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Advanced Neurologyurology
Advanced Ne Aging blood-brain barrier in stroke

Shortly after an ischemic stroke, the BBB undergoes resulting from cervical vessel dissection [11-13] . Furthermore,
significant damage . As a result of ischemic injury to neural clinical data demonstrate that in comparison to elderly
[6]
tissue, oxidative stressors accumulate and induce rapid patients over the age of 80 years, younger adults are more
degradation and functional breakdown of tight junctions, likely to present with hyperlipidemia and obesity and have
thereby opening the BBB. This enables inflammatory a history of smoking, drinking, or heavy drug use, all of
chemokines to enter the brain and cause disruptions in which are considered to act as major risk factors for stroke
both ion and water homeostasis . These localized actions in this age group [11,12,14,15] . Aside from the aforementioned
[7]
on the BBB cause further immune cell activation and hyperlipidemia and obesity, comorbid disease is much less
infiltration in response to ischemic injury, leading to the common in younger ischemic patients [11,12,15] .
release of inflammatory mediators and other molecules Ischemic stroke is much more prevalent in the
that further degrade endothelial tight junction complexes . elderly population than in young or middle-aged adults.
[7]
The loss of BBB integrity leaves the brain susceptible to Specifically, 80% of ischemic stroke occurs in the elderly
greater inflammation and edema, which may worsen (over the age of 65 years), with 25% of these cases attributed
ischemic injury and contribute to neuronal loss far beyond to those over the age of 80 years . Furthermore, these cases
[16]
acute injury [3,7] . Interestingly, due to variations in cellular occur in a larger proportion of female patients, in contrast
and molecular mechanisms, the BBB in elderly patients to what is observed in younger patients [12,14] . Older patients
undergoes far more extensive damage following ischemic (over the age of 50 years) tend to have more physiologically
injury than that observed in the younger adult brain; that is, based risk factors for ischemic stroke, including numerous
the BBB additionally deteriorates only in patients with age- vascular-related comorbidities that can influence the basal
associated health conditions [8,9] . Exacerbated degradation structure and function of the BBB. Older patients more
of the BBB leaves brains in elderly patients vulnerable to frequently report hypertension, cardiac failure, coronary
greater ischemic injury and poorer prognosis. heart disease, cardiac arrhythmia, and atrial fibrillation in
The current review outlines the cellular and molecular addition to high cholesterol [12,14] .
mechanisms of BBB damage following stroke with an
emphasis on how age influences the nature of these 2.2. Prognosis
degradative processes. Furthermore, the BBB influences Unlike elderly populations, young adults have a relatively
the delivery and efficacy of ischemic stroke treatment. good prognosis following ischemic injury. Young ischemic
Thus, the influence of age-dependent BBB degradative patients aged ≤50 years had a 100% survival rate during
mechanisms on treatments and how the BBB itself may be a 1-, 3-, and 6-month follow-ups, and this survival rate only
key therapeutic target to restore or maintain BBB function decreased to 96.8% by the 3-year follow-up . Moreover,
[11]
and integrity in the elderly population are discussed. recurrent stroke only occurs in 2% of those under the
age of 50 years . With increasing age, the incidence of
[11]
2. Age and ischemic injury ischemic stroke increases and clinical outcomes worsen.
Ischemic stroke, although much more commonly studied Ischemic tissue surrounding the infarct following injury
in young-adult-to-middle-aged animal models and is much more likely to convert into an infarction as age
human populations, is prevalent across all age groups. increases in both men and women [17,18] . In comparison to
The incidence of stroke in the elderly population is higher younger patients, those aged >50 years exhibit significantly
than in the young-adult population, and the presentation lower post-stroke cognitive function and higher rates
[12]
and clinical outcomes of stroke are highly age-dependent. of disability and social impairments , which may be
Importantly, aging populations are vulnerable to ischemic attributed to more severe injury. Middle cerebral artery
injury and may receive significantly worse prognoses. occlusion (MCAO) animal models using 18-month-old
Sprague-Dawley rats (roughly equivalent to humans over
2.1. Common etiologies and risk factors the age of 45 years) exhibited infarctions that were up to
[19]
The incidence of stroke increases with age, and thus twofold greater than those observed in 3-month-old rats
[9]
[19]
younger adults are generally at a lower relative risk. It (roughly equivalent to young adults) , following stroke .
is estimated that 10 – 20% of ischemic events occur in In addition, unlike younger rats, and aged rats experienced
those aged 18 – 50 years . In addition, compared with more severe behavioral deficits and did not significantly
[10]
[9]
other age groups, young-to-middle-aged adults differ recover after a 2-week period . A brief overview of the
quite significantly in both the etiology and presentation differing etiologies and prognoses of adult and elderly
of ischemic stroke. For instance, compared with elderly ischemic stroke patients is illustrated in Figure 1.
patients, young-adult patients presenting with ischemic Age-related comorbidities may further worsen
stroke are more likely to be male and experience a stroke prognoses in elderly patients. Diabetes and Alzheimer’s

Volume 1 Issue 2 (2022) 2 https://doi.org/10.36922/an.v1i2.1