In the complete absence of blood flow, neuronal death occurs within 2–3 minutes from the exhaustion of energy stores. However, in most strokes, there is a salvageable penumbra (tissue at risk) that retains viability for a period of time through suboptimal perfusion from collaterals. Local cerebral edema from the stroke results in a compromise of these collaterals and progression of the ischemic penumbra to infarction if the flow is not restored and maintained. Prevention of this secondary neuronal injury drives the treatment of stroke and has led to the creation of designated Primary Stroke Centers that offer appropriate and timely triage and treatment of all potential stroke patients.
● noncontrast brain CT: the usual initial diagnostic tool of choice (image in ≤ 20 mins)
● thrombectomy is the standard of care for eligible patients: cerebral ischemia (including infarct) caused by LVO of the ICA or M1 segment of the MCA, 1) when it can be initiated within 6 hours of symptom onset or 2) if perfusion studies identify viable tissue 6–24 hours from onset
○ within 4.5 hours of onset when thrombectomy not being done immediately or for patients that are not thrombectomy candidates
○ goal: “door-to-needle” (DTN) time ≤ 60 minutes
Current guidelines for the treatment of acute ischemic stroke are mainly based on the time between symptom onset and initiation of treatment. This time is unknown in patients with wake-up stroke (WUS).
It is inadequately treated in the USA and worldwide due to a lengthy history of neuroprotective drug failures in clinical trials.
The rapid development of a neuroprotective or cytoprotective compound would allow future stroke victims to receive a treatment to reduce disabilities and further promote recovery of function.
A opinion article reviews in detail the enormous costs associated with developing a small molecule to treat stroke, as well as providing a timely overview of the cell-death time-course and relationship to the ischemic cascade. Distinct temporal patterns of cell-death of neurovascular unit components provide opportunities to intervene and optimize new cytoprotective strategies. However, adequate research funding is mandatory to allow stroke researchers to develop and test their novel therapeutic approach to treat stroke victims 1).
Research has reported how excitatory amino acids act as the major excitatory neurotransmitters in the cerebral cortex and hippocampus. Furthermore, other therapeutic targets such as free radical scavenger strategies and the anti-inflammatory neuroprotective strategy have been evaluated with conflicting data in animal models and human subjects with acute ischemic stroke. Whereas promising combinations of neuroprotection and neurorecovery, such as citicoline, albumin and cerebrolysin have been tested with findings worthy of further evaluation in larger randomized clinical trials. Understanding the complexities of the ischemic cascade is essential to developing pharmacological targets for acute ischemic stroke in neuroprotective or flow restoration therapeutic strategies 2).
Therapeutic hypothermia is increasingly recognized as having a tissue-protective function and positively influencing neurological outcome, especially in cases of ischemia caused by cardiac arrest or hypoxic-ischemic encephalopathy in newborns. Yet, many aspects of hypothermia as a treatment for ischemic stroke remain unknown. Large-scale studies examining the effects of hypothermia on stroke are currently underway 3).
Brain ischemia and treatment are one of the important topics in neurological science. Free oxygen radicals and inflammation formed after ischemia are accepted as the most important causes of damage. Currently, there are studies on many chemopreventive agents to prevent cerebral ischemia damage. The aim of Aras et al is to research the preventive effect of the active ingredient in genistein There is currently no promising pharmacotherapy aside from intravenous or intra-arterial thrombolysis. Yet because of the narrow therapeutic time window involved, thrombolytic application is very restricted in clinical settings. Accumulating data suggest that non-pharmaceutical therapies for stroke might provide new opportunities for stroke treatment 4).
Progression of focal stroke symptoms still constitutes a serious clinical problem for which heparin has insufficient effectiveness in clinical practice. New therapies, ideally preventive, are needed 5).
After cerebral ischemia, revascularization in the ischemic boundary zone provides nutritive blood flow as well as various growth factors to promote the survival and activity of neurons and neural progenitor cells. Enhancement of angiogenesis and the resulting improvement of cerebral microcirculation are key restorative mechanisms and represent an important therapeutic strategy for ischemic stroke.
Improvements in acute ischemic stroke (AIS) outcomes have been achieved with intravenous thrombolytics (IVT) and intra-arterial thrombolytics vs supportive medical therapy. Given its ease of administration, noninvasiveness, and most validated efficacy, IVT is the standard of care in AIS patients without contraindications to systemic fibrinolysis. However, patients with large-vessel occlusions respond poorly to IVT. Recent trials designed to select this population for randomization to IVT vs IVT with adjunctive endovascular therapy have not shown improvement in clinical outcomes with endovascular therapy. This could be due to the lack of utilization of modern thrombectomy devices such as Penumbra aspiration devices, Solitaire stent-trievers, or Trevo stent-trievers, which have shown the best recanalization results. Continued improvement in the techniques with using these devices as well as randomized controlled trials using them is warranted 7).
With the emergence of new technologies in imaging, thrombolysis and endovascular intervention, the treatment modalities of acute ischemic stroke will enter a new era 8).
Within 3 h from symptom onset, the existence of FLAIR-positive lesions on pretreatment MRI is significantly associated with an increased bleeding risk due to systemic thrombolysis. Therefore, considering FLAIR-positive lesions on baseline MRI might guide treatment decisions in ischemic stroke 9).