Multiple Sclerosis Flashcards
Multiple sclerosis (MS)
is the most common chronic inflammatory, demyelinating and neurodegenerative disease of the central nervous system in young adults.
Multiple sclerosis (MS)
(Common)
MS has a greater Prevelance in European countries
But most common in people of European (Caucasian) descent.
Multiple sclerosis (MS)
(Chronic)
You live with this for the rest of your life
Multiple sclerosis (MS)
(Inflammatory)
It’s inflammatory, it’s is autoimmune, immune cells (T cells and B cells) are attacking tissues that are ours
Multiple sclerosis (MS)
(Demyelinating)
Oligodendrocytes make myelin in CNS
Schwann cells make myelin in PNS
Multiple sclerosis (MS)
(Young adults)
20-40s typical age for diagnosis
White matter
Where axons with myelin sheaths are
White matter having grey spots
Indicate a loss of myelin on the axon
The freckles are called plaques, and can be seen using MRI
Luxol fast blue stain
What it does is that it sticks to anywhere that there is myelin,
Histology:
Some white matter areas are blue (indicating myelin)
others have no blue stain (indicating demyelination)
Immunohistochemistry
Colours
Anti body with fluorescent probe that lights up green or red
Myelin- Red
Neurofilament- green
Yellow: myelin is starting to be affected
Immunohistochemistry
Green gaps
Red (myelin) should cover the green (axon), the gaps with just green means that there is demyelination
Can see different stages of demyelination (more/less green visible)
Immunohistochemistry
Green blob
Growth cone to try to grow back, forming that big green part, axon got cut, so there is degeneration
Immunohistochemistry
Transected axon
Beginning of Neurodegeneration
Everything not connected to the cell body will die
Progression of disability
Normal nerve cell
Phagocytes cells start to degrade the myelin
Transected cell (nuerodegenerative process) -may be the reason for progressive disability
MRI and Histology
What happens to the ventricles (filled with cerebral spinal fluid)
Expanded volume of ventricles and decreased amount of gray matter and white matter
Ventricle expansion explained
Later MS, When the axons dies, the dead tissue applies resistance to ventricle,
ventricles begin to expand,
they usually trace the brain to compare how much brain volume is loss
Losing brain volume and gaining CSF is another indication of nuerodegenerstion
Multiple
Need to have multiple occurrence of symptoms to be diagnosed p, must be spread out in time and space
Stats for Canada
Canada
1 person in 400
4,377 new diagnosis/year
75% female
90% with Relapsing remitting Multiple sclerosis
Clinical Patterns of MS
(the four stages And three types)
PPMS- PRIMARY PROGRESSIVE (ms)
Pre-symptomatic
Clinically isolated syndrome
Relapsing-remitting (ms)
Secondary progressive (ms)
Pre-symptomatic
Inflammation is present but it is below the threshold, the patient likely won’t have notice symptoms
Clinically isolated syndrome
First event that caused a symptom, but not sufficient to cause a diagnosis, need to have multiple presentations of this
First symptoms distinct, but goes away
Relapsing-Remitting
(DMT involment and both definition)
Relapse: active stage of inflammation
Remitting: non active stage of inflammations
Time between relapse and remitting vary
DMTs tries to keep the person in earlier RRMS phase
Symptoms starts to stay near the end of this phase ( likely when neurodegeneration is happening)
Diagnosis for MS
Start of Relapsing-remitting
Two events that affect different part of the body, and are separated in time, they are sufficient enough to diagnose for MS
Relapsing-Remitting
Re-myelination
Process can happen when in remission
Once the symptoms starts to stay the is process no longer works
Secondary progressive
Symptoms continuous get worse (flair up)
Goals is to reduce the amount of people in this stage
Is the true cause of Multiple Sclerosis (MS) known?
No, the true cause of MS is unknown, and it is difficult to identify causes at an individual level.
What are the main risk factors associated with MS?
The risk factors include lifestyle, environmental exposures, and genetic factors.
Smoking, sedentary behaviour, diet
Mutation in the germ cell
Vitamin D deficiency is a risk factor (lifestyle / Environmental)
What are the main risk factors associated with MS?
The risk factors include lifestyle, environmental exposures, and genetic factors.
Smoking, sedentary behaviour, diet
Mutation in the germ cell
Vitamin D deficiency is a risk factor, lifestyle / Environmental
Can MS have a family history, and how do genetic mutations arise?
Yes, MS can have a family history, but genetic mutations can also spontaneously arise or result from environmental exposures, such as radiation.
How can exposure to radiation impact genetic mutations related to MS?
Exposure to radiation (e.g., x-rays) can cause damage in sperm and egg cells, potentially leading to genetic mutations before fertilization.
What gene family is associated with MS, and how does it relate to autoimmune conditions?
The HLA (Human Leukocyte Antigen) gene family is associated with MS, as it plays a role in the immune system and is linked to autoimmune conditions through its connection to white blood cells (leukocytes).
Pathophysiology of MS (what is happening)
The presence of demyelinationnlesssions in the brain, spinal cord and optic nerve.
These lesions are characterized by breakdown of the BBB and the presence of inflammatory cells
Pathophysiology
Blood Brain Barrier
BBB is selective,inflammation makes the BBB leaky, things that are normal up’s circulating in the blood can get in there,
Broken wire vs fix wire analogy
Broken wire: demyelination
Fixed wire: remyelination
Oligodendricytes, will try to fix it, but it not not has good has it was originally
Location of demyelination affect on symptoms
Presenting symptoms of MS depend on the location of the demyelinating lesions:
● Visual
● Sensory
● Motor
● Cognitive
Optic neuritis:
pain that is worsened by eye movement, as well as vision loss that can be partial or total
Honestly a lot of eye issues, another slide goes in detail
Focal Lesion location of optic neuritis
Optic nerve
Diplopia
Double vision
Focal lesion of diplopia
focal lesions are located in the left pons and right middle cerebellar peduncle
Vertigo
, a sensation of dizziness, is a symptom of impaired balance.
Problem in the inner ear
Focal lesion of vertigo
the cerebellar hemispheres
Lhermitte’s sign and Paresthesia
Lhermitte’s sign: electrical shock radiating down the spine upon neck flexion
Paresthesia: numbness/ tingling
Location of focal lesion that cause Lhermitte’s sign and Paresthesia
located in the cervical spinal cord
sensorimotor hemisyndrome
sensory and motor deficits affecting one side of the body, which can include hemiparesis (weakness on one side of the body) and hemisensory deficits (sensory issues on one side of the body)
sensorimotor hemisyndrome focal lesion
focal lesion located in the left cerebral hemisphere of a patient will have right sensorimotor hemisyndrome.
What are focal lesions?
Areas of demyelination characteristic of all MS phenotypes, typically occurring around post-capillary venules [8] They are also known as plaques.
What happens to the blood-brain barrier in areas of focal lesions?
It breaks down
Where can focal lesions occur in the brain?
Grey matter and white matter
What is the Expanded Disability Status Scale (EDSS)
The EDSS is the most widely accepted measure of clinical disability in MS. It is a scale that ranges from 0 (a normal neurological examination) to 10 (death due to MS).
Goes up in increments of 0.5
What does the EDSS access? (8 functional system)
The EDSS assesses disability across 8 functional systems (subscales):
Pyramidal
Cerebellar
Brainstem
Sensory
Bowel and bladder
Visual
Mental (cognitive)
Other
What is an important tool for diagnosing and monitoring MS?
Magnetic resonance imaging (MRI) is an important tool for diagnosing and monitoring MS.
Timed 25 foot walk
Gait speed, timing how quickly they can walk, motor impairment, sensory issues and coordination can all slow them down
What is the Symbol Digit Modalities Test (SDMT)?
A neuropsychological test often used to assess cognitive function, particularly processing speed, attention, and visual-motor coordination. It involves matching symbols to numbers according to a key
What are the Fatigue Severity Scale (FSS) and the Modified Fatigue Impact Scale (MFIS)?
Patient-reported outcome measures used to assess the severity and impact of fatigue.
What is symptoms tied to
Many signs and symptoms, they are non specific, closely tied to where the Neurodegeneration are affecting in the body
Common measures of symptoms
EDSS
Timed 25 foot walk
SDMT (cognitive)
FSS or MFIS (fatigue)
What is the pyramidal system?
Also known as the corticospinal tract, the pyramidal system is responsible for controlling voluntary movements.
How does the doctor assess pyramidal function in the video?
Evaluating her leg strength, such as her ability to lift her leg against gravity and push down against resistance. [2, 3]
Testing her reflexes, as brisk reflexes can indicate an issue with the pyramidal system.
Clonus, dorsiflex ankle, and fooot vibrates indicate clones, it being present is pyramidal sign