Transferability of Animal Results To Human Stroke
Although multiple therapies have proven to be effective in animals, only very few have done so in human patients. Reasons for this are (Dirnagl 1999):
- Side effects: Many highly potent neuroprotective drugs display side effects which inhibit the application of effective doses in patients (e.g. MK-801)
- Delay: Whereas in animal studies the time of incidence onset is known and therapy can be started early, patients often present with delay and unclear time of symptom onset
- “Age and associated illnesses: Most experimental studies are conducted on healthy, young animals under rigorously controlled laboratory conditions. However, the typical stroke patient is elderly with numerous risk factors and complicating diseases (for example, diabetes, hypertension and heart diseases)” (Dirnagl 1999)
- Morphological and functional differences between the brain of humans and animals: Although the basic mechanisms of stroke are identical between humans and other mammals, there are differences.
- Evaluation of efficacy: In animals, treatment effects are mostly measured as a reduction of lesion volume, whereas in human studies functional evaluation (which reflects the severity of disabilities) is commonly used. Thus, therapies might reduce the size of the cerebral lesion (found in animals), but not the functional impairment when tested in patients.
Read more about this topic: Animal Models Of Stroke
Famous quotes containing the words animal, results, human and/or stroke:
“The animal merely makes a bed, which he warms with his body, in a sheltered place; but man, having discovered fire, boxes up some air in a spacious apartment, and warms that.... Thus he goes a step or two beyond instinct, and saves a little time for the fine arts.”
—Henry David Thoreau (1817–1862)
“Consider what you have in the smallest chosen library. A company of the wisest and wittiest men that could be picked out of all civil countries in a thousand years have set in best order the results of their learning and wisdom. The men themselves were hid and inaccessible, solitary, impatient of interruption, fenced by etiquette; but the thought which they did not uncover in their bosom friend is here written out in transparent words to us, the strangers of another age.”
—Ralph Waldo Emerson (1803–1882)
“I know that human good fortune never remains in the same place.”
—Herodotus (c. 484–424 B.C.)
“As the artist
extends his world with
one gratuitous flourish—a stroke of white or
a run on the clarinet above the
bass tones of the orchestra ...”
—Denise Levertov (b. 1923)