NEFL and amyotrophic lateral sclerosis: The PSQI scores in ALS patients correlated significantly with the disease progression rate [ΔFS = (48-score on the Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised, ALSFRS-R)/disease duration] [β(95% CI) = 2.867 (0.397, 5.336), p = 0.024] and plasma neurofilament light chain (NfL) levels [β (95% CI) = 0.041 (0.012, 0.070), p = 0.008).