The following is a summary of “Diagnostic value of neurofilaments in differentiating motor neuron disease from multifocal motor neuropathy,” published in the April 2024 issue of Neurology by Wohnrade et al.
Researchers conducted a retrospective study to assess the accuracy of serum neurofilament light chain (NfL) and cerebrospinal fluid (CSF) phosphorylated neurofilament heavy chain (pNfH) in distinguishing between motor neuron disease (MND) and multifocal motor neuropathy (MMN).
They conducted a retrospective, monocentric study involving 16 patients diagnosed with MMN and 34 incident cases of MND. A subgroup comprising 24 patients with MND with a dominance of lower MN was analyzed separately. NfL levels in serum were assessed through an automated immunoassay using Ella, while pNfH levels in CSF were measured via enzyme-linked immunosorbent assay. The Area Under the Curve (AUC) and optimal cutoff values were calculated based on Youden’s index, and correlations with demographic characteristics were examined.
The results showed that neurofilament levels were markedly elevated in MND compared to MMN (P<0.001), with a strong correlation between serum NfL and CSF pNfH (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%) demonstrated excellent performance distinguishing MND from MMN. Optimal cutoff values were ≥ 44.15 pg/mL (serum NfL) and ≥ 715.5 pg/mL (CSF pNfH), respectively. Similar outcomes were observed in lower MN dominant MND. Only one patient with MMN had serum NfL levels exceeding the cutoff, while two patients with MND had neurofilament concentrations below the cutoffs, both experiencing a slow disease progression.
Investigators concluded that elevated neurofilaments, measured by serum NfL and CSF pNfH, effectively support the diagnosis of MND, particularly in cases with unclear differentiation from MMN.
Source: link.springer.com/article/10.1007/s00415-024-12355-8