[Usefulness of functional magnetic resonance imaging and spectroscopy in the diagnosis of frontotemporal dementia].

Early diagnosis of frontotemporal dementia is difficult, especially at its early stages, being mainly misdiagnosed as a psychiatric condition. The main source of uncertainty comes from the primacy of behavioral disturbances, for which sufficiently validated detection tools are not available. The increasing development of magnetic resonance (MR) techniques permits a triple approach that combines morphology, biochemistry and perfusion in the study of dementing neurodegenerative conditions. A 64-year-old male patient is described with prominent behavioral disturbances and a frontotemporal pattern of cognitive impairment. He met criteria for frontotemporal dementia. Conventional MR imaging showed minimal frontotemporal atrophy. A moderate hypoperfusion of the frontal lobes was observed in the MR perfusion study. The spectroscopy showed a decrease of the n-acetyl-aspartate peak in the medial frontal region with normal values in the medial parietal region. The whole MR imaging study aided to distinguish frontotemporal dementia from other conditions, such as brain structural processes and depression, offering relevant information for prognostic and therapeutic purposes. The usefulness of the new MR imaging techniques in the early diagnosis of dementing neurodegenerative conditions must be confirmed by larger studies accompanied by pathological material.