W6 Neuromuscular function & Disorders of brain function

Is muscular dystrophy a disorder of muscles or the nervous system? Explain
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The drugs glucocorticoids may be used to slow the decline in muscle strength for those with DMD by suppressing the activity of cytotoxic T cells in necrotic muscles.treatment for DMDAnother potential treatment DMDcreatine monohydrate supplementation which may be useful for increasing muscle strength.potential new treatments for DMDTreatments with myostatin blockers or overexpressing follistatin genes in mice, has been shown to result in much larger and stronger musclesKnow that curare is a neuromuscular blocker that acts on the post junctional membrane of the motor endplate and blocks nicotinic type 1 receptors to causeflaccid paralysisHow does Botulin toxin work?Know how organophosphates and nerve gases like sarin workKnow how black widow spider toxin worksWould curare, physostigmine, neostigmine, botulism toxin, black widow spider toxin, aminoglycoside antibiotics, organophosphates, and nerve gases like soman, cause flaccid or spastic paralysis?Myasthenia GravisDoes MG condition more often affect men or women?Describe the cause of myasthenia gravisGive three mechanisms that contribute to the loss or dysfunction of acetylcholine receptors in the neuromuscular junction.What is believed to be the inciting factor involved in leading to MG autoimmune condition?Initially, which muscles are most commonly affected and what symptoms may occur due to weakness of these muscles?Which other muscles are often affected as MG progresses?During which time of the day are the symptoms of muscle weakness typically the worst?What is a myasthenic crisis and what can bring it on?What is the name of the drug sometimes used to diagnose myasthenia gravis?What is its mechanism?What do electrophysiology studies demonstrate and what is detected by an immunoassay test for myasthenia gravis?Describe why neostigmine, pyridostigmine, corticosteroids, plasmapheresis, and thymectomy may be useful in the treatment of myasthenia gravis.Know that with polyneuropathies, peripheral axons can be damaged and or demyelinated. Know that with polyneuropathies, both sensory and motor function may be disrupted.knowDoes GBS cause flaccid or spastic paralysis?What are paresthesias and where in the body is this typically experienced first in GBS?Do GBS patients experience exaggerated reflexes? Why or why not?Does muscle weakness and paralysis typically ascend or descend and are symptoms experienced symmetrically or asymmetrically with GBS?Where in the body is pain most often experienced in those with GBS?What are some manifestations related to GBS affecting neurons of the autonomic nervous system (ANS)?How quickly do the manifestations of weakness and paralysis progress and worsen with GBS?What types of infections often precede GBS cases and what are the names of the bacteria associated with these infections?Other than infections, what else sometimes precedes GBS?What are the two main subtypes of GBS?And what are the main causes for axon or myelin injury with each subtype?Describe molecular mimicry as it relates to the pathogenesis of GBS.Describe the characteristics of the CSF obtained from a spinal tap that are consistent with a diagnosis of GBS.Briefly describe nerve conduction studies and electromyography.Why is plasmapheresis, IV immunoglobulin therapy, antibiotic therapy, and anti-coagulant therapy useful in GBS treatment?Are corticosteroids useful for treatment?Why are GBS patients usually 46 treated in the ICU?Do most GBS patients end up dying? If not, how long do patients take to recover and why?Know that the basal ganglia or nuclei form complex neural circuits that connect various deep brain nuclei with each other and with the thalamus and cerebral cortex. Know that basal nuclei make up inhibitory and stimulatory feedback loops that are important in the planning and coordinating of motor movements.knowAcetylcholine is a stimulatory neurotransmitter in the striatum (caudate and putamen, among others) of the basal nuclei and is especially important to initiate voluntary movement. Inhibitory circuits release dopamine that acts to inhibit the activity of antagonistic muscles, thus facilitating movement. Those with basal nuclei disorders such as Parkinson disease, show an increase in muscle tone, and uncontrolled movements at rest.PD factsDoes PD affect men or women more?Which neurons degenerate and which neurotransmitter is decreased in PD?Is this disease caused by the environment or genetics?Exposure to what environmental substances has been shown to increase the risk for PD?What is paraquat and MPTP?Know that head injuries may also increase the risk for PD?Where is the substantia nigra located and what type of neurons does it mostly contain?What does substantia nigra mean?When 80% of dopaminergic neurons of the substantia nigra die, patients begin to get the symptoms associated with PD.Give a definition for the following symptoms - akinesia, bradykinesia, cogwheel rigidity, and resting tremor.What are the cardinal manifestations or central triad of symptoms for PD?What does the acronym TRAP stand for?Why are patients prone to falls, why do they drool, and why do they have slow speech?What are some symptoms demonstrating that PD is affecting the autonomic nervous system (ANS)?Know that cognitive dysfunction presents late in disease progression in some of those with PD.Know that exercise is very important in the treatment of PD; it is believed that exercise causes the release of growth factors for neurons.Do medications used to treat PD increase or decrease acetylcholine and dopamine?How do LDopa and phenylalanine get into the brain?How does dopamine get into the brain?What are the 2 main enzymes that breakdown L-Dopa?Name some side effects that are caused by dopamine in the peripheryWhat is the name of the enzyme that converts L-Dopa into dopamine in the brain?Name 2 enzymes that breakdown dopamine in the brain.Recall that Lewy bodies are abnormal aggregates of protein that develop inside some nerve cells involved with PD. A major component of this aggregate is a protein alpha-synuclein. The changes in alpha-synuclein that come with PD cause it to form aggregates that are toxic to neurons. These aggregates can be released by neurons and taken up by others, allowing them to spread to other brain areas.Know that ALS is a mixed lower motor neuron (LMN) and upper motor neuron (UMN) disorder. What does the name mean?What is the common nickname for ALS disease?Does ALS affect sensory or motor neurons or both?What is the typical age of onset for this disease and does it more often affect men or women?Typically, how long can a patient expect to survive after the onset of symptoms?Know that ALS affects LMNs located in the anterior horn of the spinal cord, as well as motor nuclei of the brainstem and UMNs with cell bodies in the precentral gyrus of the frontal lobe.A mutation in a gene that codes for superoxide dismutase (SOD1) was originally thought to impair the ability to rid the body of free radicals, but now scientists think that mutated SOD1 proteins will fold incorrectly and form aggregates that are toxic to neurons or trigger apoptosisDescribe the manifestations for ALS.What is being destroyed that leads to the symptoms of MS?Know that MS is an autoimmune disorder that affects white matter.What is the typical age for the onset of symptoms in those that are affected by MS?Does it more often affect men or women?Those with which HLA expression are more prone to developing the disease?It is believed that low levels of which vitamin and living where may increase the risk for development of MS?Which neurons become demyelinated?What is the name of the cell in the CNS that forms myelin and what is the function of myelin in neurons?What does heat cause in MS patients?It is believed that TH1 and TH17 cells target myelin antigens and release cytokines. Recall learning from earlier in the semester that TH1 cells release IFN-γ that activates macrophages, and TH17 cells act to recruit leukocytes. Activated leukocytes cause the demyelination.The plaques of MS contain CD4+ T cells and some CD8+ T cells as well as macrophages and plasma cells (humoral immunity also plays a role as certain immunoglobulins (IgG) can be detected in the CSF of these patients).Know that many nerves are affected leading to common symptoms such as: fatigue, paresthesia, optic neuritis, diplopia, pain, ataxia, dysarthria, incontinence, constipation/diarrhea, cognitive dysfunction and psychological disturbances (depression, unstable mood).What is Lhermitte sign?Give a brief description of the 4 categories that the course of the disease may fall under: progressive relapsing, secondary progressive, primary progressive, and relapsing remitting.What is pleocytosis?Know that some patients with MS have moderate pleocytosis and also have elevated levels of IgG in the CSF. Know that MRI is useful to detect lesions, monitor progress of lesions, and evaluate the effectiveness of treatment.How do corticosteroids, interferon-beta, and glatiramer act in the treatment of MS?Which chronic problems of MS do the drugs baclofen, dantrolene, diazepam, and cholinergic drugs help with?What are the two main types of stroke and give a basic description of each?Which is more common and which has a higher fatality rate?What is a silent CNS infarction and TIA (transient ischemic attack)?What are risk factors for stroke?Why does atrial fibrillation and mitral valve disease increase the risk for stroke?Know why red blood cell disorders like polycythemia and sickle cell disease also increase the risk for stroke.Why is hormone replacement therapy for women after menopause no longer recommended?Why does heavy alcohol consumption and cocaine use increase the risk for stroke?Describe the meaning of the term penumbra as it relates to TIAs and strokes.Know that "mini stroke" or "brain angina" are ways to describe a TIA.What causes the TIA and why is it important to diagnose a TIA?What is the basic difference between a large vessel (thrombotic) stroke and an embolic stroke?Name two locations that cerebral emboli mostly originate from.What are some cardiac conditions that predispose one to the development of emboli that could lead to embolic stroke?Name two predisposing factors for hemorrhagic stroke.Know that CT and MRI are important for diagnosing stroke to distinguish between ischemic and hemorrhagic stroke, and to rule out intracranial lesions that may present with similar symptoms.Understand why tissue plasminogen activator (tPA) is useful in the treatment of stroke.How quickly should it be administered to a patient with acute ischemic stroke after the onset of symptoms?What is the major complication associated with the use of tPA?Know that post stroke deficits include motor, speech/language, cognitive, sensory, visual, and behavioral deficits.Be able to explain the following terms: dysarthria, receptive aphasia, expressive aphasia, hemineglect, apraxia, agnosia, paresthesia, neuropathic pain, hemianopia (also called hemianopsia), and monocular blindness.Comparing viral vs bacterial caused meningitis, which is more common and which is more severe?What are the 3 enteroviruses that most commonly cause viral meningitis?Explain the differences in CSF findings that are important to differentiate between bacterial and viral meningitis. In your explanation include types of white blood cells, protein content, and sugar content.What are some risk factors for contracting meningitis?Know how microbes that cause meningitis can be spread.Know that the bacteria replicate in the CSF and then lyse and release endotoxins that induce inflammationKnow that meningitis can affect cranial nerve function (cranial nerve palsies) and block the flow of CSF (hydrocephalus).Know that the most common symptoms of acute bacterial meningitis are sudden onset of headache, fever, and nuchal rigidity. Other symptoms may include photophobia, nausea and vomiting, and altered mental state. Patients are also at increased risk for seizures, cranial nerve palsies (ie., CN VIII - deafness), and hydrocephalus.Understand the difference between the Kernig sign and Brudzinski sign and how they are performed to assess whether meningeal irritation is present.A CSF sample is taken by way of a lumbar puncture.Why is it important to administer corticosteroids just before starting antibiotic treatment?What makes encephalitis different from meningitis and which type of microbe most often cause encephalitis?What does the term parenchyma mean?Which neurons does poliovirus selectively destroy?Because of the degeneration of nerve cell bodies, patients with encephalitis more often experience neurological disturbances such as disorientation, lethargy, delirium, and coma compared to those with meningitis.Know that clinical features of a seizure include sensory, motor, and psychic manifestations.What is a convulsion?What are some common causes for provoked seizures?What is the cause for unprovoked seizures?What is epilepsy?What are the 2 broad categories of epileptic seizures?What is a general definition of a focal seizure and what are the 2 forms of focal seizures?What is an aura?happens right before a seizure Recall that an aura can occur before a seizure and before a migraine headache.What are some manifestations that occur with focal seizures?What are some differences between a focal impaired awareness seizure and an absence seizure?Does a generalized seizure involve one or both hemispheres?Explain and give a quick description for each type of generalized seizureThe older terminology "grand mal seizure" explains which type of generalized seizure.What does the old terminology petit mal seizure refer to?What is the postictal phase?What are some characteristics of absence seizures and what is the difference between typical and atypical absence seizures?Describe the difference between myoclonic and tonic seizures.Why are atonic seizures called "drop attacks"?Understand the importance of ruling out other reversible causes for dementia such as vitamin B12 deficiency, thyroid dysfunction, electrolyte imbalance, and other brain diseases (CT scan or MRI is important)What does the pneumonic DEMENTIA mean and recall that this would help us to rule out other causes of dementia?What is amyloid precursor protein (APP)?Recall the enzymes alpha-secretase, gamma secretase and beta secretase and how they work to produce normal breakdown of APP or amyloidogenic breakdown of APP.Recall that APP breakdown can lead to an insoluble peptideamyloid beta (A-beta).Amyloid beta is a normal by-product of APP breakdown and consists of 36-43 amino acids. The amyloid beta40 monomer is much more prevalent and easier for the brain to process compared to the amyloid beta42 monomer that is much more likely to aggregate to form the senile plaques of AD.Amyloid beta is broken down several ways including via phagocytosis by microglia and receptor mediated internalization by astrocytes.The protease neprilysin is also important in the degradation of amyloid beta.Another protein called Tau is important in stabilizing the microtubule tracks that serve to transport cellular products from the cell body to the axon terminal and vice versa.Transport from the soma to the axon terminal is known as anterograde transport and transport from the axon terminal to the soma is known as retrograde transport.The enzyme choline acetyltransferase (ChAT) is produced in the soma and transported by the microtubule tracks (supported by Tau) to the axon terminal (anterograde transport) where it transfers an acetyl group to choline to form the neurotransmitter acetylcholine (ACh).In the pathogenesis of AD, amyloid beta activates an intracellular kinase that phosphorylates Tau proteins. In the phosphorylated state the Tau proteins aggregate inside the cell to form what are called neurofibrillary tangles or just tangles.The extracellular plaques and the intracellular tangles do a lot of damage and the neurons start to die. This causes the brain to shrink because the gyri get thinner and the sulci widen. Areas of the neocortex and hippocampus shrink greatly, while the CSF-filled ventricles actually become larger.Areas of the primary sensory cortex mostly remain unaffected by the disease process.Cholinergic neurons are very important in learning and memory. Cholinergic dysfunction in AD is due to decreased cholinergic neurons, decreased choline uptake, decreased ACh release, decreased ChAT, and decreased nicotinic receptors. The reduction in ChAT in Alzheimer disease can be correlated with the number of plaques and disease severity.Certain genetic factors increase the chance to develop AD at a younger age. Mutations in the APP gene and presenilin genes increase the risk for AD.The genes, presenilin 1 and presenilin 2, code for subunits that make up the gamma secretase enzyme. Mutations in these genes happen in certain familial forms of AD and result in a gain of function that causes gamma secretase to generate increased amounts of amyloid beta, especially A-beta42 which is particularly prone to aggregate and form more amyloid plaquesThose with Down Syndrome also often develop early onset AD. The gene coding APP is located on chromosome 21 and those with Down syndrome have an extra copy of chromosome 21, so they have an extra APP gene which results in increased expression of APP.The Apo E gene codes for Apo lipoprotein E which is a protein that can assist with removal of amyloid beta. Individuals inherit one Apo E gene from each parent. Several different versions or alleles of the Apo E gene exist including E2, E3, and E4. The E3 allele is the most common and is found in more than 50% of the general population. Inheriting an Apo E4 gene from each parent increases the risk for developing Alzheimer disease because Apo lipoprotein E4 is not as effective at removing amyloid beta. The Apo E2 allele may actually be protective.What are the hallmark symptoms of AD?Describe the symptoms during the initial stage, moderate stage, and advanced stages of AD.In addition to memory loss, know that patients in the initial stages will start to experience mild changes in personality such as social withdrawal and loss of sense of humor.The moderate stage may last several years and patients begin to experience language deficits, lack of ability to problem solve, loss of math skills, loss of learned motor skills, and may become depressed and/or aggressive. Some patients become hostile toward family members or caregivers. Those in the moderate stage may become unable to live on their own.In the advanced stage, patients become mute, incontinent, and bedridden. For most patients, the advanced stage lasts 1.5 to 2 years. Patients usually die from aspiration pneumonia (due to losing the ability to swallow), infection, or cardiac arrest.What is the only way to confirm a diagnosis of AD?Assessment using The Mini-Mental State Exam (MMSE) can assist in measuring cognitive impairment.How are acetylcholinesterase inhibitors, NMDA receptor antagonists, antiinflammatory agents, and antioxidants useful in the treatment of AD?What activities and environmental factors are believed to be associated with higher or lower risk for development. What are higher risk and lower risk activities?Give a brief and simple description and cause for the following conditions and how they cause dementia: Vascular Dementia, Frontotemporal Dementia, Wernicke-Korsakoff Syndrome, and Huntington Disease.Give a basic description of what narcolepsy is.Know that individuals with the HLA-DQB1*06:02 variation have an increased risk for developing narcolepsy especially if they are exposed to infections like strep throat or influenza (many new cases after the H1N1 influenza epidemic of 2009).What is Orexin? What is it also called? What does it do?An age between 10 and 20 years is when individuals are most prone to disease development.What are the tetrad of symptoms for narcolepsy?Define the terms hypersomnia, cataplexy, hypnagogic hallucinations, hypnopompic hallucinations, and sleep paralysis.