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Diseases morphologically characterized by frontotemporal lobar degeneration have relatively recently been considered as a group of frontotemporal dementias. This group is characterized by a tendency to early clinical onset of dementia, common genetic and morphological features, as well as a possible association with diseases such as amyotrophic lateral sclerosis and atypical parkinsonism syndrome. Historically, Pick's dementia (Pick's disease) was described as the first of the frontotemporal dementias, which is morphologically characterized by the presence of argyrophilic Pick's bodies represented by 3R-tau protein in the neurons of the cerebral cortex. Despite the characteristic clinical and morphological picture due to the relative rarity, the diagnosis of Pick's dementia is infrequently made by both clinicians and pathologists. The article presents current data on frontotemporal dementia. A case of Pick's dementia with characteristic clinical manifestations in the form of early onset of behavioral and personality disorders, as well as specific morphological changes in the brain, is described.

Tauopathies are neurodegenerative diseases that are characterized by pathological accumulation of tau protein. Tau is hyperphosphorylated in the brain of tauopathy patients, and this phosphorylation is proposed to play a role in disease development. However, it has been unclear whether phosphorylation is different among different tauopathies. Here, we investigated the phosphorylation states of tau in several tauopathies, including corticobasal degeneration, Pick's disease, progressive supranuclear palsy (PSP), argyrophilic grain dementia (AGD) and Alzheimer's disease (AD). Analysis of tau phosphorylation profiles using Phos-tag SDS-PAGE revealed distinct phosphorylation of tau in different tauopathies, whereas similar phosphorylation patterns were found within the same tauopathy. For PSP, we found 2 distinct phosphorylation patterns suggesting that PSP may consist of 2 different related diseases. Immunoblotting with anti-phospho-specific antibodies showed different site-specific phosphorylation in the temporal lobes of patients with different tauopathies. AD brains showed increased phosphorylation at Ser202, Thr231 and Ser235, Pick's disease brains showed increased phospho-Ser202, and AGD brains showed increased phospho-Ser396. The cis conformation of the peptide bond between phospho-Thr231 and Pro232 (cis ptau) was increased in AD and AGD. These results indicate that while tau is differently phosphorylated in tauopathies, a similar pathological mechanism may occur in AGD and AD patients. The present data provide useful information regarding tau pathology and diagnosis of tauopathies., Competing Interests: Declaration of competing interest The authors declare that they have no competing interests., (Copyright © 2021 Elsevier Inc. All rights reserved.)