Strokes – surely those are an illness affecting the elderly, aren’t they? OK, they affect middle-aged, overworked men too. But did you know that in Estonia, three to four newborns leave the hospital with a diagnosis of stroke each year?
Later on, perinatal stroke is diagnosed in another six to seven small children. Perinatal means that the stroke happened during pregnancy, at the time of birth, or right after birth.
Taking into account that nearly 14 000 children are born in Estonia every year, perinatal stroke can be considered to be relatively rare. Rael Laugesaar, Junior Research Fellow at the Department of Pediatrics at the University of Tartu, says that both perinatal stroke and stroke in small children are more frequent than people think. “Unfortunately, neither the doctors nor people in general have sufficient awareness of strokes in children”.
Her doctoral thesis, defended six years ago, shed light on the fact that in relation to the population of Estonia, perinatal stroke occurs more often here than in any other country in the world. Perinatal, prenatal, or newborn strokes are those that occur from the 20th week of pregnancy until the point when the baby is 28 days old.
As clinical symptoms are often missing or low-key, the diagnosis of a stroke can be delayed. The first symptoms of a stroke that may be spotted in children are often related with development of motor skills (movements a baby makes with his arms, legs, feet, or his entire body) – or, more precisely, a delay in these.
“For example, when the baby is about four months old and the parents notice that he or she grabs toys only with one hand, or doesn’t rest the sole of one of their feet on the ground when learning to walk, there are enough reasons to visit a child neurologist, with a possible need for additional clinical examinations”, Laugesaar explains. It might turn out that the reason of these signs is hemiparesis – partial paralysis of one half of the body – and then the child receives a post-factum diagnosis of perinatal stroke.
When a child unexpectedly develops weakness of one part of the body, a speech disorder, or a balance disorder, it might be a sign of childhood stroke. Its occurrence in Estonia is about the same level as in other countries: 2.73 cases per 100,000 children each year.
Childhood stroke is similar to the strokes adults have: symptoms can appear suddenly and anywhere. Half-body weakness, as well as disturbed speech and thought, can take effect in the midst of a school lesson, at home, at the choir recitation, while training – absolutely anywhere! It’s important to recognize these symptoms and arrive at the hospital as quickly as possible.
The Reasons Why Children Have Strokes Are Unknown
The doctors’ recommendations for preventing strokes in adults usually include practicing a healthy lifestyle, treating heart diseases, and lowering blood pressure and cholesterol levels, in addition to trying to avoid diabetes and give up smoking. All of these are well-known long-term factors and preconditions that increase the risk of stroke.
But who or what is to blame when a stroke happens in a child, an infant, or a fetus? No one? Yes, in many cases a stroke affects an absolutely healthy child. Why? Often the reason is unclear. The only sure thing is that when it comes to children, strokes cannot be considered a “lifestyle disease”.
A stroke can come about when a blood vessel has shut down in the brain (ishemic stroke) or blown out altogether (hemorrhagic stroke), meaning the blood vessel has burst and broken. The latter amounts for 40 per cent of stroke cases in children and 15 per cent in adults. Laugesaar found that about half of hemorrhagic strokes have a common cause – anomalies of the blood vessels.
One of these anomalies is arteriovenous malformation. This difficult name has been given to a formation made of arteries and veins, reminding one of a grandmother’s messed up ball of yarn. Malformed blood vessels have thinner walls, so they can break and burst more easily. Hemorrhagic stroke can also be caused by the widening of an artery, known as an aneurysm, as well as by disturbances in the clotting of blood.
“It’s not always possible to answer why such anomalies happen, but often the reason has been of a genetic variety. These children must definitely be subject to some additional, more precise research, so the cause can be found”, said Rael Laugesaar. It’s important to find the causes, as this would pave way for cause-oriented care, or in other words personalized medicine. Complications could be prevented as well.
It has also been noticed that perinatal stroke often co-occurs with abnormalities during pregnancy or childbirth. “In most cases, perinatal stroke has occurred during pregnancy”, Laugesaar elaborated. This is verified by the damage patterns visible thanks to computer-tomographic and magnet-tomographic observations. “In many cases, this gives us a way to decrease the feeling of guilt over something that supposedly went wrong during the childbirth, as well as doubts as to whether the birth support had been given correctly”.
Two New Discoveries
According to Laugesaar, scientists have reached a consensus in that the reasons for perinatal stroke are hidden deep in the placenta. Things hinting at the shortcomings of placenta include the small posture and the light weight of the newborn. One of the possible reasons could also be the mother smoking during pregnancy, as well as several genetic risks. Still, one can name no dominant risk factors yet.
The same can be said of childhood stroke, except that many scientific studies have proven that there is a correlation between childhood stroke and chickenpox.
“For a long time, there have been attempts to link childhood stroke and previous infections. For example, it has been proven that after having chickenpox, the virus can still live on in nerve cells. In certain conditions, it can even travel into the central nervous system, causing chronic infection of the brain’s blood vessels”, Laugesaar explained.
The Good News Behind the Bad News
“Your child had a stroke” – these words are emotionally hard and frightening for parents to hear, no matter what the age of the child. But it is a fact that a child’s brain is significantly more plastic than an adult’s brain, and thanks to that, younger people can usually beat the disease quite well, along with efficient rehabilitative care.
It’s true that those who have received the diagnosis of a stroke are required to have life-long regular rehabilitative care. In that way the brain damage will not interfere with normal life too much and most of the children can go on with their studies at a regular school.
Regular rehabilitative care is especially important in the case of hemiparesis, since it makes the muscles more spastic and prevents complications, such as a limb becoming shorter or joints becoming unmovable. After a stroke, children should remain under the doctor’s supervision.
Which kind of rehabilitative care is the most suitable for a child diagnosed with a certain kind of stroke? This was the question that Laugesaar studied over the last four years, using a personal research grant given to her with the help of her colleagues.
“The most important thing that we found was that in the case of perinatal stroke, the long-term result depends on which part of the patient’s brain has been damaged. For example, if it is an arterial ishemic stroke resulting in damage to the cortex, then in later life these children are more susceptible to cognitive and speech-related disturbances, as well as epilepsy. With them, hemiparesis is less common.
On the other hand, in children with periventricular venous infarction, the white matter tracts in the brain are damaged, and they most often develop hemiparesis. Cognitive and speech-related disturbances are less common, also with lower risk of epilepsy”, Laugesaar told.
“Using radiological diagnosis, we are better at advising parents and deciding which function needs the most development during rehabilitative care”.
In addition to that, research has shown that cognitive disorders tend to manifest during a longer period of time. “We can evaluate a child at an age of four and say that the rehabilitation has been really good, but when it’s time to go to school learning disabilities might manifest. That is why our main message is that doctors shouldn’t stop working with these kids: children with diagnosed with a stroke must receive continuous and complex restorative and rehabilitative care; they also have to be monitored, with regular evaluation of their abilities”.
Did you know?
- There are two kinds of stroke in children: perinatal stroke (between 20 weeks of pregnancy until 28 days after birth) and childhood stroke (affecting children aged from one month to 18 years).
- Strokes in children are similar to those that happen to adults, due to severe and sudden symptoms: weakness in one side of the body, disturbed speech, disturbances in keeping balance, and maintaining consciousness.
- Rael Laugesaar was the first to start studying the frequency and risk factor for strokes in children in Estonia at the beginning of the 2000s. For the last four years she has been studying how the children diagnosed with stroke during her doctoral studies are doing right now.
- The goal of Rael Laugesaar’s personal research grant is to improve the quality of advice given to parents whose children are affected by stroke, as well as more efficient planning of early rehabilitative care. To achieve these goals, the likeliness of problems occurring later, as well as factors impacting the prognosis, must be known.
Katre Tatrik is the editor of the popular Estonian-language science portal ERR Novaator.