Multiple sclerosis (MS) is defined as an inflammatory demyelinating disease characterised by the presence of episodic neurological dysfunction in at least 2 areas of the CNS (brain, spinal cord, and optic nerves) separated in time and space.
MS is the most common cause of neurological disability among young adults. MS is most commonly diagnosed between 20 to 40 years old. Irreversible disability can occur, but life expectancy is generally not affected.
Defintion Multiple Sclerosis: Incurable disease of the central nervous system that can affect the brain, spinal cord and optic nerves. Guillain–Barré syndrome: Rapid-onset muscle weakness caused by the immune system damaging the peripheral nervous system. Motor Neuron Disease: Motor neurone disease is largely a sporadic disease of middle and elderly life presenting in the sixth and seventh decades. The classic form of the disease is also referred to as amyotrophic lateral sclerosis and presents with a mixture of upper and lower motor neurone features, such as wasted fasciculating biceps with a brisk or easily obtained biceps deep tendon reflex. The rarer variants of the disease can have a pure upper motor neurone presentation, primary lateral sclerosis, or a pure lower motor neurone presentation, progressive muscular atrophy. Myasthenia Graves: Autoimmune disease characterized by muscle weakness that fluctuates, worsening with exertion, and improving with rest. In about two-thirds of the patients, the involvement of extrinsic ocular muscle presents as the initial symptom, usually progressing to involve other bulbar muscles and limb musculature, resulting in generalized myasthenia gravis. |
Neuron Anatomy
Watch Neurology - Neuron structure and function |
Spinal Cord
Watch Neurology - Spinal cord and Glial cells |
Motor Pathways
Watch Motor Pathway |
TYPES OF MULTIPLE SCLEROSIS BASED ON DISEASE ONSET | |
Relapsing remitting (85% of onset) | Discrete attacks that evolve over days to weeks, followed by some degree of recovery over weeks to months; the patient has no worsening of neurologic function between attacks |
Primary progressive (10% of onset) | Gradual progression without acute attacks or improvements |
Secondary progressive (50% of Relapsing remitting may evolve to secondary progressive) | Initial relapsing remitting disease, followed by gradual neurologic deterioration not associated with acute attacks |
Relapsing progressive (5% of onset) | Like primary progressive, but with some superimposed relapses |
TYPES OF MULTIPLE SCLEROSIS BASED ON DISEASE COURSE | |
Clinically isolated syndrome (commonest first presentation of multiple sclerosis) | Probable first episode of relapsing-remitting multiple sclerosis (eg optic neuritis, transverse myelitis or brainstem episode). If two or more white matter lesions on MRI then about 80% chance of eventual multiple sclerosis; if MRI is normal then only about 20% chance |
Similar Disease but not multiple sclerosis
Common symptoms
Remember Fever or fatigue with a temporary worsening of symptoms is not a relapse but rather a pseudorelapse |
Remember Relapse rate reduced during pregnancy, especially in 3rd trimester. Increase in relapse rate in 6 months after delivery |
COMMON SIGNS AND SYMPTOMS SUGGESTIVE OF CNS DEMYLELINATION | |||
Site | Condition | Symptoms | Sign |
Optic nerve | Optic neuritis | Pain on eye movement, blurred vision | Reduced monocular visual acuity, colour desaturation |
Cerebellum | Cerebellar disease | Unsteadiness | Limb or gait ataxia; horizontal or torsional gaze evoked nystagmus |
Spinal cord (usually multifocal and asymmetric) | Partial myelitis affecting pyramidal tracts | Upper or lower limb weakness | Pyramidal distribution weakness |
Partial myelitis affecting spinothalamic tract and posterior columns | Unilateral or bilateral limb numbness or paraesthesias L’Hermitte’s phenomenon (short electric shock-like sensation on neck movement) | Sensory level | |
Brainstem | |||
Medial longitudinal fasciculus
|
Internuclear ophthalmoplegia | Blurred or double vision | Internuclear ophthalmoplegia |
Bowel/bladder | Loss of upper motor neuron control | Constipation, urinary frequency, urge incontinence, erectile dysfunction |
DEMYELINATING SYNDROMES DIFFERENTIAL DIAGNOSIS
Central
Peripheral
Neuromyelitis Optica |
Other differential diagnosis
Diagnosis Multiple sclerosis remains a clinical diagnosis supported by:
Diagnosis
Remember Attacks may be patient-reported or objectively observed, and must last for a minimum of 24 hours |
Typical sites of lesions on MRI |
Periventricular white matter (if at right angles to the corpus callosum, these are referred to as ‘Dawson fingers’) |
Juxtacortical white matter |
Corpus callosum |
Optic nerve |
Infratentorial structures (pons, cerebellar peduncles and cerebellum) |
Spinal cord |
Course of disease
Side note With symptoms of relapse, it is vital to establish whether the symptoms are definitely neurological. Intercurrent infection, fever, increased environmental temperature, heightened body awareness and depression can all produce ‘pseudorelapses’. Many ‘attacks’ simply reflect heightened body awareness and anxiety, particularly in the first year after diagnosis |
Acute Relapse
Prevention of relapse
Pharmacology Alemtuzumab is a humanised monoclonal Ab binds CD52 (on B cells). Live vaccines are contraindicated. Side effects: Good pastures, 2-3% ITP, 20-30 % autoimmune thyroid disease at 5 years. |
Pharmacology Natalizumab Monoclonal antibody that works by selective inhibition of adhesion molecules, slowing entry of T cells through cerebral capillaries. Used in patients intolerant of/not responding to other immunomodulators. Side effects: fatigue, hypersensitivity hepatotoxicity and has been associated with progressive multifocal leukoencephalopathy |
Treatment of Complication of MS
Lifestyle modification
Complications
Prognosis
"Each patient ought to feel somewhat the better after the physician's visit irrespective of the nature of the illness."
-Warfield Theobald Longcope