Movement disorders can result from dysfunction of:
- LMN (cell body or axon)
- Neuromuscular junction
- muscle fibers
* These have an indirect effect on UMNs
What is primary neuropathy vs. primary myopathy?
PN: damage to the LMN (cell body or axon) or neuromuscular junction
PM: damage to the muscle fiber
The size and number of motor in a muscle can be measured using ___________. Changes in _____, _______, and ________ can provide clues to disease processes.
What is fibrillation?
Spontaneous firing of the sarcolemma
In primary neuropathy, the number of motor units ________ but size (potential) ________.
In primary neuropathy, denervated muscle fibers secrete substances that induce branching of nearby axons. New axon branches re-innervate the formerly denervated muscle fibers.
Symptoms are (6):
- muscle weakness
- fasciculations (looks like little ripples of movement under the skin)
- reduced reflexes
- emotional lability
- possible somatosensory abnormality (if sensory nerve affected)
In primary myopathy, the number os motor units ___________, but size (potential) _________.
Muscle fibers secrete ___________ which communicate with the ______. Without this, the _____ will die, and the number of muscle units will _________.
Symptoms of primary myopathy are (6):
- trophic substances
weakness, fatigue, atrophy, muscle cramps, stiffness, and/or muscle spasms
when muscle atrophy is congenital, it's called ________. Non-congenital muscle atrophy can be caused by (4):
toxins, drugs, endocrine abnormalities, inflammation
Specific movement disorders at the level of:
Amyotrophic Lateral Sclerosis
Amyotrophic Lateral Sclerosis
how many people?
Average life expectancy after diagnosis?
What % will die within this average?
What are the symptoms (5):
What do doctors do as a quick test?
What type affects speech and swallowing early on?
- Lou Gherig's disease
- 1 in 20,000 (about 30,000 each year)
- 40 - 60 (primarily males)
- 3-5 years
- muscles weakness/atrophy, fasiculations, muscle cramps, tight/stiff (spastic) muscles, exaggerated reflexes (hyperreflexia)
- Babinski's sign (toes flare)
*research also shows that higher level cognition may be lost
Death in ALS often occurs because of:
which two tracts are affected?
What is the etiology?
Does infection play a role?
There is a promising drug that may:
- Respiratory failure
- Corticobulbar (more rare-speech and swallowing) and corticospinal
- Mostly unknown
- No one has proven role of infection
- increase life expectancy 1-3 months (may be beneficial for bulbar ALSO
What is the pathophysiology of ALS?
Degeneration of LMN and UMN, some neurons are spared such as optic nerves and nerves that control the bladder
What are some postulations about ALS causes?
- 5-10% are genetic
- Glutamate becomes overstimulated
- Autoimmune responses impair the motor neurons
- environmental exposure/toxins/infection/dietary deficiency
Myasthenia Gravis is a ________ neuropathy.
How many have it in US?
who is it more common in at what age?
What is the disease course?
- 20 in 100,000
- females (20-40) and in both genders between 50-70
- Course is characterized by gradual progression of symptoms with frequent remissions and relapses
What are the symptoms of Myasthenia Gravis?
- Weakness and fatigue of voluntary muscles, including muscles of facial expression
- Ocular symptoms (diplopia, blurred vision)
- Slurred, nasal, or horse speech (when speech is ongoing)
- dysphagia and respiratory complications (progressively worsens as client continues to perform function)
What is the pathophysiology of Myasthenia Gravis?
Immune system generates _____ against _______ receptors. Antibodies bind to receptors and interfere with the actions of ACh at the ______________. Secondary ________ changes also occur in neuromuscular junction that make transmission less _______.
Why is motor function hard to maintain?
- neuromuscular junction
With each action potential, the ACh decreases
What are some possible causes of myasthenia gravis?
Is it treatable?
- Thymus gland irregularities (65% of cases, in 10% of these, there is a benign tumor in the thymus gland, which is the principal organ of the immune system)
- heritable defect in immune regulation
- viral infection
There are meds to help manage symptoms (immunosuppressants, anticholeresterate agent that prolongs action of the ACh)
Affects what percent of people over age 50?
- increased muscle tone (rigidity)
- slowness of movement (bradykinesia)
- resting tremors (hand, jaw)
- postural instability
- difficulty initiating voluntary movements (akinesia)
- depression and cognitive deficits
- blank expression
- hypokinetic dysarthria
1% and white people are more likely to get it than black people
What is the pathophysiology of of Parkinson's?
Neurons in the _________ degenerate, and many surviving neurons show ______ which contain alpha-synuclein proteins.
Loss of ________ releasing axons results in an increase of _________ output from the globus pallidus to thalamus and a decrease of ________ from the thalamus to the cortex.
The degeneration of __________ neurons accounts for non-motor symptoms of PD
- Substantia Nigra
- Lewy Bodies
What are some possible causes of Parkinson's?
- Early Onset is genetic usually, Late Onset is not
- Environmental toxins may increase risk
- viruses, mitochondrial dysfunction, and oxidative stress
What are symptoms of Huntington's Disease?
What is this often misdiagnosed as?
- Excessive motor movements (hyperkinesia)
- Uncontrollable movements (chorea) writhing movements
- impairment of voluntary movement (dyskinesia)
- psychological and cognitive disorders (memory and hallucinations
- hyperkinetic dysarthria
What is the Etiology of Huntington's Chorea?
- Mutation in a gene that codes for the huntingtin protein. A normal gene has about 37 glutamines, a mutated gene has as many as 150. These proteins aggregate, accumulate, and trigger neuronal death. The protein is thought to counteract signals that trigger cellular death (keeps cell alive).
- HC is genetic, 50% of offspring will get it
What is the pathophysiology of Huntington's Chorea?
Loss of nuerons in the basal ganglia and cerebral cortex. Loss of inhibitory output from basal ganglia (putamen/caudate nucleus) to thalamus account for abnormal movements. There is a decrease in inhibition from thalamus to cortex, and an increase in excitation to the cortex. Cortical degeneration results in cognitive and personality disorders. There is too much dopamine (opposite of PD) and there are enlarged ventricles as a result of the loss of neurons.
What types of treatment are there for Huntington's?
- Palliative in nature
- research looking into gene transplants, stem cell transplants, and neurosurgery