a cross sectional study 2018
With adulthood and ageing, there is a reduced amount of new myelin formed in the context of a learning task or following demyelination 88,89 , in association with impaired oligodendrogenesis
In a study of CSF NfL levels in a longitudinal multicenter cohort, patients with PSP and MSA had higher levels of CSF NfL than the PD group, whereas the control group had lower levels of NfL ( An accurate assessment of the amount of elevated NfL in CSF may be hampered by the fact that CSF NfL may also increase with age due to degenerative changes in axons, even though its elevated levels correspond with the severity of cognitive impairment in patients ( 3.2 Neurotransmitter-related biomarkers In general, patients with PD have degeneration of dopaminergic neurons in the SN compacta, decreased dopamine levels in striatal areas, and decreased levels of the dopamine metabolites homovanillic acid (HVA) and dihydroxyphenylacetic acid (DOPAC)
Several changes in structural (reduced tendon CSA and fibril diameter), cellular (decreased cell proliferation and stem/progenitor cell quantity), and mechanical properties (reduced modulus and strength), beyond just alterations to AGE-mediated crosslinks, occur in tendon during the aging process and have been recently reviewed in detail (Svensson et al ., 2016)
