Frontotemporal dementia (FTD) is a new label for clinical Pick’s disease (PiD) because the eponymic term is increasingly restricted to the pathologic finding of Pick bodies. This restriction created the impression that PiD is rare and that it is difficult to diagnose. FTD is also a term most often used for behavioral and personality alterations. Primary progressive aphasia (PPA) and corticobasal degeneration (CBD), formerly the extrapyramidal variety of PiD, are also part of the syndrome. Recently, chromosome 17 localization and tau mutations were discovered in familial forms of the disease.
FTD consists of behavioral and personality changes, often beginning with apathy and disinterest, which may be mistaken for depression. Disinhibition and perseverative, compulsive behavior often appear at the same time. A quantifiable frontal behavioral inventory is useful in the diagnosis beyond a checklist.
The second type of presentation is progressive language loss (PPA). A less common variety is semantic dementia; the meaning of nouns and objects is lost. As the disease progresses, all components tend to overlap. CBD and progressive supranuclear palsy (PSP), although described as distinct entities, show a great deal of clinical, pathologic, genetic, and biochemical overlap. The evidence suggests they also belong to the complex. The association of motor neuron disease (MND) with FTD and other varieties of the complex is also reviewed.
Clinical Pick’s disease or Pick Complex includes the overlapping syndromes of FTD, PPA, CBD, PSP, and FTD-MND. The neuropathological and genetic spectrum should be viewed with emphasis on the commonalities rather than the differences, allowing the recognition of the relatively high frequency of this presenile syndrome.
From the Department of Clinical Neurological Sciences, St. Joseph’s Hospital, University of Western Ontario, London, Ontario, Canada.
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