Spectrum of clinical and FDG-PET patterns of patients with frontotemporal dementia (FTD) in a tertiary care hospital

Abstract

Introduction. Frontotemporal dementia (FTD) is a common cause of cognitive impairment, behavioral changes and language deficits. in this study we assessed the clinical and FDG-PET characteristics of our patients and compared them with available international and Indian data on FTD. Methods. All patients were evaluated with a neuropsychological battery followed by 18F-FDG-PET scan, in addition to all necessary dementia work-up. Results. 15 FTD patients (m:f = 11:4) had a mean age of presentation of 67.4 (8.6) years, with a mean interval of 1.7 (0.7) years from the symptom onset to diagnosis. those with 10 or less years of education had an earlier presentation. a positive family history was present in 20%. The mean MMSE score was 18.8 (4.6). Disinhibition was the most common symptom seen in 60%. Apathy was less frequently noted. FDG-PET scan showed predominantly anterior cingulate and anterior temporal hypometabolism, with asymmetry in 67%. 2 cases diagnosed as fvAD had a revised diagnosis of bvFTD after FDG-PET scan. 1 patient of nfvPPA was mute at presentation with a history of agrammatism with hypometabolism in left inferior frontal and superior temporal regions. Conclusions. There were significant variations compared to international/Western literature, with later age of presentation, shorter interval from onset to presentation, lower MMSE scores, with disinhibition rather than apathy as the commonest symptom. FDG-PET showed similar areas of involvement but with less extensive hypometabolism compared to other studies with a lesser frequency of asymmetry. FDG-PET scan is a useful adjunct for evaluation of FTD patients.