NRGN and frontotemporal dementia: At the same time, a study examining plasma neuronal-derived exosomes showed that patients with AD and frontotemporal dementia displayed lower levels of plasma neuronal-derived exosomal neurogranin (232 ± 56.5 pg/ml and 1117 ± 227 pg/ml, respectively) compared to the control group (2208 ± 354 pg/ml) [89].