Neurofibrillary tangle

Overview
Neurofibrillary tangles were first described by Alois Alzheimer in one of his patients suffering from the disorder now referred to as Alzheimer's disease.

Pathophysiology
Neurofibrillary tangles are pathological protein aggregates found within neurons in cases of Alzheimer's disease. Tangles are formed by hyperphosphorylation of a microtubule-associated protein known as tau, causing it to aggregate in an insoluble form. (These aggregations of hyperphosphorylated tau protein are also referred to as PHF, or "Paired Helical Filaments"). The precise mechanism of tangle formation is not completely understood, and it is still controversial whether tangles are a primary causative factor in the disease or play a more peripheral role.

It is also believed that neurofibrillary tangles are seen in Creutzfeldt-Jakob disease. Neurofibrillary tangles are also found in Supranuclear Palsy.