Diagnosis

Multiple sclerosis

Etiology

Cause [ce3]

• Unknown

• Hypothesis: An unknown trigger

  • Infection

  • Exposure to chemicals

  • Lack of sun exposure

  • Low vitamin D levels

  • Genetic predisposition --> immune dysfunction

Pathophysiology [ce3]

1. Lymphocytic infiltrate and macrophages lead to inflammatory plaques:

   • Injury to the blood-brain barrier

   • Neurodegeneration to axons (myelin sheaths), neurons, and synapses

2. The location of the demyelinating lesions usually dictates the type of clinical deficit:

   • Vision impairment/loss

   • Numbness and tingling

   • Motor symptoms: paresis, tremors, spasticity, and fatigue

   • Sensory symptoms: paresthesia, dysesthesia

   • Urinary and bowel symptoms: incontinence, retention, urgency, constipation, diarrhea, and reflux

   • Cognitive impairment: memory impairment, difficulty concentrating

   • Vestibular symptoms: vertigo, gait imbalance

   • Bulbar dysfunction: dysarthria and dysphagi

   • Psychiatric symptoms: depression and anxiety

   • Brainstem symptoms: facial asymmetry, diplopia, oscillopsia

3. As inflammation resolves, some remyelination occurs, but some recovery of function could be due to neuroplasticity

Classification [9hc][ce3]

• Relapsing-remitting (80% of cases): Benign course with complete remission between relapses

• Primary progressive (15-20%): A gradual deterioration from onset without relapses

• Secondary progressive: An initial relapsing-remitting course, then a more gradual neurological decline

• Progressive-relapsing (5%): A gradual deterioration with superimposed relapses

Epidemiology

Incidence per 100.000 [ukt][sh4][roz][dik][4ur][tn7][bdc][vtd][yd3]

Prevalence per 100.000 [ukt][sh4][roz][dik][4ur][tn7][bdc][vtd][yd3]

Approach

• Blood test: WBC, CRP, thyroid function tests, vitamin B12

• Ophthalmoscopy

• Lumbar puncture

• MRI caput

• CSF electrophoresis

• EEG

• Visual evoked potentials

Diagnostic criteria

1. Two or more attacks

2. Objective clinical evidence of 1 lesion

Treatment

1. Treatment of acute relapse: [9hc]

   • IV Methylprednisolone 1 g daily for 3-7 days (followed by a short prednisone taper)

   • IV immunoglobulin

   • Plasma exchange (plasmapheresis)

   • Dexamethasone

   • Treat precipitants of MS: infection, fever, urine retention

2. Immunomodulatory therapy for the underlying immune disorder

   • Interferons (IFN beta)

   • Sphingosine 1-phosphate receptor modulators (siponimod, fingolimod, ozanimod)

   • Monoclonal antibodies (enatalizumab, alemtuzumab, ocrelizumab, ublituximab)

   • Cyclophosphamide, Mitoxantrone

3. Symptomatic therapy

   • Fatigue: amantadine, methylphenidate, and fluoxetine

   • Depression: Selective serotonin reuptake inhibitors

   • Spasticity: Baclofen

   • Pain: Tricyclic antidepressants

   • Sexual dysfunction: Oral phosphodiesterase type 5 inhibitors (sildenafil)

   • Optic neuritis: Intravenous methylprednisolone

Differential diagnoses

Acute disseminated encephalomyelitis, Antiphospholipid syndrome, Arteriovenous malformation, Balo concentric sclerosis, Behcet's disease, Brain tumor, Central pontine myelinolysis, Encephalitis, Fabry disease, Herpes simplex, Herpes zoster, HIV, Hyperthyroidism, Hypothyroidism, Lyme disease, Migraine, Optic neuritis, Primary lateral sclerosis, Progressive multifocal leukoencephalitis, Radiation myelitis, Sarcoidosis, Schilder's disease, Sjogren syndrome, Spinal cord infarction, Spinal cord injury, Spinal cord tumor, Stroke, Susac syndrome, Syphilis, Systemic lupus erythematosus, Transverse myelitis, Trigeminal neuralgia, Vasculitis, Vitamin B12 deficiency, Wegener's granulomatosis