NM I Unit 6: Demyelinating disorders

what are the classifications of autoimmunity

systemic

organ specific manifestation

what is systemic autoimmunity

the entire body is somewhat affected

what are examples of systemic autoimmunity (3)

systemic lupus erythematosus

rheumatoid arthritis

dermatomyositis

what is organ specific manifestation autoimmunity

the organ that is targeted by the immune system is based on the receptor sensitivity of the organ

what are examples of organ specific autoimmune diseases (4)

Hashimoto's thyroiditis

Graves disease

Type I diabetes

Myasthenia's gravis

what tissue is effected in multiple sclerosis and Guillain Barre syndrome

myelin

what is affected in Guillain barre syndrome

PNS

what is affected in MS

CNS

what is autoimmunity

an immune mediated response to self antigens where an individuals immune system begins to attack the body by way of the generation of autoantibodies

what occurs to the natural autoimmunity in the body if an individual is susceptible

it becomes exaggerated

what are believed causes of autoimmunity (6)

genetic

environment

lifestyle

diet

stress

aging

what was found to be a large influence to local or systemic inflammatory response

the microbiome

what occurs in autoimmunity when stresses are added

inflammatory cytokines are released causing activation of self reactive lymphocytes that ultimately cause destruction of target tissue

what is molecular mimicry

the immune system mistakes the body for pathogenic molecules

what are some stresses that may trigger autoimmunity in the body (7)

infections

hormones

pathogens

food antigens

heavy metals

drugs

stress

what is seen in autoimmune diseases with food

individuals may see less exacerbations with removal of certain foods such as gluten, dairy, or soy intolerance

what heavy metals can lead to autoimmunity

amalgam or silver tooth fillings which contain up to 50% mercury which is neurotoxic

what is the ultimate factor that allows for autoimmunity genetic factors to be expressed

the environemtn

what are individuals with an autoimmune disorder have an increased risk for if the problem is not mitigated

they are more prone to other autoimmune pathologies

what is myelin

an insulator to nerves that also aids in the transmission and action potentials since they only occur at nodes of ranvier

what are the initial symptoms seen in MS

visual disturbances such as diplopia and nystagmus

paresthesia

may have an initial attack with functional deficits such as bradykinesia, early and significant fatigue, abnormal tone, tremor, ataxia, pain, dysarthria and weakness

what are the initial symptoms of Guillain Barre syndrome

tingling and numbness in the distal extremities ultimately leading to ascending paralysis

how is MS diagnosed

imaging

what is seen on an MRI in MS

lesion in the form of white plaques are seen in T2 MRIs

what are Dawsons fingers

extensions of white plaques around the corpus callosum in the sagittal view of an MRI for MS

how is Guillain Barre syndrome diagnosed

electrodiagnostic testing is used to assess neuromuscular and bioelectrical activity to determine firing rate of muscles and nerves

what two electrodiagnostic tests are used to diagnose Guillain Barre

nerve conduction studies

electromyography

can a PT do electrodiagnostic tests

yes if they are certified

what is segmental demyelination

an abnormality along the course of an axon that is otherwise considered typical

when is segmental demyelination commonly seen

with general compression injuries

how is axon degeneration diagnosed

using needle electromyography

what is Wallerian degeneration

the degeneration of an axon after having been severed from the cell body

when is wallerian degeneration commonly seen

severe compression

neural ischemia

trauma

when are diagnostic tests for MS or GBS done

10-14 days after symptom onset in order to rule out axo deficits

what is neurapraxia

a type of segmental demyelination seen as mild compression of a nerve leading to a conduction block within an axon

the axon and surrounding connective tissue remain intact

what is axontmesis

axonal degeneration where there is some Wallerian degeneration resulting from severe pressure, stretching, or trauma where there is some axonal involvement

what occurs to the nerve conduction in axonotmesis

the velocity is somewhat normal as the myelin is intact but the amplitude of motor and sensory potentials are decreased

what would be seen in a nerve conduction test with a demyelinating disorder

slowed signals to identify GBS and Acute inflammatory demyelinating polyneuropathy or acute motor axonal neuropathy

what is the recovery of nerves

1 mm a day

what is neurotmesis

the most severe nerve injury where there is axonal degeneration and damage to the connective tissue surrounding the nerve

what is the main difference between axonotmesis and neurontmesis

there is usually no recovery with neurotmesis

what are the precautions for electrodiagnostic testing

Pacemaker (nerve conduction studies)

anticoagulants (needle EMG)

blood transmittable disease

what are the main MS subtypes (4)

clinically isolated syndrome

Relapsing remitting MS

Primary progressive MS

secondary progressive MS

what is clinically isolated syndrome

the first episode of neurological symptoms resulting from inflammation and demyelination in the CNS

what is active clinically isolated syndrome

distinct attacks or relapses followed by periods of remission which eventually progresses to relapsing remitting MS

what is relapsing remitting MS

the most common form of MS that has clearly defined relapses seen with worsening symptoms followed by periods of emission where symptoms partially or completely subside

what is primary progressive MS

gradual and continuous worsening of neurological function from onset without distinct relapses or periods of remission

what are the forms of primary progressive MS

active (progression)

non active (no progression)

what is secondary progressive MS

develops in pts who initially had relapsing remitting MS and the disease transitions to a progressive phase where symptoms gradually worsen with or without relapses

what causes relapsing episodes in MS

inflammation and demyelination in the CNS leading to temporary or prolonged functional decline

what are common triggers for relapsing episodes of MS (3)

viral bacterial infections

major organ system diseases

stress

what are pseudo exacerbations

temporary symptom flare ups due to external factors like heat or fatigue

how can MS present

acute or chronic depending on lesion location

how do symptoms begin in MS

they develop rapidly over minutes or hours

what is the most common symptom of MS

visual disturbances

what may be seen with brainstem lesions affected CN 2, 4, and 6 or the medial longitudinal fasciculus

impairments in conjugate gaze and control of eye movements

diplopia

what is seen with MS lesions to the cerebellum (5)

ataxia

hypotonia

truncal weakness

postural tremor

impaired balance

what is another name for GBS

acute inflammatory demyelinating polyradiculoneuropathy (AIDP)

what is GBS

an immune mediated disease affecting the nerve roots and peripheral nerves attacking Schwann cells that make the myelin sheath of peripheral nerves

what are the initial symptoms of GBS

rapid symmetrical bilateral onset with possible autonomic dysfunction

flaccid paralysis

potential sensory deficits

what is acute motor axonal neuropathy GBS

pure motor GBS

what is Miller Fisher syndrome

GBS with involvement of cranial nerves

what is chronic inflammatory demyelinating polyradiculoneuropathy GBS

progressive relapsing form of GBS

what may be seen in the acute phase of GBS

the rapid progressive neuropathy may affect the diaphragm which can result in mechanical ventilation

what autonomic symptoms may be seen in GBS

Diaphragm involvement

cardiac arrest

how long is the acute phase of GBS

about 10 days

when does maximal paralysis occur in GBS

within 1-2 days of onset

how fast do pts reach peak severity of GBS

50% within 1 week

7% in two weeks

80% by three weeks

what typically occurs around 2-4 weeks of GBS

a plateau

when does recovery occur in GBS

months to years after onset

what is associated with poor prognosis of GBS

severity of muscle weakness

need for respiration support

Do most GBS pts return to walking

yes 80% return by 6 months, 20% with an aid, and 3% unable

what are the two major deficits seen in GBS

weakness and fatigue

what is seen in reflexes with GBS

diminished or absent

what sensory symptoms are seen in GBS

often a stocking glove distribution in the hands and feet

tingling, numbness, and decreased vibratory sense

what pain presentation is seen in GBS

symmetrical muscle aching especially in large groups which worsens as the disease progresses becoming more severe at night

pts may become hypersensitive

what can impact prognosis in demyelinating diseases (6)

disease subtype

point in disease process

age related neuroplasticity

motivation

nutrition

environmental characteristics

what is the difference in the presentation of MS and GBS

GBS is more acute while MS is more progressive

what clinical test is the gold standard for MS in predicting outcomes

the expanded disability status scale

what other clinical tests can be used for MS to predict outcomes (2)

MS functional composite

MS quality of life 54

what clinical test is used to predicting outcomes in GBS

the modified erasmus GBS outcome score

what does the modified erasmus GBS outcome score predict

the inability of a pt with GBS to walk independently after 6 months of having the disease

what are the recommended outcome measures addressing multiple domains in MS (2)

Modified fatigue impact scale

MS functional composite (outpt)

what does the modified fatigue impact scale assess

the self perceived impact of fatigue on cognitive, psychosocial, and physical domains in pts with MS

what does the MS functional composite assess

it addresses cognition, gait, and UE function

what are the MS outcome measures to assess activity (gait) (2)

12-item MS walking scale\timed 25 ft walk

what does the 12 item MS walking scale assess

self perceived walking ability

what does the 25 ft walk assess

gait speed

what are the outcome measures addressing participation restrictions in MS (5)

Functional assessment of MS

MS quality of life 54

MS impact scale

MS international QOL questionnaire

MS quality of life inventory

what does the MS quality of life inventory assess

it contains outcome measures relating to health status, fatigue, sexual function, bowel and bladder control, visual and mental health deficits, and social support

what outcome measure is used to assess body function and structures in GBS

medical research council sum score (MRC-SS)

what does the MRC-SS assess

UE and LE strength in critical care pts

what outcome measure is used to assess activity limitations in GBS

GBS disability scale

what outcome measure is used to assess participation restrictions in GBS

inflammatory Rasch-built overall disability scale

what does the trunk control measurement scale assess

assesses trunk control movements in different positions

what is the estimated LOS in an acute hospital with GBS

34 days

what is the estimated STG timeframe in an acute hospital with GBS

2 weeks

what is the estimated LTG timeframe in an acute hospital with GBS

2-4 weeks

what is the average LOS in post acute rehab with GBS

28 days

what is the estimated STG timeframe in a post acute rehab with GBS

2-3 weeks