Ischemic Preconditioning: The Long-Awaited Savior of Neuroprotection. Has It Arrived?

Human urinary kallidinogenase in acute ischemic stroke: A single-arm, multicenter, phase IV study (RESK study)

Aims

Human urinary kallidinogenase (HUK) has shown favorable efficacies in acute ischemic stroke (AIS) treatment. We sought confirmation of the safety and efficacy of HUK for AIS in a large population.

Methods

RESK study enrolled patients with AIS of anterior circulation to receive HUK infusion. The primary endpoint was the incidence of treatment‐emergent adverse events (AEs). Secondary endpoints assessed neurological and functional improvements and stroke recurrent rate.

Results

Of 1206 eligible patients, 1202 patients received at least one dose of HUK infusion and 983 (81.5%) completed the study. The incidence of treatment‐emergent AEs and serious AEs were 55.99% and 2.41%, respectively. Pre‐specified AEs of special interest occurred in 21.71% of patients, but the majority were mild and unrelated to therapy. Hypertension, age, treatment time, and drug combination were identified to be associated with drug‐related blood pressure reduction. Neurological and functional evaluations revealed favorable outcomes from baseline to post‐treatment assessment. The cumulative recurrence rate of stroke was 2.50% during the 90‐day assessment.

Conclusion

HUK had an acceptable safety and tolerability profile in AIS patients. Besides, HUK demonstrated the neurological and functional improvements in AIS, further confirming its clinical efficacy in a real‐world large population.

Intracranial atherosclerotic disease

Intracranial atherosclerosis (ICAS) is a progressive pathological process that causes progressive stenosis and cerebral hypoperfusion and is a major cause of stroke occurrence and recurrence around the world. Multiple factors contribute to the development of ICAS. Angiography imaging techniques can improve the diagnosis of and the selection of appropriate treatment regimens for ICAS. Neither aggressive medication nor endovascular interventions can eradicate stroke recurrence in patients with ICAS. Non-pharmacological therapies such as remote ischemic conditioning and hypothermia are emerging. Comprehensive therapy with medication in combination with endovascular intervention and/or non-pharmacological treatment may be a potential strategy for ICAS treatment in the future. We summarized the epidemiology, pathophysiological mechanisms, risk factors, biomarkers, imaging and management of ICAS.

Limb remote ischemic post‑conditioning reduces injury and improves long‑term behavioral recovery in rats following subarachnoid hemorrhage: Possible involvement of the autophagic process

Hemorrhage‑related neurologic injury is a primary cause of disability and mortality following subarachnoid hemorrhage (SAH). The aim of the present study was to investigate the potential neuroprotective effect and the possible role of autophagy in limb remote ischemic post‑conditioning (RIPostC) using an endovascular puncture rat model of SAH. RIPostC was induced by three cycles of occlusion (10 min) and release (10 min) in the bilateral femoral artery using an aneurysm clip. Early RIPostC began immediately following SAH, delayed RIPostC began following a 30 min delay and the repeated RIPostC group underwent the protocol every day for 3 days. Brain water content, SAH grading, terminal deoxynucleotidyl transferase dUTP nick end labeling‑DAPI staining, transmission electron microscopy, and neurological and behavioral tests were conducted three days following surgery. Long term outcomes of behavior and memory were assessed using a rotarod test and Morris water maze test 1 month subsequently. Biomarkers of autophagy, including Beclin‑1 and light chain 3 (LC3), were assessed using western blotting. The results of the present study demonstrated that, compared with other groups, repeated RIPostC was able to alleviate brain edema, prevent neuronal apoptosis, and improve short term and long term neurological function and memory. Beclin‑1 and LC3 in the cortex were upregulated following treatment with repeated RIPostC. Autolysosomes increased 3 days following SAH and were maintained for 1 month in the repeated RIPostC group. Therefore, the present study indicated that the optimized repeated RIPostC may provide a noninvasive strategy to induce neuroprotection, and improve the short and long term outcomes of SAH‑related cerebral injury, possibly involving the autophagy pathway.

White matter injury in ischemic stroke

Stroke is one of the major causes of disability and mortality worldwide. It is well known that ischemic stroke can cause gray matter injury. However, stroke also elicits profound white matter injury, a risk factor for higher stroke incidence and poor neurological outcomes. The majority of damage caused by stroke is located in subcortical regions and, remarkably, white matter occupies nearly half of the average infarct volume. Indeed, white matter is exquisitely vulnerable to ischemia and is often injured more severely than gray matter. Clinical symptoms related to white matter injury include cognitive dysfunction, emotional disorders, sensorimotor impairments, as well as urinary incontinence and pain, all of which are closely associated with destruction and remodeling of white matter connectivity. White matter injury can be noninvasively detected by MRI, which provides a three-dimensional assessment of its morphology, metabolism, and function. There is an urgent need for novel white matter therapies, as currently available strategies are limited to preclinical animal studies. Optimal protection against ischemic stroke will need to encompass the fortification of both gray and white matter. In this review, we discuss white matter injury after ischemic stroke, focusing on clinical features and tools, such as imaging, manifestation, and potential treatments. We also briefly discuss the pathophysiology of WMI and future research directions.