To understand how stroke occurs and the damage it can cause, it is useful to understand the basic anatomy of the brain. The signs and symptoms of a stroke depend on which region of the brain is affected and how severely.
The Cerebrum
The Cerebrum is the largest part of the brain and is made up of four distinct lobes: the frontal lobe, the temporal lobe, the parietal lobe and the occipital lobe. Each of these lobes has different functions, and some of these functions may overlap.
Frontal lobe – Involved in motor function, problem solving, spontaneity, memory, language, initiation, judgment, impulse control, and social and sexual behavior
Temporal lobe – Controls memory, hearing, and understanding of speech and allows a person to distinguish between sounds and smells
Parietal lobe – Controls sensory comprehension, interpreting taste, touch, temperature, pain, movement and orientation
Occipital lobe – Processes visual stimuli
The cerebrum can be anatomically divided into two parts; the right and left hemispheres. The right hemisphere controls the left side of the body, and the left hemisphere controls the right side. This aspect of brain anatomy explains why stroke symptoms often only affect one side of the body.
The Cerebellum
The cerebellum is located behind the brain stem. While the frontal lobe controls movement, the cerebellum “fine-tunes” movement. This area of the brain controls fine motor movement, balance, and the brain’s ability to determine limb position. A stroke in the cerebellum can lead to paralysis or "jerky" muscle movements.
The Brain Stem
Located at the top of the spinal column, the brain stem controls breathing, heart rate, blood pressure, and alertness. Brain stem strokes can disrupt breathing, causing sudden death.