Demyelination and associated diseases

A rare neurological disorder that causes serious speech difficulties.

A few days ago, news came out that a famous Spanish radio and television presenter, named Josep Lobatóshared on Instagram a video with his progress in recovering the speech he had lost due to a demyelinating disease. 

In it you can intuit the effort Lobató must make to pronounce words as simple as "no" and "yes", something that healthy adults can do automatically, without paying any attention to performing the chain of movements necessary to do so.

Naturally, most of the information related to the presenter's health is confidential, and not much is known about whether Josep Lobató will be able to fully recover his speech or not. However, But that does not mean that the viralization of his video has not helped many people to show their support and solidarity.to which I join.

What exactly is a demyelinating disease and why can it cause someone to have trouble speaking? Below I give a brief explanation on the subject, but first it is necessary to know what is a substance called myelin.

What is myelin?

Myelin is a substance that, by covering the part of the nerve cells that elongates to reach distant places (called axon), makes the inside of the neuron relatively isolated.

And what is the usefulness of this? Basically, the fact that the myelin sheaths cover the axon making it look like a string of sausages allows the electrical impulses traveling along it to go much faster. We can imagine it as if wrapping the channel through which electricity travels would make it more channeled and advance only where it can, that is, through the axon and not on the outside. Thanks to the myelin these nerve impulses are not scattered everywhere, losing their power..

Whether nerve impulses travel slower or faster is not simply a matter of patience; for the brain to function well, many networks of neurons need to be synchronized and sending massive amounts of information all the time. That means that there are mental processes that can only be performed if there are many nerve cells working at the expected speed, and that if the electrical signals sent by some neurons are much slower, the whole process fails as a whole. This explains in part what demyelinating diseases are.

Demyelinating diseases

A demyelinating disease, as its name suggests, is characterized by a process of demyelination, i.e., the destruction of the myelin sheaths that cover part of the neurons. that cover part of the neurons.

This does not simply mean that, because of this disease, we are doing things much more slowly. Although the speed at which nerve impulses travel through neurons may seem quantitative, since there are many different speeds, a significant delay in signal transmission produces qualitatively different consequences from what would happen without that delay. This is why demyelination is not limited to making us speak more slowly, for example, but can also cause us to lose the ability to can cause us to lose the ability to speak..

The other consequences of demyelination

But the effects of demyelinating disease are not only related to speech. Myelin covers the axons of all types of neurons, regardless of whether or not they play a role in the functioning of speech, and so the destruction of myelin sheaths can make itself felt in our ability to perform many types of actions.

Some diseases in which demyelination occurs, for example, are Pelizaeus-Merzbacher disease, in which symptoms include spasticity, involuntary eye movements or dementia, or leukodystrophies, which are related to the appearance of spasms and vision problems, among other ailments. But the best known demyelinating disease is multiple sclerosis, which affects all types of processes and is very harmful to the entire Central Nervous System in general.

These diseases are another example that in our mental life not only neurons are important, but there are other elements that interact with them to make everything work as it should.