When you hear the word "stroke," the first picture that pops into your mind is likely to be of an elderly individual. It's true that older adults are at greater stroke risk; the chance of having a stroke doubles with each decade of life after the age of 55. But did you know that infants and children can also suffer stroke? It can even occur before birth.
According to the National Stroke Association, stroke affects 6 in every 100,000 children in the US. It is also one of the 10 leading causes of death among children in the country.
The rate of stroke is much higher in adults than children. Every year, more than 795,000 men and women suffer a stroke and around 130,000 die from the condition. However, studies have found stroke rates are on the rise in children in the US.
In 2011, a study published in the Annals of Neurology reported a 51% increase in ischemic stroke incidence among boys aged 5-14 from the period 1995-96 to 2007-08, while girls aged 5-14 saw a 3% rise in ischemic stroke in the same period.
In many ways, stroke in children - commonly referred to as pediatric stroke - can present more challenges than stroke in adults.
The early signs of stroke in children are much more subtle than in adults, meaning they often go unrecognized. According to the International Alliance for Pediatric Stroke (IAPS), newborns who suffer stroke may not even begin to show any symptoms until the age of 4-8 months.
What is more, because parents, caregivers and even health care professionals do not often associate stroke with children, it may be ruled out as a possibility. As a result, many children fail to receive adequate treatment.
A 2014 study conducted by Dr. Mark Mackay, director of the Children's Stroke Program at the Royal Children's Hospital and Murdoch Children's Research Institute in Melbourne, Australia, and colleagues found that only half of interviewed parents whose children suffered stroke thought their child's symptoms were serious enough to call 911, while 21% of parents adopted a "wait-and-see" approach. What is more, only 36% considered stroke as a possible cause of their child's symptoms.
As with most health conditions, early treatment for stroke is key. Unfortunately, around 20-40% of children die after a stroke, and of those who do survive, around 50-80% will have lifelong neurological problems, such a partial or total paralysis.
May is American Stroke Awareness Month. In this Spotlight, we investigate the risk factors for pediatric stroke, the signs and symptoms to look out for, as well as the treatment options for the condition.
Perinatal stroke and childhood stroke
There are two types of pediatric stroke: perinatal stroke and childhood stroke.
Perinatal stroke, also referred to as fetal or prenatal stroke, occurs between the last 18 weeks of pregnancy and the first 30 days of birth. In the US, perinatal stroke occurs in about 1 in every 2,800 live births.
Most cases of perinatal stroke are ischemic, caused by blood clots breaking off from the placenta and becoming lodged in the child's brain.
Childhood stroke occurs between the ages of 1 month and 18 years. Unlike adults, in whom ischemic stroke is most common, children are equally as likely to have ischemic stroke as they are hemorrhagic stroke - caused by a brain bleed from a ruptured blood vessel.
Around 60% of all pediatric strokes occur in boys, and African-American children are at greater stroke risk than Caucasian and Asian children.
The risk factors for pediatric stroke
Among adults, high blood pressure, irregular heartbeat and atherosclerosis - hardening of the arteries - are some of the most common risk factors for stroke. These factors rarely cause stroke in children, however.
According to the American Stroke Association, around half of all pediatric strokes are triggered by an underlying condition, most commonly sickle cell disease - an inherited blood disorder - and congenital heart disease.
Other underlying conditions that may raise a child's stroke risk include head and neck infections, abnormal blood clotting, head trauma and systemic conditions, such as autoimmune disorders.
Maternal history of infertility, premature rupture of membranes during pregnancy, maternal preeclampsia and chorioamnionitis - inflammation of the fetal membranes due to a bacterial infection - may also increase a child's stroke risk.
Though cardiovascular-related risk factors for stroke in adults are rare in children, recent studies have indicated an increase in these risk factors among the younger population. This is down to a rise in high blood pressure, obesity, diabetes, high cholesterol and tobacco and alcohol use among youth.
A 2014 study published in the journal Neurology also suggested colds and other minor infections in childhood may temporarily raise a child's stroke risk.
"We've seen this increase in stroke risk from infection in adults, but until now, an association has not been studied in children," commented study author Dr. Heather Fullerton, director of the University of California-San Francisco Pediatric Stroke and Cerebrovascular Disease Center.
"It is possible that inflammatory conditions contribute more to the stroke risk in children, however, further research is needed to explore this possible association."
It is important to note, however, that in around half of all childhood stroke cases, no previous risk factor can be determined.
What are the signs and symptoms to look out for?
As mentioned previously, it can be very hard to spot stroke symptoms among very young children. Around 40% of infants do not show symptoms of early stroke; a parent may not know their baby has suffered stroke until months later when they show reduced movement or weakness on one side of their face.
Repetitive twitching of the face, arm or leg can be an indicator of stroke in newborns, as can a pause in breathing alongside prolonged staring and extreme fatigue.
As children develop, the signs of symptoms of stroke are very similar to those in adults. Weakness or numbness on one side of the body and problems speaking or understanding language - such as slurred speech or problems understanding simple instructions - may be signs of stroke.
Other signs of stroke among children may include severe headache, vomiting, fatigue, severe dizziness and appearance of seizures.The American Stroke Association stress that the F.A.S.T. acronym is an easy way to remember the sudden signs of stroke in both children and adults:
- Face drooping. Is one side of the face numb or drooping? Is the individual able to smile?
- Arm weakness. Is one arm numb or weak? Ask the individual to lift both arms. Does one arm drift downward?
- Speech difficulty. Is the individual's speech slurred? Do they find it hard to speak or are they hard to understand? Can they correctly repeat a simple sentence, such as "the sky is blue?"
- Time to call 911. If the individual shows any of these symptoms, call 911 immediately, even if the symptoms disappear. Check the time at which first symptoms appear.
"Think stroke, act fast and call 911. That message applies to adults and children," says Dr. MacKay. "Getting to the hospital quickly is an essential first step to develop strategies to improve access to emergency treatment in children."
Treatment options for pediatric stroke
For adults suffering ischemic stroke, the first port of call in terms of treatment is the medication tissue plasminogen activator (tPA), which works by dissolving any blood clots that are blocking the arteries, restoring blood flow to the brain. Such treatment must be administered within 3 hours of symptom onset - 4.5 hours for some patients.
The use of tPA among young children with ischemic stroke, however, is controversial. Since children and adults have physiological differences, health care professionals are concerned about the drug's safety and efficacy among children - something that is currently being investigated.
As such, stroke treatment for children tends to vary depending on the cause of their stroke and any underlying medical conditions they may have. A child whose stroke was caused by a heart defect, for example, may be treated with blood-thinning medication, such as warfarin or aspirin.
Children who suffer stroke have around a 15-18% chance of suffering another stroke. Therefore, many children may receive treatment to prevent stroke recurrence, such as antithrombotic therapy - medication that stops blood clots from forming or growing.
One crucial treatment for the majority children who suffer stroke is rehabilitation therapy, which can involve physiotherapy, occupational therapy and speech therapy.
Sixty percent of children experience neurological problems, such as hemiplegia or hemiparesis cerebral palsy, following stroke. Rehabilitation therapy can really help reduce the neurological effects of stroke, and the earlier treatment is started, the more likely it is to succeed.
Severe delays in diagnosis of pediatric stroke
But as Dr. MacKay's study showed, many parents either do not consider the possibility that their child is suffering a stroke or are unable to recognize the signs, which can severely delay treatment.
Dr. MacKay's findings revealed that the average time from symptom onset of pediatric stroke to arrival at the emergency room was 1.8 hours, with some arrivals taking up to 4 hours.
And it is not only parents who may overlook the signs and symptoms of pediatric stroke - doctors can too. Studies have found that in the US, it can often take longer than 24 hours to diagnose stroke in children.
A report from ABC News in 2011 provides evidence of this, revealing how it took more than 25 hours for doctors to diagnose a 15-year-old boy from Ohio with stroke.
Because of the delay in diagnosis, the boy had to have a part of his skull removed to ease pressure from the build up of blood in his brain.
In a 2008 interview, Dr. Fullerton said she believes a delay in diagnosis of pediatric stroke has fallen into a gap in clinical care. "It is a rare disorder in general, and so most child neurologists will not be very comfortable in caring for children with stroke," she said, adding:
"Stroke is considered more a disease of adults, but then adult stroke neurologists aren't familiar of the etiologies of stroke in children or how to manage stroke in children, and so they're often uncomfortable with caring for a stroke in a child.
It can be difficult to diagnose the etiology of their strokes. It often takes sophisticated imaging studies and studies that are done by very experienced practitioners. It really often does take a team approach to figure out why a child has had a stroke and figure out what is the best way to prevent more strokes in that child."
While stroke is much rarer in children than adults, it is important that parents, caregivers and health care professionals are aware that children can be affected by the condition and take note of the signs and symptoms that may arise.
Not only is May American Stroke Awareness Month, 2nd-8th May is dedicated to World Pediatric Stroke Awareness Week. Set up by the IAPS and not-for-profit organization Brendon's Smile(resource no longer available at www.brendonssmile.org) last year, the campaign aims to raise awareness of pediatric stroke around the globe and educate communities about how the condition can impact children's lives.
Visit the IAPS website to find out more about pediatric stroke and how you can help raise awareness of the condition.