Late-onset schizophrenia (LOS) occurs after the age of 40, and most researchers classify onset after 60 as a very late onset schizophrenia. LOS has different demographic, clinical and neuropsychological characteristics than regular schizophrenia1. A subset of LOS may present with cognitive and behavioural impairment consistent with young-onset Frontotemporal Dementia (FTD)2. However, differentiating FTD from LOS can be difficult at the initial phase, which may delay the diagnosis (mean time 4-5 years from the first onset of psychosis).
Arterial spin labelling (ASL) is a type of fMRI which measures tissue perfusion with an intrinsic tracer3,4. The relatively simple and cost-effective option than FDG-PET scans makes ASL a potential imaging modality for making a clinical diagnosis of dementia. In this study, a correlation between ASL and SPECT is demonstrated. ASL finding in the study is consistent with FTD5.
A genetic study is pending and the current working diagnosis is behavioural variant FTD.