Longitudinal measurement of serum NfL was performed in patients with central cord syndrome ( CCS , n = 4 ) , motor-incomplete SCI ( iSCI , n = 10 ) , motor-complete SCI ( cSCI , n = 13 ) and healthy controls ( HC , n = 67 ) , and correlated with clinical severity , neurological outcome , and neuroprotective effect of the drug minocycline .