High CSF neurofilament heavy chain levels in neuromyelitis optica

The neurofilament heavy chain (NfH(SMI35)),a biomarker of axonal damage in the CSF, was measured in patients with neuromyelitis optica ( NMO) and multiple sclerosis (MS). Significantly high CSF NfH(SMI35) levels (> 0.73 ng/mL) were found in 6 of 24 (25%) of the patients with NMO but none of the patients with MS (0/24). This finding suggests that axonal damage is more severe in NMO than in MS.