Week 3 - Multiple Sclerosis Flashcards
What is Multiple Sclerosis?
A demyelinating disease of the central nervous system affecting the brain, spinal cord and optic nerves
Autoimmune demyelination results in?
Lesion specific symptoms
What are 4 lesion specific symptoms of MS?
Visual loss/symptoms
Sensory loss
Motor weakness
Vestibular system dysfunction
What are nodes of Ranvier?
The periodic gap in the insulating sheath (myelin) on the axon of certain neurons that serves to facilitate the rapid conduction of nerve impulses.
What is the action potential?
An explosive release of charge between a nerve cell (neuron) and its surroundings
What is Saltatory conduction?
The propagation of action potentials along myelinated axons from one node of Ranvier to the next node, increasing the conduction velocity of action potentials
Why does demyelination occur in MS?
The blood brain barrier breaks down causing an autoimmune response. This causes the macrophages and antibodies to attack the myelin around neurons, which cause plaque formation and reduce saltatory conduction.
What are the 4 types of MS?
Relapsing Remitting MS (RRMS)
Secondary Progressive MS (SPMS)
Primary Progressive MS (PPMS)
Progressive Relapsing MS (PRMS)
What is Relapsing Remitting MS?
Episodes of acute worsening with recovery and stable course between relapses.
What is Secondary progressive MS?
Gradual neurological deterioration with or without superimposed relapses. Typically develops from RRMS
What is Primary Progressive MS?
Gradual, nearly continuous neurological deterioration from onset of symptoms
What is Progressive Relapsing MS?
Gradual neurological deterioration from onset of symptoms with subsequent superimposed relapses.
Which is the most common type of MS?
Relapsing remitting, 85% of cases
What causes MS?
Genetic
Infection
Environment
What are risk factors of MS?
Vitamin D deficiency under 15
Childhood obesity
Cigarette smoking
What gender is more likely to have MS?
Female, 2.5:1
What is the average age of onset?
25-35 years
How is MS diagnosed?
The revised McDonald Diagnostic Criteria
What are the most common initial symptoms of MS
Visual/oculomotor (49% of cases) Weakness/sensory disturbance in one or more limbs (40%) Incoordination (23%) Genitourinary/bowel dysfunction (10%) Fatigue Heat intolerance
What determines which symptoms are seen in a person with MS?
The location of the affected nerve fibres.
What are the 5 categories of symptoms of MS?
- Sensory
- Motor
- Visual
- Cognitive and communicative
- Psychological
What are sensory symptoms of MS?
Numbness Tingling Pins and needles Tightness Pain Hypersensitivity
What are motor symptoms of MS?
Increased muscle tone in affected limbs Spasticity Exaggerated deep tendon reflexes Clonus Muscle weakness Dysphagia
What is clonus?
Clonus is involuntary and rhythmic muscle contractions caused by a permanent lesion in descending motor neurons.
What is dysphagia?
Difficulty swallowing
What 3 impairments are caused by impairment of cranial nerves?
Impairment of smell
Impairment of visual pathways
Uhthoff’s phenomenon
What is Uhthoff’s phenomenon?
The worsening of MS symptoms when the body gets overheated, whether it be from hot weather, exercise, fever, or saunas and hot tubs
How is vision impaired by cranial nerve impairment?
Impairment of oculomotor pathways Optic neuritis Partial or complete loss of vision Double/blurred vision Pain Nystagmus
What are signs of impairment of cerebellar pathways in MS?
Dysmetria Dysdiadochokinesia Decomposition of complex movements Action tremor in head and limbs Truncal ataxia Scanning speech
What is dysmetria?
Improper measuring of distance in muscular acts
What is Dysdiadochokinesia?
The inability to perform rapid alternating muscle movements eg. pronation/supernation.
What is an action tremor?
A tremor that occurs with the voluntary movement of a muscle
What is truncal ataxia?
A wide-based “drunken sailor” gait characterised by uncertain starts and stops, lateral deviations and unequal steps
What is scanning speech?
A type of ataxic dysarthria in which spoken words are broken up into separate syllables, often separated by a noticeable pause, and spoken with varying force.
What are signs of impairment of the genitourinary system?
Sexual dysfunction, eg. muscular control, altered sensation
Bladder issues eg. urgency and incontinence.
What are signs of cognitive and communicative issues in MS?
Memory loss
Difficulty with complex ideas
Reduced attention span
Slurred speech
What are signs of psychological impairment in MS?
Depressed
Euphoric
Impulsivity
Emotional lability
What is emotional lability?
Rapid, often exaggerated changes in mood, where strong emotions or feelings (uncontrollable laughing or crying, or heightened irritability or temper) occur.
What is the prognosis of MS?
Difficult to predict, however life expectancy is reduced by 5-10 years compared to age matched normal.
How many relapses do patients with RRMS have per year?
1-2
True or false; most patients with RRMS convert to SPMS 10-20 years from onset?
True
What % of patients are unable to work after 10 years with MS?
50-80%
How is MS treated?
Immunomodulatory therapy (IMT) and drugs to relieve and modify symptoms.
What does immunomodulatory therapy do?
Aims to modify the underlying immune disorder and its response
How are MS relapses managed?
Corticosteroids and high dose IV methylprednisolone
How are symptoms of MS managed?
Botox for spasticity
Pain medication
Sexual problems - viagra
Depression and fatigue - Fluoxetine
What is the role of Allied health in MS care?
Management of activity limitations Treatment of complications Minimise the impact of condition on activity and participation in life. Maintenance of life roles Addressing specific symptoms.
