Main content
Course: Health and medicine > Unit 8
Lesson 11: Multiple sclerosisMultiple sclerosis treatment
Visit us (http://www.khanacademy.org/science/healthcare-and-medicine) for health and medicine content or (http://www.khanacademy.org/test-prep/mcat) for MCAT related content.
These videos do not provide medical advice and are for informational purposes only. The videos are not intended to be a substitute for professional medical advice, diagnosis or treatment. Always seek the advice of a qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read or seen in any Khan Academy video. Created by Jaffer Naqvi.
Want to join the conversation?
- Why do the t-cells get across the blood-brain barrier in the first place?(13 votes)
- The disease starts when the blood-brain barrier (BBB) is weakened. The BBB can be damaged by stress, inflammation, or chemical processes thought to be triggered by disease, drugs, air pollution or smoking. Possible links between gut health and the strength of the BBB have been explored through work on the microbiome. A failure of the immune system is also necessary for MS, some mutation makes the myelin look like it is presenting an antigen to the T-cells.(3 votes)
- How do the immunosuppressants stop the t-cells from crossing the blood-brain barrier?(8 votes)
- A basic function of corticosteroid is to induce the synthesis of lipocortin-1 which then binds to cell membranes preventing the phospholipase A2 from coming into contact with its substrate arachidonic acid. This leads to diminished eicosanoid production. Eicosanoids are 20-carbon fatty acids which follow cascade system leading to inflammation. Other steroid compounds also reduce the production of antibodies by suppressing the lymphocytes.(6 votes)
- what type of treatments are used for neuropathy(4 votes)
- 1. TCAs preferred for reduced anticholinergic side FX: nortriptyline QHS (drowsiness) or desipramine QAM (wakefulness)
2. SNRIs have similar MOA to TCAs and are used to avoid TCA side FX: duloxetine or venlafaxine
3. gabapentin or pregabalin - used with or as alternative to TCAs. Titrate gabapentin 300 mg QD up to 300 mg TID.(2 votes)
- what if immunosuppressants are given and the patient gets a bacterial or viral infection like common cold etc. would they need to be shifted to a clean room of a hospital?(4 votes)
- What are some side effects of the medication? Wouldn't suppressing the immune system increase your chances of getting sick? If so, how would someone deal with that?(2 votes)
- There are a whole range of problems that come with taking steroids long term... cushing's syndrome, increased sensitivities to illness, fluid retention, hormone imbalance, depression, weight gain ... the list goes on...(3 votes)
Video transcript
- [Voiceover] So we know
that in multiple sclerosis the immune system is attacking
the central nervous system, but we don't really know
why it's doing that. So in other words, we don't really know what the true cause of the disease is. Because we don't know the
true cause of the disease, there is no known cure for it. However, there are a
lot of treatment options available for people. A really common class of drugs that people take are the disease-modifying drugs. So how do these act? Well, remember that in multiple sclerosis, we can really track the way that the disease progresses over time. So on the X axis we have time, right, in terms of the lifespan of the individual and on the Y axis we have
the severity of the disease, that is how much damage
does the brain accumulate. There are four different
types of multiple sclerosis, each characterized by the way that they progress over time. The most common type is the relapsing-remitting form. So you can tell here, you know, there's a relapse over
here and relapse is really when the brain starts to accumulate a lot of damage and the
symptoms start to flare up and the severity increases. And you have a remission over here. This is when the brain kind of starts to heal itself and the
symptoms go away for a bit and the disease itself starts to improve. This type affects about 80% to 85% of those who have multiple sclerosis. Because it's so common,
most of the treatment options that we have, right,
those disease-modifying drugs, address this type. There are other types
of multiple sclerosis, but unfortunately they don't really respond well to these drugs. So what are these disease-modifying
drugs going to do? Well, they're actually
going to modify the course at which this disease progresses. So what do I mean by that? Well, if you take these
drugs, then it's most likely that the graph will probably look something like this instead. So you can already tell some of the major differences, right? One, that the severity of these relapses is decreased and two, the remission time has also increased so what you're doing is you're slowing the
progression of the disease. That's why we call them
disease-modifying drugs because they modify the
progression of the disease. So what are some disease-modifying drugs? Well, most of them are immunosuppressants and I think this word is actually pretty self explanatory. These guys are going to
suppress the immune system. So one example of an immunosuppressant are the corticosteroids. These are steroid hormones that are actually released by the adrenal glands above your kidneys, but they can also be given to a person as medication and then you also have
the beta interferons. So an interferon is a
chemical that's released by the immune system
to manage inflammation. A beta interferon will
suppress the inflammation. So how do these work? What's going on at the cellular level? Well, we kind of have to understand the pathophysiology, right? So let's say we have a neuron over here. As usual, this neuron will have myelins surrounding the axon and then next to this neuron you may have a blood vessel. Around this blood vessel is kind of a wall, right, known as the blood brain barrier. This blood brain barrier is gonna stop immune cells like
this T-cell over here from crossing over and entering the brain. So this guy's ordinarily trapped in the blood vessel, but
in multiple sclerosis this blood brain barrier becomes pretty leaky and this guy is able to make his way across. This is actually one of the first points in which these immunosuppressants can act. They can actually stop that T-cell from crossing the blood brain barrier and in doing so he's not even gonna interact with the brain
at all to begin with. So now the immune system has limited access to the brain, but this isn't the only site where the immunosuppressants can act. Maybe the T-cell actually manages to make his way across
the blood brain barrier. The T-cell will look at that myelin and it'll recognize it as foreign. In doing so, this will trigger an alarm. So this T-cell is gonna release a whole bunch of chemicals
called cytokines. These cytokines are going to alert a whole bunch of other immune cells so maybe you have a B-cell over here that responds to those cytokines or maybe even a macrophage and this will lead to inflammation. The one thing your
immunosuppressants can do is it can ensure that the T-cell doesn't react so vigorously to the myelin. If it doesn't react as much, it may not release so many cytokines. If it doesn't release as many cytokines, then those cytokines won't really be able to recruit the other cells of the immune system so ultimately what we have is a dampened immune response. The immune system isn't really able to act as vigorously and
as aggressively anymore. So, of course, these
disease-modifying drugs will kind of relieve
some of those symptoms, but they do so by addressing the pathophysiology. But there are alternative ways to really address those symptoms. So what we want to do is we want to think of different types
of symptom management. So instead of kind of just
taking those medicines, you can also do a number
of other alternative things to really address those symptoms directly. So let's say we have a person over here and let's say this person
has multiple sclerosis. What are the symptoms they may experience? Well, one, they may have
a lot of fatigue, right, so they may just be really physically exhausted all the time. In addition to that, they may also have this stiffness of their muscles where their muscles are contracting too much and this can lead to a lot of pain. They may also have muscle weakness and numbness in their arms. So these are a lot of symptoms, right, so how do we address them? Well, we can have the person visit a physical therapist. So here we have a physical therapist and really what they're gonna do is they're gonna have this person perform a number of
different physical tasks. Maybe they'll help them do some stretching exercises. Maybe they'll help them walk a little bit more normally and ultimately this will kind of help relieve those symptoms. But there are still other symptoms that maybe a physical therapist might not be able to help out with. So remember that in multiple sclerosis, a lot of people may actually experience cognitive dysfunction and just as a brief review, remember that cognition includes functions like attention, working memory, and decision making. These functions can be pretty heavily impaired in multiple sclerosis and this can be really problematic because cognitive dysfunction is really one of the major reasons why people have to leave their jobs. So how can we address this? Well, we can have the person undergo what's called cognitive
rehabilitation therapy. So in cognitive rehabilitation therapy, the primary goal is to kinda
restore these functions and the way to do that
is to have the person perform a set of mental tasks, right, so they may play a few games where they try to remember a few things and all sorts of things
that will really help them kind of strengthen their
cognitive abilities and in doing so, their cognition will start to improve, right. So it's kinda like physical therapy, except instead of working with your body you're working with your mind. So these are some of the alternative ways to manage your symptoms without taking those disease-modifying drugs.