DEGENERATIVE DISEASES OF BASAL GANGLIA AND BRAINSTEM-Dementia with Lewy Bodies

Question 1

About 10% to 15% of individuals with PD develop dementia, with increasing incidence with
advancing age.

Question 2

What is the characteristic of Dementia with Lewy Bodies?

Answer 2

Characteristic features of this disorder include a f**luctuating course, **hallucinations, and prominent frontal signs.

While some affected individuals have pathologic

• *evidence of AD** (or, less frequently, other degenerative diseases associated with cognitive
  changes) in combination with the findings of PD, in others the most prominent histologic correlate appears to be the **presence of Lewy bodies in a wide range of cortical
  locations. **[57,] [58]

These inclusions are less distinct than those observed in the brainstem but similarly contain predominantly α-synuclein.

Question 3

Immunohistochemical staining for α-synuclein also
reveals the presence of abnormal neurites, which contain aggregated protein—called_________ even though he never saw them!

Answer 3

Lewy
neurites

Question 4

What is the gross pathologic finding in Dementia with Lewy body?

Answer 4

In this setting, the gross pathologic findings typically
include depigmentationof thesubstantia nigraandlocus ceruleus, paired with relative
preservation of the cortex, hippocampus, and amygdala.

Question 5

The burden of cortical Lewy bodies is
usually extremely low, and the mechanism by which this disease wreaks havoc on cognitive
functioning is not clear.

It has been suggested that Lewy body diseases represent a continuum;
there is evidence that Lewy bodies and Lewy neurites are found first in the __________, progress
over time to reach the midbrain (when it becomes manifest as PD), and can eventually progress
across the nervous system to reach the cortex (and manifest as dementia with Lewy
bodies).

Answer 5

medulla