Structure | α-syn pathology | Structural imaging | Functional imaging | Molecular imaging |
---|---|---|---|---|
Vagus nerve | Positive | NA | NA | NA |
Gastrointestinal tract | Controversy | NA | NA | Decreased 11C-donepezil standard uptake values in the small intestine and pancreas following a rostral-caudal gradient [43] |
Olfactory bulb | Positive | NA | NA | |
Olfactory tract | Positive | NA | NA | |
Olfactory cortex | Positive | Decrease of olfactory sulcus depth; decrease of piriform cortex volume [68, 71] | Reduced activation in amygdala and hippocampal formation after olfactory stimulation [72–74]; decreased regional homogeneity and functional connectivity within olfactory cortex and decreased connectivity within limbic/paralimbic networks [75] | Reduced glucose metabolism in bilateral medial prefrontal cortex and parieto-occipito-temporal cortex [76]; positive correlations between UPSIT scores and acetylcholinesterase activities in hippocampal formation, amygdala and neocortex [70]; positive correlations between UPSIT scores and vesicular monoamine transporter type 2 binding potential in striatum [70]; positive correlations between UPSIT scores and dopamine transporter binding potential in hippocampus, amygdala and striatum [78] |