Non-Alzheimer fronto-temporal degenerative dementia. A neurobehavioral and pathologic study.

In contrast to Alzheimer's disease (AD), which predominantly affects the limbic system and association neocortex, degenerative dementias have been identified that show greatest damage in frontal and temporal neocortex. This "lobar atrophy" was first described by Arnold Pick over 100 years ago. We present four autopsy-documented, non-AD cases of fronto-temporal degeneration (FTD), each with neurobehavioral assessment. Three of the patients presented with personality change and the fourth with non-fluent aphasia; memory was initially preserved in all, and only later did dementia become evident. At autopsy, the hippocampi were relatively spared in all cases. One patient had classic Pick-body temporal lobe Pick's disease (PD), 2 had frontal lobe-predominant atrophy with severe degeneration of caudate and substantia nigra (so-called "generalized Pick's"), and the fourth had temporal lobe degeneration without Pick bodies or cells. We propose that subgroups of FTD be categorized both by microscopic features and gross patterns of atrophy, and that subgroups of FTD be kept separate for neurochemical and genetic studies. Neurobehavioral and neuropsychological evaluation early in the course of unusual degenerative dementia can aid in distinguishing FTD cases from AD patients for clinical and drug studies.