Multiple Sclerosis Flashcards
Where does multiple sclerosis affect?
White matter, the central nervous system - it doesn’t affect the peripheral nerves
What is the disease mechanism of MS?
Activated T cells cross the blood brain barrier causing demyelination - acute inflammation of myelin sheath - loss of function - post inflammatory gliosis
What is meant by gliosis?
Reactive change of glial cells in response to damage to central nervous system - in most cases it involves proliferation or hypertrophy of several different types of glial cells including astrocytes, microglia and oligodendrocytes.
(proliferation and hypertrophy of glial cells after damage to the CNS)
What is seen on MRI of MS patients?
Lesions or plaques
Axonal loss is seen as black holes on MRI - later seen as cerebral atrophy
Where is MS rare?
Rare in indigenous population of africa and australasia
What is the pathogenesis of MS?
Complex genetic inheritance - association with autoimmune disease
What percent of MS cases present with a relapse?
80%
What are the likely features of relapse?
Optic neuritis
Sensory symptoms
Limb weakness
Brainstem diplopia/vertigo/ataxia
Spinal cord - bilateral symptoms and signs +/- bladder
Ataxia: Loss of full control of body movements
What is the presentation of optic neuritis?
Subacute visual loss
Pain on moving eye
Distorted colour vision
Initial swelling of optic disk
Optic atrophy is seen later
Relative afferent pupillary defect (pupil dilates when light shines)
What is the differential diagnosis for optic neuritis?
- Neuromyelitis optica
- Sarcoidosis
- Ischaemic optic neuropathy
- Toxic/ drugs/ B12 deficiency
- Wegeners granulomatosis
- Local compression
- Lebers hereditary optic neuropathy
What is the result of brainstem relapse?
Cranial nerve involvement
Pons - internuclear ophthalmoplegia - ophthalmoplegia is paralysis of muscles within or surrounding the eye
vertigo, nystagmus, ataxia, diploplia
Define myelitis
Inflammation of the spinal cord
Define transverse myelitis
Inflammation of the spinal cord
Inflammation results in damage to the nerve cells and loss of their myelin sheath leading to reduced conductivity
Transverse implies that the inflammation extends across the entire width of the spinal cord
What are the common features of transverse myelitis
What are the common features of transverse myelitis (complete myelitis)?
Weakness in arms and legs
Pain
Sensory alterations
Bowel and bladder dysfunction
What is the diagnosis of MS?
•MS=episodes of demyelination disseminated in space and time
May be clinical or MRI based diagnosis
Posers criteria
Macdonald criteria
When might further relapses occur?
Within months or years of first relapse
What signs and symptoms do MS patients accumulate?
Fatigue
Temperature sensitivity
Sensory
Stiffness of spasms
Balance, slurred speech
Swallowing
Bladder and bowel
Diplopia, oscillopsia, visual loss
Cognitive - demential / emotional liability
Oscillopsia is a visual disturbance in which objects in the visual field appear to oscillate
What are the things to look for on examination of a patient with suspected MS?
–Afferent pupillary defect
–Nystagmus or abnormal eye movements
–Cerebellar signs
–Sensory signs
–Weakness
–Spasticity
–Hyperreflexia
–Plantars extensor
For every 10 lesions seen on MRI, how many relapses are expected?
1 - scans and patient symptoms and signs often do not correlate
What do white spots indicate on an MRI?
Not necessarily MS - White spots are common in smokers and hypertensives
What indicator is used in MRI?
Gadolinium - indicates acute inflammation
What are other investigations for MS?
Lumbar puncture - oligoclonal bands present in CSF but not serum - Oligoclonal bands – sign of inflammation in the CNS – should only be found in CNS and not in the blood, MS is isolated to the CNS. Bands in CNS and serum just means widespread inflammation.
Bloods - exclude other inflammatory conditions
Chest X-ray
Visual/Somatosensory evoked response
What is the differential diagnosis for MS?
Acute disseminating encephalomyelitis
Other autoimmune disease - SLE
Sarcoidosis
Vasculitis
Infection such as limes disease, HTLV - 1
What are the types of MS?
Relapsing remitting
Secondary progressive
Primary progressive (this does not have relapses but is constantly progressive)
Sensory (does not run into disability)
Malignant
What percentage of relapsing remitting MS go on to develop secondary disease?
Most:
–25% 10 years from onset
–50% 20 years
–75% after 35 years.
What is the likelihood of affecting daily life vs causing severe disability?
1/4 MS never affects activities of daily living
15% severely disabled quickly
1 in 4 will require a wheelchair at some point
What are the good prognostic indicators?
–female
–Present with optic neuritis
–Long interval between 1st and 2nd relapse
–Few relapses in 1st 5 years
What are the bad prognostic indicators?
– male
–Older age
–Multifocal symptoms and signs
–Motor symptoms and signs
What are the features of primary progressive MS?
- Often presents in 5th and 6th decade
- No relapses
- Spinal symptoms
- Bladder symptoms
- Prognosis poor
- M:F = 1:1
What is the treatment for acute relapse?
Look out for underlying infection
Oral prednisolone
Rehabilitation
Symptomatic treatment
Vaccination usually advised to prevent further viral infections
Relapses reduced during pregnancy, however there is an increased risk in the first 3 months postpartum
What are the first line treatments in the effort to modify the disease?
s/c or i/m injections:
beta interferons
glatiramer acetate
Oral treatments:
Teriflunomide
Dimethyl Fumarate
What are the side effects of these drugs?
Flu-like symptoms
Injection site reaction
Abnormalities of blood count and liver function
What is the effect of these drugs?
Reduce the relapse rate - 1/3
No effect on progression of disability
Not a cure
Daily - weekly IM/SC injection
What are 2nd line agents?
Natalizumab
Fingolimod tablets
Alemtuzumub
How do we treat symptoms of spasticity?
Muscle relaxants, antispasmodics, physiotherapy
How do we treat symptoms of dysaesthesia?
Amitriptyline, gabapentin
How do we treat symptoms of Urinary issues?
Anticholinergic treatment, bladder stimulation, catheterisation
How do we treat symptoms of constipation?
Laxitives
How do we treat problems with sexual dysfunction?
sildenafil
What other symptoms are treated?
Fatigue
Depression
Cognitive function
Tremor
Vision (oscillopsia - carbamazepine)
Speech / swallowing - SALT
Motor / sensory impairment - multi disciplinary team
All these symptoms are treated the same way, regardless of the presence of MS
What is the multi-disciplinary team for MS?
- MS nurse
- Physiotherapy
- Occupational therapy
- Speech and language therapy
- Dietician
- Rehabilitation specialists
- Continence advisor
- Psychology/psychiatry
What are the components of Charcot’s triad?
What is Lhermitte’s sign?
Electric shock runs down back and radiates to the limbs when bending neck forward
