DEGENERATIVE DISEASES AFFECTING THE CEREBRAL CORTEX-Corticobasal Degeneration Flashcards
What is Corticobasal Degeneration?
This is a disease of the elderly, with considerable clinical and neuropathologicheterogeneity.
Because of the extrapyramidal signs and symptoms in this disorder, it can also be grouped with
syndromes of basal ganglia dysfunction.
What is the morphology of corticobasal degeneration on macroscopic exam?
On macroscopic examination there is cortical atrophy, mainly of the motor,
- *premotor, and anterior parietal lobes.** These regions of cortex show severe loss of neurons,
- *gliosis, and “ballooned” neurons (neuronal achromasia**) that can be highlighted with
- *immunocytochemical methods for phosphorylated neurofilaments.**
What is the morphology of corticobasal degeneration on microscopic exam?
Tau immunoreactivity has
been found in astrocytes (“tufted astrocytes”), oligodendrocytes (“coiled bodies”), basal
ganglionic neurons,and,variably, cortical neurons.
Clusters of tau-positive processes
around an astrocyte (“astrocytic plaques”) and the presence of tau-positive threads in gray
and white matter may be the most specific pathologic findings of corticobasal degeneration.
The substantia nigra and locus ceruleus show loss of pigmented neurons, neuronal
achromasia,andtangles.
Similar to progressive supranuclear palsy, the tau deposits in
corticobasal degeneration contain predominantly 4R tau.
What is the most pathologic finding of orticobasal degeneration?
Clusters of tau-positive processes
around an **astrocyte (“astrocytic plaques”) **and the presence of tau-positive threads in gray and white matter may be the most specific pathologic findings of corticobasal degeneration.
What is the similarity of progressive supranuclear palsy to corticobasal degeneration?
Similar to progressive supranuclear palsy, the tau deposits in
corticobasal degeneration contain predominantly 4R tau.
What are the Clinical Features of Corticobasal Degeneration?
The disease is characterized by extrapyramidal rigidity, asymmetric motor disturbances (jerking
movements of limbs),andsensory cortical dysfunction(apraxias, disorders of language);
cognitive decline occurs, and may be prominent in some cases. The same MAPT haplotype
linked to progressive supranuclear palsy is also highly associated with corticobasal
degeneration
