Multiple Sclerosis(MS) is disorder of central nervous system characterised by Demyelination, Inflamation and Sclerosis supposed to be either immune mediated or due to defective myelin production or combination of both.

Myelin sheath is produced by cells called oligodendrocytes. Myelin sheath is necessary to conduct electrical signals through neurons.

Genetics, Lifestyle and Environmental factors are believed to be contributing to the development of the disease and viral infection is believed to be the triggering factor.


Multiple Sclerosis in many patients starts as Clinically Isolated Syndrome (CIS), it is the term used for the very first episode of neurological symptoms in demyelinating diseases. It is currently considered as the best indicator of future probability of development of multiple sclerosis. In multiple it typically develops over days in which

  • 45% of cases presents with signs of motor and sensory deficits
  • 20% of cases presents with optic neuritis
  • 10% of cases presents with brain stem dysfunctions
  • 25% of cases shows more than one of the above

Types Of Multiple Sclerosis

Multiple Sclerosis International Federation Classifies MS into 4 types

  1. Clinically Isolated Syndrome (CIS)
  2. Relapsing Remitting Multiple Sclerosis(RRMS)
  3. Primary Progressive Multiple Sclerosis(PPMS)
  4. Secondary Progressive Multiple Sclerosis(SPMS)

MS may present itself in three basic pattern as mentioned below

  • RELAPSING – 85% of all the cases shows this pattern. In this the symptoms comes and goes away lasting for few days to months.
  • PROGRESSIVE – 10% of all the cases shows this pattern. In this form the symptoms develops and persists and keeps building up over time.
  • COMBINED – In this the symptoms appears stays there and keeps building even further on every subsequent attack. In many cases it starts as relapsing and later turns into progressive form

A patient may show symptoms of neurological deficits in any part or system depending upon the region of Central nervous system involved. The most commonly affected regions are white matter of optic nerve, brain stem, basal ganglia, spinal cord, white matter tract close to lateral ventricles causing following common symptoms.

  • Weakness
  • Fatigue
  • Mood disorders
  • Depression
  • Anxiety
  • Cognitive disorders
  • Hypoaesthesia
  • Paraesthesia
  • Spasms
  • Ataxia
  • Pain
  • Optic neutitis
  • Diplopia
  • Nystagmus
  • Dysarthria
  • Dysphagia
  • Incontinence of stools and/or urine
  • Retention of stools and/or urine

Though present in many other condition but still regarded as classical symptom of Multiple Sclerosis called “Lhermitte’s Phenomenon” is observed in many cases; where in; patient feels electric shock like pain running up and down the spine and through the spine towards the limbs.

Uhthoff’s Phenomenon is seen in patients with demyelinating diseases especially in Multiple Sclerosis, wherein the nerve impulse conduction is blocked whenever the body gets overheated due to hot climate or over exercise or fever etc. and symptoms subsides as soon as body temperature normalises.

Scales to Measure Severity and Quantifying Disability of MS

  • Multiple Sclerosis Composite – It is a scale developed by National Multiple Sclerosis Society to measure severity of MS basically used by reasearchers. It is based on testing timed movement of arm walking and cognitive ability.
  • Expanded Disability Status Scale (EDSS Scale) – Quntifies disability in eight different Functional System each having its own score based on clinical findings


Multiple Sclerosis typically shows lesions with inflamation and cholestrol crystal deposits resulting into destruction of neuronal myelin sheath.

MS is believed to be partly immune mediated disorder, if not fully. Still its exact causative factors are not known but is believed to be combination of genetic and environmental factors.

It is believed that inflamatory process is triggered due to T-cell that crosses Blood-Brain Barrier and enters brain due to increased permeability of capillaries as a result of infection or some other unknown factors. This infiltration and harbouring of T-cell into brain causes inflamatory process which not only directly damages myelin sheath but also damages oligodendrocytes which are responsible for production and regeneration of myelin sheath. Thus resulting into deficient myelin sheath. Also there is seen release of astrocytes due to dying oligodendrocytes and cholestrol crystal deposits which further triggers inflamatory process damaging even further. The inflamatory process finally leaves behind scars or so-called “Plaques of Multiple Sclerosis”.

Multiple usually damages myelin sheath of white matter. Myelin sheath is responsible for electrical signal conduction and White Matter is responsible for conduction of signals between two regions of Grey Matter. A deficient or damaged myelin sheath results into deficient signal conduction.

Its observed that MRI taken during acute episode of MS typically show more scars or so-called Sclerotic Plaques of Multiple Sclerosis compare to MRI taken later on. This indicates that to some extent brain has capablity to recover many of the damages after an acute episode of MS.


There is no definitive test available for confirmation of Multiple Sclerosis. Even risky and invasive technique like Biopsy is not definitive.

Usually non-invasive techniques like Intravenous Injected Gadolinium Contrast MRI are used in suspected cases. Gadolinium doesnot cross normal blood brain barrier, so if found in brain after Intravenous injection it suggests leaky blood brain barrier.


  • NAJA

Leave a Reply

Your email address will not be published. Required fields are marked *

Help us fight Spam, please solve below math: *