Reverse fox test for detecting visuospatial dysfunction corresponding to parietal hypoperfusion in mild alzheimer's disease

Background/Aim:We developed a novel visuospatial clinical task to detect parietal dysfunction in mild Alzheimers disease (AD). Methods: A total of 65 outpatients, including 47 with mild AD and 18 cognitively and neuroradiologically normal individuals with subjective memory impairment (NL), performed the Reverse Fox test and underwent brain single photon emission tomography. Patients with AD were divided into subgroups according to the results of the Reverse Fox test (successful vs unsuccessful). Results: Success in the Reverse Fox test was achieved by 31.9% of patients with AD and 94.4% of NL. The unsuccessful AD subgroup had reduced perfusion of the medial parietal and bilateral temporoparietal regions compared with the successful AD subgroup. Conclusions: Failure in the Reverse Fox test was related to parietal hypoperfusion in patients with mild AD. Our findings suggest that the Reverse Fox test may be one of the useful supporting tools for detecting mild AD at outpatient clinic.