DEGENERATIVE DISEASES AFFECTING THE CEREBRAL CORTEX-Pick Disease

Question 1

What is Pick disease ?

Answer 1

It is a (lobar atrophy) is a rare, distinct, progressive dementia characterized clinically by
early onset of behavioral changes together with alterations in personality (frontal lobe signs)
and language disturbances (temporal lobe signs).

While most cases of Pick disease are
sporadic, there have been some familial forms identified and linked to mutated tau protein.

Question 2

What is the morphology of pick’s disease?

Answer 2

The brain invariably shows a pronounced, frequently asymmetric, atrophy of
the frontal and temporal lobes with conspicuous sparing of the posterior two thirds of the
superior temporal gyrus and only rare involvement of either the parietal or occipital lobe.

Question 3

What pattern can distinguished Pick disease from AD on gross examination?

Answer 3

The atrophy can be severe, reducing the gyri to a wafer-thin (“knife-edge”) appearance.

Note: Thispattern of lobar atrophy is often prominent enough to distinguish Pick disease from AD on
gross examination.

In addition to the localized cortical atrophy there may also be bilateral atrophy of the caudate nucleus and putamen.

Question 4

What is the microscopic findings in Pick’s disease?

Answer 4

Microscopically, neuronal loss is most severe in the outer three layers of the cortex.

Some of
the surviving neurons show a characteristic swelling (Pick cells), while others contain Pick
bodies, which are cytoplasmic, round to oval, filamentous inclusions that are only weakly basophilic but stain strongly with silver methods ( Fig. 28-39 ).

Ultrastructurally, these are
composed of straight filaments, vesiculated endoplasmic reticulum, and paired helical
filamentsthat areimmunocytochemically similar to those found in AD, and contain 3R tau.

Question 5

What is the difference between the neurofibrillary tangles of AD from Pick bodies?

Answer 5

Unlike the neurofibrillary tangles of AD, Pick bodies do not survive the death of their host
neuron and do not remain as markers of the disease.

Question 6

What are Pick bodies?

Answer 6

which are cytoplasmic, round to oval, filamentous inclusions that are only weakly basophilic but stain strongly with silver methods

Question 7

Answer 7

Pick disease. Pick bodies are round homogeneous neuronal cytoplasmic
inclusions that stain intensely with silver stains.