What is this malady of mine, Amyotrophic Lateral Sclerosis (ALS)? I’ve researched it not to find a cure — none is known at this time — but so I don’t waste time on what cannot be a cure.
ALS is a progressive neurological disease in which motor neuron cells deteriorate and die. Motor neurons send signals from the brain (upper motor neurons) via the spinal cord (lower motor neurons) to muscles throughout the body.
Motor neurons control all voluntary muscle movement including walking, talking, chewing and breathing. As the signals they send grow weaker, the muscles they control waste away until at last the brain can no longer initiate and control voluntary movements.
Different groups of muscles are controlled by motor neurons in different parts of the brain (see illustration below). About 70% of patients first develop symptoms in their arms or legs. About 25% first notice speech or swallowing problems (bulbar onset) — I’m one of those — and about 5% start with symptoms in their trunk.
No matter where the first symptoms appear, the great majority of ALS patients end up losing function in all muscles. We lose the ability to speak, eat, move, and even breathe. Most of us die from respiratory failure, usually within 2 to 4 years, although about 10% of us survive for 10 or more years.
The literature says all ALS patients develop symptoms throughout their body but the chief neurologist I met at Lehigh, PA who has worked in the field the longest told me that’s not correct. Some patients with bulbar onset ALS do not develop symptoms in other muscle groups.
Up to 10% of ALS patients inherit it from a parent via mutations in any one of over a dozen genes. The remaining 90%, of which I am one, are believed to have a genetic predisposition to the disease that is activated by an environmental factor.
Genes are contained in chromosomes located mainly in the cell nucleus. Every chromosome contains hundreds to thousands of genes and every human cell contains 23 pairs of chromosomes. We have about 20,000 to 23,000 genes all told, around 400 random ones of which are, on average, defective in any one of us.
The entire structure and function of our body is governed by the proteins it synthesizes and that operation is controlled by genes. Proteins are both building blocks for muscles, connective tissues, and other structures and they also, in the form of enzymes, carry out nearly all chemical processes within the body. Our body produces thousands of different enzymes.
Our genetic system is highly complex. Its operations incorporate error-correction mechanisms but it can go wrong with an enormous variety of results. It amazes me it works at all!
How might errors (mutations) occur? They can occur spontaneously. When a cell divides, for example, it makes a copy of its DNA, the molecule that carries the genetic instructions controlling its operation. Sometimes the copy is not quite perfect. Environmental factors such as radiation, chemicals, bacteria and viruses can also cause DNA to break down and when it does, the cell may not repair it perfectly.
How does the body defend against environmental risks carried in the blood? The walls of the blood vessels in the human brain are high-density cells that limit what substances can pass from the bloodstream to the brain more than the cell walls of capillaries do elsewhere in the body.
Severe inflammation such as I had in reaction to the Brown-tail Moths can temporarily weaken the bond between those cells making them a less effective barrier.
We know far more about how our genetic system works than we did even ten years ago but not yet enough. Western medicine has no cure for ALS because its cause or causes are at this point still a mystery. The only existing medication that slows its progression extends life by only a couple of months. I take it.
Motor neurons are different from other cells because the genes that govern their operation are different. Restoring their operation is not a matter of developing a drug to kill an external attacker such as a bacterium. We’re not dealing with something that moves from one group of motor neurons to all others. An environmental factor is triggering a change in our motor neurons’ genetic programming.
Curing ALS will require correcting the motor neurons’ genetic programming. This December 10, 2017 report describes a potential approach based on CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats), a naturally occurring bacterial defense system.
CRISPRs are repeating sequences of genetic code interrupted by “spacer” sequences – remnants of genetic code from past invaders. The system of which they are part serves as a genetic memory that helps the cell detect and destroy invaders when they return.
CRISPRs can be programmed to target specific stretches of genetic code and edit DNA at precise locations, thus permanently modifying genes in living cells. The first method to engineer CRISPR to edit the genome in mouse and human cells was published in January 2013.
In its current form, CRISPR isn’t technically gene therapy. Rather than replacing a diseased gene with a good one, it goes into the nucleus and directly cuts out faulty genes.
Meanwhile, since there is not yet a gene therapy for ALS, I am taking a treatment that has cured a significant number of MS patients and more recently, a number of ALS patients, too. It is based on the idea that the body can, if treated in the right way, heal itself.
The treatment was developed by a doctor of Tibetan medicine who, earlier in his career, was sent by the Dalai Lama to reestablish Tibetan medicine in Mongolia and who is now based in San Diego, CA. I am receiving this treatment from the first Westerner to qualify as a doctor of Tibetan medicine, a truly amazing achievement. Her mentor is the Tibetan doctor who developed the treatment.
I will add comments to this post as I learn more about ALS. I knew little about biology eighteen months ago and would be very grateful for comments by anyone who can correct or add to what I’ve learned so far.