Diagnostic value of neurofilaments in differentiating motor neuron disease from multifocal motor neuropathy.

OBJECTIVE: To evaluate the performance of serum neurofilament light chain (NfL) and cerebrospinal fluid (CSF) phosphorylated neurofilament heavy chain (pNfH) as diagnostic biomarkers for the differentiation between motor neuron disease (MND) and multifocal motor neuropathy (MMN). METHODS: This retrospective, monocentric study included 16 patients with MMN and 34 incident patients with MND. A subgroup of lower motor neuron (MN) dominant MND patients (n = 24) was analyzed separately. Serum NfL was measured using Ella automated immunoassay, and CSF pNfH was measured using enzyme-linked immunosorbent assay. Area under the curve (AUC), optimal cutoff values (Youden's index), and correlations with demographic characteristics were calculated. RESULTS: Neurofilament concentrations were significantly higher in MND compared to MMN (p < 0.001), and serum NfL and CSF pNfH correlated strongly with each other (Spearman's rho 0.68, p < 0.001). Serum NfL (AUC 0.946, sensitivity and specificity 94%) and CSF pNfH (AUC 0.937, sensitivity 90.0%, specificity 100%) performed excellent in differentiating MND from MMN. Optimal cutoff values were ≥ 44.15 pg/mL (serum NfL) and ≥ 715.5 pg/mL (CSF pNfH), respectively. Similar results were found when restricting the MND cohort to lower MN dominant patients. Only one MMN patient had serum NfL above the cutoff. Two MND patients presented with neurofilament concentrations below the cutoffs, both featuring a slowly progressive disease. CONCLUSION: Neurofilaments are valuable supportive biomarkers for the differentiation between MND and MMN. Serum NfL and CSF pNfH perform similarly well and elevated neurofilaments in case of diagnostic uncertainty underpin MND diagnosis.

Transcriptomic profiling of cerebrospinal fluid identifies ALS pathway enrichment and RNA biomarkers in MND individuals.

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder and the most common form of motor neurone disease (MND) which is characterized by the damage and death of motor neurons in the brain and spinal cord of affected individuals. Due to the heterogeneity of the disease, a better understanding of the interaction between genetics and biochemistry with the identification of biomarkers is crucial for therapy development. In this study, we used cerebrospinal fluid (CSF) RNA-sequencing data from the New York Genome Center (NYGC) ALS Consortium and analyzed differential gene expression between 47 MND individuals and 29 healthy controls. Pathway analysis showed that the affected genes are enriched in many pathways associated with ALS, including nucleocytoplasmic transport, autophagy, and apoptosis. Moreover, we assessed differential expression on both gene- and transcript-based levels and demonstrate that the expression of previously identified potential biomarkers, including CAPG, CCL3, and MAP2, was significantly higher in MND individuals. Ultimately, this study highlights the transcriptomic composition of CSF which enables insights into changes in the brain in ALS and therefore increases the confidence in the use of CSF for biomarker development.

Evaluation of peripherin in biofluids of patients with motor neuron diseases.

Peripherin (PRPH), a type III intermediate filament, assembles with neurofilaments in neurons of the peripheral nervous system, including lower motor neurons (LMN). To evaluate the role of PRPH in LMN degeneration, we assessed PRPH and neurofilament light chain (NfL) in cerebrospinal fluid (CSF) and serum of 91 patients with motor neuron diseases (MND) and 69 controls. Overall, we found PRPH to be more concentrated in serum than in CSF. Serum PRPH resulted significantly increased in MND patients but it was unrelated to CSF-NfL or survival in the amyotrophic lateral sclerosis (ALS) subset. PRPH might represent a marker of LMN involvement.

Diagnostic and prognostic value of CSF neurofilaments in a cohort of patients with motor neuron disease: A cross-sectional study.

Motor neuron disease (MND) is a rare group of disorders characterized by degeneration of motor neurons (MNs). The most common form of MND, amyotrophic lateral sclerosis (ALS), is an incurable disease with a variable rate of progression. The search of robust biomarkers able to discriminate among different ALS forms is paramount to properly stratify patients, and to identify those who could most likely benefit from experimental therapies. Phosphorylated-neurofilament heavy chain (p-NfH) and neurofilament light chain (NfL) are neuron-specific components of the cytoskeleton and may represent reliable markers of neuronal injury in neurological disorders. In this study, we described our cohort of ALS patients in order to investigate whether and how cerebrospinal fluid (CSF) p-NfH and NfL levels may reflect progression rate, MN involvement and the extent of neurodegeneration. CSF p-NfH and NfL were significantly increased in ALS compared with healthy and disease controls, including patients with other forms of MND, and were higher in patients with more aggressive disease course, reflecting progression rate. We also evaluated neurofilament diagnostic accuracy in our centre, identifying with high sensitivity and 100% specificity cut-off values of 0.652 ng/mL for CSF p-NfH (P < .0001) and of 1261 pg/mL for NfL (P < .0001) in discriminating ALS from healthy controls. CSF neurofilaments were significantly correlated with ALS progression rate. Overall, CSF neurofilaments appear to reflect the burden of neurodegeneration in MND and represent reliable diagnostic and prognostic biomarkers in ALS.

Association of Cerebrospinal Fluid Neurofilament Light Protein Levels With Cognition in Patients With Dementia, Motor Neuron Disease, and Movement Disorders.

Importance: Neuronal and axonal destruction are hallmarks of neurodegenerative diseases, but it is difficult to estimate the extent and progress of the damage in the disease process. Objective: To investigate cerebrospinal fluid (CSF) levels of neurofilament light (NFL) protein, a marker of neuroaxonal degeneration, in control participants and patients with dementia, motor neuron disease, and parkinsonian disorders (determined by clinical criteria and autopsy), and determine its association with longitudinal cognitive decline. Design, Setting, and Participants: In this case-control study, we investigated NFL levels in CSF obtained from controls and patients with several neurodegenerative diseases. Collection of samples occurred between 1996 and 2014, patients were followed up longitudinally for cognitive testing, and a portion were autopsied in a single center (University of Pennsylvania). Data were analyzed throughout 2016. Exposures: Concentrations of NFL in CSF. Main Outcomes and Measures: Levels of CSF NFL and correlations with cognition scores. Results: A total of 913 participants (mean [SD] age, 68.7 [10.0] years; 456 [49.9%] women) were included: 75 control participants plus 114 patients with mild cognitive impairment (MCI), 397 with Alzheimer disease, 96 with frontotemporal dementia, 68 with amyotrophic lateral sclerosis, 41 with Parkinson disease (PD), 19 with PD with MCI, 29 with PD dementia, 33 with dementia with Lewy bodies, 21 with corticobasal syndrome, and 20 with progressive supranuclear palsy. Cognitive testing follow-up occurred for 1 to 18 years (mean [SD], 0.98 [2.25] years); autopsy-verified diagnoses were available for 120 of 845 participants with diseases (14.2%). There was a stepwise increase in CSF NFL levels between control participants (median [range] score, 536 [398-777] pg/mL), participants with MCI (831 [526-1075] pg/mL), and those with Alzheimer disease (951 [758-1261] pg/mL), indicating that NFL levels increase with increasing cognitive impairment. Levels of NFL correlated inversely with baseline Mini-Mental State Examination scores (ρ, -0.19; P < .001) in the full cohort (n = 822) and annual score decline in the full cohort (ρ, 0.36, P < .001), participants with AD (ρ, 0.25; P < .001), and participants with FTD (ρ, 0.46; P = .003). Concentrations of NFL were highest in participants with amyotrophic lateral sclerosis (median [range], 4185 [2207-7453] pg/mL) and frontotemporal dementia (2094 [230-7744] pg/mL). In individuals with parkinsonian disorders, NFL concentrations were highest in those with progressive supranuclear palsy (median [range], 1578 [1287-3104] pg/mL) and corticobasal degeneration (1281 [828-2713] pg/mL). The NFL concentrations in CSF correlated with TDP-43 load in 13 of 17 brain regions in the full cohort. Adding NFL to ß-amyloid 42, total tau, and phosphorylated tau increased accuracy of discrimination of diseases. Conclusions and Relevance: Levels of CSF NFL are associated with cognitive impairments in patients with Alzheimer disease and frontotemporal dementia. In other neurodegenerative disorders, NFL levels appear to reflect the intensity of the neurodegenerative processes.

Cerebrospinal Fluid Neurofilaments May Discriminate Upper Motor Neuron Syndromes: A Pilot Study.

BACKGROUND: Patients presenting with upper motor neuron (UMN) signs may widely diverge in prognosis, ranging from amyotrophic lateral sclerosis (ALS) to primary lateral sclerosis (PLS) and hereditary spastic paraplegia (hSP). Neurofilaments are emerging as potential diagnostic and prognostic biomarkers for ALS, but the diagnosis of UMN syndromes still relies mostly on clinical long-term observation and on familiarity or genetic confirmation. OBJECTIVES: To test whether phosphorylated neurofilament heavy chain (pNfH) may discriminate different UMN syndromes at diagnosis and to test their prognostic role among these diseases. METHODS: We measured the cerebrospinal fluid (CSF) and serum pNfH of 30 patients presenting with UMN signs and diagnosed with ALS, hSP, and PLS, plus 9 healthy controls (HC). RESULTS: ALS patients had higher levels of pNfH in CSF and serum compared to HC (p < 0.001 and p < 0.001 in CSF and serum, respectively) and PLS (p = 0.015 and p = 0.038) and hSP (p = 0.003 and p = 0.001) patients. PLS and hSP patients had similar CSF and serum pNfH concentrations, but a higher CSF pNfH concentration, compared to HC (p = 0.002 and p = 0.003 for PLS and hSP, respectively). Receiver operating characteristic curves for discriminating ALS from PLS and hSP showed an area under the curve of 0.79 for CSF and 0.81 for serum. In multivariable survival analysis including relevant clinical factors CSF pNfH represented the strongest variable predicting survival (HR 40.43; 95% CI 3.49-467.79, p = 0.003) independently of clinical group. CONCLUSIONS: Despite some statistical instability of the results due to limitations in sample size, our study supports the role of CSF pNfH as a prognostic biomarker for motor neuron diseases presenting with UMN signs. A potential power to discriminate between ALS and other UMN syndromes at presentation, and between all of the examined MND and HC, has been detected for both CSF and serum pNfH.

Lower motor neuron syndrome in a patient with HER2-positive metastatic breast cancer: A case report and review of the literature.

Paraneoplastic neurological syndromes are very rare and often associated to breast, ovarian and small cells lung cancers. Paraneoplastic motor neuron diseases (MNDs) are even rarer, and frequently described in patients with breast cancer. We presented the first case of patient affected by HER2-positive breast tumor and possible paraneoplastic lower motor neuron disease. In literature, few cases are reported but no one highlights the tumor receptors' profile. Instead, HER2-positive breast cancers are prone to be related to anti-Yo-associated paraneoplastic cerebellar disorders. Anti-onconeural antibodies positivity can be rarely found, confirming that paraneoplastic MND have no specific biomarkers. The presence of CSF oligoclonal bands (OBs) suggests the presence of immune-mediated mechanism, in absence of other possible OBs causes.

Clinical value of neurofilament and phospho-tau/tau ratio in the frontotemporal dementia spectrum.

OBJECTIVE: To examine the clinical value of neurofilament light chain (NfL) and the phospho-tau/total tau ratio (p/t-tau) across the entire frontotemporal dementia (FTD) spectrum in a large, well-defined cohort. METHODS: CSF NfL and p/t-tau levels were studied in 361 patients with FTD: 179 behavioral variant FTD, 17 FTD with motor neuron disease (FTD-MND), 36 semantic variant primary progressive aphasia (PPA), 19 nonfluent variant PPA, 4 logopenic variant PPA (lvPPA), 42 corticobasal syndrome, and 64 progressive supranuclear palsy. Forty-five cognitively healthy controls were also included. Definite pathology was known in 68 patients (49 frontotemporal lobar degeneration [FTLD]-TDP, 18 FTLD-tau, 1 FTLD-FUS). RESULTS: NfL was higher in all diagnoses, except lvPPA (n = 4), than in controls, equally elevated in behavioral variant FTD, semantic variant PPA, nonfluent variant PPA, and corticobasal syndrome, and highest in FTD-MND. The p/t-tau was lower in all clinical groups, except lvPPA, than in controls and lowest in FTD-MND. NfL did not discriminate between TDP and tau pathology, while the p/t-tau ratio had a good specificity (76%) and moderate sensitivity (67%). Both high NfL and low p/t-tau were associated with poor survival (hazard ratio on tertiles 1.7 for NfL, 0.7 for p/t-tau). CONCLUSION: NfL and p/t-tau similarly discriminated FTD from controls, but not between clinical subtypes, apart from FTD-MND. Both markers predicted survival and are promising monitoring biomarkers for clinical trials. Of note, p/t-tau, but not NfL, was specific to discriminate TDP from tau pathology in vivo. CLASSIFICATION OF EVIDENCE: This study provides Class III evidence that for patients with cognitive issues, CSF NfL and p/t-tau levels discriminate between those with and without FTD spectrum disorders.

Cerebrospinal fluid neurofilament light concentration in motor neuron disease and frontotemporal dementia predicts survival.

OBJECTIVE: To aid diagnostics, patient stratification and studies seeking to find treatments for the related diseases motor neuron disease (MND) and frontotemporal dementia (FTD), there is a need to establish a way to assess disease severity and the amount of ongoing neurodegeneration. Previous studies have suggested that cerebrospinal fluid (CSF) neurofilament light (NFL) may serve this purpose. METHODS: We cross-referenced the Swedish mortality registry with the laboratory database at Sahlgrenska University Hospital to produce a dataset of CSF NFL concentrations and mortality information for 715 MND patients, 87 FTD patients, and 107 healthy controls. Biomarker concentrations were analysed in relation to recorded cause of death and time of death. RESULTS: MND patients had significantly higher CSF NFL concentrations than FTD patients. Both groups had significantly higher concentrations than the healthy controls (mean 709% increase in MND and 307% increase in FTD). Higher concentrations of CSF NFL were associated with shorter survival in both MND and FTD. CONCLUSIONS: The results of this study strengthen the notion of CSF NFL as a useful tool for determining disease intensity in MND and FTD patients. Further studies in patient cohorts with clinically subtyped and genetically classified diagnoses are needed.

Neurofilaments in the diagnosis of motoneuron diseases: a prospective study on 455 patients.

OBJECTIVES: Biomarkers for the diagnosis of motoneuron diseases (MND) are urgently needed to improve the diagnostic pathway, patient stratification and monitoring. The aim of this study was to validate candidate markers for MND in cerebrospinal fluid (CSF) and specify cut-offs based on large patient cohorts by especially considering patients who were seen under the initial differential diagnosis (MND mimics). METHODS: In a prospective study, we investigated CSF of 455 patients for neurofilament light chain (NfL), phosphorylated heavy chain (pNfH), tau protein (Tau) and phospho-tau protein (pTau). Analysed cohorts included patients with apparently sporadic and familial amyotrophic lateral sclerosis (ALS) and primary lateral sclerosis (PLS) (MND, n=253), MND mimics (n=85) and neurological control groups. Cut-off values were specified, and diagnostic performance and correlation with progression were analysed. RESULTS: Nfs were significantly higher in the MND group compared to the control groups, whereas Tau and pTau did not differ. At a cut-off level of 2200 pg/mL for NfL, a 77% diagnostic sensitivity (CI 71% to 82%), 85% specificity (CI 79% to 90%) and 87% positive predictive value (PPV) (CI 81% to 91%) were achieved. For pNfH, we calculated 83% sensitivity (CI 78% to 88%), 77% specificity (CI 71% to 83%) and 82% PPV (CI 77% to 86%) at 560 pg/mL. There were no significant differences between sporadic and genetic ALS or PLS. Nf levels were elevated at early disease stage, and correlated moderately with MND progression and duration. CONCLUSIONS: Neurofilaments in CSF have a high relevance for the differential diagnosis of MNDs and should be included in the diagnostic work-up of patients. Their value as prognostic markers should be investigated further.

Label-Free LC-MS/MS Proteomic Analysis of Cerebrospinal Fluid Identifies Protein/Pathway Alterations and Candidate Biomarkers for Amyotrophic Lateral Sclerosis.

Analysis of the cerebrospinal fluid (CSF) proteome has proven valuable to the study of neurodegenerative disorders. To identify new protein/pathway alterations and candidate biomarkers for amyotrophic lateral sclerosis (ALS), we performed comparative proteomic profiling of CSF from sporadic ALS (sALS), healthy control (HC), and other neurological disease (OND) subjects using label-free liquid chromatography-tandem mass spectrometry (LC-MS/MS). A total of 1712 CSF proteins were detected and relatively quantified by spectral counting. Levels of several proteins with diverse biological functions were significantly altered in sALS samples. Enrichment analysis was used to link these alterations to biological pathways, which were predominantly related to inflammation, neuronal activity, and extracellular matrix regulation. We then used our CSF proteomic profiles to create a support vector machines classifier capable of discriminating training set ALS from non-ALS (HC and OND) samples. Four classifier proteins, WD repeat-containing protein 63, amyloid-like protein 1, SPARC-like protein 1, and cell adhesion molecule 3, were identified by feature selection and externally validated. The resultant classifier distinguished ALS from non-ALS samples with 83% sensitivity and 100% specificity in an independent test set. Collectively, our results illustrate the utility of CSF proteomic profiling for identifying ALS protein/pathway alterations and candidate disease biomarkers.

Untargeted 1H-NMR metabolomics in CSF: toward a diagnostic biomarker for motor neuron disease.

OBJECTIVES: To develop a CSF metabolomics signature for motor neuron disease (MND) using (1)H-NMR spectroscopy and to evaluate the predictive value of the profile in a separate cohort. METHODS: We collected CSF from patients with MND and controls and analyzed the samples using (1)H-NMR spectroscopy. We divided the total patient sample in a 4:1 ratio into a training cohort and a test cohort. First, a metabolomics signature was created by statistical modeling in the training cohort, and then the analyses tested the predictive value of the signature in the test cohort. We conducted 10 independent trials for each step. Finally, we identified the compounds that contributed most consistently to the metabolome profile. RESULTS: Analysis of CSF from 95 patients and 86 controls identified a diagnostic profile for MND (R(2)X > 22%, R(2)Y > 93%, Q(2) > 66%). The best model selected the correct diagnosis with mean probability of 99.31% in the training cohort. The profile discriminated between diagnostic groups with 78.9% sensitivity and 76.5% specificity in the test cohort. Metabolites linked to pathophysiologic pathways in MND (i.e., threonine, histidine, and molecules related to the metabolism of branched amino acids) were among the discriminant compounds. CONCLUSION: CSF metabolomics using (1)H-NMR spectroscopy can detect a reproducible metabolic signature for MND with reasonable performance. To our knowledge, this is the first metabolomics study that shows that a validation in separate cohorts is feasible. These data should be considered in future biomarker studies. CLASSIFICATION OF EVIDENCE: This study provides Class III evidence that CSF metabolomics accurately distinguishes MNDs from other neurologic diseases.

CSF flow dynamics in motor neuron disease.

OBJECTIVE: To assess cerebrospinal fluid (CSF) flow dynamics involvement in the pathogenesis of amyotrophic lateral sclerosis (ALS), we conducted CSF flow studies on 40 individuals with motor neuron diseases (MNDs) including ALS, and 28 age-matched normal and disease [cervical spondylosis (CS)] controls. METHODS: The CSF pulsatile velocity anterior to the cervical cord at level C5 during one heart beat was determined non-invasively by phase-contrast electrocardiography-triggered magnetic resonance imaging. RESULTS: In MND, caudal CSF velocity peaked at 25% of the cardiac cycle after the R wave (UT(c)/RR), showing an increased delay in comparison to normal controls, while amplitude H(c) was significantly larger than that in CS. DISCUSSION: We conclude that CSF flow dynamics of MND differ from those of controls and may thus facilitate differentiation of MND from CS.

Contrasting effects of cerebrospinal fluid from motor neuron disease patients on the survival of primary motor neurons cultured with or without glia.

Motor neuronal (MN) degeneration in motor neuron disease (MND) often starts focally before spreading to neighbouring MN populations, suggesting soluble factors may contribute to disease propagation. Whether cerebrospinal fluid (CSF) from MND patients contains such factors has been difficult to prove. We aimed to determine the effect of glia on the response of MNs to CSF from MND patients. Primary rat spinal MNs grown in mono-culture or cocultured with glia were exposed to CSF from patients (MND-CSF) or controls (Con-CSF) and survival measured by cell counting. In mono-culture both MND-CSF and Con-CSF reduced MN survival with MND-CSF reducing MN survival by less than Con-CSF. In coculture MN survival was unchanged by exposure to MND-CSF while exposure to Con-CSF improved MN survival. In separate experiments, murine MNs grown in mono-culture and stressed by growth factor withdrawal were partially rescued by the application of monocyte chemoattractant protein-1 (MCP-1), a trophic factor previously found to be elevated in MND-CSF. Our results suggest that MND-CSF may contain factors harmful to MNs as well as factors protective of MNs, the interplay of which is altered by the presence of glial cells. These preliminary results further emphasize the importance of MN environment to MN health.

Microglial upregulation of progranulin as a marker of motor neuron degeneration.

Frontotemporal lobar degeneration (FTLD) and amyotrophic lateral sclerosis (ALS) are overlapping neurodegenerative disorders. Mutations in the growth factor progranulin (PGRN) gene cause FTLD, sometimes in conjunction with ALS; such mutations are also observed in some ALS patients. Most PGRN mutations underlying FTLD are null mutations that result in reduced PGRN levels. We investigated PGRN expression in human ALS and in mouse models of motor neuron degeneration. Progranulin plasma or CSF levels in newly diagnosed ALS patients did not differ from those in healthy or disease controls (PGRN mutation-negative FTLD and Alzheimer disease patients). In the mutant SOD1 mouse model of ALS, spinal cord PGRN levels were normal in presymptomatic animals but increased during the degenerative process. This increase in PGRN correlated with enhanced expression of PGRN in microglia. In CSF, PGRN levels were normal in presymptomatic and early symptomatic animals, but with disease progression, a raise in PGRN was detectable. These data indicate that upregulation of PGRN is a marker of the microglial response that occurs with progression in motor neuron diseases.

Coexistence of parkinsonism, dementia and upper motor neuron syndrome in four Czech patients.

BACKGROUND: The parkinsonian complex of Guam is an endemic neurodegenerative condition, which has been described only in the islands of the Guam archipelago and at the Kii peninsula of Japan. Up to now, only one "sporadic" case has been described (including the autopsy) in Japan. STUDY OBJECTIVE: To describe the clinical, laboratory and neurophysiological characteristics of the neurodegenerative disorder presenting in 4 patients with the complex syndrome of parkinsonism, amyotrophic lateral sclerosis (ALS), and dementia. PATIENTS AND METHODS: Four consecutive patients of Caucasian and Czech origin, presenting with the complex syndrome of slowly progressive parkinsonism, amyotrophic lateral sclerosis and dementia were examined clinically, including neuropsychological examination, and they were assessed using magnetic resonance imaging, electromyography and evoked potentials. The blood and CSF samples were also examined, and the levels of inflammatory and neurodegenerative markers (beta-amyloid, cystatin C and tau-proteins) were assessed. RESULTS: The clinical phenotype in all four patients corresponded to the one described in the parkinsonian complex of Guam, including the presence of a cognitive deficit at the level of mild to severe dementia. The findings of EMG examination in all cases were those typically seen in ALS, and they met the El Escorial criteria. CSF levels of neurodegenerative markers (tau-protein) were elevated in all four patients. CSF levels of inflammatory markers were normal. CONCLUSION: The unique appearance of the syndrome typical for the endemic Guam complex in patients of Caucasian origin in Europe raises a question of endemicity and heredity of the Guam complex and deserves further research.