Exam 3 Flashcards
What is the pattern of a normal muscle biopsy?
- Mosaic Pattern
- -Fiber types are scattered and not grouped in a particular pattern
What do neurogenic diseases involve?
*Involves nerve cell bodies, axons and/or dendrites involved
What is a needle EMG?
- Denervated muscle is spontaneously active at rest (fibrillation potentials)
- Short duration (<3 ms) and low amplitude (<300 µv), fibrillation potentials occur in semi-rhythmical runs (<30/second).
How does regeneration occur?
*through collateral sprouting
What does neuron atrophy cause?
*Causes muscle atrophy of the same muscle fiber type
What occurs with reinnervated muscle fibers?
- since motor neuron type determines muscle fiber type, re-innervated muscle fibers assume histochemical properties of neuron (change fiber type).
- results in muscle fiber type grouping due to re-innervation (as opposed to the mosaic pattern of normal muscle).
What do myogenic/myopathies involve?
*Involve muscle degeneration
What occurs with a myogenic disease needle EMG?
*Low muscle activity at rest
What would occur in a muscle biopsy of a myogenic disease?
- Muscle fiber atrophy in a random fashion
- all muscle fiber types are affected
- retains the mosaic pattern but fewer overall number and size of all types of muscle fibers
What are examples of Neurogenic diseases?
- Compression of nerve roots or peripheral nerves (PTP 565 – Fundamentals class)
- Bell’s Palsy*
- Diabetic polyneuropathy*
- Alcoholic polyneuropathy
- Polio and post-polio syndrome
- Amyotrophic lateral sclerosis (ALS)*
- Guillian-Barre syndrome (GB)*
What is an example of a myogenic disease?
*Muscular dystrophy
What are the fibers in a normal muscle biopsy?
*Muscles may have proportionately more fast-glycolytic (FG) muscles fibers as compared to slow, oxidative (SO) secondary to its function
What is Bell’s Palsy
- Lesion of CN VII
- -demyelination in mild cases
- -demyelination and axonal damage in more severe cases
- Innervation to upper face is bilateral
- Innervation to lower face is unilateral (from opposite hemisphere)
How does Bell’s Palsy typically present?
*Presents as flaccid paralysis on the ipsilateral side of the face, affecting the upper and lower quadrants of the face
What is the Etiology of Bell’s Palsy?
- Unknown in most cases
- May be secondary to viral infection causing swelling in auditory canal (remember that CN VII goes through the auditory canal)
- In a small number of cases, secondary to acoustic neuroma impinging on nerve
What are the motor signs of Bell’s Palsy?
- Flaccidity
- –Mouth droops
- -Nasolabial fold is flattened
- -Eyelid does not close
What are the sensory signs of Bell’s Palsy?
*Decreased taste on ipsilateral tongue
What are the ANS signs of Bell’s Palsy?
*Decreased tearing (dry eye)
What is the incidence of Bell’s Palsy?
- 20/100,000 US each year
* Affects 20,000-100,000 people in US per year
What is the onset of Bell’s Palsy?
- Typical onset is overnight
* Onset more common between 20-40 YO
What populations will have a greater risk of getting Bell’s Palsy?
*Diabetics and pregnant women and people with MS
What is the Medical treatment for Bell’s Palsy?
- High-dose corticosteroids for 5 days followed by a tapered dose for another 5 days
- Antiviral medications, e.g. acyclovir
- –Improves outcomes when paired with corticosteroids
- Eye patch, artificial tears (methylcellulose eye drops every 4 hours)
- Gentle massage and gentle heat occasionally used
- PT for muscle retraining only if problems persist
- –E-stim for facial muscles
- 70% of people completely recover within 2-3 weeks (in simple cases) or 3-6 months (in severe cases)
What is diabetic polyneuropathy?
*Affects PNS axons primarily (some de-myelination
What is the etiology of Diabetic polyneuropathy?
*Disrupted microcirculation
What is the onset of Diabetic polyneuropathy?
- After long duration diabetes
- –In diabetics who have had diabetes for 25+ years, 50% have this condition
- Occurs in insulin-dependent and non-insulin dependent diabetes
- Some regeneration with control of diabetes
What is the large nerve fiber involvement in diabetic polyneuropathy?
*Large nerve fiber sensory involvement of MANY NERVES IN LOWER LEGS & FEET
(Ia, Ib & II – from muscle spindles & GTOs)
—most common
—painless paresthesias in bilateral feet and lower legs
decreased vibration and proprioception sense
What is the small nerve fiber involvement in diabetic polyneuropathy?
- Small nerve fiber sensory involvement (A delta & C afferent fibers)
- –deep aching pain in legs and burning feeling in feet
- –decreased touch, pain, and temperature sensations
- –nocturnal pain and paresthesias
What are the S&S of peripheral neuropathy?
- Numbness or reduced ability to feel pain or changes in temperature, especially in the feet and toes
- A tingling or burning feeling
- Sharp, jabbing pain that may be worse at night
- Pain when walking
- Extreme sensitivity to the lightest touch — for some people, even the weight of a sheet can be agonizing
- Muscle weakness and difficulty walking
- Serious foot problems, such as ulcers, infections, deformities, and bone and joint pain
What are the screening/examination tests of diabetic polyneuropathy?
- NVCs
- Monofilament screening with 5.07/10 gm. filament
- Vibration
What are the complications with diabetic polyneuropathy?
- Diabetic ulcers
* 50% of non-traumatic amputations in US are performed on individuals with diabetes
Where are the lesion sites of ALS?
*anterior horn cells (alpha & gamma motor neurons (LMN signs)), lateral corticospinal tract, motor nuclei of brainstem, and motor area of frontal lobe
What occurs in ALS?
- primary pathologic defect is in the motor neuron cell body (specific to anterior horn cell in the spinal cord)
- motor cells in the brainstem motor nuclei (cranial nerves)
- pyramidal cells in the primary motor cortex thus loss of the upper motor neurons in corticospinal tracts (Betz cells)
What are the possible causes of ALS?
- Definitive cause is unknown currently
- Mitochondria
- Currently, the most prevalent theory is that a SOD1 gene mutation causes the superoxide dismutase (SOD) enzyme to function improperly. This SOD enzyme is a strong anti-oxidant that the mitochondria need to perform their respiratory function. The respiratory and ATP function is compromised and the nerve cell begins to atrophy.
What are OTHER possible causes of ALS?
- Glutamate (and certain related neuropeptides) are elevated in the cerebrospinal fluid and blood in ALS patients up to concentrations that could be neurotoxic. Over-excitation of glutamate-sensitive cells in the nervous system may result in their premature degeneration and death.
- Premature aging
- Exogenous toxins (e.g. heavy metals)
- Viral diseases (due to similarities between ALS and poliomyelitis (both are anterior horn diseases) > suggest viral origins)
- Immunologic disturbances (frequent occurrence of unusual antibodies in the blood or nervous system of patients with ALS and animal studies)
- Heredity: 5% to 10% of all cases of ALS are familial
What are the stats of ALS?
- 0.1% of adult deaths in U.S.
- ALS is a disease of late middle life and is rarely seen prior to age 40.
- 90% of all cases begin between the ages of 40 and 70 years
- some predominance in men (estimated at 1.5-2.0 males to 1 females)
What are the S&S of ALS?
- First sign is usually asymmetric, distal weakness (e.g. difficulty in manipulating objects with the fingers or dragging one leg during walking)
- By the time the patient’s complain of weakness, they often have lost 80% of their alpha motor neurons in the areas of weakness
- Early signs: severe muscle cramps and/or fasciculations at rest
- EMG
- –spontaneous fibrillations
- –fasciculations with giant unit spikes upon voluntary activity
- Progress to muscle atrophy and severe muscle weakness
- –decrease in number of muscle fibers
- –type II fibers tend to atrophy earlier and more rapidly than type I fibers
- Cranial nerve cell atrophy leads to dysarthria, dysphagia, difficulty in chewing, tongue weakness and fasciculations may be prominent (the hypoglossal, facial, and trigeminal nuclei are most severely involved)
- Control of bladder, bowel, and autonomic function is largely unimpaired, however, some studies report sub-clinical involvement
What are the sensory S&S of ALS?
- THERE ARE NONE!!!
- sensory systems or the special senses are rarely involved (this is primarily a motor neuron cell body disease), however, pain and paresthesia are often reported
What are the LMN signs of ALS?
- Progressive muscle atrophy
- Weakness (asymmetric weakness is often a presenting sign)
- Fasciculations (especially evident in tongue, deltoid)
- Muscle cramps (painful)
What are the UMN signs of ALS?
- Spasticity
- Hyperreflexia
- Positive Babinski
What are the Statistics of ALS?
- Death in 2-5 years commonly from respiratory compromise
- Life expectancy of a patient with ALS can vary from less than 1 year to more than a decade with ventilator support
- Average survival rate is 4.1 years
- 20% survive more than 5 years
- Those who have ALS before age 50 generally live longer
- Those that have early CN involvement usually live less years post-Dx
- Stephen Hawkins is the exception
What are the interventions for ALS?
- General care revolves around the relief of discomfort and minimization of musculoskeletal, integumentary, and systemic effects
- Problems with swallowing, speech, postural control, and respiration are common so that equipment/therapy must be targeted to these needs (IPE – team approach)
- Therapy is directed at preventing contractures, skeletal deformity and/or respiratory complications, maintaining activity level, and recommending and issuing equipment as needed.
- Muscle spasms – stretching, increased movement, quinine or baclofen
- Diet – anti-oxidants – vitamins E and C
- In general, encourage a balance between activity and rest. “Do no harm” philosophy.
- If more than one third of the motor units are intact, exercise led to hypertrophy. If less than one third of the motor units are intact, vigorous exercise damaged the muscles
- If the patient shows evidence of significant, persistent weakness following institution of an exercise program or persistent morning fatigue, the therapist must redesign the HEP and monitor the patient’s activity level and response to HEP carefully
What is GB?
- An acute polyneuropathy affecting the peripheral nervous system
- May be an autoimmune attack on both the Schwann cells and peripheral and cranial nerves by circulating antibodies
What is the etiology of GB?
- acute – develops rapidly
- often follows the flu or respiratory infection
- may be idiopathic
- Guillain–Barré syndrome is rare (1-2 cases per 100,000 people annually), but is the most common cause of acute non-trauma-related paralysis.
- can occur at any age, but mostly 50-80
- More common in men than women
What are the characteristics of GB?
- The disorder is characterized by symmetrical weakness that usually affects the lower limbs first, and rapidly progresses in an ascending fashion.
- Individuals generally notice weakness in their legs, manifesting as “rubbery legs” or legs that tend to buckle, with or without numbness or tingling (“Jeff”)
- As the weakness progresses upward, usually over periods of hours to days, the arms and facial muscles also become affected.
When the cranial nerves are involved with GB what can it lead to?
- Oropharyngeal dysphagia (drooling, or difficulty swallowing and/or maintaining an open airway)
- Respiratory complications
- –Can cause life-threatening complications, in particular if the respiratory muscles are affected or if the autonomic nervous system is involved
- –Most patients require hospitalization and about 30% require ventilator assistance
- Facial weakness is also common
What form does Sensory loss occurs with GB?
*takes the form of loss of proprioception
What are common symptoms of GB?
- Pain is a common symptom in GBS, presenting as deep aching pain, usually in the weakened muscles
- In severe cases of GBS, loss of autonomic function is common, manifesting as wide fluctuations in blood pressure, orthostatic hypotension, cardiac arrhythmias
What is the course of the disease of GB?
- Maximal onset in less than 4 weeks (often in a few days)
- Static phase (plateau of 2-4 weeks)
- Recovery takes months to years
- Recurs in 10% of cases
When is there poor prognosis with GB?
- Onset at an older age
- Extended time before recovery begins
- Need for artificial respiration
What is the mortality rate of GB?
*5%
What is the progression of weakness of GB?
- At 6 months, 85% are ambulatory
- At 1 year, 20% remain significantly handicapped by weakness
- At 2 years, 8% have not achieved full recovery
What is the diagnosis of GB?
- Nerve conduction studies
* Studies of the cerebrospinal fluid
What is the intervention of GB?
- Supportive medical care
- Plasmaphoresis – filtering the blood plasma to remove circulating antibodies responsible for the destruction of the Schwann cells and peripheral and cranial nerves
- Intravenous immunoglobulins
What is the Etiology of MS?
- more than 2.3 million people worldwide
- female > males (women 2-3 x more often than men)
- predominantly Caucasian population
- high frequency: Northern US, Scandinavian countries and northern Europe
How does age affect MS?
- Most people are diagnosed between the ages of 20 and 50
* Although MS can occur in young children and significantly older adults
What are the genetic factors of MS?
- MS occurs in most ethnic groups, including African-Americans, Asians and Hispanics/Latinos, but is more common in Caucasians of northern European ancestry.
- More common in areas farthest from the equator.
- United States - about one chance in 750 of developing MS
- For first-degree relatives of a person with MS, such as children, siblings or non-identical twins, the risk rises to approximately one in 40
- The identical twin of someone with MS (who shares all the same genes) has a one in four chance of developing the disease.