CSF neurofilament proteins in the differential diagnosis of dementia.

BACKGROUND: Neurofilament (NF) proteins are major cytoskeletal constituents of neurons. Increased CSF NF levels may reflect neuronal degeneration. OBJECTIVE: To investigate the diagnostic value of CSF NF analysis to discriminate in relatively young dementia patients between frontotemporal lobe degeneration (FTLD) and early onset Alzheimer's disease (EAD; onset < or = 65 years of age), and in elderly dementia patients between dementia with Lewy bodies (DLB) and late onset AD (LAD; onset > 65 years of age). METHODS: In CSF of 28 FTLD, 37 EAD, 18 DLB and 33 LAD patients, and 26 control subjects, we analysed NF light chain (NFL), phosphorylated NF heavy chain (pNFH), amyloid beta42 protein (Abeta42), total tau and tau phosphorylated at threonine 181 (p-tau181). RESULTS: CSF NFL levels were higher in FTLD patients compared with EAD patients (p<0.001), and diagnostic accuracy of p-tau181 and Abeta42 analysis improved with addition of NFL analysis (sensitivity 86%, specificity 100%). CSF pNFH levels were elevated in DLB, LAD and FTLD compared with controls (p<0.05) but no significant differences were found between the dementia groups. CONCLUSIONS: In the diagnostic workup of relatively young dementia patients, CSF NFL levels may play a role in the discrimination between FTLD and EAD, especially in combination with Abeta42 and p-tau181 analysis.

CSF analysis differentiates multiple-system atrophy from idiopathic late-onset cerebellar ataxia.

BACKGROUND: Differentiating idiopathic late-onset cerebellar ataxia (ILOCA) from ataxia due to the cerebellar subtype of multiple-system atrophy (MSA-C) can be difficult in the early stages of the disease METHODS: The authors analyzed the levels of various CSF biomarkers in 27 patients with MSA-C and 18 patients with ILOCA and obtained cut-off points for each potential biomarker to differentiate MSA-C from ILOCA. RESULTS: Increased levels of neurofilament light chain (NFL) and neurofilament heavy chain (NFHp35) and decreased levels of the neurotransmitter metabolites homovanillic acid (HVA), 5-hydroxyindoleaceticacid (5-HIAA), and 3-methoxy-4-hydroxyphenylethyleneglycol (MHPG) were observed in MSA-C compared with ILOCA patients. Receiver operating characteristic analysis showed high sensitivity and specificity levels for NFL, NFHp35, and MHPG analysis. At a cut-off of 24.4 ng/L for the NFL analysis, a sensitivity of 79% and a specificity of 94% were obtained for differentiating MSA-C from ILOCA. At a cut-off point for NFHp35 of 129.5 ng/L, sensitivity was 87% and specificity 83%. Analysis of MHPG levels (cut-off 42.5 nM) resulted in a sensitivity of 86% with a specificity of 75%. A multivariate logistic regression model selected NFL, MHPG, and tau as independent predictive biomarkers that separated the MSA-C and ILOCA groups. CONCLUSIONS: Increased levels of neurofilament light chain and tau and decreased levels of 3-methoxy-4-hydroxyphenylethyleneglycol were associated with high accuracy levels in differentiating the cerebellar subtype of multiple-system atrophy from idiopathic late-onset cerebellar ataxia (LOCA). CSF analysis may thus serve as a useful tool in early diagnostic differentiation of LOCA.

An enzyme immunoassay to quantify neurofilament light chain in cerebrospinal fluid.

Neurofilament light chain is a component of the axonal cytoskeleton. The concentration of the neurofilament light chain in cerebrospinal fluid may reflect axonal damage or the extent of white matter damage. In this study we describe a sensitive immunoassay for the detection of neurofilament light chain in cerebrospinal fluid using commercially available materials. The detection limit of the assay was 5 ng/l and the assay was linear up to 390 ng/l. Mean recovery was 91.5% and inter-assay and intra-assay coefficients of variation were below 18%. Strongly increased levels of neurofilament light chain were observed in patients with cerebrovascular accidents, subarachnoid hemorrhage and severe traumatic brain injury, suggesting the occurrence of axonal damage in these conditions.

Protein S-100B, neuron-specific enolase (NSE), myelin basic protein (MBP) and glial fibrillary acidic protein (GFAP) in cerebrospinal fluid (CSF) and blood of neurological patients.

In this study, data about protein S-100B, neuron-specific enolase, myelin basic protein and glial fibrillary acidic protein in cerebrospinal fluid and blood of patients with an acute or chronic progressive neurological disorder with brain damage are reviewed. Especially in disorders with acute brain damage, determination of these proteins in CSF and blood can be helpful to establish structural and/or functional brain damage to determine severity and prognosis of the disease process and to monitor treatment effects.

Serum- and CSF-concentrations of brain specific proteins in hydrocephalus.

OBJECT: Hydrocephalus is characterised by elevated intracranial pressure (ICP) and gives rise to brain damage. The aim of this study was to investigate the significance of brain specific proteins as markers in the evaluation of brain damage in hydrocephalus. Therefore we determined the levels of four brain specific proteins in cerebrospinal fluid (CSF) and serum of symptomatic hydrocephalic patients. METHODS: During 41 CSF shunt-operations (both primarily placed shunts and shunt-revisions) CSF and blood samples were obtained and analysed for neuron-specific enolase (NSE), S-100b, glial fibrillary acidic protein (GFAP) and myelin basic protein (MBP). The results were compared with an age-matched control group. Patients with varying clinical symptoms, denoting different levels of increased intracranial pressure prior to surgery, were included in this study. RESULTS: We observed significantly increased CSF-levels of S-100b and GFAP in the hydrocephalic patients, whereas NSE and MBP were markedly increased only in patients with very severe symptoms. Serum levels of all proteins were only minimally increased and did not correlate with CSF-levels. The slightly elevated levels of CSF-NSE in most of the patients suggest only subtle neuronal damage, which is not related to permanent neurological symptoms. The elevated levels of S-100b and GFAP are indicative of a reactive astrogliosis, which has also been demonstrated in histopathological studies. No demyelination seems to occur, according to the normal levels of MBP observed in this study. CONCLUSIONS: Although CSF levels of brain specific proteins are elevated in hydrocephalic patients, indicating brain damage due to hydrocephalus, neither CSF- nor serum-concentrations of brain specific proteins seem to be valuable tools in the clinical evaluation of the severity of hydrocephalus.