* To establish the current usage of the term Pick's disease in Europe
* To develop clinical, neuroimaging, neuropsychological and neuropathological criteria for the diagnosis of Pick's disease defined neuropathologically by the presence of Pick cells and Pick bodies.
* To contribute to the understanding of the pathophysiology of the disease utilising molecular genetic studies of hereditary cases.
Participating centres will develop a database of Pick's disease cases. These will be classified as definite where a specific neuropathological diagnosis has been made; probable where Pick's disease was the main clinical diagnosis; possible where Pick's disease entered the differential diagnosis. Analysis of cases will focus upon a core syndrome, hereafter referred to as classical Pick's disease (Group 1), defined neuropathologically by focal, lobar or asymmetric atrophy with Pick cells and Pick bodies. However, since the presence of Pick bodies may represent a later stage of the disease a second group of cases (Group 2) with Pick cells alone will be analysed. A third group (Group 3) will comprise cases of probable and possible Pick's disease which neuropathologically were found to have other histopathological features; this group will enter the analysis for comparison purposes only.
Analysis of cases will provide validated clinical and neuropathological criteria for diagnosis of classical Pick's disease. It is proposed that three levels of diagnosis (definite, probable and possible) will be permitted. Advances in the molecular genetics of the degenerative dementias will be applied throughout the study including a DNA archive of Pick's disease cases. At the end of the study it is proposed that the clinical criteria, the computerised database and the DNA archive will he made available to clinicians and researchers.