Parkinson\u27s disease (PD), one of the most common neurodegenerative disorders, is characterized by motor and non-motor symptoms. We evaluated the impairment in recognizing emotional facial expressions in PD patients using morphing techniques and investigated the related structures with brain perfusion on single photon emission CT (SPECT) using the threedimensional stereotactic surface projection (3D-SSP) technique. Finally, we demonstrated that PD patients displayed a prominent degree of hypoperfusion in the occipital lobe, while also demonstrating an impairment in recognizing the facial emotions for both anger and happiness.The ability to recognize the facial emotions for happiness has been shown to be closely associated with a decreased cerebral blood flow (CBF) in the right occipital lobe.In PD patients, an impairment in recognizing emotional facial expressions might be partially due to an occipital cortical dysfunction. As the present study is a preliminary one, further studies are thus needed to elucidate the mechanism of such impairments in recognizing emotional facial expressions in PD patients
