Impairment of decision-making cognition in a case of frontotemporal lobar degeneration (FTLD) presenting with pathologic gambling and hoarding as the initial symptoms

OBJECTIVE: The aim of this study was to use the Iowa Gambling Task (IGT) to examine decision-making cognition in a patient with mild frontal variant of frontotemporal dementia (fv-FTD). BACKGROUND: Although fv-FTD may present with bizarre and dramatic behavioral changes, traditional executive tasks are sometimes preserved in patients with mild fv-FTD. Some evidence suggests that tasks assessing decision-making cognition, such as the IGT, may be sensitive to detect cognitive dysfunction in patients with mild fv-FTD. Here, we report a patient with fv-FTD who presented with bizarre behavior including hoarding, pathologic gambling, and abnormal sexual behavior. METHODS: A 54-year-old man who had been diagnosed as having fv-FTD was examined using a behavioral assessment, a wide range of neuropsychologic tasks, and the IGT. Brain magnetic resonance imaging and brain Tc-ethylcysteinate dimer single-photon emission computed tomography examinations were also performed. RESULTS: Although the patient's cognitive abilities were almost fully preserved for a number of traditional neuropsychologic tasks (memory, executive function), the IGT suggested that his decision-making cognition was impaired. The Tc-ethylcysteinate dimer single-photon emission computed tomography examination revealed hypometabolism in bilateral medial frontal and orbitofrontal regions of the cerebral cortex, and also in the cingulate gyri. CONCLUSIONS: Our findings suggest that the IGT may be a sensitive tool for assessing patients with mild fv-FTD before the development of severe dementia. We speculate that the deficit in decision-making cognition observed in the present case was associated with hypometabolism in the neural networks of the frontal lobe and involving both the bilateral medial frontal and orbitofrontal regions of the cerebral cortex.