Neuron-specific enolase in diagnosis and prognosis of delirium: a systematic review

Abstract

Abstract Delirium, characterized by a sudden onset of neuropsychiatric symptoms, is a highly prevalent syndrome whose diagnosis is defined solely through clinical evaluation. Due to the often challenging reliability of assessments, especially in non-cooperative patients, there is a growing emphasis on exploring new reliable biomarkers, such as Neuron-Specific Enolase (NSE). NSE, an enzyme primarily found in neuronal and neuroendocrine tissues, has been clinically used to assess the prognosis of patients who have experienced traumatic or hypoxic brain injuries. Thus, the primary purpose of the present review is to examine the literature to determine whether NSE is applicable for diagnosis and/or prognosis of patients with delirium. Literature was searched using Pubmed, Lilacs and Scielo databases, and all published reports identified as potentially relevant were independently assessed by each reviewer. All relevant original studies were included and independent extraction of articles was performed by three authors using predefined data fields. Twenty one studies (2,311 patients) satisfied the entry criteria, among which only eight suggest a possible association between NSE and delirium, particularly in intensive care settings, and only one correlate NSE with delirium prognosis. Also, significant heterogeneity was observed among studies, varying across study design, setting, and methodologies. Furthermore, the majority of the selected studies presented severe methodological limitations, particularly small samples. In conclusion, this systematic review underscores the need for further research with larger, standardized studies to establish the reliability and validity of NSE as a diagnostic and prognostic tool for delirium. The current evidence does not sufficiently support its routine clinical application in assessing patients with delirium.

Keywords

• Delirium
• Biomarkers
• Neuron-specific enolase