We present the case of a 71-year-old woman with an 11-year history of slowly progressive decline of motor speech. Normal clinical investigations including routine magnetic resonance imaging (MRI) at 7, 8 and 10 years after the onset of speech dysfunction led to the suggestion of a psychogenic disorder. Extensive clinical, neuropsychological and neuroimaging investigations including 18F-desoxyglucose-positron emission tomography (PET), quantitative MRI and MR spectroscopy were performed to look for subtle brain pathology. Quantitative assessment of 3D-MRI, F-desoxyglucose-PET and magnetic resonance spectroscopy all demonstrated clear evidence of multifocal frontotemporal brain pathology that had not been picked up on routine MRI investigations on previous admissions. This is the longest benign history of slowly progressive anarthria reported so far. It demonstrates a possible role of quantitative neuroimaging techniques in the diagnosis of complex neuropsychiatric disorders.