Clinical Study
Airplane stroke syndrome

https://doi.org/10.1016/j.jocn.2015.12.015Get rights and content

Highlights

  • Stroke during or soon after flight is uncommon, 0.7% of our stroke admissions.

  • Unlike previous literature suggests, flight-related strokes are of diverse aetiology.

  • Endovascular clot retrieval is possible also after in-flight stroke.

Abstract

Only 37 cases of stroke during or soon after long-haul flights have been published to our knowledge. In this retrospective observational study, we searched the Royal Melbourne Hospital prospective stroke database and all discharge summaries from 1 September 2003 to 30 September 2014 for flight-related strokes, defined as patients presenting with stroke within 14 days of air travel. We hypothesised that a patent foramen ovale (PFO) is an important, but not the only mechanism, of flight-related stroke. We describe the patient, stroke, and flight characteristics. Over the study period, 131 million passengers arrived at Melbourne airport. Our centre admitted 5727 stroke patients, of whom 42 (0.73%) had flight-related strokes. Flight-related stroke patients were younger (median age 65 versus 73, p < 0.001), had similar stroke severity, and received intravenous thrombolysis more often than non-flight-related stroke patients. Seven patients had flight-related intracerebral haemorrhage. The aetiology of the ischaemic strokes was cardioembolic in 14/35 (40%), including seven patients with confirmed PFO, one with atrial septal defect, four with atrial fibrillation, one with endocarditis, and one with aortic arch atheroma. Paradoxical embolism was confirmed in six patients. Stroke related to air travel is a rare occurrence, less than one in a million. Although 20% of patients had a PFO, distribution of stroke aetiologies was diverse and was not limited to PFO and paradoxical embolism.

Introduction

Almost 2 billion people travel by air every year. The age of travellers is increasing and long-haul aircraft such as the Airbus A380 and Boeing 777 are now capable of extending flight times to 18–20 hours [1]. As such, an appreciation of the associations between air travel and illness is important.

There is no standard definition of a long-haul flight. However, flight durations longer than 8 hours or distance greater than 5000 km have been shown to significantly increase the risk of deep venous thrombosis (DVT) and pulmonary embolism (PE) [1], and this association could be driven by various factors including comorbidities and dehydration.

The association between air travel and DVT, with or without PE, was labeled “economy class syndrome” by Symington et al. in 1977, based on the theory that highly congested seating arrangements put passengers at risk [2]. Although this term has been used subsequently, the exact mechanism of the association remains unclear. The first description of stroke as a complication of long-haul air travel was in 1968 by Beighton and Richards who described a 48-year-old woman who developed a lower limb DVT during a long-haul flight and had a fatal stroke soon after landing [2]. Although this condition was called “economy class stroke syndrome”, it seems to affect business class travellers equally [2]. It may, therefore, be more accurate to call it “airplane stroke syndrome”. Although airplane stroke syndrome has been recognised for a long time, only a few cases have been described in the literature as single case reports or small case series (Table 1).

One of the potential explanations for an association between air travel and stroke is paradoxical embolism through a patent foramen ovale (PFO), which is proposed as the aetiology in 17 of 29 published ischaemic strokes (Table 1). However, the relevance of PFO in the pathogenesis of ischaemic stroke is somewhat unclear. It has been estimated that the prevalence of PFO in the general population is 25%. In ischaemic stroke patients with no other identifiable cause the prevalence is 40%, and many of these are likely to be incidental [3].

To further understand airplane stroke syndrome, we describe all identified patients, flights, and stroke characteristics in patients with flight-related stroke at the Royal Melbourne Hospital, Australia. We also report the underlying aetiology of stroke and the presence of a PFO. We hypothesised that PFO is an important, but not the sole, underlying aetiology of flight-related strokes.

Section snippets

Methods

In this retrospective, observational, single centre study, we manually searched our local prospective stroke database and all discharge summaries from the Royal Melbourne Hospital Stroke Unit from 1 September 2003 to 30 September 2014 for flight-related stroke admissions. We employed a standardised search methodology using a keyword search for the following terms: “stroke”, “plane”, “airplane”, “travel”, “flight”, “trip”, “holiday”, “PFO”, and “airport”. We subsequently manually reviewed the

Results

Over the study period we had 5727 stroke admissions. Of those, a total of 42 patients (0.73%) had flight-related strokes. Table 2 shows the baseline clinical characteristics, stroke characteristics, and outcomes in patients with and without flight-related stroke. Median patient age in the flight-related stroke group was 65 years and 22 were males. Median baseline NIHSS was 9 (1–25), indicating moderate stroke severity. The stroke subtype was ischaemic stroke in 35 patients and intracerebral

Discussion

Although airplane travel is a very common experience, flight-related stroke is fortunately uncommon. We identified 42 flights-related strokes during a period with >100 million passengers landing in Melbourne. Therefore flight-related strokes are probably a less than a one in a million occurrence.

Still, in our enriched population, 0.7% of stroke admissions were flight-related and the present series of 42 patients is by far the largest published to our knowledge (Table 1). Unlike the previous

Conflicts of Interest/Disclosures

The authors declare that they have no financial or other conflicts of interest in relation to this research and its publication.

References (15)

There are more references available in the full text version of this article.

Cited by (5)

  • Stroke in airplane passengers: A study from a large international Hub

    2022, Journal of Stroke and Cerebrovascular Diseases
    Citation Excerpt :

    Ischemic stroke was the most prevalent type of stroke in both passengers and non-passengers (69.8% and 67.7% respectively). The occurrence of ischemic stroke in the younger, low risk profile passenger is hypothesized to be related to cardioembolism,311 and atherothrombosis.2 In our passenger population small vessel disease was the most prevalent with 40% of cases with cardioembolic and large artery atherosclerosis together accounting for 26.6% of causes this is in keeping with the high prevalence of small vessel disease in patient from Middle East and South/Far Asia12 as seen from Table 2.

  • Environmental Risk Factors for Stroke and Cardiovascular Disease

    2017, Encyclopedia of Cardiovascular Research and Medicine
  • Emerging Stroke Risk Factors: A Focus on Infectious and Environmental Determinants

    2024, Journal of Cardiovascular Development and Disease
View full text