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Nervous system

Multiple sclerosis (MS)

Autoimmune inflammation and demyelination of CNS (brain and spinal cord) with subsequent axonal damage.

Although the exact cause of MS is unknown, the disease is thought to occur as an immune-mediated attack on the central nervous system (CNS). | Medcomic/Jorge Muniz

Autoimmune inflammation and demyelination of CNS (brain and spinal cord) with subsequent axonal damage.

Epidemiology

Disability-adjusted life year for multiple sclerosis
Disability-adjusted life year for multiple sclerosis per 100,000 inhabitants in 2004 | Lokal_Profil, CC BY-SA 2.5, https://commons.wikimedia.org/w/index.php?curid=8962898

Etiology

Intrinsic factors:

  • Females
  • HLR-DR2

Extrinsic factors:

  • Infection
  • Vitamin D deficiency
Multiple sclerosis (MS)
The Calgary Guide | http://calgaryguide.ucalgary.ca/

Presentation

Variable presentation:

  • Optic syndromes:
    • Acute optic neuritis (painful unilateral visual loss)
    • Relative afferent pupillary defect (RAPD) or Marcus Gunn pupil: Medical sign observed during the swinging-flashlight testwhereupon the patient’s pupils constrict less (therefore appearing to dilate) when a bright light is swung from the unaffected eye to the affected eye.
  • Brain stem/cerebellar syndromes:
    • Diplopia, ataxia, scanning speech, intention tremor, nystagmus/INO (bilateral > unilateral)
  • Pyramidal tract weakness
  • Spinal cord syndromes:
    • Lhermitte sign or barber chair phenomenon phenomenon: Electric shock-like sensation along spine on neck flexion) (CLASSIC FINDING)
    • Neurogenic bladder
    • Paraparesis (partial paralysis of the lower limbs)
    • Sensory manifestations affecting the trunk or one or more extremity
  • Uhthoff’s phenomenon: Worsening of neurologic symptoms in multiple sclerosis (MS) and other neurological, demyelinating conditions when the body gets overheated from hot weather, exercise, fever, or saunas and hot tubs.
    • Due to the effect of ↑ temperature → Nerve conduction (impulses either blocked or slowed down in a damaged nerve but once the body temperature is normalized, signs and symptoms may disappear or improve)

Clinical Course

  • Relapsing-remitting
    • M/C type
    • Least severe
Progression of MS subtypes
Progression of MS subtypes | Faigl Ladislav, Public Domain, https://commons.wikimedia.org/w/index.php?curid=7622074

Diagnosis

Clinical examination:

Relative afferent pupillary defect (RAPD):

Direct pupillary light reaction and the accompanying consensual reaction of the opposite pupil are weaker on illumination of the affected eye than on illumination of the unaffected eye due to unilateral or asymmetrical disease of the retina or optic nerve
Swinging flashlight test
Swinging flashlight test in a patient with left optic neuritis (schematic figure). The pupils react more rapidly, and to a greater extent, with illumination of the healthy right eye, compared to the affected left eye | Wilhelm, H., & Schabet, M. (2015). The Diagnosis and Treatment of Optic Neuritis. Deutsches Arzteblatt international, 112(37), 616–626. https://doi.org/10.3238/arztebl.2015.0616
  • Normal/↓ Vitamin D
  • Evoked response potential

CSF examination:

  • Oligoclonal band (DIAGNOSTIC)
  • ↑ IgG & myelin basic protein

MRI (GOLD STANDARD):

  • Periventricular plaques (areas of oligodendrocyte loss and reactive gliosis)
  • Multiple white matter lesions disseminated in space and time
Multiple sclerosis MRI animation
Animation showing dissemination of brain lesions in time and space as demonstrated by monthly MRI studies along a year | Monthly_multiple_sclerosis_anim.gif: Waglionederivative work: Garrondo – This file was derived from  Monthly multiple sclerosis anim.gif:, Public Domain, https://commons.wikimedia.org/w/index.php?curid=26444219

Differential diagnosis:

  • Spinal cord neoplasm & Spinal cord AVM: D/D Constant symptoms & lateralisation of symptoms
  • Cryptogenic stroke: Elderly, sudden onset, no remission from stroke
  • Subacute combined degeneration (SCD): Long-term Vit. B12 deficiency, alcoholics, malnutrition
  • Amyotrophic lateral sclerosis (ALS): Weakness + muscle atrophy

Management

Supportive management:

  • Counselling of patient, family & friends
  • Lifestyle changes:
    • Stop smoking
    • Weight control
    • Healthy diet

Treatment of acute exacerbation

  1. Admission into hospital
  2. IV Methyl prednisolone (2-3 days)
  3. PO Prednisolone (3-4 days)

Treatment of disease progression

  • Interferon β-1: S/E: Flu-like symptoms
  • Glatiramer: Relatively safe during pregnancy
  • Natalizumab: S/E: Progressive Multiple Leukoencephalopathy (PML)
  • Fingolomod: S/E: Worsens DM & macular oedema

Treatment of complications/symptomatic treatment:

  • Muscle spasticity: Baclofen, Dantrolene, Diazepam
  • Fatigue & narcolepsy: Amantadine, Modafinil, Methylphenidate
  • Pain: Phenytoin, Carbamazepine, Pregabalin
  • Urinary urgency: Tolterodine, Oxybutynin

Summary

Multiple sclerosis (MS)

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