By Duane Graveline, M.D., M.P.H.
My personal introduction to the incredible world of transient global amnesia (TGA) occurred six weeks after Lipitor® - atorvastatin - was started during my annual astronaut physical at Johnson Space Center. My cholesterol had been trending upwards for several years.
All was well until six weeks later, when my wife found me walking aimlessly about the yard after I returned from my usual walk in the woods. I did not recognize her, and only reluctantly accepted cookies & milk, but refused to go into my now unfamiliar home.
I "awoke" six hours later in the office of the examining Neurologist with a diagnosis of transient global amnesia, cause unknown. An MRI performed several days later was normal. Since Lipitor was the only new medicine I was taking, the doctor in me suspected a possible side effect of this drug. Despite the arguments of the examining doctors that statin drugs just did not do this, I stopped my Lipitor.
The year passed uneventfully and soon it was time for my next astronaut physical. NASA doctors joined in the chorus I had come to expect from physicians and pharmacists during the preceding year that statin drugs just did not do this!
At their bidding I reluctantly restarted atorvastatin (Lipitor) at 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 or my four children, my medical school days or my ten adventure filled years as a USAF flight surgeon, my selection as a NASA scientist-astronaut or my post-retirement decade as a writer of medical fiction.
The names of my books were like the names of my children - gone from my mind as completely as if they had never happened. Fortunately (and typically for this obscure condition), my memory returned spontaneously and again I drove home listening to my wife's amazing tale of how the day's events had unfolded.
Transient global amnesia 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 triggering events for these abrupt and completely unheralded amnesia cases have been sudden vigorous exercise, sexual intercourse, emotional crises, cold water immersion, trauma (at times quite subtle), and cerebral angiography.
Now a new trigger agent has been added; the use of the stronger statin drugs such as Lipitor®, Zocor®, Vytorin®. and Crestor®. TGA is but the tip of the iceberg of the many other forms of statin-associated memory lapses reported from distraught people. Far more common are symptoms of disorientation, confusion and unusual forgetfulness. These lesser forms of memory impairment can be easily missed in many individuals because, to a certain degree, they are the nature of us all.
On 9 November 2001, Dr. Pfreiger of the Max Planck Society for the Advancement of Science announced to the world the identity of the elusive synaptogenic factor responsible for the development of synapses - the highly specialized contact sites between adjacent neurons in the brain.
Not surprisingly, at least to specialists in the field, the synaptogenic factor was shown to be the notorious substance cholesterol. The so-called glial cells of the brain (long suspected of providing certain housekeeping functions) were shown to produce their own supply of cholesterol for the specific purpose of providing nerve cells with this vital synaptic component.
Since the lipoproteins that mediate cholesterol transport (including both LDL and HDL) are too large to pass through the blood-brain barrier, the brain cannot tap into the blood's cholesterol supply. Rather the brain must depend upon its own cholesterol synthesis, which the glial cells provide. The highly lipophilic statin drugs can easily cross the blood-brain barrier and thus directly interfere with glial cell synthesis of cholesterol.
1) I am 64 years old, exercise regularly and just retired this spring from teaching nursing. I experienced 8-10 hours of short-term memory loss last weekend. I had an MRI and echocardiogram, electrolytes, etc (all normal) and the neurologist diagnosed the episode as TGA. My witnesses say that I had about a 30 second memory and some retrograde loss extending back about 3 weeks. I now have my memory back except for about 10 hours on Saturday the 10th. I've been taking Lipitor for over a year and am currently on 10 mg. I believe that I will now stop, having just learned of this possible cause today.
2) How can I obtain more information in regard to Lipitor's cognitive side effects? I noticed that my husband became forgetful while on 10mg. He is now on 20mg and I have noticed increased forgetfulness and I think some confusion and irritability. He is 60 years old and works full time as an educator. I can't convince him that Lipitor may be a problem. I did read a brief article a while ago that mentioned forgetfulness could be related to Lipitor. Any information you have would be greatly appreciated. I am a registered nurse.
3) I just read your web page about Lipitor. My husband has been on Lipitor for a few years now and I am really worried about him. He is a heavy duty equipment mech and has always worked on cars and trucks and equipment. He has been having memory problems and stress/depression for over a year now. When I brought this to his Dr's attention, she put him on Lexapro (not sure of the spelling) and said it was depression that is causing his memory problems. After taking this for almost a year and having his confusion still getting worse he quit taking it.
He is still on the Lipitor. My next search lead me to having his hormones tested as I have found that low hormones including DHEA can cause memory problems also. He just had his blood drawn today for that. I was looking online and found your information on Lipitor. My husband's cholesterol is genetic and cannot be lowered by diet and exercise. How do we find out if it is the Lipitor that is causing his memory problems? He takes things apart and does not remember how they go back together, and when doing a small project around the house, I have to tell him how to do it. He was never like this before and we are really worried about it. He is afraid of loosing his job because it is taking him way too long trying to fix things that he use to be able to do in no time at all.
4) I just happened upon your information as I was again researching TGAs. I live in Rochester Minnesota and so have been treated by the great mayo clinic. I have had 4 major episodes of transient global amnesia and 4 minor (very short) in the last ten years. That number is way more than usual. I have been told that most people have 1 or 2. It has never been suggested to me that Lipitor which I have been taking about the same time span could have anything to do with my episodes. I will want to read your book
5) My father was rushed to the hospital last night after starting Lipitor three weeks ago and has lost about 12 hours of his memory. He is 78 and basically in perfect health. I have read your web site and am wondering if there is any further information.
6) I don't know if it's a coincidence or not, but my doctor just increased my Lipitor dosage from 5 mg a day to 10 mg a week ago. Since then I feel like I have been in a fog, unable to concentrate, and can't recall some words that I wanted to use when speaking. I found your email through a web search on the side effects of Lipitor.
7) I am 58 years old and started taking Lipitor about 9 months ago at a relatively low dose -10mg. Not connecting any of the following to the Lipitor, I began to lose concentration, become forgetful, and in general feel like I was in a fog at times. My coordination seemed off, I stumbled more than usual and when driving the car I found the car tended to drift toward the center lane, which I had never experienced before. I initially assigned these things to stresses and aging or wondering about a brain tumor.
I finally consulted my doctor as I also needed a follow up appointment to see how my cholesterol was doing. In fact my cholesterol did go down markedly, but when I raised the issues with my doctor he said he had encountered a couple of similar situations with other patients on Lipitor. I took his advice to discontinue the Lipitor and after a week I don't notice any change yet. I am still of course wondering if the Lipitor was a contributing or primary cause to these problems, and will be interested to talk to my doctor again in 6 weeks.
8) I have just been reading your online article on Lipitor and TGA Yesterday I apparently became confused while with my husband at home, and spent several hours in a local hospital ER; all tests (blood work and CT scan) showed no abnormality. Stroke and aneurysm were ruled out and the diagnosis of TGA was made. I was discharged home with the expectation that my memory would be back within 24 to 48 hours. I had never heard of TGA until last night (my earliest returning memory was yesterday evening). After a fitful night's sleep, I think that my memory is back.
9) Whilst researching TGA on the internet, hoping for some answers, I came across your article which is of particular interest to me since I have been taking Lipitor for several years - possibly three? It was prescribed by my GP following discovery of a slight occlusion in one of my carotid arteries (less than 15%). Repeat testing a year later showed no occlusion. In your experience it seems that you suffered the TGA quite soon after taking the Lipitor, whilst in mine, it has been several years with no problems.
Coincidence? Or Lipitor? Obviously this is day one following the TGA and I am nervous, trying to come to terms with what happened; I am 'missing' conversations that I apparently had with my daughter in London, and many other things that happened yesterday. It is a scary time. However, I am curious to know if there have been reports of patients suffering TGA after taking a statin for a longer period of time, such as I have been. If you know of any reports, I should welcome an email with the information as to where I can access them. Perhaps my greatest concern is that this may happen again.
10) I would like to let you know that since my husband has been taking Lipitor 20mg He has become very nasty at times and lately I have noticed that his memory seems to be failing him and when driving he has completely forgotten where he was going This man has always been a very mild mannered easy to get along with and a totally wonderful person. He is 70 yrs old and is waiting for back surgery, which I was blaming his behavior on. He also has diabetes. I am going to contact our Dr. to see what the risks are if he stops taking this medication.
11.) I have spent a lot of time with Doctors to determine what was wrong with me including a MRI that showed my brain has shrunk since starting Lipitor. I have had every battery of blood work to rule out other diseases. I just had a DNA test for the Apo gene, a test for early onset Alzheimer's, if paired, and it was not positive. In four weeks I am having a memory evaluation test at a rehabilitation facility to measure the amount of damage to my short-term memory. I am only 54 years old and used to write software specifications and hold a patent in artificial intelligence.
Duane Graveline MD MPH
Former USAF Flight Surgeon
Former NASA Astronaut
Retired Family Doctor
Updated July 2011
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