What we know about Chiari
Speech by Ray D'Alonzo
I’m going to talk about what Chiari is. What we know about it.
What we don’t know about it. Why increasing awareness about it so
important. And, what increased awareness can do towards helping
others with the disease and towards finding a cure.
Chiari is of course a brain defect where part of the cerebellum, the
cerebellar tonsils, herniate into the upper spinal canal causing
compression of the hindbrain and upper spinal cord which in turn results
in a multitude of symptoms. That’s the formal definition of the
disease if you will but what is it really like? The first thing I
can tell you is that it is not what many doctors think it is.
Unfortunately, many doctors believe it does not cause symptoms.
Others think that the symptoms it produces are mild and bothersome at
worse. Many doctors trained before MRI investigations of Chiari
have been taught that cerebellar tonsil herniations are just a variant
of normal. Many even tell patients, and I quote, “it has been
there all of your life and hasn’t caused you any problems, so it can’t
be causing you problems now”. Think about that statement. As
if nothing ever changes in the body. That is an absolutely
crushing statement for a sick patient to hear from a doctor particularly
when the doctor can not tell them what, in fact, is wrong. Yet it
happens every day. Doctors aren’t trying to be rude.
Actually it’s quite the opposite. They are trying to put the
patient at ease. Most just haven’t acquired the current
understanding of the disease, in part, because awareness is low not only
in the general public but in the professional health care establishment
as well.
As a well decompressed Chiarian, I can tell you first hand what it is like to have Chiari. As the symptoms of Chiari emerge and gradually take over, it becomes a personal prison. The closest analogy I can come up with is that it is like have the flu all the time, 24 hours a day, 7 days a week, week after week, month after month, and for many, year after year. But, it is actually much, much worse than the flu. Talking about it as if it were the flu only gives you an idea of only a fraction of the physical symptoms of Chiari. It also frequently comes with severe clinical depression and unrelenting anxiety. It causes the affected patient to slowly shut down because the patient tries to do everything in his or her power to avoid aggravating their symptoms. Soon the patient becomes afraid to do all sorts of things and slowly retreats from work, social life and even family life. It can become so bad and the weakness so great sometimes patients can not walk or use their arms to any extent. Sometimes what the patient describes as weakness is not weakness at all but when they try to use their strength they feel so bad they elect to behave in a manner resembling weakness. Many lose significant muscle mass in the arms and legs from disuse as a result. Nausea is very common and it can’t be treated with antacids or H2 blockers or any medication. Pain is common. Drugs don’t help very much with pain or headache. The extremities tingle and burn particularly with use. Bowel and bladder dysfunction is common probably because of compression to the vagus nerve or the formation of a spinal cyst. It can be difficult or painful to swallow. Vision is often blurred. The senses are frequently heightened and distorted and the patient can be hypersensitive to sound, light and even odor. It can be difficult to think clearly and find words. IQ is often lowered. Pain can be so severe in individual teeth that some patients end up getting perfectly good teeth crowned after dentists concluded that the fracture in the tooth is running oblique to the plane of the view and they can’t see the fracture. The tongue can go numb, sometime only half of the tongue, right down the middle. And, the list goes on and on. And, for many Chiarians is it not uncommon for them to present with 30 to 40 symptoms or complaints. Most of the time, the Chiari patient doesn’t describe all their symptoms to the doctor because it takes too much time or they are concerned that the doctor will write them off as mentally or emotionally unstable.
So that it was it is like to have Chiari. For many, the symptoms are not as mild as many doctors have been taught.
OK What do we know about Chiari and what do we not know about it? Well, we know a lot more than we did prior to the widespread use of MRI. But, the problem is that many health care givers were educated before the widespread use of MRI so most of what they learned about it is inaccurate or incomplete and it is not the type of subject that doctors brush up on because they rarely encounter it. We know that it is usually congenital or present from birth but we don’t know if it is hereditary. We know that it can cause severe symptoms even when the herniation is as small as 3mm although many doctors still believe that herniations must be greater than 10 mm before it can cause problems. We know that the incidence of people with herniations 3 mm or greater is estimated to be about 1 in 1,200. This means that there are about a quarter million people in the United States with Chiari malformations of the brain at least as defined by herniations of 3mm or longer. But, we really do not know how many of that quarter million are symptomatic or will become symptomatic. We do know however that three to four thousand a year will receive decompression surgery. But it is probably safe to say that at least that many and probably more also need surgery each year.
Many who are born with Chiari malformations are symptom free or asymptomatic for many years. The average age of diagnosis according to recently published studies is about 25. Some do not acquire significant symptoms until mid-life like yours truly. We don’t know however what changes occur that cause asymptomatic Chiarians to become symptomatic. There are no longitudinal data. That is data over time that tracks anatomical changes and changes in other parameters including symptoms. We do not know in the case of congenital Chiari if symptoms are brought on by further herniation of the cerebellar tonsils or if the dura which is the tough elastic membrane around the brain and spinal cord thickens around the herniated tonsils or if the cranium settles on the spine to reduce around the herniated tonsils or if the dura in general becomes stiff and less compliant to intracranial pressure pulses caused by the contraction and relaxation of the heart.
We also know that it is a difficult disease to treat. Medications are not particularly effective and many of the medications used for chronic pain or depression add unwanted side effects. We also know that medications can mask symptoms while the syndrome progresses and more neurological damage can occur.
About 20% of the time, decompression surgery fails to provide any discernable benefit. Perhaps fewer surgical failures could be realized if follow up care existed but for most it doesn’t. Because Chiari is accompanied by clinical depression almost 50% of the time and anxiety disorder 30% of the time, it is unknown to what extent the depression and anxiety could be causing physical symptoms. . We also know that most doctors can not think of a disease that can cause so many symptoms so they conclude that clinical depression is the sole problem and many Chiarians end up in the care of psychiatrists rather than in the hands of the neurosurgeon.
Diagnosing Chiari is problematic. The standard clinical neurological exam only detects certain cases when balance is seriously disturbed or when the eyes move involuntarily. But, that occurs in only the minority of cases. MRI can readily detect herniated cerebellar tonsils but often can not detect if the herniated tonsils are blocking fluid from leaving the skull. For a while, we thought that a special type of MRI known as Cine MRI which can observe if fluid is blocked by the tonsils was the answer to objectively diagnosing symptomatic Chiari but we now know that it actually doesn’t correlate that well even when interpreted by radiologists expert in Chiari.
So here we have a disease that is actually not rare but uncommon, potentially affecting a quarter of a million Americans, causes many who are afflicted to be come totally dysfunctional, is most times misdiagnosed or ignored, lacks a good objective diagnostic test, can’t be treated well with medications, is unknown or poorly understood by most physicians, but can be treated by surgery if you can make your way to a neurosurgeon who has expertise with it.
I would say that these factors make as strong a case as possible for an increased need for awareness. And, I mean awareness in the broad sense, in the general public and amongst health care professions, providers and insurers. Very important is the need for increased awareness by government researchers and institutions. Virtually no research is done on Chiari. Pharmaceutical companies can not research it because the market is too small and they can not recoup their investment. Let’s compare the situation to Lou Gehrig’s disease or ALS. There are only about 30,000 people with ALS in the United States. That is 8 times less than those with Chiari malformations. Now if you search the medical literature for clinical research trials on ALS you will get about 450 published papers. But, if you do the same search for Chiari, you will only get about 40 papers. This roughly equates to 100 times more research on ALS than Chiari per patient. Some people will tell you that there needs to be more research on ALS because it is fatal. This is true. It is practically always fatal but Chiari can be fatal as well. The medical literature has numerous documented case studies of Chiari causing fatal heart attacks and respiratory failure. Very interesting however is the epidemiological work recent done by our group which was presented at the Conquer Chiari symposium at the University of Illinois this last June which estimates that symptomatic Chiari patients are at a ten times greater risk of committing suicide than the general population. If this turns out to be true, then it causes more deaths due to depression and suicide than it does by neurogenic heart attacks and respiratory failure.
Increased awareness will accomplish two important objectives. It will result in better diagnosis and treatment for current Chiari sufferers. And, it will lead to more research, research that is very much needed to understand the origin and natural history of the disease.
Important pilot research has finally gotten underway because of people like you. The Chiari and Syringomyelia Patient Education Foundation, also known as Conquer Chiari recently awarded two key research grants. The first went to investigators at the University of Illinois who measured compliance of the dura before and after surgery using MRI. They found, that unlike flow measured by Cine MRI, that dural compliance improved after surgery and it correlated with symptom improvement. These pilot data were then submitted by the investigators for a government grant which was recently approved. This may well lead to a real objective measure for diagnosis. The second grant was awarded to a British investigator who has developed sophisticated methods for tracing cell differentiation in developing embryos. He discovered that the Chiari malformation in mice forms from early tissue in a particular area of the post-otic neural; crest. The grant is allowing him to study two critical time points in the development of the post-otic neural crest using advanced genetic labeling techniques to identify a list of high priority gene candidates for clinical geneticists to test for genetic mutations in human Chiari patients. Basically, his model will provide a rough road map to explore the human genome for the genetic defect that causes the Chiari malformation if there is one.
Increased awareness is needed more than ever. It will not only lead to educating health care providers and patients but will lead to raising private funding and shifting priorities for government funding to take the next major steps in research. It will take a great deal of money for the clinical geneticists to identify the defective gene in humans once the road map is assembled. It will take a great deal of money to do those much needed longitudinal studies so that we can learn what anatomical changes occur in the body over time that give rise to symptoms and the progression of the syndrome. This knowledge is critical in order to develop strategies for intervention. If we can find out what gene is defective and what anatomical changes occur as the patient ages, we can find treatments that will more effectively intervene.
So I ask of you here today to do just one thing. Spread the word anyway you can. And, that word is – Chiari is real. It causes significant symptoms and disability and even death. Patients need more comprehensive care not just antidepressants. And, research can find more effective treatments and potentially even a cure.