BACKGROUND: Loss of cortical neurons is a key pathological feature in 
neurodegenerative dementias. Cerebrospinal fluid (CSF) neurofilaments (Nf) are a 
biomarker for neuronal death and axonal loss.
OBJECTIVE: To perform a meta-analysis to investigate the value of CSF Nf levels 
for the laboratory-supported differential diagnosis of neurodegenerative 
dementias.
METHODS: A systematic review and meta-analysis of studies on CSF Nf heavy (NfH) 
and light (NfL) levels in patients with dementia. The dementia subgroups 
analysed were Alzheimer (AD), frontotemporal lobe dementia (FTLD), vascular 
dementia (SVD), minimal cognitive deficit (MCI).
RESULTS: We identified 12 studies on CSF NfH and NfL levels which met the 
inclusion criteria and 11 were of a quality good enough to be used in this 
meta-analysis. CSF data was available on 818 patients (306 AD, 106 SVD, 98 FTLD, 
25 MCI, 283 controls). Overall CSF NfH and NfL levels were higher in patients 
with AD, FTLD and SVD when compared to controls. The size of the effect ranged 
from 0.71 to 1.38. The strongest effect was observed for the comparison of FTLD 
patients with controls, both for NfL (1.38) and NfH (0.74). CSF NfL were also 
able to separate patients with FTLD from those with AD.
CONCLUSION: At present we cannot recommend CSF NfH and NfL levels for use as a 
screening test in the diagnosis of dementia because of the rather small effect 
size. However, both neurofilament proteins may be of value for targeted 
investigation of some patients with FTLD, SVD and AD.