Multiple Sclerosis Flashcards
(35 cards)
What is multiple sclerosis?
It is a chronic and progressive condition that involves demyelination of the myelinated neurones in the central nervous system
This is caused by an inflammatory process involving the activated immune cells against myelin
What type of reaction is multiple sclerosis?
Type IV hypersensitivity reaction = cell mediated
It is an autoimmune condition
Explain the pathophysiology of multiple sclerosis?
Myelin covers the axons of neurones in the CNS
- this is myelin helps the electrical impulse move faster along the axon
- myelin is provided by cells that wrap themselves around the axons
Multiple sclerosis typically only affects the CNS - the oligodendrocytes
- There is inflammation around myelin and infiltration of immune cells that cause damage to the myelin
○ This affects the way electrical signal travel along the nerve leading to symptoms of multiple sclerosis
When a patient presents with symptoms of a clinical “attack” of MS, for example, an episode of optic neuritis, there are usually other lesions of demyelination at the same time throughout the CNS, most of which are not causing symptoms
In early disease, re-myelination can occur and symptoms can resolve
- In later stages of the disease, re-myelination is incomplete and symptoms gradually becomes more permanent
A characteristic feature of MS is that lesions vary in their location over time, meaning that different nerves are affected and symptoms change over time
- The key expression to remember the way MS lesions change location over time is that they are “disseminated in time and space”
What is the aetiology of multiple sclerosis?
The cause of the demyelination is unclear, but there is growing evidence that it is influenced by a combination of:
- Multiple genes
- Epstein-Barr virus
- Low vitamin D
- Smoking
- Obesity
When does multiple sclerosis present?
Early onset = 20-30s
Typically presents in young adults - under 50’s
More common in women
Symptoms tend to improve in pregnancy and in the postpartum period
What is the initial presentation?
Initial presentation
- Relapse - demyelination and inflammation - Gradual onset over days - Stabilises days to week - Gradual resolution - Partial or complete recovery
What is the relapse phase presentation?
Optic neuritis - most commonly Sensory symptoms Limb Weakness Brainstem problems Spinal cord problems Myelitis
What is optic neuritis?
It involves the demyelination of the optic nerve and loss of vision in one eyes
What are the clinical signs of optic neuritis?
Pain on moving eye Colour vision disrupted Initial swelling of optic disc Optic atrophy Relative afferent pupillary defect
What are the sensory symptoms that can present in multiple sclerosis?
Trigeminal Neuralgia
Numbness
Paraesthesia - pins and needles
What are the brain stem problems that can present in multiple sclerosis?
Cranial nerve involvement
Diplopia
Pons-internuclear ophthalmoplegia - disorder of horizontal ocular movement due to a lesion in the brainstem
Vertigo / ataxia - problem with coordinated movement
Upper motor signs
What are the the spinal cord problems that can present in multiple sclerosis?
Bilateral motor and sensory symptoms
Bladder involvement
Myelitis
- inflammation of the spinal cord
What is the clinical presentation of myelitis?
Weakness / upper motor neurone changes below level of demyelination
Bladder and bowel involvement
What are some signs and symptoms of progressive phases of multiple sclerosis?
Fatigue Temperature sensitivity Sensory symptoms Stiffness or spasms Balance problems Slurred speech Bladder and bowel Diplopia/oscillopsia/visual loss Swallowing Cognitive dementia/emotional liability
What can be found in the examination of MS, where signs observed depend on where the demyelination has occurred and the stage of disease?
Afferent pupillary defect Nystagmus Cerebellar signs Sensory signs Weakness Spasticity Hyperreflexia Plantar extensor
What is Charcot’s neurologic triad?
Triad of symptoms related to multiple sclerosis
What symptoms present as part of Charcot’s neurologic triad?
Dysarthria
- difficulty or unclear speech
- plaques in brainstem interfere with conscious movements - eating and talking, or unconscious movements - swallowing
Nystagmus
- involuntary rapid eye movements
- plaques in nerves of the eyes
- can affect the optic nerve - loss of vision or optic neuritis , or eye movements - pain or double vision
Intention tremor
- plaques along motor pathways
- muscle weakness
- tremors
- ataxia
- paralysis
What are the symptoms if there are plaques in sensory pathways from skin?
Numbness
Pins and needles
Paraesthesia
What are the symptoms if there are plaques in the autonomic nervous system?
Bowel and bladder problems
Sexual dysfunction
How can multiple sclerosis affect higher order activities?
Poor concentration and critical thinking
Depression and anxiety
What are the disease patterns of multiple sclerosis?
The disease course is highly variable between individuals - Some patients may have mild relapsing-remitting episodes for life whereas others have primary progressive MS that progresses without any improvement in symptoms
- There are certain classifications used to describe the of MS in an individuals
- These patterns are not separate conditions but part of the spectrum of disease activity
Disease patterns are
- Clinical isolated syndrome
- Relapsing - remitting MS
- Primary progressive MS
- Secondary progressive MS
What is the clinical isolated syndrome?
Refers to the first episode of neurologic symptoms that last at least 24 hours, first episode of demyelination
Sometimes there are no further episodes
How does clinical isolated syndrome progress?
Further relapses are due to underlying infection
Progression
- Axonal loss is important for disease progression and development of persistent disability
Can lesions be seen in clinical isolated syndrome?
If lesions are seen on MRI it means that they are more likely to progress to MS
MS cannot be diagnosed on one episode as lesion have not been “disseminated in time and space”
