Multiple Sclerosis Flashcards
Define
inflammatory demyelinating disease of the CNS
Relapsing-Remitting MS
- COMMONEST form
- Clinical attacks of demyelination with complete recovery in between attacks
Clinically Isolated Syndrome
- Single clinical attack of demyelination
- The attack in itself does NOT count as MS
- 10-50% progress to develop MS
Primary Progressive MS
- Steady accumulation of disability with NO relapsing-remitting pattern
Marburg Variant
- Severe fulminant variant of MS leading to advanced disability or death within weeks
Causes
UNKNOWN
Autoimmune basis with potential environmental trigger in genetically susceptible individuals
Immune-mediated damage to myelin sheaths results in impaired axonal conduction
Risk Factors
- EBV exposure
- Prenatal vitamin D levels
Epidemiology
UK prevalence: 1/1000
2 x as common in FEMALES
Age of presentation: 20-40 yrs
Symptoms
Varies depending on the site of inflammation
Optic Neuritis (COMMONEST)
- Unilateral deterioration of visual acuity and colour perception
- Pain on eye movement
- Common first symptoms of multiple sclerosis
Sensory
- Pins and needles
- Numbness
- Burning
Motor
- Limb weakness
- Spasms
- Stiffness
- Heaviness
Autonomic
- Urinary urgency
- Hesitancy
- Incontinence
- Impotence
Psychological
- Depression
- Psychosis
Uhthoff’s Sign - worsening of neurological symptoms as the body gets overheated from hot weather, exercise, saunas, hot tubs etc.
Lhermitte’s Sign - an electrical sensation that runs down the back and into the limbs when the neck is flexed
Signs
Optic Neuritis
- Impaired visual acuity (MOST COMMON)
- Loss of coloured vision
Visual Field Testing
- Central scotoma (if optic nerve is affected)
- Scotoma = a blind spot in the normal visual field
- Field defects (if optic radiations are affected)
Relative Afferent Pupillary Defect (RAPD)
Internuclear Ophthalmoplegia
- Lateral horizontal gaze causes failure of adduction of the contralateral eye
- Indicates lesion of the contralateral medial longitudinal fasciculus
Sensory
- Paraesthesia
Motor
- UMN signs
Cerebellar
- Limb ataxia (intention tremor, past-pointing, dysmetria)
- Dysdiadochokinesia
- Ataxic wide-based gait
- Scanning speech
Investigations
Diagnosis is based on the finding of two or more CNS lesions with corresponding symptoms, separated in time and space - McDONALD CRITERIA
Lumbar Puncture
- Microscopy - exclude infection/inflammatory causes
- CSF electrophoresis shows unmatched oligoclonal bands
MRI Brain, Cervical and Thoracic Spine (with gadolinium)
- Plaques can be identified
- Gadolinium enhancement shows active lesions
Evoked Potentials
- Visual, auditory and somatosensory evoked potentials may show delayed conduction velocity
