Citing an outdated medical definition of the 1950s and 60s that may
prevent thousands at risk for stroke from getting appropriate evaluation
and treatment, a group of eight recognized stroke experts, including a
University of Nebraska Medical Center neurologist, have recommended a change
of the definition for transient ischemic attack (TIA). The group has published
a consensus statement in the Nov. 21 issue of the New England Journal of
Medicine.
TIA, also referred to as a mini-stroke or minor stroke, is defined
by sudden, temporary stroke-like symptoms with no resulting permanent brain
damage, which last less than 24 hours. Experienced by about 2 million people
in the United States annually, TIAs are under-recognized, under-reported
and under-treated and flag persons at high risk for having a stroke, said
Pierre Fayad, M.D., Reynolds Centennial Professor and chairman of the UNMC
Department of Neurological Sciences, whos been studying stroke for 14
years and is part of the eight-member group.
Dr. Fayad said more than 10 percent of people who experience TIAs develop
a stroke within the following 90 days, and half of the strokes will happen
within 48 hours after the TIA. Dr. Fayad said its imperative that patients
seek immediate treatment for stroke-like symptoms, even if the symptoms
resolve within the first few minutes or hours.
When the current definition was created, it stated TIAs will resolve
in 24 hours, even though there was evidence that most would resolve within
the first hour, Dr. Fayad said. Other reasons for a redefinition of TIAs
are sophisticated medical technology, new drugs and greater knowledge of
TIAs and strokes.
Not only has the public been conditioned by the definition to wait and
see if stroke-like symptoms resolve within the current defined 24 hours,
many health professionals reinforce the idea. Some patients are told to
watch their symptoms and asked to come to the emergency room only if their
symptoms do not resolve. Thats a lot of time, Dr. Fayad said.
We are saying most TIAs will resolve within an hour, but even if someone
has a TIA, clinically, they may still have stroke resulting in permanent
damage to the brain, Dr. Fayad said. TIA should be considered exactly
like a stroke until proven that its not a stroke. Anyone with symptoms
should come to the ER. The symptoms of whether its a TIA or a stroke should
be left up to the physician who evaluates them.
He said TIA is a serious disease thats not being taken seriously enough,
not only by physicians and the lay public, but also some insurance companies
that refuse to pay for admissions to the hospital after a TIA, because
they feel its unnecessary. Evaluating people whove had a TIA and finding
out the cause is crucial, he said.
We are much more savvy and now have better tools at preventing and
treating stroke, Dr. Fayad said. Back then, when the initial definition
of TIA was crafted, there was no tissue plasminogen activator (tPA), no
magnetic resonance imaging (MRI), no computerized axial tomographic scan
(CAT scan) nor magnetic resonance diffusion. In most cases, the only way
physicians could evaluate stroke was to examine the patient and at most
do an angiogram.
The advent of MR diffusion in the last three to four years has added
fuel to the debate. We know that over half of patients who have a TIA have
changes on their MRI that suggest stroke. MRI diffusion can tell us within
minutes where there is a lack of blood flow in the brain. Even for those
whose TIAs resolve, it may tell us where that lack of blood flow happened,
whereas initially, all physicians had to rely on was what the patient told
them.
Dr. Fayad hopes the consensus statement will trigger a change in attitude
of health professionals and the lay public, so people having stroke symptoms
or a brain attack go to the emergency room as soon as possible and not
wait.
Stroke is a bad disease because, you can have a heart attack and still
look normal, Dr. Fayad said. You can have surgery to your belly and still
look normal. Once you have a stroke, it shows to everyone else around you
either in minor signs where your face is a little weak or your hand is
a little weak or in major signs where you are disabled.
Of the people who’ve had one or more TIAs, its estimated that more
than a third will later have a stroke, according to the American Heart
Association. Dr. Fayad said in a recent study, researchers found 15 percent
of patients who came to the ER with a TIA ended up having a stroke or another
TIA within the following several weeks.
TPA, a drug approved by the FDA in 1996, improves the odds of being
cured from stroke by 30 percent if given within three hours from the onset
of symptoms. TPA prevents stroke by dissolving clots. Most strokes are
due to clots.
It means the patient has to arrive at the emergency room, at most,
within two hours to be able to receive tPA, which doesnt happen most of
the time, and this is why tPA is only given in about 2 percent of all patients
who have stoke in the nation, Dr. Fayad said. You cant give tPA after
three hours because it increases the risk of complications.
If the definition of TIA remains the same, then patients would be encouraged
to stay at home to find out if its going to resolve or not on its own,
and not come to the ER, and that creates more delay. Unfortunately, by
the time they realize it did not resolve, and make it to the emergency
room, it will be too late, and they cannot get treatment.
Dr. Fayad said it has become imperative to try to avoid confusing patients
and doctors with arbitrary definitions and making patients wait at home,
miss a treatment or not be treated appropriately.
Stroke deprives some people of their independence, he said. You cant
shop, cant visit friends, cant eat, cant swallow, cant see, cant talk
and cant speak. It essentially deprives us of most of what defines us
as human beings.
Symptoms of a brain attack or TIA are: sudden numbness or weakness
of the face, arm or leg, especially on one side of the body; sudden confusion,
trouble speaking or understanding; sudden trouble seeing out of one or
both eyes; sudden trouble walking, dizziness, loss of balance or coordination;
and sudden, severe headache with no known cause.
In 1999, 167,366 people in the United States died from stroke (one in
every 14.3 deaths in the U.S.) according to the American Heart Association.
About 47 percent of the deaths occurred outside the hospital. Stroke, the
leading cause of death behind diseases of the heart and cancer, also is
the leading cause of serious, long-term disability in the U.S.
Strokes cause damage to the brain either due to lack of blood flow,
either from a clot or leakage of blood into the brain. Most who have strokes
are over age 65 and about 20 percent happen in patients under 55, even
children. Arteriosclerosis (hardening of the arteries) is one of the main
causes of stroke, Dr. Fayad said.