Myasthenia Gravis

Myasthenia Gravis
By:
* Cathie Rohleder
* Sydnee Jacobson
* Ashley Cox

Pathology
* A chronic Autoimmune Disease
* Affects the Neuromuscular junction
* Postsynaptic acetylcholine receptors on muscle cells plasma membrane are no longer recognized as ‘self’ and elicit the generation of auto antibodies.
* IgG antibody is produced against the acetylcholine receptors and fixes to receptor sites, blocking the binding of acetylcholine.
* Diminished transmission and lack of muscular depolarization results.
* Several Types of Myasthenia Gravis
o Neonatal Myasthenia Gravis: A transient condition in 10% to 15% of infants born to mothers with MG.
o Congenital Myasthenia
o Juvenile Myasthenia: Onset is around 10 years of age.
o Ocular Myasthenia
o Generalized Autoimmune Myasthenia

Clinical Manifestations
* Insidious onset
o May first appear during pregnancy, during the postpartum period, or in combination with the administration of anesthetic agents.
* Complaints
o Most individuals complain of fatigue and progressive weakness.
o The person usually has a history of frequent respiratory tract infections.
* Muscles affected
o First muscles affected
+ Muscles of the eyes, mouth, face, throat and neck.
+ The most affected muscles are the extra ocular (eye) muscles and levator muscles.
o Second most affected muscles
+ Muscles of mastication, swallowing, facial expression, and speech.
o Less frequently affected muscles
+ Neck, shoulder girdle, and hip flexors
o All muscles are weak in the advanced stage of the disease.
* Other occurrences
o Myasthenic Crisis happens when extreme muscle weakness causes quadriparesis or quadriplegia, difficulty swallowing, and shortness of breath. A person in this state is in danger of respiratory arrest.
o Cholinergic Crisis occurs from anticholinesterase drug toxicity. This is similar to Myasthenic Crisis, but also includes increased intestinal motility with diarrhea and complaints of cramping, fasciculation, bradycardia, constriction of the pupils, increased salvation, and sweating. A person in this state may also be in danger of respiratory arrest.

Treatment
* Surgery
o Thymectomy: removal of the thymus gland
o A tumor is usually present in the thymus gland

* Medication
o Cholinesterase inhibitors
+ These include neostigmine and pyridostigmine
+ Helps improve neuromuscular transmission and increase muscle strength
o Immunosuppressive drugs
+ These include prednisone, cyclosporine, and azathioprine
+ Improves muscle strength by suppressing the production of abnormal antibodies
o Corticosteroids
+ Inhibits the immune system
+ Limits antibody production.
* Plasmapheresis
o remove abnormal antibodies from the blood
o Used for more serious conditions.
o Benefits last around a few weeks
* High-dose of Intravenous Immune Globulin (IVIG)
o Modifies immune system temporarily
o Provides the body with normal antibodies from donated blood
o Less risk of side effects
o Benefits last 1-2 months and takes a couple weeks to start working

Treatment
* One or more of the treatments may be used to alleviate symptoms caused by Myasthenia Gravis

Resources
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MYASTHENIA GRAVIS

MYASTHENIA GRAVIS
By Terra Cunningham

DEFINITION
* “A disorder of neuromuscular function thought to be due to the presence of antibodies to acetylcholine receptors at the neuromuscular junction”3

DISCOVERED IN
* First described in 1672 by Thomas Willis and later described in 1890 by German physicians, Samuel Goldflam, Wilhelm Erb, and Friedrich Jolly.

SYMPTOMS
* Drooping of the eyelids
* Double vision
* Difficulty smiling, speaking, swallowing
* Difficulty raising the arms
* Difficulty walking
* Difficulty breathing if chest muscle are affected

CAUSE
* The cause is unknown
* “Antibodies act against the acetylcholine receptor making a nerve come in contact with the muscle. The nerve cell conveys its message to tell the muscle to contract. The antibodies interfere with the message and the muscle contracts less efficiently. Resulting in the weakness of the arms or legs or of the muscles of the head.”4

PREVALENCE
* Today there are an estimated 50,000 cases in the United States
* Myasthenia Gravis can be found in anyone, but it is “most common in females around the third decade of life”1

TREATMENT
* Symptomatic treatment: medications that enhance the function of the acetylcholine system at the neuromuscular junction.
* Medications include – Prostigmin, Mestinon, Mytelase, Tensilon
* Long range treatment is thymectomy.
* Thymectomy is the surgical removal of the thymus gland that lies behind the breastbone and overlies the heart.

Lifestyles
* A person with Myasthenia Gravis can lead a normal life if the medications are taken in the correct dosages and at the right time of the day.

References
* Collier’s Encyclopedia with Bibliography and Index, 1988, volume 17.,Macmillan
* Dictionary of Medical Syndromes, 3rd edition, Magalini
* Dorland's Illustrated Medical Dictionary, 26th edition, 1985, Saunders
* Encyclopedia Americana, 1993, volume 19., Grolier
* The Medical and Health Encyclopedia, volume 1., Southwestern Company

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A Potpourri of Neurological Disorders

A Potpourri of Neurological Disorders
By:Stephanie Rodriguez MS RN

Chronic Neurological Problems
Headaches
* Classified based on characteristics of the headache
* Functional vs. Organic type
* May have more than one type of headache
* History & neurologic exam diagnostic keys

Not always chronic…be careful
Pattern
Tension
Migraine
Cluster
Site
Bilateral, basilar, band-like
Unilateral, anterior
Unilateral, occular
Quality
Squeezing, constant
Throbbing
Severe
Pattern
Cycles, years
Periodic, years
Remitting, relapsing
Duration
Days, weeks, months
Hours, days
30-90 min
Onset
Anytime
Prodrome, starts in AM
Nocturnal
Assoc. Sx
Stiff neck
N&V, photo/phono-phobia
Horner syndrome
ONSET: Not reliable or diagnostic

Horner’s Syndrome
HA: Essential History
* Onset this particular headache
* Character of pain, severity and duration
* Associated symptoms
* Prior history, pattern
* Original onset: prior testing, treatment
* Exertional aspects
* Other therapeutic regimens

Physical Exam
* Neurologic examination
* Inspect for local infections, nuchal rigidity
* Palpation for tenderness, bony swellings
* Auscultation for bruits over major arteries

Organic vs. Traumatic vs. Functional: Diagnostics
* CBC: underlying illness, anemia
* Chem panel: if associated vomiting, dehydrated
* U/A
* CT scan: for focal neurological signs, sinuses
* SED rate: if recent onset, > 50 yrs (temporal arteritis)
* No LP for suspected ICP; ↑ association with brain herniation (question from last time: ARTICLE

Don’t Miss It
* Caused by subarachnoid hemorrhage from an aneurysm or head injury
* “Worse headache of my life”
* Changes in LOC, focal neurological signs
* Highly correlated with CVA
* Untreated, 50 % mortality

Headache Teaching Guide
* Keep a calendar/diary
* Avoid triggers
* Medications (purpose, side effects)
o Imitrex: take med at 1st sign of HA, ↓blood flow to brain
* Stress reduction
o Dark quiet room, exercise, relaxation
* Regular exercise
* When to contact PCP

Multiple Sclerosis
Definition
MS is a chronic, progressive, degenerative disorder of the CNS characterized by disseminated demyelination of the nerve fibers of the brain and spinal cord.

Multiple Sclerosis
Etiology
* Cause is unknown.
o Possibly related to viral, immunologic, and genetic factors.
* Susceptibility appears to be inherited with 1st, 2nd, and 3rd degree relatives at slight increased risk.

Pathophysiology
* MS is characterized by chronic inflammation, demyelination, and gliosis in the CNS.
* Autoimmune process is orchestrated by autoreactive T cells (lymphocytes)
* Activated T cells migrate to CNS causing blood-brain barrier disruption.
* Subsequent antigen-antibody reaction within the CNS activates the inflammatory response leading to demyelination of axons, with plaque formation.

A: Normal Nerve Cell
B: Normal Axon
C: Myelin Breakdown
D:Myelin completely disrupted

U-tube: animation
* http://www.youtube.com/watch?v=eE_Y3KMYC0g

Disease Process: Early
* Myelin sheaths of neurons in the brain and spinal cord are initially attacked.
* Myelin sheath is damaged but nerve fiber still intact.
* Nerve impulses are still transmitted but patient may complain of weakness.
* Remission occurs if inflammatory process stops and myelin regenerates.

Disease Process: Late
* If remission does not occur, myelin disruption continues and axon is affected.
* Myelin is replaced by glial scar tissue which forms plaques in the CNS.
* Lacking myelin, nerve impulses slow, axons are destroyed, resulting in permanent loss of function.`

Symptoms
* Initially insidious with symptoms evolving over months to years.
* Systems affected depend on distribution of lesions.
* Disease process may be chronic and progressive or have periods of remission and exacerbation.
* Even in relapsing disease, overall trend is progressive deterioration of neurologic function.

Symptoms: Motor
* Weakness
* Paralysis of limbs, trunk or head.
* Diplopia
* Scanning speech
* Muscle spasticity

Symptoms: Sensory
* Numbness, tingling, parathesia.
* Scotomas (patchy blindness)
* Blurred vision
* Vertigo
* Tinnitus, decreased hearing
* Neuropathic pain
* Radicular pain

Symptoms: Cerebellar
* Nystagmus
* Ataxia
* Dysarthia
* Dysphagia

Symptoms: Emotional
* Emotional stability may be affected
* Depression common co morbidity
* Range of emotions include anger to euphoria.
* Cognitive function usually not affected.
* Emotional lability may negatively affect progress of disease.

Symptoms: Bowel & Bladder
* Symptoms depend on where sclerotic plaque is located.
* Spastic bladder indicates lesion above S2 resulting in small capacity. This yields frequency, urgency, dribbling or incontinence.
* Flaccid bladder results form disruption of reflex arc resulting in loss of sensation or desire to void.
o Crede Method
* Bowel symptoms are usually constipation.

Multiple Sclerosis Drug Therapy
Agent
Corticosteroid (ACTH, Prednisone)
Immunomodulators (B-interferon,Betaseron, Copaxone)
Immunosuppresants (Novantrone)
Cholinergics (Urecholine, Prostigmin)
Anticholinergics (Pro-bathine, Ditropan)
Muscle Relaxants (Valium, baclofen, Zanaflex)

Target Symptom
Exacerbations
Urinary retention; flaccid bladder
Urinary freq. and urgency; spastic bladder
Spasticity

Nursing Care Planning
* Impaired physical mobility
* Self-care deficit
* Impaired skin integrity; risk/actual
* Impaired elimination; urinary, bowel
* Sexual dysfunction
* Interrupted family process

Myasthenia Gravis
Definition & Pathophysiology
* Autoimmune disease of the neuromuscular junction in which antibodies attack acetylcholine (ACh) receptors.
* ACh is prevented from attaching and stimulating muscle contraction
* 90% of patients have ocular manifestations (ocular myasthenia)
* Generalized myasthenia affecting trunk and limbs less common.
* 15% of patients have abnormal thymus glands.
* No other neural disorders accompany MG.
o no sensory loss, reflexes are normal, atrophy is rare.

Myasthenic Crisis
An acute exacerbation of muscle weakness
o triggered by infection, surgery, stress, overdose or or inadequate management of medications
o If muscle weakness affects swallowing and breathing: aspiration, respiratory insufficiency, and infection may result.

Myasthenia Gravis: Symptoms
* Weakness of skeletal muscle
o Muscles are strongest in morning
o Evening: muscle weakness is prominent
* Impaired facial mobility and expression
* Prolonged speech resulting in fading voice
* Possible difficulty in chewing, swallowing
* Proximal muscles of neck, shoulder and hip may be affected
* Course of the disease is variable It most commonly affects young adult women (under 40) and older men (over 60), but it can occur at any age.
* CRISIS: myasthenic crisis is weakness affecting the muscles that control breathing, creating a medical emergency and requiring a respirator for assisted ventilation
Diagnosis
* Diagnosis may be made by H&P.
* Blood tests:
o antibodies to ACh in 90%
* EMG:
o show decreasing response to repeated stimulation of hand muscles
* Tensilon test: shows improved contractility with IV injection of medication.
* NEURO ASSESSMENT: MG expected findings: impairment of eye movements or muscle weakness without any changes in the individual's ability to feel things

Treatment
* Drug therapy – anticholinesterase agents, corticosteroids, immunosuppressants
* Surgical therapy - Thymectomy
* Plasmapheresis
* Intravenous IgG
* Rest!

Huntington’s Disease
* Autosomal dominant genetic disorder
* Deficiency in the acetylcholine and GABA results in excess dopamine.
* Symptoms:
o Clinically opposite of Parkinson’s
o Chorea, intellectual decline, emotional lability
http://www.youtube.com/watch?v=UKbC1jRjs3M
http://www.youtube.com/watch?v=gBtji6Ibbso

Huntington’s Disease: Symptoms
* Abnormal & excessive involuntary movements (chorea)
* Writhing and twisting movements of face, limbs, body.
* Facial involvement affects speech, chewing, swallowing causing aspiration, malnutrition.
* Gait deteriorates with loss of mobility.
* Mental function declines including intellect, emotional lability and psychotic behavior.

Huntington’s Disease Diagnosis
* By symptoms
* By genetic testing as an adult: IMPLICATIONS??
* By prenatal screening

Treatment
* Palliation, symptomatic
* Neuroleptics
* Antidepressants
* Chorea antagonists (Klonopin)
* Fetal tissue transplant (experimental)

Parkinson’s Disease
Definition & Pathophysiology
* Disease of the basal ganglia
* Substantia Nigra:
o Degeneration of dopamine producing neurons
o Disrupts normal balance between dopamine and acetylcholine in the basal ganglia
* Dopamine is essential for normal function of extrapyramidal motor system which controls
o posture
o support
o voluntary motion

Dopaminergic Synaptic Activity
Good to know: These neurotransmitters and functions highly related to “reward” and to psych drug actions
Symptoms
* Onset:
o gradual, insidious, and prolonged
* Classic triad:
o tremor, rigidity and bradykinesia
* Initially:
o may involve one side of the body with mild tremor, slight limp and decreased arm swing
* With progression:
o classic shuffling and propulsive gait with flexed arms and loss of postural reflexes develops
o Slowed reflexes include decrease blinking, drooling, and masked facies

Parkinson’s Presentation

Parkinson’s Disease

A firm diagnosis of Parkinson’s is made only if at least two of the classic triad symptoms are present.

Diagnosis Confirmed: improvement of symptoms once anti-parkinsonian drugs initiated

Parkinson’s Disease: Treatment

Drug
* Dopaminergic (levodopa, sinemet, parlodel, etc.)
* Anticholinergic (artane, cogentin, symmetrel, etc.)
* Antihistamine * MAO inhibitor
* COMT inhibitor’s (comtan, tasmar)

Symptom relieved
* Bradykinesia, tremor, rigidity
* Tremor
* Tremor, rigidity
* Bradykinesia, tremor, rigidity
* Slows breakdown of levodopa

Parkinson’s Disease: Treatment Surgical
* Ablation
* Deep brain stimulation
* Fetal tissue transplant

Nutritional
* Hi fiber
* Mechanical soft
* Frequent small meals
* Lo-protein in HS

Nursing Care Planning
* Impaired physical mobility
o Teaching necessary
* Dressing/grooming self-care deficit
* Impaired skin integrity-risk/actual
* Impaired urinary elimination
* Sexual dysfunction
* Interrupted family process

Seizure Disorders & Epilepsy
Definitions
Seizure:
o paroxysmal, uncontrolled electrical discharge of neurons in the brain that interrupts normal function
Epilepsy:
o spontaneously recurring seizures caused by a chronic underlying condition

Question:
* The population with the highest prevalence of new-onset epilepsy is:

A: over the age of 60
B: children under 5
C: adolescents between 12-18 yrs
D: middle-aged men

Seizure Classification
http://www.youtube.com/watch?v=CDccChHrgRA

Seizure Disorders & Epilepsy: Classifying Seizures
Two major classes:
* Generalized
* Partial

Depending on type, phases may include:
* Prodromal phase- signs & activity preceeding seizure
* Aural phase- sensory warning
* Ictal phase- full seizure
* Postictal phase- recovery

Seizure Disorders & Epilepsy: Generalized
* Absence
* Myoclonic
* Clonic
* Tonic
* Tonic-Clonic
* Atonic

Seizure Disorders & Epilepsy: Partial Seizures
* Simple: no impairment of consciousness
o Symptoms: motor, somatosensory, autonomic, psychic
* Complex: impairment of consciousness
o Simple with progression to LOC/impairment
+ Symptoms: no other features, simple partial seizure features, automatisms
o Impairment of consciousness at onset
+ Symptoms: no other features, simple partial seizure features, automatisms

Seizure Disorders & Epilepsy: Status Epilepticus
* Medical emergency
* Seizure repeated continuously
o Tonic clonic: hypoxia could develop if muscle contraction is lengthened. Also: hypoglycemia, acidosis, hypothermia, brain damage, death
+ IV administration of antiepileptics
+ Maintain airway patency

Seizure Disorders & Epilepsy: Diagnostic Studies
* Most useful tool:
o a reliable and accurate description of the event, and the patient’s health history
* PE
* Electroencephalography (EEG):
o only useful when it shows abnormalities
* Labs:
o CBC, U/A, BMP
* PET scan, CT, MRI, MRA, MRS

Drug Therapy
* Can be helpful in preventing ongoing seizures following a head injury and should be first priority to decrease likelihood of second seizure

Seizure Disorders & Epilepsy Drug Therapy for Tonic-Clonic and Partial Seizures
* Carbamezepine/ Tegretol
* Divalproex/ Depakote
* Gabapentin/ Neurontin
* Lamotrigine/ Lamictal
* Levetiracetam/ Keppra
* Phenytoin/ Dilantin
* Tiagabine/ Gabitril
* Topiramate/ Topamax
* Valproic Acid/ Depakene
* Felbamate/ Felbatol *
* Phenobarbitol**

*Felbatol has been associated with aplastic anemia
**Phenobarbitol is a barbituate
Seizure Disorders & Epilepsy
Drug Therapy for:
Absence, Akinetic, & Myoclonic Seizure
* Clonazepam/ Klonopin
* Divalproex/ Depakote
* Valproic Acid/ Depakene
* Ethosuximide/ Zarontin
* Phenobarbitol

Seizure Disorders & Epilepsy Toxic Side Effects
* Diplopia
* Drowsiness
* Ataxia
* Mental slowing
assess for dose related toxicity including nystagmus, hand and gait coordination, cognitive function, general alertness
Seizure Disorders & Epilepsy
Idiopathic Side Effects
* Skin rash
* Gingival hyperplasia (dilantin)
* Bone marrow & blood dyscrasia
* Abnormal liver function
* Abnormal kidney function

Seizure Disorders & Epilepsy: Nursing Care

* Assure oxygen and suction equipment at bedside
o http://www.youtube.com/watch?v=H2vH1igOoh0
* Safety precautions in active stage
o Support/ protect head
o Turn to side
o Lossen constricted clothing
o Ease to floor
* Time seizure, record details of seizure and post-ictal phase
* Patient teaching:
o importance of good seizure control using medication as ordered
o Medical alert bracelet
o Avoid decreased sleep, increased EtOH, fatigue
o Regular meals/ snacks

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