Which progressive irreversible brain disorder is characterized by memory loss and brain changes including amyloid plaques and neurofibrillary tangles?

• A. Alzheimer's disease
• B. Parkinson's disease
• C. Huntington's disease
• D. Lewy body dementia

Answer: (A)

This describes Alzheimer's disease, a progressive, irreversible brain disorder where memory loss and cognitive decline align with the hallmark brain changes of amyloid plaques and neurofibrillary tangles. Amyloid plaques are extracellular clumps of beta-amyloid peptide that disrupt communication between neurons, while neurofibrillary tangles are twisted tau protein inside neurons that interfere with their internal transport systems. As these pathologies accumulate, neurons die and brain regions important for memory—like the hippocampus and cortex—shrink, leading to the gradual decline in thinking and memory that characterizes the condition. Other options reflect different diseases: Parkinson’s centers on motor symptoms from dopaminergic neuron loss; Huntington’s involves genetic-caused movement disorders and caudate atrophy; Lewy body dementia features alpha-synuclein inclusions with distinct cognitive and visual symptoms. The combination of memory loss and these specific plaques and tangles points to Alzheimer's disease.