How stroke effects
your brain

Only a few minutes of lost blood flow can damage the electrical signal receptors in the brain

According to the Centers for Disease Control and Prevention (CDC), every year, more than 795,000 people in the United States have a stroke. Of those cases, about 140,000 Americans are killed by stroke each year — that’s 1 out of every 20 deaths. Many myths make stroke a life-threatening health emergency. One common misbelief is that strokes only happen to older people. “Stroke can affect all segments of life, all ages, even from childhood through adulthood,” says Dr. Alan Boulos. Dr. Boulos is Chair of the Department of Neurosurgery, Director of the Neurovascular Section, and Associate Professor of Neurosurgery and Radiology at Albany Medical Center. He has invested over 20 years researching and studying disorders of the brain and spine including stroke. He joined me recently for a special episode of HeartTalk presented by Capital Cardiology Associates that explored the effect of stroke on the brain.

There was concern from the medical community on the severe drop in visits to the emergency department (ED) in April, due to COVID-19 concerns. Hospitals outside of the pandemic hotspots, like Albany, reported almost a 50% reduction in patients seeking critical care. This was alarming to cardiologists, neurologists, ED physicians, and advance care providers who noted that patients were delaying care for serious conditions like stroke or transient ischemic attacks (TIA), otherwise known as ministrokes. Ministrokes, as they are commonly called, are brief interruptions of blood flow to the brain due to clots. “These are a harbinger of bad things that could come,” Dr. Boulos commented. According to the CDC, over a third of people who experience a ministroke have a major stroke within a year if they do not receive any treatment. In the case of a ministroke, a patient may experience the classic stroke warning signs: weakness on one side of the body, vision problems, and slurred speech. Dr. Boulos explained common ministroke scenarios that could last minutes to hours. “You may suddenly drop your coffee mug because the dexterity is not there in your hand. You may temporarily lose vision or have a gray blur in your eyesight while watching TV or reading. That was an event! It’s a sign of things that could come.”

What is a stroke?

When we think of blood flow in our body, we often think of our heart as the pump that circulates blood through our vascular system. Dr. Boulos reminds patients on the importance of blood flow to the brain. “The brain is very dependent on oxygen and blood flow, more than any other organ in the body. It takes about one-fifth of our blood flow every time the heartbeats.” Dr. Boulos defines a stroke as a condition that brings a sudden change in someone’s neurological function. The term comes from an old Greek phrase meaning someone has been struck by God. “In most cases, stroke occurs when blood flow to the brain is interrupted or blocked off either by a clot or by plaque, and that results in the brain to stop working,” he added. During a common (ischemic) stroke, patients may have trouble walking, speaking, and understanding, as well as paralysis or numbness of the face, arm, or leg. “Where the brain is affected will determine what symptoms are presented. The less common variety is the opposite,” noted Dr. Boulos. A hemorrhagic stroke is when an artery in the brain leaks blood or breaks open. In these events, the artery in the brain bursts or there is bleeding in the area between the brain and the thin tissues that cover it. “When blood sits outside the brain in the skull, that can be a life-threatening event.”

One of the challenges with stroke is that it can happen at any time to anyone. “When a stroke occurs, it has symptoms that vary from patient to patient. It can be anything from a speech problem to a blind spot developing on the right or left side of your field of vision, causing a car accident.” shared Dr. Boulos. Heart attacks traditionally present with chest pain, pressure, or shortness of breath — only about 30 percent of people will have a headache with an ischemic stroke, so pain isn’t a reliable symptom. This is why stroke is the leading cause of disability in adulthood and is the number five killer in the US. As a neurologist, Dr. Boulos detailed how stroke affects the brain. “Patients often can describe when the symptoms do begin. But there is also part of the brain that controls the recognition of those symptoms, the parietal lobe; it’s related to neglect. If stroke targets that part of the brain, we won’t recognize that our right hand is part of our body. Even if our right hand may not be working, we don’t recognize that it is a problem. As part of the stroke, it may cause symptoms that prevent us from recognizing the problem. That is why our friends, family, co-workers, and the people around us are so important. They can recognize when the victim is not behaving properly. That is a clear sign that person needs medical care!”

Mind figurine

Brain damage and recovery

Scientists at the Brain Research Centre at the University of British Columbia and Vancouver Coastal Health Research Institute found that damage to the brain can happen as soon as three minutes following a stroke. As a neurosurgeon, Dr. Boulos plays an important role after the stroke has occurred. “We often get involved in the hospital to try and manage that patent. To try and reverse the stroke or at least perform procedures that minimize the damage that the event has caused,” he shared. The extent of what we know about brain damage from stroke has evolved greatly over the years. “In the old days we used to think that the brain didn’t have the ability to produce cells, it didn’t recover once it was injured, or at best, it was poorly able to recover. That has largely been wrong.”

Your brain is divided into left and right halves, called “hemispheres.” They specialize in different things. Because of this, a stroke on the left side of your brain can be very different from a stroke on the brain’s right side. Let’s look at some symptoms of a left-brain stroke.

The American Stroke Association states that the effects of a stroke depend on several factors, including the location of the obstruction and how much brain tissue is affected. Stroke on the left side of the brain, for example, will affect the right side of the body and vice versa. One significant difference is that left-brain patients may have a slow, cautious behavioral style and speech/language problems, while right-brain patients may have a quick, inquisitive behavior and vision problems. If the stroke occurs in the brain stem, it can affect both sides of the body, and patients may be unable to speak or move below the neck. “I think it’s about rewiring synapses, the tiny brain switches that relay information from one neuron to another,” said Dr. Boulos. “The brain is a complicated electric organ/system. If the connections can be re-established, if other parts of the brain can take over function, then we can see patients recover their abilities despite their being an area of the brain that was damaged.” What is common for stroke patients are physical challenges, communicating clearly, or changes in their emotions or mood.

Let’s explore some symptoms of a right brain stroke.

Grandparents with baby

It is encouraging that recovery from a stroke event is possible; this involves dedication to rehabilitation and time. While a stroke can leave a patient disabled over a lifetime, there is a good opportunity, especially in the beginning, for rehab and recovery. Part of the problem is that this occurs very slowly, up to two years in some cases. Due to the severity of the stroke, there may not be a dramatic improvement in other patients. “I have patients who have committed to the rehab process who have been able to get better over time. How that happens within the brain is poorly understood. When you look at the image of the brain, you will see areas that are damaged by the stroke. We don’t see much change over time,” mentioned Dr. Boulos. “There is also very hopeful research around stem cells and other infusions that might accelerate the recovery process for patients that have suffered from stroke. This is still very much in the early phase, but I am very optimistic about this work.”

Written by Michael Arce, host of HeartTalk presented by Capital Cardiology Associates.

Photos by David Cassolato, Jake Ryan, and meo from Pexels