Safety and efficacy of remote ischemic conditioning in pediatric moyamoya disease patients treated with revascularization therapy

The potential mechanism and clinical application value of remote ischemic conditioning in stroke

Some studies have confirmed the neuroprotective effect of remote ischemic conditioning against stroke. Although numerous animal researches have shown that the neuroprotective effect of remote ischemic conditioning may be related to neuroinflammation, cellular immunity, apoptosis, and autophagy, the exact underlying molecular mechanisms are unclear. This review summarizes the current status of different types of remote ischemic conditioning methods in animal and clinical studies and analyzes their commonalities and differences in neuroprotective mechanisms and signaling pathways. Remote ischemic conditioning has emerged as a potential therapeutic approach for improving stroke-induced brain injury owing to its simplicity, non-invasiveness, safety, and patient tolerability. Different forms of remote ischemic conditioning exhibit distinct intervention patterns, timing, and application range. Mechanistically, remote ischemic conditioning can exert neuroprotective effects by activating the Notch1/phosphatidylinositol 3-kinase/Akt signaling pathway, improving cerebral perfusion, suppressing neuroinflammation, inhibiting cell apoptosis, activating autophagy, and promoting neural regeneration. While remote ischemic conditioning has shown potential in improving stroke outcomes, its full clinical translation has not yet been achieved.

Remote ischemic conditioning prevents ischemic cerebrovascular events in children with moyamoya disease: a randomized controlled trial

BACKGROUND

Moyamoya disease (MMD) is a significant cause of childhood stroke and transient ischemic attacks (TIAs). This study aimed to assess the safety and efficacy of remote ischemic conditioning (RIC) in children with MMD.

METHODS

In a single-center pilot study, 46 MMD patients aged 4 to 14 years, with no history of reconstructive surgery, were randomly assigned to receive either RIC or sham RIC treatment twice daily for a year. The primary outcome measured was the cumulative incidence of major adverse cerebrovascular events (MACEs). Secondary outcomes included ischemic stroke, recurrent TIA, hemorrhagic stroke, revascularization rates, and clinical improvement assessed using the patient global impression of change (PGIC) scale during follow-up. RIC-related adverse events were also recorded, and cerebral hemodynamics were evaluated using transcranial Doppler.

RESULTS

All 46 patients completed the final follow-up (23 each in the RIC and sham RIC groups). No severe adverse events associated with RIC were observed. Kaplan-Meier analysis indicated a significant reduction in MACEs frequency after RIC treatment [log-rank test (Mantel-Cox), P = 0.021]. At 3-year follow-up, two (4.35%) patients had an ischemic stroke, four (8.70%) experienced TIAs, and two (4.35%) underwent revascularization as the qualifying MACEs. The clinical improvement rate in the RIC group was higher than the sham RIC group on the PGIC scale (65.2% vs. 26.1%, P < 0.01). No statistical difference in cerebral hemodynamics post-treatment was observed.

CONCLUSIONS

RIC is a safe and effective adjunct therapy for asymptomatic children with MMD. This was largely due to the reduced incidence of ischemic cerebrovascular events.

Remote ischemic conditioning after stroke: Research progress in clinical study

BACKGROUND AND PURPOSE

Stroke is a leading cause of global morbidity and mortality, indicating the necessity and urgency of effective prevention and treatment. Remote ischemic conditioning (RIC) is a convenient, simple, non-intrusive, and effective method that can be easily added to the treatment regime of stroke patients. Animal experiments and clinical trials have proved the neuroprotective effects of RIC on brain injury including (examples of neuroprotective effects). This neuroprotection is achieved by raising brain tolerance to ischemia, increasing local cerebral blood perfusion, promoting collateral circulations, neural regeneration, and reducing the incidence of hematomas in brain tissue. This current paper will summarize the studies within the last 2 years for the comprehensive understanding of the use of RIC in the treatment of stroke.

METHODS

This paper summarizes the clinical research progress of RIC on stroke (ischemic stroke and hemorrhagic stroke (HS)). This paper is a systematic review of research published on registered clinical trials using RIC in stroke from inception through November 2022. Four major databases (PUBMED, WEB OF SCIENCE, EMBASE, and ClinicalTrials.gov) were searched.

RESULTS

Forty-eight studies were identified meeting our criteria. Of these studies, 14 were in patients with acute ischemic stroke with onset times ranging from 6 h to 14 days, seven were in patients with intravenous thrombolysis or endovascular thrombectomy, 10 were in patients with intracranial atherosclerotic stenosis, six on patients with vascular cognitive impairment, three on patients with moyamoya disease, and eight on patients with HS. Of the 48 studies, 42 were completed and six are ongoing.

CONCLUSIONS

RIC is safe, feasible, and effective in the treatment of stroke. Large-scale research is still required to explore the optimal treatment options and mechanisms of RIC in the future to develop a breakthrough in stroke prevention and treatment.

Safety and efficacy of remote ischemic conditioning in adult moyamoya disease patients undergoing revascularization surgery: a pilot study

Background and purpose

Revascularization surgery for patients with moyamoya disease (MMD) is very complicated and has a high rate of postoperative complications. This pilot study aimed to prove the safety and efficacy of remote ischemic conditioning (RIC) in adult MMD patients undergoing revascularization surgery.

Methods

A total of 44 patients with MMD were enrolled in this single-center, open-label, prospective, parallel randomized study, including 22 patients assigned to the sham group and 22 patients assigned to the RIC group. The primary outcome was the incidence of major neurologic complications during the perioperative period. Secondary outcomes were the modified Rankin Scale (mRS) score at discharge, at 90 days post-operation, and at 1 year after the operation. The outcome of safety was the incidence of adverse events associated with RIC. Blood samples were obtained to monitor the serum concentrations of cytokines (VEGF, IL-6).

Results

No subjects experienced adverse events during RIC intervention, and all patients could tolerate the RIC intervention in the perioperative period. The incidence of major neurologic complications was significantly lower in the RIC group compared with the control group (18.2% vs. 54.5%, P = 0.027). The mRS score at discharge in the RIC group was also lower than the control group (0.86 ± 0.99 vs. 1.18 ± 1.22, P = 0.035). In addition, the serum IL-6 level increased significantly at 7 days after bypass surgery in the control group and the serum level of VEGF at 7 days post-operation in the RIC group.

Conclusion

In conclusion, our study demonstrated the neuroprotective effect of RIC by reducing perioperative complications and improving cerebral blood flow in adult MMD patients undergoing revascularization surgery. Thus, RIC seems to be a potential treatment method for MMD.

Clinical trial registration

ClinicalTrials.gov, identifier: NCT05860946.

Chinese expert consensus on the treatment of MMD

Moyamoya disease (MMD), also known as spontaneous occlusion of the circle of Willis, is defined by progressive stenosis or occlusion of the internal carotid arteries, and it can progress to the anterior, middle, and posterior cerebral arteries. As these arteries are gradually stenosed, a collateral network of capillaries develops at the base of the brain, producing the characteristic reticulate appearance ("puff of smoke") on angiography. Therefore, it was named by Suzuki and Takaku in 1969 after the Japanese term "moyamoya" (Suzuki and Takaku, Arch Neurol 20:288-299, 1969). MMD is most common in East Asian countries such as Japan and Korea, and it shows a slight female predominance. MMD is mainly characterized by ischemia and hemorrhage. Hemorrhagic MMD is very rare in children, and most cases occur in adults due to the rupture of the compensatory blood vessels, which often leads to hemorrhagic symptoms (Scott and Smith, N Engl J Med 360:1226-1237, 2009). In recent years, the diagnosis rate has increased with the popularization of imaging techniques. However, the pathogenesis of MMD is still not completely understood, and there is currently no evidence to suggest that drug treatment can delay or even reverse the progression of MMD. The current drug treatment for in MMD only targets its clinical symptoms, including ischemia and hemorrhage. The main choice of treatment for MMD is surgical revascularization. As an increasing number of hospitals have developed surgical treatment for MMD, our compiling group has jointly discussed the formulation of a consensus among Chinese experts on the treatment of MMD.

Natural course and risk factors of moyamoya disease with unruptured intracranial aneurysm

Background and objective

The natural course and risk factors of moyamoya disease (MMD) associated with unruptured intracranial aneurysms involving stenosed parental arteries are scarcely studied. This study aimed to elucidate the natural course of MMD and its associated risk factors in patients with MMD with unruptured aneurysms.

Methods

Between September 2006 and October 2021, patients with MMD with intracranial aneurysms at our center were examined. The natural course, clinical features, radiological features, and follow-up outcomes after revascularization were analyzed.

Results

This study included 42 patients with MMD with intracranial aneurysms (42 aneurysms). The age distribution of MMD cases ranged from 6 to 69 years, with four children (9.5%) and 38 adults (90.5%). A total of 17 male and 25 female subjects were included (male-to-female ratio: 1:1.47). The first symptom was cerebral ischemia in 28 cases, and cerebral hemorrhage occurred in 14 cases. There were 35 trunk aneurysms and seven peripheral aneurysms. There were 34 small aneurysms (<5 mm) and eight medium aneurysms (5-15 mm). During the average clinical follow-up period of 37.90 ± 32.53 months, there was no rupture or bleeding from aneurysms. Twenty-seven of these patients underwent a cerebral angiography review, in which it was found that one aneurysm had enlarged, 16 had remained unchanged, and 10 had shrunk or disappeared. A correlation exists between the reduction or disappearance of aneurysms and the progression of the Suzuki stages of MMD (P = 0.015). Nineteen patients underwent EDAS on the aneurysm side, and nine aneurysms disappeared, while eight patients did not undergo EDAS on the aneurysm side and one aneurysm disappeared.

Conclusion

The risk of rupture and hemorrhage of unruptured intracranial aneurysms is low when the parent artery already has stenotic lesions, thus, direct intervention may not be necessary for such aneurysms. The progression of the Suzuki stage of moyamoya disease may play a role in the shrinkage or disappearance of the aneurysms, thereby decreasing the risk of rupture and hemorrhage. Encephaloduroarteriosynangiosis (EDAS) surgery may also help promote atrophy or even the disappearance of the aneurysm, thus reducing the risk of further rupture and bleeding.

Daily Remote Ischemic Conditioning Can Improve Cerebral Perfusion and Slow Arterial Progression of Adult Moyamoya Disease—A Randomized Controlled Study

Background and Purpose

Moyamoya disease (MMD) is a complicated cerebrovascular disease with recurrent ischemic or hemorrhagic events. This study aimed to prove the safety and efficacy of remote ischemic conditioning (RIC) on MMD.

Methods

In total, 34 patients with MMD participated in this pilot, prospective randomized controlled study for 1 year. 18 patients were allocated into the RIC group, and 16 patients accepted routine medical treatment only. RIC-related adverse events were recorded. The primary outcome was the improvement ratio of mean cerebral blood flow (mCBF) in middle cerebral artery territory measured by multidelay pseudocontinuous arterial spin labeling, and the secondary outcomes were the cumulative incidence of major adverse cerebrovascular events (MACEs), the prevalence of stenotic-occlusive progression, and periventricular anastomosis at 1-year follow-up.

Results

In total, 30 of the 34 patients with MMD completed the final follow-up (17 in the RIC group and 13 in the control group). No adverse events of RIC were observed. The mCBF improvement ratio of the RIC group was distinctively higher compared with the control group (mCBF−whole-brain: 0.16 ± 0.15 vs. −0.03 ± 0.13, p = 0.001). Stenotic-occlusive progression occurred in 11.8% hemispheres in the RIC group and 38.5% in the control group (p = 0.021). The incidence of MACE was 5.9% in the RIC group and 30.8% in the control group (hazard ratio with RIC, 0.174; 95% CI, 0.019–1.557; p = 0.118). No statistical difference was documented in the periventricular anastomosis between the two groups after treatment.

Conclusions

Remote ischemic conditioning has the potential to be a safe and effective adjunctive therapy for patients with MMD largely due to improving cerebral blood flow and slowing the arterial progression of the stenotic-occlusive lesions. These findings warrant future studies in larger trials.

Asymmetric lenticulostriate arteries in patients with moyamoya disease presenting with movement disorder: three new cases

OBJECTIVE

Unilateral movement disorder associated with moyamoya disease is a rare finding and the mechanism remains to be fully elucidated. Theories postulated include contralateral cerebral ischemic or hemorrhagic lesions, and/or hypoperfusion. However, few studies have reported such patients without contralateral lesions nor hypoperfusion. This study aimed to explore the potential mechanism of those who had neither contralateral cerebral lesions nor hypoperfusion.

METHODS

Neuroradiological features of lenticulostriate arteries in three cases with unilateral movement disorder associated with moyamoya disease who had neither contralateral lesions nor hypoperfusion were mainly analyzed.

RESULTS

Angiography and 3 T black-blood T1-weighted intracranial vessel wall imaging both demonstrated a significant asymmetry between bilateral lenticulostriate arteries qualitatively and quantitatively on admission. After one-year follow-up, two patients' vessel wall imaging indicated that the asymmetry diminished, and the symptoms spontaneously resolved.

CONCLUSION

This report demonstrated that patients with moyamoya disease with unilateral movement disorder who had neither contralateral lesions nor hypoperfusion may be related to the asymmetry between bilateral lenticulostriate arteries through basal ganglia.

Cerebral circulation improves with indirect bypass surgery combined with gene therapy

Angiogenesis involves new blood vessels sprouting from preexisting blood vessels. This process may serve to improve brain circulation. Moyamoya disease (MMD) is a cerebrovascular disorder causing intracranial stenosis which significantly reduces the blood supply to the brain. Mainly stroke is the first symptom of the disorder, so treatments that reduce the risk of stroke are used for patients with MMD. To prevent stroke for those with chronic cerebral hypoperfusion, more blood needs to flow to the brain, which was thought to be achieved by enhancing angiogenesis. Indirect bypass surgery, such as encephalo-myo-synangiosis (EMS), is used for revascularization. However, EMS alone sometimes cannot provide enough circulation to avoid ischemic strokes. The current study examined if EMS combined with high-mobility group box-1 (HMGB1) and vascular endothelial growth factor (VEGF) enhanced angiogenesis and increased cerebral circulation. The results indicated that HMGB1 administered with EMS increased angiogenesis through a VEGF-dependent mechanism. In addition, exercising and stem cell transplantation possess possible means to increase angiogenesis. Overall, EMS with gene therapy, maintaining fitness, and stem cell utilization may prevent or help one recover from stroke by enhancing brain angiogenesis. Thus, these treatments may be applicable for patients with MMD. This paper is a review article. Referred literature in this paper has been listed in the references section. The datasets supporting the conclusions of this article are available online by searching various databases, including PubMed.