{'fraction_non_alphanumeric': 0.03996366939146231, 'fraction_numerical': 0.007266121707538601, 'mean_word_length': 5.520710059171598, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 2, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Age‐Adjusted Serum Neurofilament Predicts Cognitive Decline in Parkinson's Disease (MARK‐PD)

We read with great interest the study by Aamodt and colleagues reporting that plasma neurofilament light (NfL) chain levels are associated with UPDRS III (Unified Parkinson’s Disease Rating Scale, Part III) score but not the Mattis Dementia Rating Scale (DRS-2), whereas plasma NfL predicted cognitive decline (DRS-2 change) but not motor worsening (UPDRS III ≥5 points). Interestingly, these findings are in line with our results that serum NfL was associated with UPDRS III but not Montreal Cognitive Assessment (MoCA) score, whereas serum NfL predicted cognitive decline (decrease in MoCA score >2 points) but not motor worsening (increase in UPDRS III >4 points) in the Biomarkers in Parkinson’s Disease (MARK-PD) study. Numerous studies have shown that blood NfL predicts cognitive decline in patients with Parkinson’s disease, but cutoff values determined by receiver operating characteristic (ROC) analysis revealed very different results. Given that serum NfL levels increase by 3.35% per year in PD