New findings from the University of Birmingham challenge the 'transient' nature of 'mini-strokes' and provide insight into the long term impact of an under-recognised condition.
Primary care follow-ups with transient ischemic attack (TIA) patients found that they had a 43% increased risk of fatigue, 26% increased risk of psychological impairment, such as anxiety or depression, and a 45% increased risk of cognitive impairment.
The research, published in the European Journal of Neurology, recommends that clinical guidelines for TIA need to be revised to acknowledge the likelihood of residual impairments and support rehabilitation for patients that can improve their quality of life.
TIAs occur when blood flow to the brain is disrupted and can cause sudden symptoms similar to those of a stroke, such as speech and visual disturbance, and numbness or weakness in the face, arms and legs which usually resolve within a few minutes to 24 hours.
Approximately 46,000 people experience a first TIA each year and there are 510,000 people living in the UK with a history of TIA. Incidence has increased in the past two decades, and patients are known to have an increased risk of having a full stroke.
Guidelines for TIA are centred around rapid evaluation of people with suspected TIA and focus on diagnosis. Follow-up for TIA patients is focused on management of stroke risk factors through medical, surgical and lifestyle interventions. Though clinical guidelines recognise that stroke patients may experience ongoing impairments which require rehabilitation; these guidelines do no extend to TIA.
The long-term impact of TIA has been unclear for some time, and the UK's leading stroke charity, Stroke Association, recommended this as a research priority in their TIA campaign report in 2014.
The Birmingham study, funded by National Institute for Health Research (NIHR) School for Primary Care Research (SPCR), used anonymised electronic primary care records from The Health Improvement Network (THIN) database, which covers approximately 6% of the UK population.
The team designed a retrospective matched cohort study of 9,419 TIA patients, and 46,511 controls were included. The median age of those in the study was 74, and 48% were male.
When compared to the control group, which were the same age and sex, TIA patients reported an increased risk of consulting for fatigue (43%), psychological impairment (26%) and cognitive impairment (45%).
Dr Grace Turner, from the University of Birmingham, explained: "There have been a number of small studies which suggest long term impacts of TIA, but nothing on this scale, and nothing that included a control group for comparison. It's further evidence of how we can use electronic patient records to further our knowledge and improve patient care."
The study design addressed limitations of previous studies by not only including the control group, but also excluding patients with previous impairments from the analysis and controlling for other confounding variables.
Dr Turner added: "These findings present an urgent need to revisit clinical guidelines for TIA. They can no longer be considered 'transient' or 'temporary', there is a potential long term impact which could affect quality of life.
"In some cases, people may not be able to return to work or participate in social activities, and there is a real impact on their quality of life. Future research should focus on improving care for TIA patients presenting signs of fatigue, anxiety, depression, or other impairments."
The team acknowledge that there is a possibility of misdiagnosis or underreporting of symptoms in follow ups, either by the patient or GP, but note that it is more likely that risk levels are higher than reported in the study.