Multiple Sclerosis Flashcards
Define multiple sclerosis?
Multiple sclerosis (MS) is a cell-mediated autoimmune condition characterised by repeated episodes of inflammation of the nervous tissue in the brain and spinal cord, causing loss of the insulating myelin sheath.
Multiple areas of scar tissue (sclerosis) form along the neurons which have been affected.
What is the aetiology of MS?
It is not fully understood what triggers the autoimmune process but it is thought to be both due to genetic and environmental factors.
Environmental factors include:
- Viral infections in early life, they also often precipitate relapses.
- There is also a higher frequency the further away from the equator.
Genetic:
- Higher incidence in patients with 1st degree relatives roughly 2% risk
- Most prevalent in caucasians.
Describe some of the key epidemiological features with regards to MS? (gender, age, ethnic group, geography)
Gender: more common in females
Age: most common onset between 40-50 year olds
Ethnic groups: Caucasian most at risk
Geographical location: Generally increased incidence correlating with distance from the equator.
What are the different patterns of MS?
Relapsing-remitting MS: symptoms come and go. Periods of good health or remission are followed by sudden symptoms or relapses. (80% of people at onset.)
Secondary progressive MS: follows on from relapsing-remitting MS. There are gradually more or worsening symptoms with fewer remissions aka after a relapse the patients baseline is reduced. (About 50% of those with relapsing-remitting MS develop secondary progressive within the first ten years.
Primary progressive MS: from the beginning, symptoms gradually develop and worsen over time (10-15% of people at onset).
Describe the common presentations of MS?
MS can present with a wide range of neurological symptoms and therefore should always be considered as a differential.
Common presentations include:
- Optic neuritis: an acute, sometimes painful, reduction or loss of vision in one eye
- Double vision due to lateral rectus weakness or nystagmus
- Facial palsies
- Fatigue a very prominent feature in MS
However may present very broadly:
- hearing
- cognitive symptoms
- weakness and paraesthesiae
- perineal numbness
What are the differential diagnoses for MS?
Hereditary spastic paraplegia (mimics hereditary MS)
Cerebral variant of SLE presents with features of MS without other clinical manifestations of SLE
Sarcoidosis
AIDs
In patients of african or asian ethnicity:
- tropical spastic paraplegia usually associated to infection
- neuromyelitis optica (an autoimmune condition which mimics MS but has different treatments very rare in caucasian’s but more common in asians and africans.
Describe the investigations used to ascertain a diagnosis of MS?
Baseline bloods to rule out any obvious causes: including B12, Ca2+ and HIV serology
To confirm a diagnosis of MS:
- Visual evoked potential studies should be used 1st line.
- MRI scan: 95% of patients have periventricular lesions and over 90% show discrete white matter abnormalities. Contrast can be used to distinguish between active and inactive inflammatory plaques.
- LP with CSF studies: show rise in total protein with increase in immunoglobulin concentration with presence of oligoclonal cases.
Describe the presentation of relapses?
Any episode of new or a sudden increase (over 24 hours) in distressing symptoms or an increased limitation on activities.
Aka can present as virtually any neurological deficit depending on which area has become demyelinated.
Describe the management of an acute relapse in MS?
Methylprednisolone as soon as possible.
Urinary tract infection must be ruled out with urinalysis before starting course.
Course is 500mg/day for 5 days given over a 4 hour infusion or orally as 5x100mg tablets.
Gastroprotection should be given (ranitidine).
Basis behind steroid use is that it suppresses the autoimmune response.
Describe the symptomatic management of spasticity and weakness in MS?
Weakness:
- Exercises and techniques to maximise strength and endurance appropriate to their circumstances.
- Specialist equipment (for posture for example), particularly important in avoidance of pressure sores
Spasticity:
- Passive stretching with physio/carers to reduce spasticity and prevent contractures
- Baclofen and gabapentin can be given to help relax muscles
- Intramuscular botulinum toxin (botox) can be injected
Describe the management of pain symptoms in MS?
Pain may be neuropathic in origin or musculoskeletal due to reduced mobility.
Suitable analgesia.
Neuropathic pain can be treated with gabapentin, carbamazepine or amitriptyline.
Describe the management of bladder problems in MS?
Rule out UTI and chek post micturation residual bladder volume with an US.
Consider home circumstances (where a toilet is)
Antimuscarinics (anticholinergics) such as oxybutinin and tolteridone can be used in overactive bladder.
Desmopressin (artificial ADH) can be used, max dose is 1 in 24hrs.
Pelvic floor exercises can be trialled.
Lastly intermittent self catheterisation or long term urethral catheterisation.
Describe how fatigue is managed in MS?
Consider an treat any underlying cause: depression, chronic pain.
Medication review can be a side effect of interferon beta.
Advise aerobic exercise may be of benefit.
Offer mindfulness based therapy or CBT.
Pharmacological: amantadine
Outline the main disease modifying therapies available in MS and there effect on relapse rate and long term disability?
Interferon beta: reduces the inflammatory process which characterises MS
Glatiramer: mimics myelin’s structure and again helps to reduce inflammation around neurons.
Both medication demonstrate a 30% reduction in relapses in the first 2 years of therpay. After this the evidence for there use is less clear.
It is thought that Glatiramer may reduce the long term disability however study sizes have been small.
Due to the cost and the question mark surrounding the long term benefit neither medication is currently recommended by NICE but can still be commissioned.
