What neurological disorder is characterized by the formation of neurofibrillary tangles?

Alzheimer's Disease is primarily characterized by the formation of neurofibrillary tangles, which are aggregates of hyperphosphorylated tau protein within neurons. These tangles disrupt cellular function and are a major pathological feature observed in the brains of individuals affected by this disease. Alongside neurofibrillary tangles, Alzheimer’s is also associated with amyloid plaques composed of beta-amyloid protein, both of which contribute to the neurodegenerative processes leading to cognitive decline.

In contrast, Parkinson's Disease mainly involves the loss of dopamine-producing neurons in the substantia nigra and the presence of Lewy bodies, which are different types of protein aggregates. Multiple Sclerosis is characterized by the demyelination of neurons but does not feature neurofibrillary tangles. Huntington's Disease involves the degeneration of certain neurons and is associated with CAG repeat expansions in the HTT gene, leading to distinct pathologies and symptoms rather than the presence of neurofibrillary tangles. Therefore, the association of neurofibrillary tangles with Alzheimer’s Disease accurately identifies it as the correct answer.