Role of neurofilament light chain to reduce diagnosis and improve outcomes for patients in a real‐world cognitive neuropsychiatry service: A retrospective MiND study

Abstract

AbstractBackgroundIt is common for patients presenting with neuropsychiatric symptoms to endure significant diagnostic odyssey. Neurofilament light chain (NfL) has shown promise in being able to differentiate between neurodegenerative and psychiatric disorders. This study aimed to assess the clinical utility of NfL in avoiding misdiagnosis.MethodIn this retrospective study, we conducted file review of patients assessed at Neuropsychiatry, Royal Melbourne Hospital between 2009 to 2020. We included all patients (n = 212) who had a CSF NfL level at their baseline assessment. Investigators blinded to NfL levels extracted clinical information including diagnoses from the initial and follow‐up assessments using documentation available. In addition, we collected follow‐up data from external services where available. Initial and follow‐up/final diagnoses were categorised as neurodegenerative disorder (ND), psychiatric disorder (PSY), mild cognitive impairment (MCI), unclear, and not‐neurodegenerative (Not‐ND). Not‐ND were individuals who did not meet the diagnosis for PSY or MCI, and did not have worsening symptoms. Based on our previous findings, we defined an NfL>582pg/mL as a positive test result for ND.ResultSo far, we have collected information from 135 patients. Of these, 14/89 (16%) patients initially diagnosed with ND were re‐diagnosed as PSY or Not‐ND. 2/30 (7%) patients initially diagnosed with PSY were re‐diagnosed as having ND. Including MCI and unclear, 32/135 (24%) had a delayed diagnosis, which could have been reduced to 14% based on baseline CSF NfL predicting ND or Not‐ND/MC/PSY. Data analysis is ongoing and full results will be presented at the conference.ConclusionBaseline CSF NfL could have aided clinicians in a real‐world clinical setting, to reduce misdiagnosis, and increase diagnostic accuracy from 76% to 86%. An elevated level could prompt assertive investigations for neurological and neurodegenerative causes. Conversely, a low NfL, could reassure against a neurodegenerative disorder, preventing unnecessary assessments. Timely and accurate diagnosis will improve outcomes and precision care for patients and families.