Mobile stroke unit use for prehospital stroke treatment-an update

Professor Klaus Fassbender: The Father of Mobile Stroke Units

Professor Klaus Fassbender is a distinguished neurologist from Germany, widely recognized for his groundbreaking contributions to the fields of neurology and neurodegenerative disease. His work has been pivotal in advancing our understanding of the pathophysiological mechanisms underlying neurodegenerative disorders, including Alzheimer's and Parkinson's disease, as well as in refining therapeutic strategies for their treatment. His studies in cerebrovascular disease have elucidated the complex molecular and cellular processes involved in ischemic and hemorrhagic stroke, leading to the development of novel therapeutic interventions, often bridging the gap between laboratory discoveries and their application in clinical settings. Professor Klaus Fassbender is "the father" of the mobile stroke unit (MSU). With the "time is brain" concept in mind, he proposed and developed the MSU concept for the first time, allowing prehospital stroke imaging, diagnosis, and treatment directly at the site of emergency. This concept reduced times between symptoms onset and treatment, resulting in an increased proportion of patients receiving treatment within "the golden hour" and leading to the improvement of functional outcomes at 90 days. Professor Fassbender's work has been instrumental in shaping contemporary approaches to diagnosing and managing stroke and neurodegenerative disease, making him a leading figure in modern neurology.

Swiss guidelines for the prehospital phase in suspected acute stroke

Acute stroke treatment has advanced substantially over the last years. Important milestones constitute intravenous thrombolysis, endovascular therapy (EVT), and treatment of stroke patients in dedicated units (stroke units). At present in Switzerland there are 13 certified stroke units and 10 certified EVT-capable stroke centers. Emerging challenges for the prehospital pathways are that (i) acute stroke treatment remains very time sensitive, (ii) the time window for acute stroke treatment has opened up to 24 h in selected cases, and (iii) EVT is only available in stroke centers. The goal of the current guideline is to standardize the prehospital phase of patients with acute stroke for them to receive the optimal treatment without unnecessary delays. Different prehospital models exist. For patients with large vessel occlusion (LVO), the Drip and Ship model is the most commonly used in Switzerland. This model is challenged by the Mothership model where stroke patients with suspected LVO are directly transferred to the stroke center. This latter model is only effective if there is an accurate triage by paramedics, hence the patient may benefit from the right treatment in the right place, without loss of time. Although the Cincinnati Prehospital Stroke Scale is a well-established scale to detect acute stroke in the prehospital setting, it neglects nonmotor symptoms like visual impairment or severe vertigo. Therefore we suggest “acute occurrence of a focal neurological deficit” as the trigger to enter the acute stroke pathway. For the triage whether a patient has a LVO (yes/no), there are a number of scores published. Accuracy of these scores is borderline. Nevertheless, applying the Rapid Arterial Occlusion Evaluation score or a comparable score to recognize patients with LVO may help to speed up and triage prehospital pathways. Ultimately, the decision of which model to use in which stroke network will depend on local (e.g. geographical) characteristics.

Does radiological conjugate eye deviation sign play a role in acute stroke imaging? A meta-analysis

BACKGROUND AND PURPOSE

The diagnostic value of non-contrast CT (NCCT) in acute stroke imaging remains indispensable, especially under emergency conditions with limited resources. The radiological conjugate eye deviation (RCED) has been demonstrated as a NCCT sign to predict acute ischemic stroke (AIS) or AIS secondary to large vessel occlusion (LVO) in recent studies. We performed a meta-analysis to gain a better understanding into the predictive role of RCED for AISs and LVO-AISs.

METHODS

We conducted a systematic literature search using PubMed, Embase, and Cochrane. The search focused on studies published between January 2000 and August 2020 that reported the predictive value of RCED for the diagnosis of AIS or LVO-AIS. Principal measurements of the meta-analysis were the overall sensitivity, specificity, the positive likelihood ratio (PLR), and the negative likelihood ratio (NLR) of RCED in predicting AIS and LVO-AIS.

RESULTS

We included 11 studies (n = 2304). For AIS, RCED had a sensitivity of 0.37 (95% CI 0.27-0.47), a specificity of 0.86 (95% CI 0.73-0.93), the area under the receiver operating characteristic curve (AUC) was 0.58 (95% CI 0.53-0.62), PLR was 2.5 (95% CI 1.5-4.4), and NLR was 0.74 (95% CI 0.65-0.84). For LVO-AIS, RCED had a sensitivity of 0.63 (95% CI 0.46-0.77), a specificity of 0.77 (95% CI 0.71-0.82), AUC was 0.63 (95% CI 0.46-0.77), PLR was 2.7 (95% CI 1.7-4.3), and NLR was 0.49 (95% CI 0.3-0.78).

CONCLUSION

RCED can be used to predict LVO-AIS. It is expected that this method will be extensively used and validated in acute stroke imaging, especially under emergency conditions with limited resources.

Improved collateral flow and reduced damage after remote ischemic perconditioning during distal middle cerebral artery occlusion in aged rats

Circulation through cerebral collaterals can maintain tissue viability until reperfusion is achieved. However, collateral circulation is time limited, and failure of collaterals is accelerated in the aged. Remote ischemic perconditioning (RIPerC), which involves inducing a series of repetitive, transient peripheral cycles of ischemia and reperfusion at a site remote to the brain during cerebral ischemia, may be neuroprotective and can prevent collateral failure in young adult rats. Here, we demonstrate the efficacy of RIPerC to improve blood flow through collaterals in aged (16-18 months of age) Sprague Dawley rats during a distal middle cerebral artery occlusion. Laser speckle contrast imaging and two-photon laser scanning microscopy were used to directly measure flow through collateral connections to ischemic tissue. Consistent with studies in young adult rats, RIPerC enhanced collateral flow by preventing the stroke-induced narrowing of pial arterioles during ischemia. This improved flow was associated with reduced early ischemic damage in RIPerC treated aged rats relative to controls. Thus, RIPerC is an easily administered, non-invasive neuroprotective strategy that can improve penumbral blood flow via collaterals. Enhanced collateral flow supports further investigation as an adjuvant therapy to recanalization therapy and a protective treatment to maintain tissue viability prior to reperfusion.

A review of mobile stroke units

PURPOSE OF REVIEW

Mobile stroke units (MSUs) for prehospital treatment and management of patients with acute stroke have been developed more than a decade ago and is currently spreading worldwide. This review discusses the history of MSU and current operations and research.

RECENT FINDINGS

Multiple studies have shown that MSU can significantly reduce treatment time with a tenfold increase of patients treated within the first 60 min of symptom onset. Recent preliminary results from the Berlin Prehospital or Usual Delivery of Acute Stroke Care trial (B-PROUD) showed a positive shift in modified Rankin Scale (mRS) scores at 3 months for patients treated in MSUs. Two German studies indicate that the MSU model is cost effective by reducing disability and improving adjusted quality-life years after stroke. The MSU model for prehospital management of acute stroke is spreading worldwide. More research is needed, however, to establish cost-effectiveness, efficacy and best setting for prehospital stroke management.

Acute telestroke in France: A systematic review

BACKGROUND

Acute telestroke is the use of telemedicine to improve acute stroke care. It has demonstrated to be a safe and effective medical practice. Since 2011, acute telestroke has been promoted by the Ministry of Health in France, and in 2018 many regions were in the process or completion of implementing telestroke. The objective of this study was to describe acute telestroke implementation in France.

METHODS

A systematic review was conducted using PubMed and ScienceDirect databases. Articles and abstracts in English and French, published between January 1st, 2000 to April 30th, 2018 were used. Studies conducted in France and that had presented an outcome evaluation of a regional acute telestroke activity were included. No meta-analysis was conducted.

RESULTS

A total of 24 studies (14 in French, 10 in English) were included, with 13 published articles (7 indexed on PubMed) and 11 abstracts. Among the 13 published articles, there were seven observational retrospective studies, one quasi-experimental before-after study, one experimental randomised controlled trial, and four medico-economic studies. All telestroke network models of care were drip-and-ship with hub and spoke organisation. The case-control studies did not show a difference with or without telemedicine. The territorial thrombolysis rate was measured in two regions, with an increase in Franche-Comté from 0.2% (2004) to 9.9% (2015), and a relative increase of 76% in Nord-Pas-de-Calais between 2009-2010 and 2012.

CONCLUSION

Implementation of acute telestroke in France had a positive clinical and public health impact but the evaluation remained limited and needs to be supported.

Mobile Stroke Units: Bringing Treatment to the Patient

PURPOSE OF REVIEW

Mobile stroke units (MSUs) have revolutionized emergency stroke care by delivering pre-hospital thrombolysis faster than conventional ambulance transport and in-hospital treatment. This review discusses the history of MSUs technological development, current operations and research, cost-effectiveness, and future directions.

RECENT FINDINGS

Multiple prospective and retrospective studies have shown that MSUs deliver acute ischemic stroke treatment with intravenous recombinant tissue plasminogen activator (IV r-tPA) approximately 30 min faster than conventional care. The 90-day modified Rankin Scores for patients who received IV r-tPA on the MSU compared to conventional care were not statistically different in the PHANTOM-S study. Two German studies suggest that the MSU model is cost-effective by reducing disability and improving adjusted quality-life years post-stroke. The ongoing BEST-MSU trial will be the first multicenter, randomized controlled study that will shed light on MSUs' impact on long-term neurologic outcomes and cost-effectiveness. MSUs are effective in reducing treatment times in acute ischemic stroke without increasing adverse events. MSUs could potentially improve treatment times in large vessel occlusion and intracranial hemorrhage. Further studies are needed to assess functional outcomes and cost-effectiveness. Clinical trials are ongoing internationally.

[Mobile Stoke Unit : Changes in the concept of stroke care over time]

BACKGROUND

Stroke continues to be a major cause of death and one of the most frequent reasons for permanent disability and dependence on caregiving at an adult age, whereby ischemic stroke is regarded as a medical condition that can be treated. One of the main reasons why patients with acute stroke are not given causal or evidence-based treatment is the delay in reaching a treatment-specialized team at a suitable clinic. After the dawning of the age of neurothrombectomy, various management concepts have been established to transfer the patient to a center with the appropriate level of treatment as quickly as possible (time is brain).

METHODS

The Mobile Stroke Unit (MSU) is an ambulance that contains all the equipment required to clarify the cause of a stroke and thus enables treatment and triage decision-making at the scene of the emergency.

RESULTS

Due to prehospital implementation of the "need-for-speed" notion, the MSU assumes a special role. Present data indicate a benefit with regard to a shortening of time to thrombolysis and an increase in treatment rates within the first (golden) hour. In addition, it is possible to make a diagnosis-based triage decision regarding a hospital with or without an endovascular treatment option.

CONCLUSIONS

The MSU allows swifter treatment and a diagnosis-based triage decision at the scene of the emergency. It is now important to continue evaluating the clinical and socioeconomic benefit of these, at first glance expensive, preclinical tools and also continue analyzing special regional aspects as well as the pros and cons of the concepts. The recently established Prehospital Stroke Treatment Organization (PRESTO) represents a promising approach.