Frontotemporal dementia (FTD) is the second most frequent dementia, after 
Alzheimer's, in patients under the age of 65. It encompasses clinical entities 
characterized by behavioral, language, and executive control dysfunction. 
Neurofilament light chain (NfL) is a new, non-disease specific, widely studied 
biomarker indicative of axonal injury and degeneration. Various studies have 
previously explored the role of NfL in the diagnostic process, monitoring, and 
prognosis of dementia. The current systematic review and meta-analysis include 
all the available data concerning the role of NfL in frontotemporal dementia and 
its use as a potential biomarker in differentiating patients with FTD from (a) 
healthy individuals, (b) Alzheimer's dementia, (c) Dementia with Lewy bodies, 
(d) Motor Neuron disease, (e) Parkinsonian syndromes, and (f) psychiatric 
disorders. We also analyze the utility of NfL in distinguishing specific FTD 
subgroups. Neurofilament light chain has a potential role in differentiating 
patients with frontotemporal dementia from healthy controls, patients with 
Alzheimer's dementia, and psychiatric disorders. Higher NfL levels were also 
noted in patients with semantic primary progressive aphasia (PPA) when compared 
with behavioral FTD and non-fluent PPA patients. Further studies exploring the 
use of NfL in frontotemporal dementia are needed.