Stroke. Warning Signs and How it Affects the Brain

Strokes can range from mild to severe. They affect so many different parts of the brain that the resulting functional implications can vary. In order to receive medical care as soon as possible to minimize the effects, it is important to learn the warning signs of a stroke. Knowing parts of the brain affected in your stroke will help you understand why you function the way you do.

A stroke occurs when the blood supply to part of the brain is decreased or interrupted, preventing the brain cells from obtaining much-needed nutrients and oxygen. Brain tissue begins to die within minutes. A stroke is deemed a medical emergency, and immediate treatment is critical. An early response can minimize damage to the brain and other complications. For every 30-minute delay, the relative likelihood of surviving a stroke with no deficits decreases by 15 %.

Sudden warning signs of a stroke

  • The onset of numbness, weakness, or paralysis of the face, arm, or leg. Often affects only one side of the body. A raised arm may drift downward, and the mouth may droop. Ask them to smile.
  • Trouble speaking, slurring words. Difficulty understanding speech and or confusion. Ask the person to repeat a short sentence, “Remember the Alamo.” Can they repeat the sentence correctly?
  • Difficulty seeing in one or both eyes. Blurred vision or double vision.
  • Severe headache with no known cause. It may be accompanied by vomiting or a change in the level of awareness.
  • Difficulty walking. Stumbling or losing balance. Sudden dizziness or a loss of coordination.

Stroke anacronym

A good way to catch a stroke in time is to follow the BEFAST mnemonic.

Originally the mnemonic used to be FAST, standing for:

F - facial drooping,

A - arm weakness,

S - speech difficulties,

T - time to get help, call 911 or get to the hospital.

This mnemonic has been used by the National Stroke Association, American Heart Association, and others to teach the public about decerning the warning signs of a stroke. FAST was first introduced in 1998 in the United Kingdom.

A study in 2017 entitled BEFAST (Balance, Eyes, Face, Arm, Speech, Time) as reducing the proportion of strokes missed using the FAST mnemonic. The suggested additions were:

B - balance impairment,

E - sudden changes in vision in one or both eyes like blurriness, double or total absence of vision.

They ascertained that of the patients with stroke with deficits perhaps amenable to quick intervention, 14% were not identified using FAST. The study also determined that revision of the mnemonic to include ambulation/leg and visual symptoms reduced missed strokes to 4%.

Types of strokes

According to WebMD, there are 5 types of strokes:

  1. ischemic stroke (lack of oxygen to the brain due to a blood clot)
    1. thrombolytic – a blood clot that forms in an artery that supplies blood to the brain
    2. embolic – a blood clot forms somewhere else in the body, travels through the blood vessels to the brain, and gets stuck there, stopping the flow of blood
  2. hemorrhagic stroke – bleeding in the brain damages nearby cells
  3. transient ischemic attack (TIA) mini-stroke – a temporary blockage of the blood flow to the brain lasting a few minutes, up to 24 hours
  4. cryptogenic stroke (stroke of unknown origin)
  5. brainstem stroke – this stroke happens in the part of the brain called the brainstem; a typical stroke usually only affects one side of the body, but a brainstem can affect both sides resulting in a “locked-in state” concerning movement.

Prevalence of stroke

According to the Center for Disease Control:

  • In 2018, 1 in every 6 deaths from cardiovascular disease was due to stroke.
  • Someone in the United States has a stroke every 40 seconds. Every 4 minutes, someone dies of a stroke.
  • Every year, more than 795,000 people in the United States have a stroke. About 610,000 of these are first or new strokes.
  • About 185,000 strokes—nearly 1 of 4—are in people who have had a previous stroke.
  • About 87% of strokes are ischemic strokes, in which blood flow to the brain is blocked.
  • Stroke-related costs in the United States came to nearly $46 billion between 2014 and 2015. This total includes the cost of health care services, medicines to treat stroke, and missed work days.
  • Stroke is a leading cause of serious long-term disability. Stroke reduces mobility in more than half of stroke survivors aged 65 and over.

Modifiable and non-modifiable risk factors

Modifiable Risk FactorsNonmodifiable Risks Factors
High blood pressure/hypertension (higher than 140/90)Age (risk of stroke increases as we age)
SmokingFamily history of a stroke
DietRace/ethnicity (risk is higher in African American, Hispanic, and Native American versus Caucasians)
Physical InactivitySex (men have more strokes than women, but women have more deaths due to stroke)
High cholesterol (aim for 70 mg/dL LDL/bad cholesterol)History of previous TIA
Being overweight
Heart disease
Diabetes (keep fasting blood sugar 80-120 mg/dL)
Alcohol (more than 1/day)
Coronary artery disease
Illegal drug use

The parts of the brain affected in a stroke

A stroke usually affects:

  • Frontal lobe – higher cognitive functions (think, understand, judge, problem-solve, learn), motor control, emotional traits, and expression
  • Parietal lobe – processing sensory input, sensory discrimination, body orientation, primary and secondary somatic area (touch, pain, temperature, position of body in space)
  • Temporal lobe – auditory reception/ hearing, expressed behavior, receptive speech, visual memory, language comprehension
  • Occipital lobe – visual reception, visual interpretation, color perception
  • Cerebellum – coordination, control of body movements/balance, fine motor control
  • Brainstem – alertness, breathing, digestion, heart control, blood pressure control, body temperature

The right hemisphere (side) of the brain controls the left side of the body, and the left hemisphere of the brain controls the right side of the body. The opposite side of the brain controls movement and sensation for one side of the body. This means that if your stroke affected the left side of your brain, you would have problems with the movement and feeling on the right side. The left side is the brain's academic, analytical, and logical side, while the right is the artistic, intuitive, and creative side.

There is no better side to having a stroke. Both hemispheres are connected by a corpus callosum structure that allows communication between the two.

Key take-aways

A stroke is a medical emergency and there are many kinds of stroke.

Strokes are very prevalent and are the leading of long-term disability.

You can modify many risk factors that can result in a stroke.

It depends on the part of the brain involved and how your functioning will be affected.

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