In this talk, I will tell you about biomarkers for Alzheimer's disease.
First, I will recapitulate the key features of the disease,
in this picture you see the first patient described with the disorder.
Her name was Auguste Deter, and she was a German patient, rather young,
suffering from a progressive memory condition.
In the next picture you see Alois Alzheimer, the physician who took care of Auguste Deter at the end of her life.
He described her symptoms, and he also described
the neuropathology that he saw upon autopsy examination.
Here is a picture of what Alois Alzheimer saw in the brain of Auguste Deter.
There are three neuropathological changes that he described.
1. Senile plaques, these are dispersed throughout the brain,
they are extracellular aggregates of a protein called β-amyloid.
2. Alois Alzheimer also described neurofibrillary tangles,
which are intraneuronal protein inclusions.
3. Finally, he described general neuronal loss, and also synaptic loss.
These brain changes start to occur in the medial temporal lobe,
then they spread throughout the temporal lobe,
up through the parietal cortex, and eventually to the frontal lobe.
This correlates with the symptoms of the patient.
The first symptoms are often mild memory disturbances,
patients may be described as suffering from mild cognitive impairment.
Eventually these problems may get so severe that they fulfil dementia criteria,
that is when the memory problems are so severe that they affect daily living.
As the brain changes spread over the brain, the symptoms get worse.
Eventually, behavioral symptoms will occur, when the disease strikes the frontal lobes.
The molecular pathology of Alzheimer's disease was described in the 1980s.