HLTH 2501: chronic degenerative disorders Flashcards
multiple sclerosis
involves a progressive demyelination of the neurons of the brain, spinal cord, and cranial nerves; there are multiple types
what is the result of multiple sclerosis
the loss of myelin interferes with conduction of impulses in the affected fibres (motor, sensory, or autonomic); this causes neural degeneration that varies in its severity
how does multiple sclerosis develop?
an inflammatory response creates a lesion that results from cells that do not normally enter the brain, but attack neurons, causing a loss of myelin in the white matter of the brain; this develops into larger areas of inflammation and demyelination termed plaques
what might be responsible for the development of multiple sclerosis?
a protein in the body’s blood-clotting mechanism that triggers the immune response; it is also believed to be an autoimmune disorder and linked to genetic and environment conditions
where do plaques commonly develop in multiple sclerosis?
in the lateral ventricles, the brainstem and the optic nerves; these appear pinkish and swollen, but later become grey and firm
who does multiple sclerosis affect more?
women between the ages of 20 and 40 and often those of European descent
signs of multiple sclerosis
blurred vision is the common early sign, weakness in the legs, diplopia (double vision), scotoma (spot in the visual field), dysarthria (poor articulation), paresthesias, and as it progresses, loss of coordination of the bladder and bowel may occur
complications arising from multiple sclerosis
those related to immobility like respiratory infection, decubitus ulcers, and contractures
diagnosis for multiple sclerosis
no definitive test but includes a history of exacerbations and remissions, involvement of multiple focal areas, and absence of other disorders; MRI’s can be used, CSF analysis, and optical coherence tomography
what are CSF serum levels like in those with multiple sclerosis?
elevated protein, gamma globulin, and lymphocytes
treatment for multiple sclerosis
interferon beta-1b can reduce frequency of exacerbations, glucocorticoids, muscle relaxants, avoiding fatigue, stress, injury, or infection, PT, OT, and speech therapy
parkinson disease other name
paralysis agitans
parkinson’s disease
is a progressive degenerative disorder that affects motor function through loss of extrapyramidal activity due to changes in the basal nuclei and substantia nigra, leading to decreased dopamine release
what does the lack of dopamine release in Parkinson’s disease cause?
leads to an imbalance between excitation and inhibition of the basal nuclei; this causes affected movement and posture by increasing muscle tone, restless tremors, muscle rigidity, difficulty in initiating movement, and instability
what neurons are lacking in Parkinson’s disease?
cortical neurons
toxins that may cause parkinson’s disease
manganese, carbon monoxide, carbon disulfide, and some pesticides
primary parkinson’s disease
usually develops after age 60 and is associated with genes, toxins, mitochondrial damage, and lewy bodies
mitochondrial damage in Parkinson’s patients
changes in the mitochondria due to oxidative stress lead to the accumulation of free radicals within the cell
lewy bodies and parkinson’s disease
these are clumps of specific substances in the affected brain cells that contain a protein called alpha-synuclein
secondary parkinsonism
may follow encephalitis, trauma, or vascular disease
drug-induced parkinson’s disease
is linked to the use of phenothiazines (antipsychotic’s)
signs of parkinson’s disease
fatigue, muscle weakness, muscle aching, decreasing flexibility, less spontaneous change in facial expression, hand tremors that progress to feet, face, tongue, and lip tremors, muscle rigidity, difficulty initiating movement, lack of associated involuntary movements, propulsive gait, bradykinesia, low voice, drolling, reduced linking, and increased risk for falls
bradykinesia
slow movements
propulsive gait
short, shuffling steps with increasing acceleration
treatment for parkinson’s disease
dopamine replacement (Levodopa), monoamine oxidase B inhibitors, anticholinergic drugs, catechol-O-methyltransferase inhibitors, antidepressant drugs, speech therapy, PT, and OT
levodopa
is a precursor of dopamine and used for parkinson’s treatment
monoamine oxidase B inhibitors
selegiline and rasagiline; these block the breakdown of L-dopa in the brain
anticholinergic drugs
include benztropine
catechol-O-methyltransferase inhibitors
include entacapone that mildly prolong the effect of L-dopa therapy by blocking an enzyme that breaks down dopamine
ALS
amyotrophic lateral sclerosis
2 other names for ALS
Lou Gehrig disease and motor neuron disease
amyotrophic meaning
muscle wasting
sclerosis means
hardening; for ALS it refers to the degenerative hardening of the lateral corticospinal tracts
ALS
is a progressive degenerative disease affecting both UMNs in the cerebral cortex and LMNs in the brainstem and spinal cord; sensory neurons are not affected; this is a fatal disease
how does ALS develop?
supportive glial cells called astrocytes secrete a neurotoxin, leading to the death of motor neurons
what does damage to the UMNs result in?
spastic paralysis and hyperreflexia
what does damage to the LMNs result in?
flaccid paralysis, with decreased muscle tone and reflexes
what does the progressive muscle weakness in ALS lead to?
affected respiratory function
signs of ALS
the upper extremities, particular the hands manifest weakness and muscle atrophy, with a loss of fine motor coordination; stumbling and falls are common, along with muscle cramping and twitching, speech loss, impaired respiration, and swallowing difficulties
treatment for ALS
to treatment to reverse the course; Rulutrek slows damage to neurons, allowing for swallowing and ventilation to remain; exercise and rest is also helpful, along with respiratory therapist, nutritionist, speech pathologist, OT, PT, psychologist, and social workers
myasthenia gravis
is an autoimmune disorder that impairs the receptors for ACh at the neuromuscular junction; cause is not known but is related to thymus disorders like hyperplasia or benign tumors
what happens in mysasthenia gravis
immunoglobulin G autoantibodies to ACh receptors form, blocking and ultimately destroying the receptor site, thus preventing any further stimulation of the the muscle; this leads to skeletal muscle weakness and rapid fatigue of the affected muscles
what muscles are often affected in myasthenia gravis
the facial and ocular muscles, followed by the arm and trunk muscles
tests for myasthenia gravis
EMG to test muscle fatigue, looking at serum antibodies, and a test that uses edrophonium chloride (Tensilon) which is a shorter-acting anticholinesterase inhibitor to prolong the action of ACh at the myoneural junction
signs of myasthenia gravis
noticeable muscle weakness, fatigue, diplopia and ptosis impairs vision, speech becomes monotone, spontaneous facial expressions are lost (droopy face), difficulty chewing and swallowing, head droops, upper respiratory infections are common and myasthenic crisis
myasthenic crisis
occurs when there is added stress such as an infection, trauma, or alcohol intake and involves an increase in weakness and fatigue, and respiratory impairment may develop
treatment for myasthenia gravis
anticholinesterase agents, glucocorticoids (prednisone) for suppressing the immune system, other immunosuppressants, plasmapheresis, and thymectomy
anticholinesterase agents for myasthenia gravis
can be neostigmine and this temporarily improves neuromuscular transmission through prolonging the action of Ach
plasmapheresis
is a process that removes antibodies from the blood and can be treatment for myasthenia gravis
huntington disease
is an inherited disorder that does not manifest until midlife and is characterized by progressive atrophy of the brain, including degeneration of neurons, particular of the basal ganglia of the frontal cortex, and dilation of the ventricles
genetic factors for huntington’s disease
is a genetic disorder via an autosomal-dominant trait carried on chromosome 4 (50% probability) and maternal inheritance delays the onset compose to paretrnal
what neurotransmitters are reduced in huntington’s disease
GABA (inhibitory neurotransmitter) and Ach
signs of huntington’s disease
mood swings, personality changes, restlessness and choreiform (rapid, jerky) movements in the arms, and possibly early signs on intellectual impairment like loss of problem-solving skills, difficulty learning, and poor judgement
how is huntington’s disease diagnosed?
DNA analysis
treatment for huntington’s disease
no therapy but the drug tetrabenazine is used to maintain mobility and other drugs for behavioral changes, as well as PT
dementia
is a progressive chronic disease in which cortical function is decreased, there are impaired cognitive skills, decreased motor coordination, loss of memory, and behavioural changes
how is normal forgetfulness distinguished from dementia
those with dementia cannot recall after being given clues, the day cannot be identified, calculations are difficult, and reminders are needed for meals and hygiene
causes of dementia
vascular disease (ex. atherosclerosis), infections, toxins, and genetic disorders
most common dementia disorder
Alzheimer’s disease
alzheimer’s disease
is characterized by a loss of intellectual function, and includes personality changes, lack of initiative, repetitive behaviours, judgement impairment, abstract-thinking, and problem-solving abilities
how does Alzheimer’s disease develop?
progressive cortical atrophy leads to dilated ventricles and widening of the sulci; neurofibrillary tangles and senile plaques are present, and these disrupt neural conduction; there is also a deficit of Ach
what is contained in the plaques in those with Alzheimer’s disease?
beta-amyloid precursor protein
causes of Alzheimer’s
unknown but is genetic, as at least four defective genes are located on different chromosomes (1, 14, and 21 are autosomal dominant traits and 21 in those with down’s syndrome); there is another late-onset AD that is associated with chromosome 19
early stage of Alzheimer’s
gradual loss of memory and lack of concentration; the ability to learn new information and to reason is impaired, along with behavioural changes; this progresses and ADL become impaired, along with wandering
late stage of Alzheimer’s disease
the person does not recognize his or her family, lacks awareness or interest, it incontinent, cannot function and motor function degenerate
treatment for Alzheimer’s disease
OT, depression and anxiety medication, anticholinesterase drugs, and providing a safe space, with a daily routine and some light exercise
4 types of dementia
Alzheimer’s disease, vascular dementia, Creutzfeldt-Jakob disease, and acquired immunodeficiency syndrome dementia
vascular dementia
is caused by cerebrovascular disease and frequently is a result of multiple small brain infarctions; common in those with hypertension
Creutzfeldt-Jakob disease
is rare, but progresses rapidly; can be cause by infection by a prion, which is an altered, infectious form of the prion protein that has a preference for nervous tissue
how does the prion protein cause Creutzfeldt-Jakob disease
it alters the shape of normal host PrPs which has a long incubation period and then is followed by rapid destruction of neurons and the formation of plaques and vacuoles in the neurons
how it Creutzfeldt-Jakob disease acquired?
can be genetic (a defect in the human prion protein gene) or have be through surgeries, corneal transplants, or other invasive procedures
how is Creutzfeldt-Jakob disease diagnosed?
MRI and EEG
treatment for Creutzfeldt-Jakob disease
no treatment but amantadine, steroids, interferon, acyclovir, antiviral agents, and antibiotics may help to alleviate symptoms
acquired immunodeficiency syndrome dementia
dementia may develop in later stages on acquired immunodeficiency syndrome and occurs when the virus itself invades brain tissue and may be exacerbated by other infectious agents like Candida, toxoplasma species, and tumors such as lymphoma
