We thank Jellinger and colleagues for their interest in our article. They are correct in indicating that our series constituted a "highly selected cohort." We were interested in a defined group of patients: those with well-documented, typical PD and late-developing dementia (representative of certain patients we see in our clinic). Brain banks, including ours, notoriously contain heterogeneous cases. Even in the best of circumstances, adequate clinical documentation may sometimes be lacking. Furthermore, brain banks tend to favor atypical as well as complex cases.1 In our series, we set a premium on a well-documented and uniform clinical picture. We used the extensive clinical records from the Mayo Clinic (Rochester, Minn), available for all of our patients, to exclude anyone who did not fit our stringent criteria. If there was inadequate documentation, the case was excluded. We started with 162 cases from our PD brain bank, of which 64 had previously been classified as dementia (similar in number to the 66 cases of dementia in the series of Jellinger and colleagues). We had extensive records on most of these cases; Mayo Clinic neurologists had conducted follow-up on all but one. Few met our entry criteria, with most excluded because of evidence of early dementia. Ultimately, we accumulated 13 historically similar cases that had been well characterized and were clinically unambiguous (without reference to the pathologic characteristics). Rather than apologize for the "highly selected cohort," we believe that this is a major strength of our study.
Ahlskog JE, Parisi JE, Boeve BF, Apaydin H, Dickson DW. Neuropathologic Changes in Parkinson Disease With Late Onset of Dementia—Reply. Arch Neurol. 2003;60(3):453-454. doi:10.1001/archneur.60.3.452-a