CNS 3 (Part 1)

Dx:

Due to:

• Multiple sclerosis

• Spongiform Encephalopathy

• Autoimmune

• Accumulation of abnormal protein

Answer explanation

Normal PrPC is a cytoplasmic protein of unknown function.

Disease occurs when PRPC undergoes a conformational change from its normal a-helix to an abnormal B-pleated sheet isoform, PRPSC.

Accumulation of PRPSC in neural tissues causes pathologic changes in neurons. Mechanism is still uncertain.

Dx

• Creutzfeldt-jakob disease

• Alzheimer's Disease

Answer explanation

Notice that there is atrophy of the brain because there is loss of brain substance. Because of the toxicity produced by the abnormal prion, the astrocytes and some of the neurons die and are taken up by the macrophages. The loss of these cells produces space (sponge like appearance)

Dx:

Pathologic Hallmark

• Alzheimer's Disease

• Amyloid (AB) and Tau

• Parkinson's

• Alpha-synuclein

What is this histologic hallmark?

• Neurofibrillary tangles

• Beta amyloid plaque

• Granulovacuolar degeneration

• Hirano bodies

Answer explanation

Neurofibrillary tangles - elongated "flame" shaped

Granulovacuolar degeneration – Vacuolation of the cells

Hirano bodies – The eosinophilic material

Cerebral amyloid angiopathy

These can be seen in what condition?

• Alzheimer's disease

• Parkinson's disease

• Huntington

• Ataxia-telangiectasia

Answer explanation

Alzheimer disease. (A) Plaques with dystrophic neurites surrounding amyloid cores are visible (arrows). (B) Plaque core and surrounding neuropil are immunoreactive for Aβ. (C) Neurofibrillary tangle is present within one neuron, and several extracellular tangles are also present (arrows). (D) Silver stain highlights a neurofibrillary tangle (black) within the neuronal cytoplasm. (E) Tangle (upper left) and neurites around a plaque (lower right) contain tau, demonstrated by immunohistochemistry.

Dx:

Distinguishable feature from AD:

Cellular inclusions:

• Frontotemporal Lobar Degeneration

• Pattern of involvement (Alteration in personality, behavior, and language (aphasia) preceding memory loss

• FTLD-tau

  TDP-43

• Lewy bodies

• Atrophy of caudate nucleus and putamen