Since that barrier is furthermore known to be more “leaky” in MSA, another element of variability is added.40 On the other hand, NfL-p is also known to be elevated in peripheral neuropathies indicating a peripheral contribution to plasma NfL.41, 42 One may therefore expect to see transient elevations as a result of falls and other injuries resulting in soft tissue damage, which are common in MSA, particularly since the levels of NfL in plasma are very low. Here, NEFL is linked to multiple system atrophy.