Understanding a stroke prognosis
No two strokes are exactly alike, but they all have one thing in common: A stroke almost always causes some brain damage. How much damage depends on the type, location, duration, and severity of the stroke. And the extent and location of damage is what largely determines the stroke prognosis -- the chance for survival or quality of life down the road.
When someone survives a stroke, the big question on everyone's mind is what the stroke survivor's life will be like. What types of physical problems will she have? How seriously disabled will she be? Will she be able to speak? Walk? Live on her own?
It's important to keep in mind that there's no magic formula for predicting the outcome, nor is there a set timeline for recovery. But there's reason for hope: Although up to 30 percent of stroke survivors suffer some permanent disability, more than half recover functional independence after a stroke.
Ischemic Versus Hemorrhagic Stroke
When considering stroke prognosis, in general, people who have ischemic strokes (caused by a blood clot) have a better chance of surviving than those who have hemorrhagic strokes (caused by a ruptured blood vessel). That's because hemorrhagic strokes have the potential to cause more damage to the brain. When a blood vessel ruptures inside the brain, the bleeding not only destroys brain cells but it can result in other serious complications, including increased pressure on the brain and spasms of other blood vessels.
But there's good news for hemorrhagic stroke survivors: Studies suggest that people who survive hemorrhagic strokes have a greater chance of recovering function than those who have survived ischemic stroke.
Evaluating a Stroke by National Institutes of Health (NIH) Guidelines
The NIH has developed a scoring system called a stroke scale that helps predict the severity and outcome of stroke. It's a complicated formula that includes 11 different factors measured during a neurological exam:
- Level of consciousness
- Visual field
- Facial movement
- Motor function in arms
- Motor function in legs
- Sensory loss
- Language problems
- Ability to articulate
Each impairment noted during the exam is assigned a certain number of points, so the higher the score, the worse the stroke:
0 No stroke
1 – 4 Minor stroke
5 – 15 Moderate stroke
15 – 20 Moderate to severe stroke
21 – 42 Severe stroke
Up to 70 percent of stroke patients who score less than 10 have a favorable outlook after a year, while less than 16 percent who score more than 20 do well.
Avoiding Another Stroke and Dealing With Uncertainty
Probably the most important factor affecting a person's future after a stroke is whether she has another stroke. There are two important factors to consider:
- Having already had one stroke increases the risk of having another.
- The risk for another stroke is highest within the first few weeks and months.
It's always important to do everything possible to prevent a future stroke.
The future after a stroke isn't always clear. There are many things that affect stroke prognosis, including impossible-to-measure factors such as how the brain heals and rewires itself. One of your most challenging tasks as a caregiver looking at stroke prognosis will be coming to terms with uncertainty about the future -- and helping the person in your care do the same.