Multiple Sclerosis Flashcards
What is multiple sclerosis?
Inflammation in CNS»_space; loss of myelination and slowing of nerve conductance.
What is likely to the be the cause of:
- pupil not constricting with light
- next day no vision
- delayed cortical response
- normal fundoscopy?
Optic neuritis.
What is optic neuritis?
Inflammation of the optic nerve.
-causes pain and loss of vision
What proportion of patients with optic neuritis go on to develop MS?
50%.
What is likely to be the cause of:
- tingly numbness starting in feet and ascending to chest
- unsteady walking and fatigued easily
- electric shock sensations when head bent?
Transverse myelitis.
What is transverse myelitis?
Inflammation inside the spinal cord.
-often targets myelin
What is Lhermitte’s phenomenon?
Electrical sensation running down back and into limbs.
-often induced by bending head forwards
What proportion of patients with transverse myelitis go on to develop MS?
50%.
What is the diagnosis if a patient suffers from optic neuritis and transverse myelitis at different times (1+ years apart)?
Multiple sclerosis.
What is the diagnosis if a patient suffers from optic neuritis and transverse myelitis at the same time?
Not definitely MS.
What investigations can be done to diagnose MS?
- MRI
- serum
- CSF analysis
How common is MS?
The most common cause of neurological disability in younf adults (UK).
What is the peak age of onset of MS?
30-40 years.
What is the sex ratio for MS?
More common in females - 2:1.
Which ethnicities have a higher risk of developing MS?
-Northern Europeans
-US caucasians
-Canadians
(Further North of equator)
What is often low in patients who develop MS?
Vitamin D levels.
-not sure why
What drives the inflammation in the CNS?
CD4+ T lymphocytes.
-produce antibodies that activate the complement system
»attack myelin
Give examples of treatments currently used.
- Interferon beta 1-b and 1-a
- Glatiramer acetate
- Teriflunamide
- Flingolimod
Why is interferon beta used to treat MS?
Reduces the number of relapses by a third.
-effective in early disease, not necessarily long term
What drug is commonly used to treat MS?
Methylprednisolone.
What is tysabri (natalizumab)?
1st humanised monoclonal antibody approved for MS treatment.
How does tysabri work?
Inhibits adhesion molecules on surface of immune cells and prevents migration to brain.
-attaches to a4-integrin
What do monoclonal antibodies end in?
- mab.
e. g. infliximab
What are new oral therapies for MS? (3)
- Fingolimod
- Teriflunomide
- Dimethyl fumarate
How does fingolimod work?
Internalises S1P1 receptors»_space; blocks lymphocyte exit from nodes.
-lymphocytes don’t»_space; CNS
How are patients who suffer at least 2 relapses in 2 years treated if JC virus -ve?
Tysabri (1-2 years), then fingolimod.
How are patients who suffer at least 2 relapses in 2 years treated if JC virus +ve?
Straight onto fingolimod.
What is JC virus?
John Cunnigham virus.
What can JC virus cause in MS patients?
Progressive multifocal leukoencephalopathy (PML).
How is aggressive MS treated (3-4 relapses)?
Alemtuzumab (chemotherapy).
What are the types of progression of MS? (4)
- Relapsing-remitting MS
- 1* progressive MS
- 2* progressive MS
- Progressive relapsing MS
How do most patients present?
Most present with relapsing-remitting MS (85%).
-develops to progressive
What is the consequence of presenting with 1* progressive MS?
Faster progression than relapsing-remitting MS.
What does an MRI scan of a patient with relapsing-remitting MS show?
Increased brain lesions.
-over years
What does an MRI scan of a patient with progressive MS show?
Brain atrophy.
-over years
What is spastic paraparesis?
Disorder leading to progressive stiffness and contraction in lower limbs.
-suggests spinal cord problem
What proportion of MS patients are confined to a wheelchair within 10 years?
15%.
What are symptoms of progressive MS?
- Tremour and spasticity
- Fatigue
- Mood problems
- Pain and sensory problems
- Genitosphincteral problems
What are potential targets for neuroprotective therapy?
- Inflammatory mechanisms
- Genetically determined (e.g. degeneration)
- Demyelination
- Growth factor depletion
What type of disorder is MS?
Autoimmune.
Is MS curable?
No, but it is treatable.
What is the most common progression of MS?
Relapsing phase followed by progressive phase.
What is a spinal cord injury?
Disruption to spinal cord»_space; change in motor, sensory or autonomic function.
Is the spinal cord often cut in half when injured?
No, very rarely.
-normally inflammatory cascade»_space; damage
What are upper motor neurons?
Motor neurons originating from the motor region of the brain, brainstem, cerebellum and spinal cord.
What are lower motor neurons?
Motor neurons that come off the brainstem of spinal cord.
-i.e. spinal and cranial nerves
What sort of lesion is a cauda equina lesion?
Lower motor neuron lesion.
-spinal nerves
What is the sex ratio of spinal cord injuries?
4: 1.
- More common in males
What sort of age distribution do spinal cord injuries have?
Bimodal distribution.
-peaks in young age and old age
What is the prevalence of spinal cord injuries in the UK?
40,000.
How does the incidence of spinal cord injuries alter across the week? Suggest why.
Highest at the weekend (40%).
-alcohol, recreational activities, etc.
What are the 2 types of causes of spinal cord injuries?
Congenital
Acquired
What are the main congenital causes of spinal cord injury? (4)
- Spina bifida
- Birth trauma
- Congenital spinal anomaly
- Spinal muscular atrophy
What are the main acquired causes of spinal cord injury? (5)
- Vehicle crashes (trauma)
- Bacterial abscesses (infection)
- Inflammation
- 2* tumour
- Degeneration
How is the level of spinal cord injury examined?
- Dermatomes (light tough, pinprick)
- Myotomes (manual muscle testing)
What does a cervical lesion (C1 to T1) cause?
Tetraplegia/quadriplegia.
if hand/arm affected
What does a thoracic lesion (T2 to L5) cause?
Paraplegia.
What scale is used to grade spinal cord injury?
AISA impairment scale.
A»_space; D
What does A on the AISA impairment scale mean?
COMPLETE - No motor or sensory function is preserved in S5.
-faecal incontinence
What does D on the AISA impairment scale mean?
INCOMPLETE - Motor function preserved and at least half of key muscles below the neurological level have a muscle grade of 3+.
What does muscle grade 3 indicate?
Full range of movement against gravity.
-can normally walk again
What are the 2 categories of spinal pathways?
- Descending motor tracts
- Ascending motor tracts
What are the 2 types of descending motor tracts?
- Lateral corticospinal
- Anterior corticospinal
What are the 3 types of ascending motor tracts?
- Dorsal column
- Anterolateral spinothalamic
- Spinocerebellar
Where do descending motor tracts begin?
In the motor cortex.
What are the clinical types of spinal cord lesion? (4)
- Anterior cord
- Posterior cord
- Central cord
- Brown-sequard syndrome
What typically causes anterior cord lesions?
Vascular lesions.
-blood enters cord anteriorly
Who are central cord lesions more common in?
Elderly.
What is Brown-Sequard syndrome?
A lesion in spinal cord»_space; weakness or paralysis (hemiparaplegia) on one side of the body and a loss of sensation (hemianesthesia) on the opposite side.
What is the prognosis for mobility if A on the AISA scale?
1%.
What is the prognosis for mobility if D on the AISA scale?
100%.
What proportion of
88%.
What proportion of 65-80 yr olds who suffer from a spinal cord injury reach there adjusted life expectancy?
50%.
What is the average life expectancy of >80 yr olds who suffer from a spinal cord injury?
2.5 years.
What are common injuries associated with spinal cord injuries? (4)
- Limb (20%)
- Chest (19%)
- Head (12%)
- Abdominal (3%)
What can lesions above T6 and spinal shock lead to?
Excessive vagal stimulation.
What does excessive vagal stimulation cause?
- Bradycardia
- Asystole
How is excessive vagal stimulation avoided?
- Atropine prior to intubation
- Suctioning
What can cause autonomic dysreflexia?
Lesions above T6.
How does autonomic dysreflexia present?
- Headache
- Hypertension
- Facial flushing
What are acute complications of spinal cord injuries? (3)
- UTIs (e.g. stones)
- Respiratory infection
- Pressure sores (e.g. osteomyelitis)
What are the chronic complications of spinal cord injuries? (2)
- Progressive neurological decline (e.g. syringomyelia)
- Rheumatological complications (e.g. hetertopic ossification)
How are spinal cord injury complications managed?
- Bed rest
- Skin care
- Bladder care
- Prevent thromboembolic complications.
