OCCTH 585 - Alzheimer's Disease Questions And Answers Already Graded A+

Brain Atrophy - ️️Severe shrinking of the entire cortex Severely enlarged ventricles Severe shrinkage of hippocampus Rate of neuronal loss accelerates as the disease progresses Whole brain weight decreased by 10% to 19% Not evenly distributed Mostly in gyri of association areas Relatively less: primary motor, primary somatosensory and primary visual cortices -- Mostly the medial temporal lobe is affected -- - If it is purely AD, motor and sensation normal Top 9 Early Signs - ️️1. Memory loss 2. Changes in mood 3. Misplacing belongings 4. Hard to complete familiar tasks 5. Confusion of time nd place 6. Social withdrawal 7. Poor judgement 8. Struggling to communicate 9. Changes in vision Alzheimer's disease - ️️One of the most common types of dementia. Not a process of accelerated brain aging. Specific characteristics in neurons. - Insidious onset - cognitive and behavioural impairments Neuropathology - ️️- Dedriditc modicfication Normal aging - degenerative changes in dendrites of pyramidal neurons Dendritic changes and Neurocortical degeneration - ️️Resulting from: - β-amyloid plaques - neurofibrillary tangles Normal Adults - ️️Also develop plaques: - Neuritic (senile) plaques (not strictly intraneuronal) - Around late 80s - Amount much less than AD - Very few neurofibrillary tangles (entirely intraneuronal, lead to death of neuron)Density of Plaques - ️️- Temporal lobe is most severely affected - Hippocampus volume is reduced by up to 60% in advanced AD - Reduced connectivity of the hippocampus with other brain regions β-amyloid plaques - ️️Defective breakdown of a benign substance known as amyloid precursor protein (APP) Produce sticky, insoluble shards of β-amyloid plaques - stick together, form dense plaques, damage axons, lead to development of neurofibrillary tangles Types of Dementia - ️️- Alzheimer's disease - Vascular dementia - Lewy bodies - Frontotemporal dementia Neural systems for AD - ️️Limbic System: - Impacts our behaviout - Plays a role in basic instincts such as sleping and eating - Plays a role in emotions - impacts sense of smell - The hippocampus, which is part of the limbic system, is important for learning and short term memory - the part of the brain where short-term memories are converted to long-term memory for storage - also where verbal and visual memory are processed Circadian rhythms are affected (day-night cycle) Suprachiasmatic necleus within the hypothalamus (circadian clock) Neurotransmitter abnormalities - ️️Tracks form by cholinergic neurons (containing acetylcholine) are destroyed Nucleus basalis has projections to cortical areas, volume reduce by ~70% in AD Facts about AD - Sporadic - ️️90% of AD is late onset, around 65, no known genetic cause Facts about AD - Familial - ️️10% of AD, Genetic mutations, Usually early onset Facts about AD - Age - ️️Risk doubles every five years after the age of 65 Facts about AD - History of Head Injury - ️️Speculated to increase the neuronal secretion of amyloid History of depression History of electroconvulsive therapy (ECT)Facts about AD - Genetic predisposition - ️️Chromosome 21, 14, 1 Increase production of amyloid *Down syndrome Facts about AD - Protective Factors - ️️Environmental toxins?? aluminum Educational level, physical inactivity?? Language?? (bilingual) Vascular Dementia - ️️15% to 20% of all cases of dementia 10% of patient first diagnosed with stroke show signs of dementia within 6 months, one third in about 4 years Frontotemporal dementia - ️️Pick's disease 5% of all cases of dementia Young age Primarily progressive aphasia Cortico-basal degeneration Bilateral atrophy of both the frontal and the anterior temporal lobes and degeneration of the striatum Plaques made of amyloid protein are a defining feature of AD but are not typically seen in frontotemporal dementia