The origin of atypical BSEs is unknown.
However our data do emphasize the unresolved questions regarding the origin of atypical scrapie, which as yet remains unknown.
This implies the possibility of a sporadic origin of atypical scrapie [ 47].
This reinforces the hypothesis of a sporadic origin of atypical BSE [ 30].
The origin of atypical scrapie is still unclear, and whether the disease has an infectious origin remains a major question.
Within the sample, neutrophils, spindle cells of mesenchymal origin without atypical characteristics and some haemosiderin-laden histiocytes were rarely observed.
However, exploring the role of genetic factors in the origin of atypical scrapie would require estimation of penetrance of different mutations, but this estimate is not currently available.
However, if a spontaneous origin of atypical scrapie is the rule, then the disease will stay present at the observed level.
All patients have had generalized seizures (although in some cases, the generalized seizures were only in febrile contexts) and 68% exhibited multiple seizure types (17/25) including partial seizures (of frontal or temporal origin) and atypical absences.
The case definition used was the following: any acute encephalopathy of unknown origin, with atypical focal neurologic signs or encephalomyelitis in any person who died between January 1 and September 30 , 2001 in the Brunca Region.
The origins of atypical variants remain to be investigated.
