The vast majority of neuroimaging research on brain perfusion has investigated the effects of acute nicotine exposure, rather than the consequences of chronic cigarette smoking [18]. The few published reports specifically investigating chronic smokers indicate globally decreased brain perfusion relative to NSC, as measured by CT 133Xe inhalation [103,104] in older adults and single proton emission computed tomography (SPECT) [105] in adults aged 35.5 ± 8.4 years; perfusion was inversely related to cigarette pack-years [105]. In a Xe-CT-based longitudinal study with community-dwelling older adults, decreases in global cerebral perfusion were independently associated with chronic smoking controlling for other vascular risk factors [106,107].
