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Learning medicine is hard work! Osmosis makes it easy. It takes your lectures and notes to create
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much more. Try it free today! The name of the disorder transverse myelitis
can be broken down. Transverse means extending completely across
something – in this case, it refers to going across the spinal cord, and myelitis means
inflammation of myelin which is the fatty substance surrounding nerves. So, in transverse myelitis there’s inflammation
that damages the myelin as well as the rest of the neuron across a section of the spinal
cord. Now, neurons are the main cells of the nervous
system. They’re composed of a cell body, which contains
all the cell’s organelles, and nerve fibers, which are projections that extend out from
the neuron cell body. Nerve fibers are either dendrites that receive
signals from other neurons, or axons that send signals along to other neurons. Where two neurons come together is called
a synapse, and that’s where one end of an axon sends neurotransmitters to the dendrites
or directly to the cell body of the next neuron in the series. The axons are intermittently wrapped in a
fatty substance called myelin. Myelin is extremely important to neurons,
because it helps to allow an action potential to propagate much faster. An action potential is an electrical signal
that races down the axon, triggering the release of neurotransmitters or a chemical signal,
on the other end. Without myelin this signal propagation is
very slow and inefficient. Since some of these neurons can be very long,
especially ones that go from the spinal cord to the toes, the fact that myelin helps speed
up action potentials is super important! Now, the spinal cord is composed of both grey
and white matter. Grey matter consists of cell bodies. It’s in the middle of the spinal cord and
is shaped like a butterfly. Surrounding the grey matter is white matter,
which consists of the myelinated axons of various neurons. The neurons in the spinal cord form different
neural tracts that carry information to and from the brain. There are three main tracts to remember. The corticospinal tract is a descending pathway
that carries motor information from the brain to different muscles in the body and it controls
voluntary muscle movement. The dorsal column is an ascending pathway
that carries sensory information about pressure, vibration, fine touch, and proprioception–or
the awareness of one’s bodily position in space. Finally, the spinothalamic tract is another
ascending pathway and it’s divided into two parts. The lateral tract carries sensory information
for pain, and temperature, while the anterior tract carries information for pressure and
crude touch–or the sense one has been touched, but without being able to localize where they
were touched. Autonomic neurons are also located in the
spinal cord–these help regulate processes like urination, digestion, and heart rate. These neurons hitch a ride with the various
tracts, but their cell bodies are found in the spinal cord. For example, the sympathetic division, or
the fight response, has its cell bodies in the thoracic and lumbar regions and make up
the lateral horns of the grey matter. In transverse myelitis there’s inflammation
of the spinal cord across an entire spinal cord segment, or even multiple segments in
some instances. Most commonly, the inflammation occurs at
the thoracic level but can also occur in the cervical and lumbar regions as well. The inflammation may be caused by an infection,
an autoimmune disease like multiple sclerosis, or it could just be idiopathic, meaning there
is no identifiable cause. Some well known pathogens that trigger inflammation
include mycoplasma pneumonia, herpes and dengue viruses, and schistosomiasis – a parasitic
disease. Ultimately the inflammation damages the myelin
or the neurons themselves in the spinal cord. When this occurs, neurons become unable to
communicate with one another and messages going up and down the spine fail to get delivered. Symptoms of transverse myelitis depend on
which tracts are damaged – and usually affect sensory, motor, or autonomic function on both
sides of the body. There’s usually a well defined sensory level
– meaning that the symptoms only affect the body below a certain level of the spinal cord. Damage to the corticospinal tract causes weakness
and problems with voluntary muscle movement below the level of the spinal cord segment. Damage to the spinothalamic tract causes a
loss of temperature and pain sensation. And damage to the dorsal-column pathways causes
problems with balance and spatial orientation. Diagnosis of transverse myelitis can be done
with a lumbar puncture which is when a needle is used to collect cerebrospinal fluid from
around the spinal cord. In transverse myelitis there’s usually an
increase in white blood cells. In addition, an MRI, or magnetic resonance
imaging, can be used to spot areas of inflammation in the spinal cord. Treatment of transverse myelitis depends on
the underlying cause. If there’s an autoimmune process, it may
be helpful to use steroids or plasmapheresis, which is where antibodies are filtered out
of the blood. All right, as a quick recap transverse myelitis
is inflammation across a certain level in the spinal cord. It’s a rare disease which can be triggered
by an infectious or autoimmune process. The symptoms are related to the affected part
of the spinal cord. When the corticospinal tract is affected a
person will have problems with voluntary movement, and when the spinothalamic tract is damaged
a person will have problems sensing pain. Lastly, if the dorsal column pathway is damaged,
a person will have problems with balance and spatial orientation.

9 thoughts on “Transverse myelitis – causes, symptoms, diagnosis, treatment, pathology

  1. Myelitis means inflammation of spinal cord. Myelos means marrow, either bone marrow or spinal "marrow" or cord. When it's going about inflammation of myelin, then it must be "myelinitis". Please fix it.

  2. Hi my name is Lizzie
    I have been a fan of your videos for the last 2 years and they have really helped me both at high school in year 12 and university. You actually inspired me to create my own channel and try and help educate people with fun videos like you guys.

    I have been trying to grow and am having heaps of trouble. I was wondering if you have any tips or if you could do me a massive favour and share one of my videos or give me a shout out.

    If not I love your videos and will keep following them. Thankyou ❤️

  3. emf's can effect the spinal components and thus can be a factor in this condition. evil people will exploit this information to manipulate your bio-functioning.(WARNING)
    May the LORD help us!

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