Excerpted from the book:
Lipitor, Thief of Memory, by Graveline and Richardson.
( Currently in the publication process.)
Transient Global Amnesia (TGA) probably has been around as long as
man but the first reported case of this bizarre theft of memory was
made in 1955. TGA, simply put, is the sudden inability to formulate
new memory, known as anterograde amnesia, combined with varying
degrees of retrograde memory loss, sometimes for decades into the
past. Until recently, the most common trigger events for these
abrupt and completely unheralded amnesia cases have been sudden
vigorous exercise, sex, emotional crises, cold water immersion, head
trauma and cerebral angiography. In the past four years, however, a
new trigger agent has been added – the use of the stronger statin
drugs such as Lipitor, Zocor and Mevacor. Statin drug associated TGA
is now being seen with increasing frequency in emergency rooms
across the country. When one reviews the mechanism of action of
these cholesterol lowering agents, known collectively as HMG- CoA
reductase inhibitors, their potential for memory impairment becomes
very easy to understand.
My own introduction into the incredible
world of TGA occurred six weeks after Lipitor was started during my
annual astronaut physical at Johnson Space Center. My cholesterol
had been trending upward for several years and "the time had come"
according to my flight surgeon doctors. My dosage was 10 mg daily. A
blood study at six weeks showed my total serum cholesterol had
plummeted from 240 to 150 mg on this amazingly effective drug and
all was well until several days later when my wife found me
aimlessly walking about the yard after my usual walk in the woods
that morning. I did not know WHO she was, AND I reluctantly accepted
cookies and milk but refused to go into my now unfamiliar home.
Somehow she got me to my family doctor and later that day to a
neurologist who found my examination normal except for the amnesia
and made the diagnosis of TGA, cause unknown. About six hours after
its onset and while in the office of the neurologist the condition
abruptly passed and I felt well enough to drive home while my wife
related this incredible tale of how I had spent my day. The MRI
several days later was normal. Since Lipitor was the only new
medicine I was on, the doctor in me made me suspect a possible side
effect of this drug and, despite the protestations of the examining
doctors that statin drugs did not do this, I stopped the drug. The
year passed uneventfully and soon it was time for my next astronaut
physical. NASA doctors joined the chorus I had come to expect from
physicians and pharmacists DURING THE ENSUING year, that statin
drugs did not do this and at their bidding I reluctantly restarted
Lipitor at one-half the previous dose. Six weeks later I again
descended into the black pit of amnesia, this time for twelve hours
and with a retrograde loss of memory back to my high school days.
During that terrible interval, when my entire adult life had been
eradicated, I had no awareness of my marriage and four children, my
medical school days, my ten adventure filled years as a USAF flight
surgeon, my selection as scientist astronaut or of my post
retirement decade as a writer of medical fiction. The names of my
books - like the names of my children – WERE gone from my mind as
completely as if they had never happened. Fortunately and typically
for this obscure condition my memory returned and again I drove home
listening to my wife's amazing tale of how my day (and hers) had
gone. She said that if I asked her once, "What IS happening?", I
must have asked her ten thousand times during that terrible period
when all recall was lost.
It was then after this retrograde loss
during which time my "teenage" brain told me I had never been
married, had no children, had never been to medical school and knew
nothing of the space program that I first posed the question, "What
if I had been flying my taildragger at the time? My flight
instruction had come during my ten years as a USAF flight surgeon.
If my ability to pilot an aircraft had been eradicated by this
event, what might have been my reaction? How could I ever have
brought it in for a safe landing? My personal conviction is that
since my technical skills and training had vanished during this 35
year period, I probably would have panicked and crashed! What
alternatives existed? With total amnesia of my life during my flight
training period, I knew nothing of flying. The same could be said
for my medical training or my status as a father of four. My
adolescent brain would have laughed at the joke being played on my
mind. The more I thought about this, the more convinced I became
that this was an issue of major concern to others. I had been a USAF
flight surgeon for ten years, an Army flight surgeon to a helicopter
squadron for fourteen additional years and an FAA aviation medical
examiner throughout the entire time period. No one was in a better
position to pose the question of the potential for statin associated
amnesia than a flight surgeon who had experienced it.
How much of previously learned behavior
persists during an attack of transient global amnesia? What does the
medical literature reveal? Unfortunately, my review of the existing
case reports is far from reassuring as to the question of retention
of specific learned skills during an episode of TGA. Riding a
bicycle is a skill usually preserved because rarely does a
retrograde element extend that far back into a person's past life.
Driving an automobile also is a skill usually maintained in our TGA
episodes simply because it was learned early on. Many cases of
people with TGA tell of their touringthe country in their mysterious
auto journey, stopping as usual for gasoline and other necessities
but when once home and confronted with credit card evidence of
purchases and travel, they deny vehemently that they ever could have
done such a mad thing. Their amnesia for the trip is complete but
their ability to operate a motor vehicle is preserved. A bicycle
repair man steadfastly continued to repair bicycles throughout his
TGA attack, oblivious to the loss of all recent events in his life
including his recent marriage and new wife. A ballroom dancer
continued to glide about the floor with almost no hitch except to
his perceptive associate who recognized his friend had abruptly
reverted to old dance steps learned many years previously. During
his attack the retrograde component of his TGA had wiped out those
steps learned in the past recent months. Similarly, a man fluent in
English reverted to Spanish, the language of his childhood, during
his TGA attack. He had lost English completely.
Although a literature review reveals no
specific instances of TGA while flying, the inference is inescapable
- unless the TGA victim had learned the essential of flying very
early on, the ability to pilot an aircraft might be lost completely
during an event. Even if the airline or military pilot involved did
have light aircraft training in his younger days, with abrupt onset
TGA, he would hardly be equipped to handle the incredible shock of
suddenly "awakening" to the totally unfamiliar controls of a
multi-engine jet transport, F-14 fighter or Apache helicopter where
such specific training had come many years later and now finding
himself in the "black zone" of a retrograde TGA episode. The outcome
of such an event would likely be disaster. One wonders how many
"pilot error" aircraft accidents just might have a TGA factor since
there would be complete absence of clues to the investigative board.
This potential problem of statin drug
associated memory dysfunction while flying is further confounded by
the reality that amnesia is but the tip of the iceberg of the many
other forms of memory lapses that occur far more commonly. An
increased tendency for disorientation, confusion and forgetfulness
can be easy to miss in many individuals, for a certain degree of
this is in the nature of all of us. And although I have focused this
presentation directly on pilots and, by inference, flight crews,
what of commercial truck and bus drivers and heavy equipment
operators? What about the operators of dangerous tools? The list is
limited only by one's imagination.
As to recommendations, at the very least, patients on statin drugs
and their prescribing doctors must be informed of the potential for
impaired brain function. Vigilance on the part of both patient and
doctor can only be helpful and may spot a tendency for memory lapses
early but Even this can hardly be expected to foresee TGA, which
customarily strikes with no warning. It is hardly reassuring that
although most of the cognitive case reports occur soon after the
statin drug is started or an increase in dosage is made, some of
worst cases have occurred after several trouble free years on a
fixed dosage. One can only caution against the current tendency for
ever increasing use of statin drugs for primary prevention such as
we now see in both military and civilian pilots. The mind-robbing
potential of this class of drugs is not only theoretical - it is
real. Responsible physicians must take heed.
Duane Graveline MD MPH
Former USAF flight surgeon
Former NASA astronaut
Retired family doctor
June 2003
