Unravelling the mystery of MS | Jack van Horssen | TEDxUHasseltSalon

the brain is the most interesting organ and I agree with the statement because the brain allows us to think to feel to love and to store memories and it doesn't come as a surprise that brain disorders like multiple sclerosis have a significant impact on the quality of life you're on holiday in the mountains of Austria and suddenly you're confronted with the problem of this blurred vision it takes several days and the problems resolve back home you go to the general practitioner and tells him the story he or she refers you to the neurologist and the neurologist performs a clinical examination in addition he makes an MRI scan and upon careful examination of this scan you are confronted with the fact that there are several white spots within the brain typically seen in MS patients you're scared what about my future can I get children do I need medications do I end up in a wheelchair and if so how long will it take those are some of the basic questions that demonstrate the impact of this devastating disease on the quality of life remember the patient suffers from a blurred vision in this case this is caused by a lesion in the optic nerve the nerve that connects the eye with the brain the problems resolved and disappear in time either spontaneously or due to medication later on it can take months it can take years you don't know there is a new relapse in this case you encounter problems with walking caused by a lesion in the spinal cord again these symptoms disappear and later on you have again problems with your vision double vision in this case caused by lesions deep within the brain this is a typical pattern of young MS patients and referred to as relapsing remitting problems come and go either spontaneously or due to medication what do we know about a mess actually very little we don't know the exact cause of this devastating disease but looking at this map this distribution map of a mess it tells us that environmental factors have to be involved ms is a highly prevalent disease in the northwest europe canada one in a thousand pay people suffer from a mess and if you take a look in scotland even one in five hundred patients even one in five hundred people are diagnosed with MS so we're not talking about a rare disease this global map distribution tells us that environmental factors are involved environmental factors like exposure to sunlight the diets but also the genetic signature these are all factors that play an important role in the disease progression if we need to know what causes a mess and what happens in the brain of MS patients we need to look further into the central nervous system the central nervous system comprises the brain and the spinal cord and if you take a look within the brain you see that it is very well protected both externally by the skull in the spinal column as well as from the inside by the blood-brain barrier the blood-brain barrier a vascular structure that is rather impermeable however it allows the entry of glucose and oxygen for the neurons and in the same time it restricts the entry of unwanted substances but also immune cells here you see a section of the brain you can clearly see the different colors the white color the gray color you can also see that the brain has a specific structure the corpus callosum brain in general way 1.2 to 1.4 kilos and yes man we do have a bigger brain however this corpus callosum is more developed in females this corpus callosum that connects to both hemispheres allows multitasking and hence female do much better in multitasking than men let's go back to the central nervous system if you take a look in the gray matter we see that there are the there are the neuronal cell bodies the neuronal cell bodies that receive input from other neurons by very fine processes the dendrites and there is one long process this long process transmits the signals to other neurons or muscle cells in order to rapidly propagate the signal we have the myelin sheet a thin white fatty substance that is enveloped around the axon here you see again that the white matter is mainly within the central nervous system whereas the gray matter can be mainly found at the surface of the brain so and the outside we have the cell bodies on the inside the accents containing the myelin this myelin forms a protective layer around the axons and it allows rapid conduction of electric signals from one neuron to another or from a neuron to a muscle cell what happens in in ms is that immune cells damage the myelin sheath around the axons and therefore you see that there is a disturbed conduction of electric signals giving rise to the clinical symptoms people experience and finally end up in a wheelchair but what is happening therefore I use this cartoon in rat we have the axons in green the myelin that forms this protective sheet around the axons and in the middle of blood vessel and due to an unknown trigger which is likely the immune system immune cells the blood-brain barrier and start to invade the central nervous system there they damage the protective myelin layer and eventually even phagocytose they take up the myelin these active lesions are filled with immune cells and these lesions give rise to the clinical symptoms we saw in the relapsing remitting phase of the disease however in time usually after 10 to 15 years most of the patients that start with this reduction limiting form of ms enter the progressive phase of the disease this progressive phase of the disease is characterized by a steadily increase in the clinical disability of patients and in this case the neurologists have no treatment options if you're diagnosed with progressive MS there is nothing to offer so we need to know more about the processes that are occurring in the brain of progressive MS here you see a brain slab of somebody of the diet of progressive MS and you can clearly see the d myelinated spots within the white matter if we take a closer look at these lesion alaria we see they're completely d myelinated axons are gone and this lesion is now densely populated with another cell type the astrocytes a star-shaped cell that starts to produce extracellular matrix proteins to fill up the gap this ostrogothic scar gives the name to ms multiple sclerosis lesions MS besides these alts fly optic lesions there's another very important cardinal feature of progressive MS which is illustrated in this picture here I show you in brain slap in which the myelin sheath is stained in brown you don't need to be a pathologist to identify the white matter lesions in this case you can find them around the brain ventricles and also in the corpus callosum the structure that connects the two bird hemispheres if you closely look you see that there is not only demyelination within the white matter but there is extensive demyelination of the more superficial layers the gray matter and this gray matter demyelination often exceeds the white matter pathology and we know from research that cortical lesions are characterized not only by demyelination but also by neuronal loss and a Ronal damage and these neuronal loss and neuronal damage correlate very well with the clinical disability even better than the white matter lesions so what causes is the these gray matter lesions we're still working on that but it's likely that inflammation also plays an important role in this pathology not only the cortex is involved in the disease but also the structure here is completely d myelinated the hippocampus a small brain structure that is important in short-term memory hence it's doesn't come as a surprise that a lot of the progressive MS patients also suffer from cognitive impairments and memory deficits and sometimes these patients even tell you that those cognitive problems are experienced as more severe than the fact that they end up in a wheelchair the fact that inflammation plays such an important role in the disease has led to the identification of several immunomodulatory and anti-inflammatory drugs that are on the market nowadays ten years ago there were only two to three treatment options not very effective in the last ten years there is a dramatic increase in new very potent anti-inflammatory drugs that can be used in the clinic this is the overall picture I told you about the relapsing remitting phase of the disease patients experience new clinical relapses that are associated that inflammation in time 10-15 years most of those patients enter the progressive phase of the disease where there are no treatment options but there is hope the development of these new very potent anti-inflammatory drugs might shift this line towards the right and it's likely that several of these very potent drugs will shift this line towards the right so that patients cannot enter the progressive phase of the disease thank you [Applause]

Channel: TEDx Talks

Views: 33,309

Keywords: TEDxTalks, English, Belgium, Science (hard), Biology, Brain, Cells

Id: LlOf0ImoRqc

Length: 11min 53sec (713 seconds)

Published: Fri Dec 09 2016