A short introduction to MULTIPLE SCLEROSIS

INTRODUCTION

MULTIPLE SCLEROSIS is a condition of the central nerves system (which indudes the brain and the spinal cord). MS does not effect any other nerves in the body! The damage to the nerves in the central nerves system is caused by the body's own immune system attacking the nerves, myelin sheath, which just as if you had cut your hand, the platelets in your blood fill the damaged area forming a scar which in tum disrupts the nerve impulses. And there you have Multiple Sclerosis.

CLINICAL DIAGNOSIS

Diagnostic criteria

Doctors should always suspect MS when someone between the ages of 20 and 50 presents with characteristic systems. These vary widely from person to person, and even over time, depending on where myelin damage has occurred. Although MS may lead to disability, one in five of those diagnosed will have no permanent disability, but in 10 per cent, disability worsens from the outset (primary progressive MS). More usally, it follows various patterns of relapse and remission. In most cases, symptoms appear suddenly.

The initial symptoms of MS often include:

  • Reduced, double or blurred vision
  • Pain
  • Tingling or numbness in the extremities
  • Vertigo and dizziness
  • Balance and walking difficulties
  • Weakness
  • Bladder or bowel problems

 

The possible manifestations of MS are numerous, a combination of signs, symptoms and events can occur at separate times and in different places, but symptoms can indude:

  • numbness or tingling in the hands and feet
  • weakness
  • balance and walking difficulties
  • reduced, blurred, or double vision
  • dizziness and vertigo
  • bladder and bowel problems
  • speech difficulties
  • mood swings
  • sexual dysfunction
  • fatigue
  • pain
  • tinnitus or hearing problems
  • ataxia (lack of muscle control and coordination)
  • spasticity (abnormally increased muscle tone)
  • tremor
  • reduced breathing
  • cognitive dysfunction (such as lack of concentration,
  • forgetfulness)
  • depression
  • temperature sensitivity
  • reduced exercise/activity tolerance
  • anxiety,

Diagnostic procedures and tests

The diagnostic process may not provide definitive answers, and in some cases, may be lengthy, both of which can be very stressful. There is no single definitive diagnostic test for MS; diagnosis has to be based on clinical and laboratory evidence.

For this reason, the diagnosis should be the responsibility of a consultant neurologist, who has the specialist knowledge and experience to interpret results and exclude other possible conditions (Freeman et al 1997). Estimates suggest that as many as one person in 10 is misdiagnosed with MS. The introduction of more sensitive imaging and laboratory techniques has reduced, but not yet eliminated; this problem (Herndon 1994).


 A diagnosis of MS (Sibley 1990) is usually based on combination of:

  • medical history and neurological examination
  • evoked potential tests
  • magnetic resonance imaging (MRI scan)
  • laboratory analysis of cerebrospinal fluid, known as lumbar puncture (this procedure is less frequently used nowadays).

Medical history

Symptoms-what they are, how long they have been present, how often they occur, and where they occur-as well as any other significant current or previous health problems, will be discussed at the initial consultation with the neurologist.

Neurological examination

If MS is suspected, a basic neurological examination should reveal some abnormality. Some of the criteria routinely assessed include vision, gait, motor power, coordination, speech, reflexes, sensation and mental status (Sibley 1990). If vague, symptomatic complaints cannot be substantiated by objective evidence of neurological deficits, the case for a diagnosis of MS is considerably weakened (Herndon 1994; Rolak 1996).

Evoked potential tests

These use painless electrodes, placed on the scalp, to measure the speed at which electrical impulses travel along damaged nerves. Evoked potential tests can pinpoint specific central nervous system pathways affected by inflammation and demyelination. They can therefore indicate the need for MRI, to establish if there are other. "silent" lesions which are not producing symptoms.

There are three main variations of this test: visual evoked potential, which assesses impulse conduction through the optic nerve on visual stimulation, and is the most frequently used of the three; auditory evoked potential, which tracks impulses through the auditory nerve; and the somato-sensory evoked potential, which measures conduction through sensory pathways in response to stimulation of the skin (Rolak 1996; Holland et at 1996).

MRI

Magnetic resonance imaging, known as MRI, indicates areas of inflammation in the white matter of the central nervous system, and it has revolutionised the diagnosis of MS. However, it is not a definitive test. Brain lesions resembling those found in MS appear on the MRI brain scans of 10 per cent or more of healthy, middle-aged people (Triluzi & Scotti 1998). Conversely, some people with MS may have normal MRI brain scans. Positive MRI changes are nevertheless seen in about 95 per cent of people with definite MS (Rolak 1996). Spinal cord MRI, combined with brain MRI, can improve the accuracy of diagnosis in some people.

MRI may also be inconclusive in people with mild forms of MS, or in the early stages of the disease (McDonald 1998). Other diseases, including Lyme disease, human T cell lymphotropic virus infection, and systemic lupus erythematosus, can produce similar brain images: thorough clinical and laboratory assessment should eliminate these possibilities (Sibley 1990).

MRI has been used in clinical trials to follow disease progression and assess the effectiveness of new treatments.

However, scan results do not always reflect the level of clinical disability (Clanet and Berry 1998): a person can have many lesions, yet little disability, or severe disability, with few or no detectable lesions.


Cerebrospinal fluid (CSF)

Analysis of the cerebrospinal fluid, obtained by lumbar puncture, may be particularly useful in confirming the diagnosis when clinical examination and other tests have proved inconclusive. In 90 per cent of people with MS, it reveals abnormal levels of certain

immune system proteins, particularly immunoglobulin G (lgG). Analysis of these proteins reveals a characteristic pattern referred to as oligoclonal bands (McDonald 1998). This pattern appears in only 2 per cent of people without MS. The pattern occurs in other diseases, but ones which are unlikely to be confused with MS (Rolak 1996). The main difficulty with this test is that about a third of people develop severe headache after the procedure, the pain of which can last several days. Lying prone after the sample has been drawn may help the puncture site to close, and drinking plenty of fluids will replace those lost during the procedure (Holland et al 1996).

MS usally follows one of four patterns:

  • Benign
  • Relapsing - remitting
  • Secondary progressive
  • Primary progressive

~ Benign - Mild, infrequent attacks, followed by full recovery; with on permanent disability after 15 or more years; affects about 20 per cent of people with MS

~ Relapsing - remitting - Attacks, where symptoms come on quickly over a day or or a few days, are followed by a period of remission for days, month, or even years, during which symptoms ease or disappear. During a relapse, old symptoms may recur or new ones may appear. Disability may become more severe with each attack. Hospital treatment is usually required for the worst relapses. Over 70 per cent of people start of with this form of MS.

~ Secondary progressive - Begins as relapsing - remitting MS, but after repeated attacks, remissions cease. Symptoms progressively worsen.
Around 50 per cent of people will eventually develop secondary progressive MS, usually within 10 to 15 years of onset Some people can continue to have attacks as well as progressive symptomns.

~ Primary progressive - Symptoms and disability worsen from the outset, with no distinct relapses. Rates of progression vary. Affects about 10 per cent of people with MS.

I have been informed that there may be a reform of the above to:

Relapsing - remitting

Secondary progressive

Primary progressive

Relapsing - remitting progressive