Correlations of cerebrospinal fluid neurofilament light chain levels with clinical and electromyography findings in amyotrophic lateral sclerosis.

BACKGROUND

This study aimed to examine correlations between cerebrospinal fluid neurofilament light chain (CSF NfL) levels, and clinical and electrophysiological findings in amyotrophic lateral sclerosis (ALS). Compare CSF NfL and total protein levels between ALS and other central nervous system (CNS) neurodegenerative disorders.

METHODS

This retrospective study analyzed 46 ALS patients (Gold Coast criteria) and 33 non-ALS neurodegenerative controls. We documented time from symptom onset to diagnosis, revised ALS Functional Rating Scale (ALSFRS-R) scores at CSF sampling, initial involvement regions (bulbar/cervical/lumbosacral), and extent of lower motor neuron (LMN) involvement.

RESULTS

ALS patients had significantly higher CSF NfL levels than non-ALS controls (4221 ± 2585 vs. 3004 ± 2788 pg/mL, p = 0.025). In the ALS group, CSF NfL levels showed significant inverse correlation with ALSFRS-R scores (r = -0.332, p = 0.024), and patients demonstrating involvement in all four-region on needle electromyography exhibited the highest CSF NfL levels. Among the ALS cohort 18 patients (39%) had died by the last follow-up, and patients who died during the study exhibited significantly higher baseline CSF NfL levels (median: 5115 pg/mL) compared to surviving patients (median: 3276 pg/mL; p = 0.007).

CONCLUSIONS

Our study demonstrated that CSF NFL levels were significantly elevated in ALS compared to other neurodegenerative disorders. Higher CSF NFL concentrations correlated with more rapid functional decline, more extensive LMN degeneration, and poorer survival outcomes.