Multiple Sclerosis Flashcards
Definition of MS
A chronic, progression disease of the CNS (brain, optic nerves, spinal cord) that affects sensation, movement and body functions
What are the 4 types of MS
Relapsing-remitting (RRMS)
Primary Progressive (PPMS)
Secondary Progressive (SPMS)
Progressive Relapsing
Relapsing-Remitting (RRMS)
Around 85% of MS cases
- Suffer distinct attacks of symptoms which then fade away partially or completely
- Periods between relapses characterised by a lack of disease progression
Primary Progressive (PPMS)
5-10%
- Symptoms gradually get worse over time
- Does not experience acute attacks
Secondary Progressive (SPMS)
Proceeds RRMS, occurs in 65% RRMS
- Sustained build up of disability, independent of any ‘relapse’.
- Develops into SPMS after 15 years of being diagnosed of MS
- Less recovery following attacks, persistently worsening functioning during and between attacks, and/or fewer attacks accompanied by progressive disability
Progressive Relapsing
Gradual progression of disability from the onset of the disease, accompanied by one or more acute relapses, with or without full recovery
Causes of MS
Auto immune disorder where immune system attacks its own healthy tissue.
- Autoimmune response destroys myelin sheath that surrounds CNS nerves
- Unknown reason
- Myelin sheath assists with conduction of messages from brain along the nerves
- With MS, myelin sheaths scarred, causing messages from brain to become slowed or blocked
Risk Factors of MS
- Age: any age, most commonly between 15 and 60
- Gender: Women 2 x more likely than men
- Family Hx: Higher risk if parent or sibling has MS
- Certain infections: Epstein-Barr
- Race: White people - Asian, African, Native American lowest risk
- Climate: More common in countries with cooler climates
- Certain autoimmune diseases: Thyroid disease, type 1 diabetes, inflammatory bowel disease
- Smoking
MS IS NOT CONTAGIOUS OR INFECTIOUS
Epidemiology- Incidence of MS
- 134 diagnosed in NZ each year
- Male to female ratio 1:3
- 1 in 1000 in NZ has MS
Epidemiology - Prevalence of MS
- About 3000 living with MS in NZ (2006)
- 75% women and 25% men
- Overall prevalence is 71.9 per 100,000
- Maori have substantially lower prevalence
Pathophysiology of MS
Demyelination of CNS:
- Destruction of oligodendrocytes (myelinate CNS) and reactive astrogliosis
- Immune cell infiltration across main blood barrier
- Promotes inflammation, demyelination, gliosis and neuroaxonal degeneration
- Disrupts neural signalling
- Activated T helper cells recruit additional immune cells which increases the immune response
- These destroy the lymphotoxin and TNF alpha that damage the oligodendrocytes
- B cells, auto anti bodies and complement factors enter the CNS once the inflammation process has started causing additional damage to the CNS
- T cells are part of the immune system however sometimes they do more harm than good
- Begin to attack our CNS
- T cell secrete cytokines which results in B cells and macrophages
- B cells transform into plasma cells and release antibodies that attack the myelin
- Macrophages release nitric oxide chemicals onto the myelin causing further damage to CNS
- The longer this occurs, the more difficult it is for our nerve cells to carry nerve signals
What produces myelin?
Oligodendrocytes
Your patient has noticed a significant increase in muscle tone - what are the most important factors to check?
Does the patient have an infection, fever or untreated pain?
Most common lesion location of MS
Plaques that result from MS can be anywhere in the CNS
- Majority tend to be in the white matter around the lateral ventricles of cerebellum, BG, brainstem, Motor cortex, cerebral peduncles, spinal cord and optic nerve
Lesions in Grey White junction of associative, limbic, prefrontal cortex
Correlated with COGNITIVE DYSFUNCTION…
