most prevalent non-injury related cause of long-term neurological disability in younger adult

autoimmune disease

not directly fatal

life expectancy = 6-11yrs

epidemiology

• onset 20-40years

• 2.5x females compared to males

  • males more severely affected

• more common increasing distance from equator

  • ?vit d

• 1/5 wil have affected relative

• smoking and EBV exposure

Patterns

• inflammatory demyelination

  • white and grey matter of CNS

  • peripheral nervous system unaffected

  • loss of myelin and neuronal/axonal injury

  • over time remyelination can repiar some of this damage

  • Plaques formed from dense clusters

• location, frequncy and balance of injury vs. repair determines pattern and associated diability

• unpredictable course and prognosis

• Typically begins with sudden episode

  • blurring one eye (optic neuritis)

  • double vision (diplopia)

  • unsteadiness

  • sensory impairment

    • upwards from legs

  • dysfunction in limbs

• increasing severity over days - weeks then gradual resolution - patiral/complete over several weeks

• first episode = clnically isolated syndrome

• if 2nd episode or subclinical changes on MRI -> relapsing-remitting MS

Relapsing-remitting MS

• most common pattern (85%)

• recurrent acute neruo episodes = relapses

  • residual symptoms suddenly increase or new symptoms developing

• recovery gradual

  • residual symptoms often remain

• 1 relapse q2yrs

  • frequency and severity vary widely

• high frequency during first 2 years

  • linked to increase likelihood of people devleoping secondary progressive MS and long term disability

Secondary progressive MS

• 2/3 with R-R MS

  • within 15yrs of diagnosis

• progressive worsening of neruological function

  • independent of acute relapses

    • low-grade degenerative process

    • long-term disability in peopel with MS

  • acute attacks may still occur

Benign MS

• 1/10

• period of 10-20yrs without significant disability

Primary progressive MS

• 1/10 with MS

• develop insidiously and progressively from outset

diagnosis

McDonald criteria:

2 or more episodes of inflammatory demyelination to cocur on seperate occasions at lease 30d apart in differnet locations

spearation in time and spacea can be estabilshed with single MRI

• may report positive or negative symptoms

• positive

  • muscle spasm

  • 1/5 will various forms of neuralgia

    • tingling/burning/pruritic sensations in skin of limbs, trunk, face

  • electric shock sensation down spine when neck is flexed (Lhermitte’s symptom)

    • characteristic but not specific

• Negative

  • visual disturbance

    • decrease VA

    • diploplia

  • numbness

  • motor dysfucntion

    • weakness

    • gait disturbances

    • ataxia

  • bladder dysfunction

  • bowel/erectile dysfuction

• may experience transient worsening of symptoms due to heat

  • Uhthoff’s symptom

• optic neuritis

  • 1/4 of people with MS present with this

  • more prevalent among younger women

  • impairment of VA

  • reduced colour vision

    • red desaturation

    • ishihara plates detect reduction in colour perception in 88%

  • eye pain - especially on movement

  • swelling may be observed

  • RAPD present

  • after attck disc may appear pale

    • optic atrophy

• Internuclear opthalmoplegia

  • damage to neuronal connections

  • abducens (VI) and oculomotor (III) cranial nerve nuclei

  • affects horizontal gaze

  • when looks laterally to unaffected side

    • impairment of adduction in affected eye

    • lags behind unaffected eye

    • ‘adduction’ lag

• extensor plantar response

  • can be seen

Differential diagnosis

• psychiatric

• sciatica/msk injury

• carpal tunnel syndrome nad other peripheral nerve disorders

Investigations

• MRI = sensitivity of 95%

  • history often underestimates disease severity

  • other asympomatic cns lesions will be detected on MRI \~80% of people

• Visual evoked potentioals

  • subclincal demyelination of optic nerve

  • non specific and may be N in half MS

• Oligoclonal bands in CSF

  • present 95% iwth well established MS

  • rarely required where characteristic history and MRI changes

Treatment

• 3x disease modifing agents

  • require SA from neurologist

  • complex actions on immune function and mechanism uncertain

  • similar, limited effects on course

  • 1/3 reduction in frequnce of relapses

  • non appear effective with secondary progressive MS

• Acute relapses managed with methylprednisolone

  • relapses more common who have viral infections or major life events

• influenza vaccination may reduce likelihood of MS relapses and minimise risk of respiratory complciations

Other sympotms

• Fatigue

  • 85% of those with MS

  • muscle weakenss and ataxia also present

  • consider

    • depression

    • poor sleep

    • pain

    • inadequate nutrition

  • exercise

  • pysiotherapy

  • aspirin and amantadine = some benefit

• pain affects 2/3

  • restricted movmeent or muscle spasms

  • peripheral pain can be managed with analgesics and physiotherapy

  • CNS lesions also cause pain

• bowel dysufcntion

  • constipation/faecal incontinence 60%

  • fuild/fibre increased before laxative considered

  • overflow incontinence

  • may have difficulty initiating bowel movmeent

    • digital rotatoy stinulation

    • or suppositories

      • bisacodyl or glycerl

  • loperamide = first line

• bladder dysfunction

  • anticholinergics

    • may cause incomplete bladder emptying

    • urinary self-catherisation

  • nocturia

    • desmopressin

      • subsidised by neurologist

• Spasticity and spasm

  • physiotherapy

  • cannabidiol plus tetrahydrocannabinol oromuscoal spray = adjunctive treatment for moderate to severe spasitiicyt

    • not subs

    • erquires ministerial approval

    • contraindicated in severe psychiatric disorders/psychosis

  • baclofen 5mg tds increase 3 day intervals - maintence = 30-80mg/day

  • orphenadrine 100mg bd

  • Dantrolene 25mg od increase to 25mg 2-4 times/day every 4-7 days

  • diazepam

  • Fampridine

19mg orally bd

Managing disability

• cognitive impairment

  • 1/2