Related Experiment Videos
Real and imagined clinicopathological limits of "prion dementia"
1Laboratory of CNS Studies, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892.
Abstract:
The term "prion dementia" has been proposed to replace "spongiform encephalopathy", to accommodate the existence of atypical forms of these "prion protein" (PrP) cerebral amyloidoses that may not show spongiform changes in the brain. We tested brain tissue extracts for the presence of PrP from 46 cases (including 13 familial cases) of non-spongiform dementias with a variety of associated neurological signs, referred to our laboratory for primate transmission studies. None of the cases transmitted disease to primates, and none had PrP detectable by western immunoblots of extracted brain tissue. We conclude that prion dementias are not lurking undetected within the larger landscape of neurodegenerative disorders, and that their clinicopathological limits are, except for a small number of previously reported familial cases, essentially those of spongiform encephalopathy.
Insights
Prion dementias, a proposed term for prion protein amyloidoses, were investigated in non-spongiform dementia cases. Research found no evidence of prion protein or disease transmission, suggesting prion dementias are limited to spongiform encephalopathies.
Area of Science:
- Neurology
- Neuroscience
- Pathology
Background:
- The term "prion dementia" has been proposed to encompass atypical prion protein (PrP) cerebral amyloidoses that may lack spongiform changes.
- This broadens the definition beyond traditional spongiform encephalopathies.
Purpose of the Study:
- To investigate the presence of prion protein (PrP) in non-spongiform dementias.
- To determine if these conditions represent atypical prion dementias transmissible to primates.
Main Methods:
- Brain tissue extracts from 46 non-spongiform dementia cases were analyzed.
- Primate transmission studies were conducted.
- Western immunoblots were used to detect PrP.
Main Results:
- None of the tested dementia cases transmitted disease to primates.
- Prion protein (PrP) was not detectable in any of the brain tissue extracts via western immunoblot.
- This indicates a lack of prion involvement in these cases.
Conclusions:
- Prion dementias are not prevalent within the broader category of neurodegenerative disorders.
- The clinicopathological spectrum of prion dementias is largely confined to spongiform encephalopathies, with few exceptions in previously reported familial cases.