Travel Reference
In-Depth Information
such discrimination. (A physician should examine participants in expeditions beforehand
so hypertension or other disorders predisposing to strokes can be detected and treated.)
Although many persons survive strokes, frequently with surprisingly little or no disab-
ility, the prognosis is still serious, particularly at high altitudes where cold and reduced at-
mospheric oxygen add to the stress.
The symptoms of stroke are distinct because they happen quickly and include the fol-
lowing, depending upon which portion of the brain is involved:
The sudden onset of numbness or weakness of the face, arm, or leg, particularly on one
side of the body
The sudden onset of confusion, trouble speaking, or trouble understanding speech
The sudden onset of impairment of sight in one or both eyes
The sudden onset of difficulty walking, dizziness, loss of balance, or loss of coordina-
tion
The sudden onset of a severe headache with no known cause
The sudden onset of personality changes such as combativeness, indecisiveness, or ir-
ritability
Moreseverestrokesmaybeprecededbyaheadache,butunconsciousnessfollowsfairly
quickly and rapidly progresses to a deep coma in which no response to any stimuli can
be elicited. (These events may take place almost instantaneously.) Breathing is noisy and
maybeveryirregular(Cheyne-Stokesrespirations).Paralysisisusuallypresent,mostcom-
monly affects one side of the body, and may include the face as well as the extremities.
However, paralysis is difficult to evaluate if the individual is comatose.
The recommended course of action for anyone suspected to be having the onset of a
stroke in an accessible location is to have the person transported to an emergency care cen-
ter as quickly as possible. At the center the individual could be immediately treated with
tissueplasminogenactivator(tPA)todissolvethebloodclotwithinanartery.However,tPA
is effective only when administered within the first three hours after the onset of a stroke.
For persons in wilderness situations, evacuation within that time is commonly impossible.
Regardless of the severity of symptoms, anyone with a stroke should be evacuated to
lower altitude without delay. Oxygen should be administered at altitudes above 8000 feet
(2400 m). An open airway must be maintained if the individual is unconscious. Elevated
blood pressure should be treated if medications are available. After a lower elevation is
reached, a conscious individual with hypertension should rest for several days. A physi-
cian's care is essential. Such recovery as will occur requires months.
Transient Ischemic Attack
A transient ischemic attack (TIA) is an episode in which an individual develops symp-
toms identical to those of a stroke, but the symptoms disappear. By definition, the symp-
toms of a TIA disappear within twenty-four hours, but for most individuals the symptoms
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