizing blood flow until the thrombectomy can be performed. “It is a rescue maneuver, not a treatment.”

Co-authors, disclosures and funding sources are listed in the abstract.

Statements and conclusions of studies that are presented at the American Heart Association’s scientific meetings are solely those of the study authors and do not necessarily reflect the Association’s policy or position. The Association makes no representation or guarantee as to their accuracy or reliability. Abstracts presented at the Association’s scientific meetings are not peer-reviewed, rather, they are curated by independent review panels and are considered based on the potential to add to the diversity of scientific issues and views discussed at the meeting. The findings are considered preliminary until published as a full manuscript in a peer-reviewed scientific journal.

The Association receives funding primarily from individuals; foundations and corporations (including pharmaceutical, device manufacturers and other companies) also make donations and fund specific Association programs and events. The Association has strict policies to prevent these relationships from influencing the science content. Revenues from pharmaceutical and biotech companies, device manufacturers and health insurance providers and the Association’s overall financial information are available here.

Additional Resources:

###

About the American Stroke Association

The American Stroke Association is devoted to saving people from stroke — the No. 2 cause of death in the world and a leading cause of serious disability. We team with millions of volunteers to fund innovative research, fight for stronger public health policies and provide lifesaving tools and information to prevent and treat stroke. The Dallas-based association officially launched in 1998 as a division of the American Heart Association. To learn more or to get involved, call 1-888-4STROKE or visit stroke.org. Follow us on Facebook, X.

Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.