BY ED SUSMAN
HONOLULU—Stimulating the sphenopalatine-ganglion in patients with acute stroke appears to be safe and may improve 90-day functional outcomes in some patients, researchers reported here at the 2019 International Stroke Conference, sponsored by the American Stroke Association.
Placing a stimulating device behind the nose to dilate blood vessels and improve blood flow to the brain did not appear to work in the intention-to-treat population, but in a pre-specified subgroup—those in whom the stroke had confirmed cortical involvement—treated patients had better outcomes, said Ashfaq Shuaib, MD, professor of medicine at the University of Alberta, Edmonton.
In the modified intention-to-treat analysis of pooled studies, about 48.9 percent of the 634 patients who had actual stimulation had outcomes considered better than expected on a sliding dichotomy assessment compared with 44.6 percent of the 619 patients who had the device implanted but received a sham stimulation (p=0.13), Dr. Shuaib reported in his oral late-breaker presentation.
When the researchers analyzed those patients who had a confirmed cortical involvement stroke, there was a significant positive finding, he said. Of the 294 people treated with stimulation, 34 percent achieved better than expected outcomes—achieving a 0–2 score on the modified Rankin Scale (mRS), while 26 percent of the 313 patients with cortical involvement strokes achieved better than expected outcomes (p=0.005).
The primary efficacy endpoint was improvement beyond expectations on the mRS at 90 days using a sliding dichotomy, assessed in primary populations of: 1) modified intention to treat, and 2) confirmed cortical involvement, Dr. Shuaib explained.
The researchers combined populations in the Impact 24A and Impact 24B trials that included 1,253 patients. In the confirmed cortical involvement group, approximately 31 percent had atrial fibrillation while in the intention-to-treat population, about 25 percent had atrial fibrillation.
"Use of sphenopalatine-ganglion stimulation in these patients was safe; there was no difference in adverse events, and placement was fast and robust," Dr. Shuaib said. "This meta-analysis further supports that in acute ischemic stroke patients with confirmed cortical infarcts, sphenopalatine-ganglion stimulation started within 24 hours reduces post-stroke disability over the entire outcome range and increases the proportion of patients who are alive and independent three months after stroke."
Commenting on the study, Mark J. Alberts, MD, chief of neurology at Hartford Hospital and professor of neurology at the University of Connecticut, told Neurology Today At the Meetings: "I find these results interesting and intriguing. Their suggestion that by dilating the blood vessels in the cortical region where there is a lot of collateral blood flow makes sense."
"Using this as a treatment for stroke is somewhat unique and novel. The concept is that by stimulating these ganglia cells you are going to dilate the blood vessels in the brain and you are going to improve blood flow. They found very positive results when they looked at function at 90 days as measured by the modified Rankin Scale score in the cortical subgroup."
"Having said that, this is sort of a subgroup of a subgroup of a pooled analysis, so I think we need further study on this. About half the patients in the study had cortical involvement. In general, about 60–75 percent of strokes involve the cortical area, so this subgroup does reflect general practice," Dr. Alberts said.
"The 24-hour time window to perform this procedure is compelling and encouraging because a lot of folks such as those with 'wake up' strokes could be helped," Dr. Alberts said. "I think we need further research and a broader range of outcome measures. That study should focus just on these cortical stroke subjects. A 10 percent absolute improvement in functional outcome is not bad. It could add to our treatment options."
Dr. Shuaib received research grants for the RESPECT PFO (Aga Medical), REDUCE PFO (WL Gore), RESPECT ESUS (BI), POINT (Emmes), NAVIGATE (Bayer), and THALES (AstraZeneca) studies. He serves on the speakers' bureau for Bristol-Myers Squibb, Bayer, Pfizer, and Servier. He has served on the advisory boards of Bayer, Pfizer, and Brainsgate.
LINK UP FOR RELATED INFORMATION:
ISC Abstract LB12: Shuaib A, Bornstein NM, Diener H-C, et al, for the ImpACT-24 Steering Committee. Sphenopalatine-ganglion stimulation for the treatment of acute ischemic stroke: Pooled meta-analysis of the Impact 24A and Impact 24B trials.