“Dr Irena’s” Health Tips – No. 5

We recently had contact with a retired UK doctor who now lives in North Cyprus and met her at Kamiloglu Hospital – Kyrenia Medical Centre where she was looking after reception/patient liaison along with other English speaking people who are giving their time to ensure a good medical service for English speaking expatriates.

Irena kindly offered to write some articles about basic health issues which may be of interest to our readers.

By Irena Hulson

Strokes

What is a stroke?

A stroke, also known as a cerebrovascular accident or CVA, occurs when part of the brain loses its blood supply and the part of the body that the blood-deprived brain cells control stops working. This loss of blood supply can be ischemic because of lack of blood flow, or hemorrhagic because of bleeding into brain tissue. A stroke is a medical emergency because strokes can lead to death or permanent disability, plus there are now opportunities to treat ischemic strokes but that treatment needs to be started in the first few hours after the signs of a stroke begin. The patient, family, or bystanders, should call an ambulance and activate emergency medical services immediately should a stroke be suspected.

A transient ischemic attack (TIA or mini-stroke) describes an ischemic stroke that is short-lived where the symptoms resolve spontaneously. This situation also requires emergency assessment to try to minimize the risk of a future stroke. By definition, a stroke would be classified as a TIA if all symptoms resolved within 24 hours.

Strokes are often described based upon the function of the body that is lost and by the area of the brain that is affected. Most commonly in strokes that involve the brain, the symptoms involve either the right or left side of the body. In strokes that affect the brainstem or the spinal cord, symptoms may present on both sides of the body.

Motor function or the ability for the body to move may involve only a part of the body, like the hand or arm, or the whole side (both extremities). Weakness on one side of the body is called hemiparesis (hemi= half + paresis=weak) and is hemiplegia (hemi=half +plegia=paralysis).

Similarly, sensory function, the ability to feel, can be localized to a hand or an arm or involve more of the body.

Other symptoms like speech, vision, balance, and coordination help locate the part of the brain that has stopped working and helps the health care professional make the clinical diagnosis of stroke. This is an important concept since not all loss of neurologic function is due to stroke and if the anatomy and physiology do not match the loss of body function, other diagnoses may be considered that can affect both brain and body.

A lacunar stroke describes a single tiny penetrating artery branch that occludes with either debris or a clot to cause the stroke. The area of the involved brain is small but can still cause significant neurologic deficits, just like a stroke involving a larger blood vessel and more brain tissue. In some cases, however, the stroke is silent, meaning that no obvious body function is lost and an old lacunar stroke can be seen as an incidental finding on CT or MRI scans of the head done for other reasons. The term lacunae means empty space and a tiny empty space of an old lacunar stroke can be seen on imaging where brain tissue has been lost.

What are the different types of stroke?

Strokes are usually classified by what mechanism caused the loss of the blood supply, either ischemic or hemorrhagic. A stroke may also be described by what part of the brain was affected (for example, a right temporal stroke) and what part of the body stopped working (stroke affecting the left arm).

Ischemic stroke

An artery in the brain being obstructed or blocked causes an ischemic stroke, preventing oxygen-rich blood from being delivered to brain cells. The artery can be blocked in a couple of ways. In a thrombotic stroke, an artery can narrow over time because of cholesterol buildup, called plaque. If that plaque ruptures, a clot is formed at the site and prevents blood from passing to brain cells downstream, which are then deprived of oxygen.

In an embolic stroke, the artery is blocked because of debris or a clot that travels from the heart or another blood vessel. An embolus or embolism is a clot, a piece of fatty material or other object that travels within the bloodstream that lodges in a blood vessel to cause an obstruction.

Blood clots that embolize usually arise from the heart. The most common cause of these blood clots is a heart arrhythmia called atrial fibrillation, where the upper chambers of the heart, the atria, do not beat in an organized rhythm. Instead, the chaotic electrical rhythm causes the atria to jiggle like a bowl of jelly. While blood still flows to the ventricles (the heart’s lower chambers) to be pumped to the body, some blood along the inner walls of the atrium can form small blood clots. If a clot breaks off, it can travel or embolize to the brain, where it can cause a stroke.

The carotid arteries are two large blood vessels that provide the brain with blood supply. These arteries can narrow, or develop stenosis, with cholesterol plaque that builds up over time. The surface of the plaque is irregular and bits of debris can break off and cause an embolism to block blood vessels downstream in the brain.

Hemorrhagic stroke

When a blood vessel leaks and spills blood into brain tissue, those brain cells stop working. The bleeding or hemorrhage is often due to poorly controlled high blood pressure that weakens the wall of an artery over time. Blood may also leak from an aneurysm, a congenital weakness or ballooning of an artery wall or from an AVM (arteriovenous malformation), a congenital abnormality where an artery and vein connect incorrectly. The bleeding can form a hematoma that can put pressure on small vessels and decrease or shut off blood flow to brain tissue.

Describing a stroke by anatomy and symptoms There are four major arteries that supply the brain with blood.

• The right and left carotid artery are located in the front of the neck and their pulse can be felt with the fingers.
• The right and left vertebral arteries are encased in bone as they run through the vertebrae in the neck. As the two enter the brain, they join to form the basilar artery.
• The carotid arteries and the vertebrobasilar arteries join to form the Circle of Willis at the base of the brain and from this circle, arteries branch off to supply the brain with blood.

The left side of the brain controls the right side of the body and vice versa. Speech tends to be located in the dominant hemisphere, most often the left-brain.

The anterior and middle cerebral arteries provide blood supply to the front two-thirds of the brain, including the frontal, parietal, and temporal lobes. These parts of the brain control voluntary body movement, sensation, speech and thought, personality, and behaviour.

The vertebral and basilar arteries are considered the posterior circulation and supply the occipital lobe where vision is located, the cerebellum that controls coordination and balance, and the brainstem that is responsible for the unconscious brain functions that include blood pressure, breathing and wakefulness.

Strokes – What causes them and how to help prevent them

High blood pressure has long been pegged as a risk factor for stroke, but a new analysis suggests that even slightly elevated blood pressure levels raise the odds of suffering a stroke.

The sweeping review analyzed data from 760,000 study participants who were followed for up to 36 years. The researchers found that people with “prehypertension” — higher-than-optimal blood pressure not officially defined as high blood pressure — were 66 percent more likely to experience a stroke than those with normal blood pressure.

“This analysis confirms evidence from many studies, and I think it continues to warn physicians and the public that more vigorous control of blood pressure is important for reducing stroke risk,” said Dr. Ralph Sacco, chairman of neurology at the University of Miami Miller School of Medicine, who was not involved in the research. “The findings confirm that even mild to moderate levels of elevated blood pressure are important for determining stroke risk.”

According to the U.S. Centers for Disease Control and Prevention, stroke is a leading killer in the United States, causing about 130,000 deaths annually. Clots that stop blood and oxygen flow in parts of the brain trigger most strokes. High blood pressure defined as readings of 140/90 mm Hg or higher, affects about one of every three American adults, according to the American Heart Association.

For the new review, Chinese researchers from Southern Medical University in Guangzhou examined 19 separate studies on the risk of developing a stroke in those with prehypertension, dividing them into high and low groups that placed blood pressure levels over 130/85 mm Hg in the high range. Between 25 percent and 54 percent of study participants had pre-high blood pressure, which is higher than the optimal level of 120/80 mm Hg.

Nearly 20 percent of the strokes suffered by study participants were due to pre-high blood pressure, according to the study. Those in the high-range group were 95 percent more likely to develop a stroke than those with normal blood pressure, while participants in the low-range group were 44 percent more likely.

Results were the same even after researchers adjusted for other factors influencing stroke risk such as high cholesterol,  diabetes and smoking.

“A good point is, even if your blood pressure has been normal “If you see it creeping up, it’s time to start asking how you can get it down.”

Guidelines adjusting “goal” blood pressure levels for adults over 60 years of age (without diabetes or chronic kidney disease) from 140/90 or less to 150/90 or less.

Risk factors such as heredity and age might predispose people to higher blood pressure levels, but careful lifestyle choices can help keep levels under control.

“Losing weight, becoming more physically active and reducing sodium consumption are three key behaviours you can do to reduce blood pressure if you’re in the prehypertension range,” Sacco said. “If it can’t be controlled well enough, you’ll need to use medication. There are numerous excellent medications out there for blood pressure control, but it’s important to couple them with lifestyle changes.”

In the United States, about 400,000 people a year suffer from a stroke and up to 40% of these strokes may be fatal. The cost of strokes is not just measured in the billions of dollars lost in work, hospitalization, and the care of survivors in nursing homes. The major cost or impact of a stroke is the loss of independence that occurs in 30% of the survivors. What was a self-sustaining and enjoyable lifestyle may lose most of its quality after a stroke and other family members can find themselves in a new role as carers.

The most common risk factors for stroke are high blood pressure and increasing age. Diabetes and certain heart conditions, such as atrial fibrillation, are other common risk factors. When strokes occur in younger individuals (less than 50 years old), less common risk factors are often involved. These risk factors include drugs, such as cocaine or amphetamines, ruptured aneurysms, and inherited (genetic) predispositions to blood clotting. Another example of a genetic predisposition to stroke occurs in a rare condition called homocystinuria, in which there are excessive levels of the chemical homocystine in the body. Furthermore, scientists are trying to determine whether the non-hereditary occurrence of high levels of homocystine at any age can predispose to stroke. Another rare cause of stroke is vasculitis, a condition in which the blood vessels become inflamed. Finally, there appears to be a very slight increased occurrence of stroke in people with migraine headache.

Following are 5 warning signs of a stroke:

1. Sudden numbness or weakness of face, arm or leg, especially on one side of the body.
2. Sudden confusion, trouble speaking or understanding.
3. Sudden trouble seeing in one or both eyes.
4. Sudden trouble walking, dizziness, loss of balance or coordination.
5. Sudden, severe headache with no known cause.

If you or someone you know has these symptoms, contact a healthcare professional immediately!

Editor’s Note

The opinions, advice or proposals within the article are purely those of the author and do not, in any way, represent those of Cyprusscene.com