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…
How is the Limbic System affected?
Inappropriate behaviour (impulsive, lack of insight, making off remarks), inappropriate emotional response (increased aggression and violent behaviour), changes to mood (depression), limited awareness of risks (poor judgement)
How is the Prefrontal cortex affected?
May impact movement initiation, increased difficulty choosing goals, planning goals and executing plans + monitoring results
- may also have difficulty with independent living
Lesions located in frontal lobes, dorsal midbrain, pons, parietal and temporal lobes associated with…?
Bowel and bladder dysfunction
How is the frontal lobe affected?
Pre-motor area
- Trunk instability, difficulty with anticipatory strategies for balance, external cues,
Supplementary motor area
- trouble with initiation, using internal cues
Broca’s area
- Problem with fluency of language (expressive aphasia, can’t plan sentence to communicate what you’re thinking)
How is the dorsal midbrain affected?
Parinaud’s syndrome - inability to move eyes up and down (paralysis of up gaze)
How is the pons affected?
Sleep disturbances, sensory problems, arousal dysfunction, locked-in syndrome (consciously away of what is going on BUT unable to move any part of the body except the eyes)
How is the parietal affected?
Loss of discriminative somatosensation (localisation, size, shape, texture, 2pts, proprioception)
How is the temporal affected?
Loss of localisation of sounds
Lesions located at Corpus Callosum, Inferior / superior longitudinal fascicles, occipitofrontal fascicles, corticospinal tracts
Correlated with coordination impairment
How is the corticospinal tract affected?
Loss of voluntary motor function bilaterally at level of lesion and below (dermatomes affected: C6 onwards)
For more progressive and chronic forms of MS, where is there damage?
Damage to the axon
Benign MS
One or two relapses and remission resulting in full recovery and no disability
Clinical Features of MS
Bladder dysfunction - failure to empty
Constipation or loss of control of the bowels
Fatigue (80% of people with MS)
Pain
Spasticity - feelings of stiffness and wide range of involuntary muscle spasms
Dysarthria (slurring, unclear articulation of words, difficulty controlling loudness) + Dysphonia (hoarseness, breathlessness, nasality, poor control of pitch) + Swallowing problems (dysphagia)
Difficulty to concentrate and poor memory (difficulty to organise, plan, focus)
Visual - sudden onset of double vision, poor contrast, eye pain, heavy blurring
Emotional changes - severe depression, mood swings, irritability, episodes of uncontrollable laughing and crying
Heat sensitivity - elevated core temp can alter effective conduction of nerve impulses causing fatigue
Diagnosis of MS
NO single set of symptoms
1) Medical Hx and Neurological exam
2. MRI - detects presence of MS plaques or scarring, cannot differentiate between old and new lesions
3) Visual Evoked Potential (VEP) - recordings of NS electrical response to stimulation of specific sensory pathways (demyelination will cause slower response time)
4) Lumbar puncture - can detect levels of certain immune system proteins
5) Blood tests - can rule out other conditions
What is the first line of treatment for MS?
Medication
What types of medications to treat MS?
Gilenya - reduces relapses and disability progression in RRMS
Aubagio Teriflunomide - Interfares with WBC’s
Tecfidera Dimethyl Fumerate - reduces inflammation in brain caused by MS + helps protect cells that form myelin against attacks
Tysabri Naralizymab - Locks onto T cells and stops them from crossing blood-brain barrier
Stem Cell transplant - targets stem cells, replace or repair damaged cells or tissues
Stem cell transplant autologous haematopoietic stem cell transplant (AHSCT) - reset immune system so stops attacking person’s own CNS
Diet and Nutrition
Exercise - helps manage symptoms and disease progresison
Medicinal Cannabis
Prognosis of MS
The longer you can maintain a healthy brain = the better the prognosis
- SELDOM life or death issues BUT QoL issues
Prognosis of RRMS (88%)
Some people have been known to go many years or decades without new relapses
- A relapse doesn’t mean that you disability will progress as in most cases following a relapse and a period of recovery there will be no lasting damage
- Some cases - depending on severity and localisation of new brain lesions disability progression may occur
Prognosis of PMS (12%)
Disability will occur much faster
- Men tend to progress faster than women by 38%
Influencing factors for prognosis (factors suggesting a better disease course)
- Diagnosed at young age (20-30s)
- New relapses in first years after diagnosis
- Complete recovery from relapses with no long-term damage
- Long intervals between relapses
- Symptoms that are sensory in nature (numbness and tingling)
Differential diagnosis of MS
SHOULD NOT rush to diagnose MS
- Gullian Barre Syndrome (attacks myelin sheath in lower motor neurons)
- Spinal cord neoplasms
- Schilder disease
- Sarcoidosis
Outcome Measures for MS
- Expanded Disability Status Scale (EDSS) GOLD STANDARD (0-10, scoring in 0.5 increments)
- Neurologic Rating Scale (NRS) (8 categories of 22 parameters, -10 - 100)
- Multiple Sclerosis Impact Scale (MSIS)
