A stroke occurs when the blood supply to part of the brain is interrupted, causing brain cells to die from a lack of oxygen and nutrients. Strokes can occur in any part of the brain, including the right cerebral hemisphere, leading to a right hemispheric stroke. The resulting effects depend on the area of the brain affected and how quickly medical intervention occurs.
Understanding Stroke Location
Strokes are generally categorized into two main types: ischemic and hemorrhagic, and either type can affect the right hemisphere. An ischemic stroke, the most common type, occurs when a blood vessel supplying the brain becomes blocked, often by a blood clot or plaque buildup. This blockage prevents blood from reaching the brain tissue, causing cell death.
A hemorrhagic stroke, accounting for a smaller percentage of cases, happens when a blood vessel in the brain leaks or ruptures, causing bleeding into the surrounding tissue. This bleeding damages cells by depriving them of blood flow and causing pressure buildup. Regardless of the type, the location of the damage determines the specific effects experienced by the patient. The brain functions on a contralateral principle, meaning the right hemisphere controls movement and sensation on the body’s left side.
The Unique Effects of Damage to the Right Hemisphere
Damage to the right hemisphere results in distinct symptoms, beginning with motor and sensory deficits on the left side of the body. This is typically seen as weakness or paralysis, known as hemiparesis or hemiplegia, affecting the face, arm, and leg on the left. The right brain is also specialized in processing spatial and visual information, so a stroke here often causes severe deficits in these areas.
A hallmark of a right-sided stroke is hemi-spatial neglect, where a person is unaware of or ignores the left side of their body and the left visual field. This is not a vision problem but a profound attention deficit. It can be severe, causing a person to ignore objects, people, or even food on the left.
Right hemisphere damage frequently leads to changes in emotion and behavior, including impulsivity and poor judgment. Patients might struggle to process non-verbal cues and have difficulty recognizing emotions in others. They may also experience anosognosia, an unawareness or denial of their own deficits. Spatial difficulties extend beyond neglect to problems with depth perception, judging distances, and navigation.
How Right-Sided Strokes Differ from Left-Sided Strokes
The key difference between right-sided and left-sided strokes lies in the functions predominantly controlled by each hemisphere. For most people, the left hemisphere is the dominant side for language, meaning a stroke there often causes aphasia, a difficulty in speaking or understanding language. Conversely, a right-sided stroke typically spares the core language centers, so patients usually do not develop aphasia.
Instead of affecting the words themselves, a right hemisphere stroke may impair the ability to understand the tone or prosody of speech, making it hard to grasp humor or sarcasm. Behavioral differences are also notable; patients with right-sided damage often display quick, impulsive behavior and a lack of insight into their physical limitations. In contrast, patients with left-sided strokes are often more cautious and may become depressed due to their acute awareness of their language loss.
Emergency Response and Rehabilitation
The urgency of a stroke is not determined by its location, and recognizing the signs and calling for immediate help is paramount. The FAST acronym (Face drooping, Arm weakness, Speech difficulty, Time to call) provides a simple way to recognize a stroke. Emergency medical services can begin life-saving treatment on the way to a specialized stroke center.
Rehabilitation after a right-sided stroke focuses on addressing unique cognitive and motor challenges, including physical, occupational, and speech therapy. Therapy must specifically target the management of left-sided neglect to draw attention toward the neglected space. Managing the patient’s impulsivity and lack of awareness is also a major focus for the rehabilitation team to ensure safety and cooperation.