Final answer:
The twisting and tangling of neurons, along with the cortical shrinkage found upon autopsy, are indicative of Alzheimer's disease, rather than other conditions like a stroke, heart attack, or transient ischemic attack.
Step-by-step explanation:
The autopsy findings of high incidence of twisted and tangled neurons, coupled with cortical shrinkage and other symptoms observed, suggest that Dan may have died from Alzheimer's disease.
Alzheimer's disease is characterized by the accumulation of amyloid plaques and neurofibrillary tangles in the brain, along with significant neuron loss, especially in the hippocampus, leading to brain volume reduction.
Comparisons between a normal brain and an Alzheimer's patient's brain, as seen in figures provided, illustrate these considerable changes, which are not typically associated with the effects of a stroke, heart attack, or transient ischemic attack.