Yan Hou, MD, PhD
Bornstein NM, Saver JL, Diener HC, Gorelick PB, Shuaib A, Solberg Y, et al.. Sphenopalatine Ganglion Stimulation to Augment Cerebral Blood Flow. A Randomized, Sham-Controlled Trial. Stroke. 2019;50:00-00.
Preclinical studies have demonstrated that sphenopalatine ganglion (SPG) stimulation is a potent method to enhance collateral flow and reduce infarct size in stroke animal models. The ImpACT-24A Investigators performed a sham-controlled, randomized trial to test the efficacy and safety of SPG stimulation as a potential therapy for patients with acute anterior circulation ischemic stroke who are not eligible for reperfusion therapy.
A total of 253 patients with acute anterior circulation ischemic stroke with moderate deficit (median NIHSS of 11) within 24 hours of onset not treated with tPA or thrombectomy either received SPG (n=153) or sham (n=100) stimulation. The primary efficacy outcome is mRS improvement beyond expectation at 90 days, which was defined as an mRS score one or more points better than expected based on a prognostic model. Although SPG stimulation only showed a 9.7% higher rates of mRS improvement beyond expectations in the intention to treat population (SPG vs. sham: 49.7% vs. 40%, odd ratio 1.48, p=0.13); there was a 23% higher rate of mRS improvement beyond expectations in the subgroup of patients with confirmed cortical involvement (SPG vs. sham: 50% vs. 27%, odd ratio 2.7, p=0.03). The different beneficial effects of SPG stimulation between patients with cortical infarcts and deep subcortical infarcts was considered due to more robust collateral arterial networks in superficial leptomeningeal arteries supplying the cortical layers. SPG stimulation was not associated with any increase in serious adverse events, symptomatic intracranial hemorrhage, or mortality. Only two serious adverse events were considered possibly related to the implantation (one epistaxis and one torn extraction).