diffuse cortical atrophy symptomsmoderate diffuse cortical atrophysupratentorial cortical atrophyfrontoparietal cortical atrophydiffuse cortical atrophy braincortical and subcortical atrophycortical and cerebellar atrophybifrontal cortical atrophyposterior cortical atrophycerebral cortical atrophysevere cortical atrophymoderate cortical atrophy