Migraines Are Unique Brain Disorder
By LAURAN NEERGAARD, AP Medical Writer
WASHINGTON (AP) - The pain of a migraine
can be so
intense
it's disabling.
Your head pulses, usually on one side,
for hours or
even days.
Moving worsens the throbbing.
You're nauseated,
sensitive to light and sound.
Sometimes you have an ``aura,''
seeing
pinpoints of light or other
visual disturbances
before the headache
hits.
Some 28 million Americans suffer this pain.
Yet half don't realize
that migraines -
and not some other headache -
are to blame,
and
millions go without treatment.
That's particularly disturbing to experts because,
in a revolutionary
shift, scientists are discovering
that migraines
are caused not by the
abnormal blood vessels
once blamed
but by a unique
electrical
disorder of brain cells.
The findings open new avenues
to attack
these tenacious headaches,
and suggest
treating migraines
is
important because
people
who
suffer very frequent attacks
seem
vulnerable
to physical changes
inside the brain
that could lead
to
chronic pain.
``We should probably be treating very quickly,''
Dr. K. Michael
Welch of the
University of Kansas
Medical Center in Kansas City,
whose neurological research is spurring
this
new view of
migraines,
told a recent meeting
at the National Institutes of
Health.
One-fifth of sufferers are candidates for medicines
that can cut
frequent attacks by half,
yet fewer than
1 million get preventive
therapy,
said Dr. Richard Lipton
of New York's Albert Einstein
College of Medicine.
Once a migraine hits,
only a fraction use
the
most powerful prescription treatments.
Why?
Too many primary care physicians
don't know
how to treat
migraines, specialists say.
At a recent seminar, only 45 percent
of family physicians shown
migraine symptoms
got the diagnosis right.
Plus, only one-third of
patients
have that classic
aura
before an attack
yet many doctors
erroneously think
no aura means no migraine, Lipton said.
Scientists once thought migraines were caused
by abnormally
dilated blood vessels.
Hence, many pain relievers work
by
constricting blood vessels.
But new imaging devices allow scientists
to watch patients' brains
during a migraine attack,
and they're discovering sufferers have
abnormally excitable neurons, or brain nerve cells.
When something triggers a migraine,
those neurons suddenly fire
off
electrical pulses at the back of the brain,
firings that ripple
across the brain's top
and then back down to the brainstem,
where
important pain centers are located,
Welch explains. This electrical
``wave''
spreads like water ripples when you
throw a pebble in a
lake.
In minutes, blood flow jumps, until the wave passes
and blood
flow
sharply drops.
The resulting pain comes from either
the brainstem activation or
blood vessels
inflamed by the rapidly changing blood flow - or both.
SOME FACTS ON MIGRAINES
- Total U.S. migraine prevalence was virtually the same
in 1999 (12.6
percent) as in 1989 (12.1 percent)
-
Current incidence (28 million) has
increased
since 1989 (24 million) with the growth in population.
-
Only 48 percent of respondents who met
the clinical definition of
migraine
report ever having had their condition
diagnosed by a
physician.
-
80 percent said their migraine headaches
were severe or extremely
severe,
and 24 percent reported seeking
emergency room care as a
result of an attack.
-
The new data show that one in every four U.S. households has a
migraine sufferer. This is 13 percent of the American population.
Despite significant advances in prescription
medications designed
specifically to treat migraine,
57 percent of migraine headache sufferers
report still using only over-the-counter (OTC)
medications
for treatment,
virtually the same percentage
as 10 years ago (59 percent).
While sufferers with a physician diagnosis
tend to have more severe
migraines
and report more symptoms versus
the undiagnosed, there is
a high level
of suffering reported by both groups:
THROBBING PAIN
(85 percent diagnosed
vs. 85 percent undiagnosed)
SENSITIVITY TO LIGHT
(89 percent diagnosed
vs. 72 percent undiagnosed)
PAIN ONE SIDE
(64 percent diagnosed vs. 55 percent
undiagnosed)
NAUSEA
(80 percent diagnosed vs.
66 percent undiagnosed)
Experiments in which scientists use a powerful magnet
to stimulate
neurons provide startling evidence
that some people's brains are
predisposed to
hyperexcitability. When people prone to
migraines
were stimulated, they literally saw spots
similar to a migraine's
aura.
One even went into a migraine as
spellbound scientists
watched.
But when people who don't get migraines
were
stimulated, their neurons weren't affected.
In real life what triggers these neurons?
Too much or too little
sleep, hunger, bright lights,
certain foods, women's fluctuating
estrogen levels.
Adding to the push for treatment,
very frequent migraine attacks
seem to physically change
the brainstem's pain centers, sometimes
leading to constant headaches, Welch says.
While scientists use the findings to hunt
better treatments, helpful
medicines
are already available.
Most notably, some drugs that fight epilepsy
by suppressing
abnormal neuron firings
- Depakote and Gabapentin -
also prevent
migraines, says Dr. Stephen Silberstein
of Thomas Jefferson
University Hospital in Philadelphia.
The four most powerful
prescription treatments, called ``triptans,''
shrink inflamed blood
vessels.
And women often are helped by adjusting
birth control or
hormone therapy
to stabilize estrogen levels.
The treatments aren't perfect.
But too many patients never see a
doctor,
or see one who follows the outdated practice
of trying less
powerful drugs first, Lipton says.
His advice: Don't give up -
if one
drug doesn't help, demand another.
Article and References - Lauran Neergaard covers health and medical
issues
for The Associated Press in Washington. &
Stewart, Lipton, et al.
"Journal of the American Medical Association",
1992, vol. 267, No. 1, pages 64-69.