Neurodegenerative Disease Overview

in this video we're gonna look at neurodegenerative diseases beginning with alzheimers disease Alzheimer's disease is a major cause of dementia the pathogenesis involves amyloid beta peptide and tau proteins so if we were to cut a section here of the brain and looked look at it and look at the difference between a normal brain compared to an Al's imus brain so on the left here we can see a normal brain these areas that I'm circling correlate with language and memory areas and if we were to compare this the brain to a patient who has Al's Imus we can see straight away cortical atrophy as well we can see loss of these these areas associated with language and memory and thus people who have Alzheimer's disease present with problems with language and memory so if we were to zoom into and look at the pathology in more detail of a of this of a brain of an Alzheimer's patient we can see that there is things within the soma of the neuron these yellow things every person here are actually neurofibrillary tangles which are made up of the microtubules the tau proteins also outside of the neuron we can see the accumulation of peptides these are known as amyloid plaques which are made from the amyloid beta peptide so these are essentially the hallmarks of Alzheimer's disease the neurofibrillary tangles and the amyloid plaques the next neurodegenerative disease that we're going to talk about is amyotrophic lateral sclerosis also known as motor neuron disease and this is the disease that Steven Hawkings has and there's a movie about it it's called a theory of everything if you haven't watched it you should and essentially motor neuron disease as the name suggests affects the neurons that control the motor aspects of things such as movement you know a cardiac function everything to do with moto so if we were to you know cut a section of the spinal cord here we can see some hallmarks of northern urine disease so again modern urine disease is a degenerative disease so it causes muscle weakness because we cannot you know we're not using our muscles as effectively due to the problem with the nervous system and muscle weakness will subsequently lead to disability and then progressively it can it will lead to death motor neuron disease causes upper and lower motor neuron signs and symptoms motor neuron disease can be sporadic in 90% of cases or familial in 10% of cases so if we were to compare on the left normal to patient has motor neuron disease we see in modern neuron disease we see ventral root thinning as well as spinal cord atrophy now we see ventral root thinning because actually the motor fibers actually leave through the ventral part of the spinal cord and thus because we have weakened we have problems with the neurons motor neurons we see atrophy we see ventral root thinning so the neurons again coming from the ventral root we see loss of myelinated neurons and subsequently we have muscle weakness so again the neurons leaving the ventral part of the spinal cord these are the motor nerves we see loss of myelin healing neurons we see loss of these neurons and thus subsequently it will lead to muscle weakness and progressively it will lead to death and a disability and death the next neurodegenerative disease is Frederick's a texia which is an autosomal recessive disorder in this in this condition we have loss of loss of function of the fxn gene which is a mitochondrial gene that normally encodes for a taxon so because we have lost of this gene we have a decrease in frataxin the clinical manifest nation of Friedreich's ataxia include neurological dysfunction cardiomyopathy as well as diabetes mellitus so looking at it in a more pathological from a more pathological view if we cut a cross section of the spinal cord here and compared comparing normal to a one with Fredericks ataxia we can see straight away we have a trophy of the dorsal root we have a trophy of the dorsal column and we have a trophy and problems of this some tracts within the spinal cord and this this shows us that we have essentially Frederick's architecture is a problem with sensory because the dorsal root is responsible for the sensory neurons bringing information into our body and the dorsal column is important for bringing these signals up to their brain the next neurodegenerative disease is Huntington's disease it is an autosomal ODIs some'll dominant disease characterized by perform movements dystonia psychiatric problems as well as dementia cutting a cross section of the brain of Huntington's we can see differences with it to a normal brain so in Huntington's our brain we can see dilation of the ventricles we can see a decrease in brain size due to loss of straddle neurons the caudate nucleus incorrect putamen and as well we mentioned we have a ventral ventricle dilation now if we focus on a normal brain first we have genes CAG repeats within our cells about ten to twenty six CAG repeats that encode for proteins the CAG the Huntington protein but if we but in Huntington's we have a problem normality of this gene instead of having between 10 or 26 CAG repeats we have 37 to 80 CAG repeats and the diagnosis for Huntington's is if we have more than 40 CAG repeats so more than 40 CAG repeats in the gene means that we that we can be fairly sure of Huntington's disease instead of having between 10 or 26 CAG repeats we have 37 to 80 CAG repeats and thus this causes a massive long Huntington protein and this is essentially known to be the cause of Huntington's disease so patients who have a family history of Huntington's disease once they turn 18 they could check their genes to see if they've abnormality in the Huntington genes more than 40 CAG repeats and interestingly enough the signs and symptoms of Huntington's disease come about midway through three in life so essentially in your 30s the next neurodegenerative disorder is Parkinson's disease Parkinson's disease is where we have dopamine a neurotransmitter called dopamine depletion in the area of the brain called the substantia [ __ ] it's characterized by tremors rigidity bradykinesia and postural hype post postural instability so these are the cardinal signs of Parkinson's so if we're to cut a cross section of the brain and compare a normal brain to a patient as Parkinson's disease we can see that in this area which is known as a basal ganglia we have problems so the basal ganglia is made up of many different components including the caudate nucleus caudate putamen as well as a substantial Niagra so if we were to take with her to look at the neurons coming from the substantia Niagra in a normal patient and compared to a Parkinson's disease patient we see that we have dopamine being released in from this area so we have you know high to normal amounts of dopamine whereas if we were to see a patient with Parkinson's disease we see lower amounts of dopamine less dopamine being secreted to the other neuron and this leads to the signs and symptoms of Parkinson's disease Parkinson's disease is also associated with Lewy body formation which can which is which is correlated or associated with a dementia the next condition is spinal muscular atrophy which is somewhat similar to modern neuron disease it is an autosomal recessive disease caused by a genetic Fault in the smn1 gene in spinal muscular atrophy we have degeneration again of the ventral horn of the spinal cord as well as the motor nucleus in the lower brainstem in this condition in spinal muscular atrophy we see symmetrical proximal muscle weakness so again if we were to take a cross section of the spinal cord here and compare a normal spinal cord to the one-of-a of spinal muscular atrophy we see atrophy of the ventral horn as well as the lower part of the brainstem the last condition we're going to talk about is not a neurodegenerative disease but it's very similar it's known as multiple sclerosis and again it's not a neurodegenerative disease and the reason it's not is because it is a autoimmune disease that a FET that targets the myelin that surrounds the neurons within the central nervous system so again if we were to draw the brain and brain stem and the spinal cord normally in the central nervous system we have myelin wrapping around the neurons which helps it which helps insulate the neurons helps in conduction of signals as well as regeneration if we were to look at a multiple sclerosis in neuron we see damage to the myelin sheath due to the due to the immune cells so we have damage to the myelin sheath which distorts and interrupts normal signaling and we have different types of multiple sclerosis we have relapsing remitting we have primary progressive we have secondary relapsing remitting as well as we have relapsing progressive you

Channel: Armando Hasudungan

Views: 69,736

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Keywords: neurology, neurodegenerative, neurodegeneration, alzhiemers disease, dementia, huntington's disease, parkinson's disease, what is ALS?, motor neuron disease, multiple sclerosis, overview, lecture, armando hasudungan, brain dieing, aging brain, pathophysiology, pathogenesis, animation, different types of brain disease, brain disease

Id: RImBxfVH9H4

Length: 11min 29sec (689 seconds)

Published: Tue Feb 02 2016