Multiple Sclerosis Flashcards
Pathophysiology of multiple sclerosis
Autoimmune demyelination of the myelinated neurones in the CNS
Who typically gets multiple sclerosis
Typically presents in young adults under 50 yo
Symptoms improve when pregnant and post partum
Myelination in the central and peripheral nervous system
CNS - oligodendrocytes
PNS - Schwann cells
Features of MS
Episodic - relapsing and remitting
Disseminated in time and space - lesions change location with time
Risk factors for MS
EBV
Low vitamin D
Smoking
Obesity
Presentation of signs and symptoms in MS
Symptoms progress over 24 hours and at first presentation can persist for days to weeks before improving
Features of MS
Optic neuritis - unilateral vision loss
Diplopia - internuclear opthalmoplegia and conjugate lateral gaze disorder
Focal weakness:
- Bell’s palsy - unilateral facial palsy - CN VII
- Horners syndrome
- Limb paralysis
- incontinence
Focal sensory symptoms:
- trigeminal neuralgia
- numbness
- paraesthesia
- Lhermitte’s sign
Ataxia - positive Romberg’s sign
Internuclear opthalmoplegia
Dysfunction in the nerve fibres that connect between the cranial nerve nuclei that control eye movement
Conjugate lateral gaze dysfunction
When looking laterally towards the affected eye, the affected eye will not be able to abduct
Lhermitte’s sign
Electric shock sensation that travels down the spine and into the limbs when flexing the neck due to stretching the demyelinated dorsal column indicating disease in the cervical spinal cord in the dorsal column
Types of MS
Clinically isolated syndrome - cannot be diagnosed as MS as require at least 2 episodes
Relapsing - remitting
Secondary progressive - relapsing and remitting at first but now does not completely remit and there is worsening and permanence
Primary progressive - Worsening of disease and neurological symptoms from the point of diagnosis without initial relapsing and remitting
How to diagnose MS
Symptoms must be present over 1 year (primary progressive)
Diagnosis made by neurologist
Investigations:
- MRI whole spine
- Lumbar puncture - oligoclonal bands in CSF
Optical neuritis presentation
Central scotoma - enlarged blind spot
Pain on eye movement
Impaired colour vision
Relative afferent pupillary defect
Differentials for optic neuritis
Sarcoidosis SLE Syphilis Measles Mumps Lyme disease
Treatment of optic neuritis
Urgent referral to ophthalmology
Steroids
Recovery takes 2 - 6 weeks
