Alzheimer’s Disease- Presentation, Symptoms, Diagnosis/Workup Flashcards
To stay healthy, neurons must do what 3 things?
Communicate with each other
Carry out metabolism
Repair themselves
In AD, what happens to these 3 processes?
They’re all disrupted!
Alzheimer’s disease definition
brain atrophy with ventricular enlargement with degeneration of cholinergic and other neurons, absent or minimal vascular disease, neuronal loss
Cardinal signs of AD
Neurofibrillary tangles, senile plaques, accumulation of beta-amyloid
Beta-amyloid plaque definition
dense deposits of protein and cellular material that accumulates outside and around nerve cells
Precursor to beta-amyloid plaque
Amyloid precursor protein (APP)
How are beta-amyloid fragments made?
Enzymes cut the APP into fragments of protein (beta-secretase and gamma-secretase) –> beta-amyloid fragments come together in clumps to form plaques –> the plaques disrupt the work of neurons –> affects the hippocampus and other areas of the cerebral cortex
Neurofibrillary tangle defintion
Twisted fibers that build up inside the nerve cell
How are neurofibrillary tangles made?
Stabilizing tau molecules become abnormally hyperphosphorylated –> unstable –> fall apart –> tangled clumps of tau proteins form neurofibrillary tangles
Preclinical AD presentation
Affected regions will shrink as nerve cells die; changes can begin 10-20 years before symptoms appear
First sign of AD
Memory loss!
How does memory loss progress in AD?
“The clock ticks backwards,” you lose your most recent memories first and lose the earliest ones last
Mild-moderate AD presentation
Cerebral cortex begins to shrink as more neurons stop working and die
Mild signs of AD
memory loss, confusion, trouble handling money, poor judgement, mood changes, increased anxiety
Moderate signs of AD
increased memory loss and confusion, problems recognizing people, difficulty with language and thoughts, restlessness, agitation, wandering, repetitive statements
