A next-generation, adaptive, multi-pinhole system, AdaptiSPECT-C, dedicated to SPECT brain imaging is currently under development in our research team. Attenuation and scatter correction have proven to be critical to enhance image quality and quantification for brain imaging. The motivation for this investigation was to determine the enhancement in image quality by adding scatter correction strategy in addition to attenuation correction for brain imaging with AdaptiSPECT-C. An ideal scatter correction strategy was investigated in this GATE simulation study using a brain perfusion phantom and compared to the reference case for which an air attenuation medium was considered. We demonstrated that the use of the attenuation and the ideal scatter correction strategy significantly enhanced the imaging performance of AdaptiSPECT-C in case of clinical 123I brain perfusion imaging. In addition, our study concluded that the use of an attenuation correction without compensating for scatter strongly degrades the contrast of the reconstruction, despite a quantitative improvement compared to the case for which no correction was used.