Underlying pathology identified after 20 years of disease course in two cases of slowly progressive frontotemporal dementia syndromes

ABSTRACT

We report two cases from the frontotemporal lobar degeneration (FTLD) spectrum with remarkably slow progression. The first case demonstrated insidious-onset behavioral symptoms and personality changes resembling behavioral variant of frontotemporal dementia, followed a benign course over 26 years, his brain autopsy revealed the diffuse form of argyrophilic grain disease. The second case presented with slowly progressive cognitive and motor deficits, reminiscent of the corticobasal syndrome, deteriorated slowly over 22 years, his brain autopsy revealed FTLD-TDP with C9ORF72 pathology. These two cases confirm the notion of slowly progressive frontotemporal lobar degeneration caused by an underlying FTLD pathology, rather than a phenocopy. 

KEYWORDS:

• Frontotemporal lobar degeneration
• slow progression
• phenocopy
• argyrophilic grain disease
• c9orf72 mutation
• tdp-43

Acknowledgments

The study was funded by R01-AG37491. We thank Drs. Ivnik, Trenerry and Fields from Mayo Clinic, and Dr. Glenn E. Smith, PhD University of Florida, for their role in the neuropsychological testing, and Lennon G. Jordan, CNMT for his assistance in creating the figures for case 1.

Patient consent

Both patients have signed consent for their data to be used for the purposes of research. None of the data reported in this manuscript can be used to identify the patients presented.

Disclosure statement

No potential conflict of interest was reported by the author(s).