Last month we talked about cardiovascular disease (heart disease); this month we are going to take a closer look at strokes.

What is the difference between a stroke and a heart attack?

A stroke affects the brain whereas a heart attack affects the heart. When I was a kid, I always heard about people having either or, but had no idea what either was.

All I knew was it wasn’t good. There are many similarities between the two conditions, but with proper lifestyle changes you can reduce your chance of having a stroke or heart attack.

A stroke occurs when there is an interruption of blood flow to the brain. This decrease in blood flow causes brain cells in the affected area to die.

Brain function is diminished and neurological symptoms become evident.

There are two types of strokes, ischemic and hemorrhagic. Ischemic strokes represent 80 per cent of all strokes.

During this type of stroke, there is a decrease in blood flow due to a blockage (plaques, blood clot, or embolus) of one of the arteries in the brain.

During hemorrhagic strokes, a blood vessel that supplies the brain ruptures, and there is uncontrollable bleeding in the brain.

The brain is the most complex organ in your body. It consists of over 100 billion neurons (a type of cell) and is responsible for everything you do, think and say.

It is the control centre of the body, and it initiates, interprets and regulates the entire body. Each part of the brain has a specific function.

Depending on where the stroke occurs in the brain, the activities associated with that area will inevitably be affected.

The brain is divided into three main areas, the brain stem, cerebellum and the cerebrum.

The brain stem is located at the bottom of the brain and connects to the top of the spine.

This part of the brain is associated with maintaining essential body functions that are autonomic. These body functions are done automatically (breathing, heartbeat, swallowing, and eye movements) without you consciously “thinking” about them. Strokes that occur in this part of the brain are usually fatal, due to the important functions it controls.

The cerebellum is a “lump,” that is also located at the base of the brain.

It is more posterior (back of skull) than the brainstem, but appears to be a part of it. This part of the brain is primarily associated with simple movements and balance.

The ability to pick objects up, walk, coordination and balance are controlled in this area.

A stroke here will result in clumsiness, lack of coordination, shaking and other movement disorders.

The cerebrum is known as the “thinking brain”, and is the largest of all the three parts.

The cerebrum contains many convoluted folds (twists and turns) of brain matter, that is synonymously associated with your image of a brain. This is where thinking and intellectual skills are performed. Motor control of muscles is also associated with this area.

The cerebrum is subdivided into halves (right and left hemisphere) and lobes. Each half physically looks identical to one another. But in most people the left hemisphere is more developed, thus dominant. The right hemisphere controls more artistic functions such as music, drawing and the ability to recognize faces. The left hemisphere is more mathematical and scientifically inclined. Calculations, mathematical skills, reasoning and the ability to understand language and the written word are controlled in this hemisphere.

Each hemisphere has four lobes which divides the brain into smaller more specific parts of the cerebrum. The frontal lobe is located at the front of the cerebrum and it controls motor functions (movements). The parietal lobe is behind (posterior) to the frontal lobe and it is concerned with sensory activities. The temporal lobe is behind your temples and is responsible for hearing, memory and auditory perception. The occipital lobe is the fourth and final lobe, and it is associated with vision. It is located at the back of the brain, above the cerebellum.

If a stroke occurs in the occipital lobe, the person will have problems with vision. If it occurs in the temporal lobe, hearing and memory will be affected. By knowing what is controlled where in the brain, you will be able to know where the stroke occurred.

Knowing the anatomy of the brain and what a stroke is will help you better understand why the changes in behaviour occur. Next month we will talk about the treatment, prevention and causes of stroke. Until next month, take care and drive safely!

– Dr. Jerry Singh, B. Kin., D.C., runs Trans Canada Chiropractic at 230 Truck Stop in Woodstock, Ont. He can be reached at 1 888 252-7327, or e-mail singhjerry@hotmail.com.