myasthenia gravis, alzheimers disease, multiple sclerosis, guillain-barre syndrome and bell palsy

8/12/2019 Myasthenia Gravis, Alzheimers Disease, Multiple Sclerosis, Guillain-Barre Syndrome and Bell Palsy

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offending Antibodies

directed at acetylcholine receptor sites

Myasthenia Gravis

- autoimmune disorder affecting the myoneural junction- voluntary muscles weakness- 60,000 women than men- 20-40 early onset- 60-70 for men- purely motor disorder (no effect on sensationa & coordination)

Pathophysiology

CM

Initial

1. diplopia (double vision)

2. ptosis (drooping of the eyelids)

other

1. face (bland expression) and throat muscle weakness (bulbar symptoms)

2. generalized weakness(extremities & intercostals muscles)

3. dysphonia (voice impairment)

4 risk for choking and aspiration

5. decrease vital & respiratory failure

Assessment and diagnostic findings

1. acetylcholinesterase inhibitor test ( used to diag. MG)

acetylcholinesterase inhibitor

-stops breakdown acetylcholine = inc. availability

Edrophonium chloride (Tensilon)

-fast-acting acetylcholinesterase inhibitor(via IV)

- 30 sec. after inject. facial muscle weakness and ptosis (resolve5 mins)

atropine

- control SE of edrophonium (bradycardia, sweating, and cramping)2. MRI

3. EMG (electromyography) detects a delay or failure of neuromuscular

transmission, 99% confirming MG

Med. Mgt

1. anticholinesterase

2. immunosuppressive therapy

3. plasmapheresis

4. thymectomy

No cure, treatments do not stop the production of the acetylcholine

receptor antibodies

thymic hyperplasia or thymic tumor

impaired transmission of impulse

across the myoneural junction

fewer receptors are available for

stimulation

weakness in voluntary muscle


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Pharmacologic Therapy

1. Pyridostigmine bromide (Mestinon)

-anticholinesterase

-1stline of therapy

-inhibiting break of acetyl and inc. availability at NJ

-dose gradual inc. to a daily maximum (qid)

AE

1.fasciculations

2. abdominal pain

3. diarrhrea

4. inc. oropharyngeal secretions

fewer SE compare to other anticholinesterase med.

2. Immunomodulating drugs

- if Mestinon not effective

-reduce production of antibody

corticosteroids - suppress immune response

prednisoneinitially given when symptoms improve

3. cytotoxic med

- if steroids not effective

Azathioprine (Imuran)

- inhibits T cells & reduces acetylcholine receptor antibody levelsTherapeutic Effect may not be evident for 3 12 months

Serious AE

1. leukopenia

2. hepatotoxicity

monthly evaluation of liver enzymes & WBC is necessary

4. Intravenous immune globulin (IVIG)

- treat exacerbation/longterm adjunctive basis

-easy/pooled human gamma-globulin

-improve in few days

Procaine (Novocain)- avoid / informed dentist

Plasmapheresis

- plasma exchange (treat exacerbation)- pt plasma & plasma components removal- daily or alternate day- 75% improvements but last only few weeks

Surgical Mgt.

1. Thymectomy

- transsternal surgical(to removed entire gland)

- 3yrs before it can benefit from procedure

Complications

1. Respiratory failure

Nsg. Mgt

1. pt and family teaching

2. educational topic (self-care,med mgt, E conservation, help ocular

manifestation, prevention & mgt of complications)

Note: anticholinesterase med must be administered on time

Myathenic crisis

- repi. distress- dysphagia- dysarthia- ptosis- diplopia- muscle weakness


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Alzheimers Disease

- irreversible, degenerative neurologic disease- insidiously, losses of cognitive fxn & distru. in behavior & affect- 40, uncommon before 65- not normal part of aging

Factors

1. inc. age

2. environmental

3. dietary

4. inflammatory factor

5. genetics

6. neurotransmitter changes

7. vascular abnormalities

8. stress hormones

9. circadian changes

10. head trauma

11. seizure disorders

Types

1. familial or early onset AD

- rare

-


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1. immobile

2. death (pneumonia, malnutrition, or dehydration)

Assessment and Diagnostic findings

- autopsy- history , PE- CBC, chemistry profile & vit. 12, thyroid hormone levels- electroencephalography, CT- MRI- examination of the CSF

Depression

- mimic early-stage- MMSE test (chpter 12-2)

Med mgt

- manage cognitive & behavioral symptoms- no cure and no way to slow the progression

Drugs

1. cholinesterase inhibitors (CEIs)

2. donepezil hydrochloride (Aricept) & memantine (Namenda)

3. rivastigmine tartrate (Exelon)

4. galantamine hydrobromide (Razadyne)

5. tacrine (cognex)

- enhance acetylcholine uptake in the brain

- used for mild to moderate symptoms

- Aricept & memantine (receptor gonist, moderate to severe)

- improve. 6 to 12 m but cessation of med. results in disease progression

- recommend continuing at least in moderate stage

- CEI with memantine for mild to moderate cognitive symptoms

behavioral and psychosocial therapies

-

agitation- psychosis

- depressionNsg. Mgt

- promoting function and independence- physical safety- self care- reducing anxiety- agitation- improving communication- socialization- adequate nutrition- balanced activity & rest- family education


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Multiple Sclerosis

- is an immune-mediated- progressive demyelinating disease of the CNS- impaired transmission of nerve impulses- any age but typically 20-40 years of age- women- Europe, new Zealand, southern Canada

factors

- environmental factors- genetic predisposition- virus

patho

T cells remain in CNS promote infiltration of other agents

damaged immune system

immune system attacks

demyelination

interrupts flow of nerve impulse

optic nerves, chiasm, tracts; cerebrum; brain stem, cerebellum spinal cord

S&Sx MS


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CM

benign course

- symptoms are mild- does not seek treatment

MS type & course

1. Relapsing-remitting (RR) course

- 8085 %- acute attacks with full recovery- with sequelae & residual deficit upon recovery- 50 % progress to secondary progressive course

2. primary progressive course

- 10%- disabling symptoms steadily increase- rare plateaus and temporary improvement- quadriparesis, cognitive dysfunction, visual loss- brain stem syndromes

3. secondary progressive

- MS begins with an initial RR course, followed by progression of

variable rate, which may also include occasional relapses and minor

remissions.

4. progressive-relapsing (PR)

- least common 5%

- MS shows progression from onset but with clear acute relapses

with or without recovery.

Primary symptoms

1. fatigue

2. depression

3. weakness

4. numbness

5. difficulty in coordination

6. loss of balance

7. pain

8.visual disturbances

9.blurring of vision10. diplopia

11. patchy blindness and total blindness

12. spasticity

13. ataxia

Gerontologic Considerations

secondary progressive disease

- average 35 years after onsetAssesment and diagnostic findings

1. MRI

observe plaques in CNS

2. Electrophoresis of CSF

- identifies presence of oligoclonal banding

3. evoked potential studies

- help define the extent of the disease process and monitor changes

5. urodynamic studies

- bladder dysfunction

6.neuropsychological testing- assess cognitive impairement

7. sexual history

- identify changes in sexual function

Med mgt

- no cureGoals

- to delay the progression, manage chronic symptoms, treat acuteexacerbations


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Pharmacologic therapy

1. disease-modifying therapies

- reduce frequency, duration of relapse

- number & size of plaques

- all med. require injection

interferon beta-1a (Rebif) & interferon beta-1b (Betaseron)- administered subcutaneously

Avonex

- intramuscularly once a week.Side effects

1. flulike symptoms (managed w/ acetaminophen & ibuprofen)

2. potential liver damage, fetal abnormalities, and depression

NOTE: for optimal control should be started early in the course of the

disease

Glatiramer acetate (Copaxone)

- reduces the rate of relapse in RR course- decrease # plaques- subcutaneously daily- it acts by increasing the antigen-specific suppressor T cells

Side effects

1. minimal and manageable

Note: it takes 6 months for evidence of an immune response to appear

IV methylprednisolone

- key agent treating acute relapse in RR course- shorten the duration of relapse- 1 gram IV daily for 3days, ff by oral taper of prednisone

SE

1. mood swing2. weight gain

3. electrolyte imbalance

Mitoxantrone (Novantrone)

- via IV infusion every 3 months- reduce frequency of relapse w/ secondary-progressive or

worseining relapsing-remitting MS

SE

- cardiac toxicitysymptom mgt

spasticity

1. Baclofen

2. GABA agonis

disabling spasm and contractures

1. nerve blocks or surgical intervention

fatigue

1. amantadine (Symmetrel)

2. pemoline (Cylert)

3. fluxetine (Prozac)

ataxia

1. beta adrenergic blocker (Inderal)2. antiseizure agents (Neurontin)

3. benzodiazepines (Klonopin)

bladder and bowel problems

1. anticholinergic agents

2. alpha-adrenergic blockers

3. antispasmodic agents

UTI1. ascorbic acid ( vit. C)


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Guillain-Barre syndrome

- autoimmune attack on the peripheral nerve myelin- acute, rapid segmental demyelination of peripheral nerves and

cranial nerves

- dyskinesia,hyporeflexia,paresthesias- 12 cases per 100,000- males between 16 and 25 and between 45 and 60 years of age- 60% - 75% recover completely- 20% - 25% residual deficits (rapid disease progression)- does not affect cognitive function or LOC

causes

viral infection

- campylobacter jejuni- cytomegalovirus - Epstein-barr virus- mycoplasma pneumonia- H. influenza and HIV

Patho

CM

classical features

1. areflexia

2. ascending weakness

3. sensory symptoms

4. Miller-fisher varian ( paralysis of ocular muscle ataxia, and arefexia)

other

1. muscle weakness

2. diminished reflexes of the lower extremities

3. hyporeflexia and weakness may progress to tetraplegia

3. neuromuscular respiratory failure

4. paresthesias

Assement and diag findings

1. history of viral illness

2. changes in vital capacity and negative inspiratory force

3. Evoked potential studies

medical management

- require intensive care1. respiratory therapy or mechanical ventilation

2. elective intubation

3. anticoagulant agent

4. anti-embolism stocking or sequential compression boot to preventthrombosis and pulmonary emboli

5. plasmapheresis and IVIG ( IVIG DOC)

6. ECG

cell-mediated and humural immune attack

on peripheral nerve myelin proteins

(ganglioside GM1b)

inflammatory demyelination

interrupted nerve conduction and axonal loss

S&sx


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Bells Palsy

- facial paralysis- caused by unilateral inflammation of the 7th cranial nerve- unknown- 45 year of age- pressure paralysis

causes

- vascular ischemia- viral disease- autoimmune disease

CM

1. tearing

2.painful sensations in face, ear, eye

3. speech difficutles

4.unable to eat on affected side

Med management

- to maintain muscle tone oof the face and to prevent or minimizedenervation

- 35 weeks recoverycorticosteroid therapy (prednisone)

- reduce inflammation and edema- reduces vascular compression and permits restoration of blodd

circulation to the nerve.

analgesic

- controlled facial pain

myasthenia gravis, alzheimers disease, multiple sclerosis, guillain-barre syndrome and bell palsy

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