An Analytic Review of Neuropsychiatric Syndromes in the Intensive Care Unit

Neuropsychiatric syndromes are characterized by disturbances in cognition, emotions, behavior, and represent the complex intersection between neurology and psychiatry, particularly in the critically ill. Despite this vulnerability in critically ill patients and the implications of the high level of care required in critical care settings, intensivists often face difficulty in the prompt recognition and management of neuropsychiatric syndromes. This in part may be reflective of the several overlapping and nonspecific clinical features (i.e. agitation, altered mentation, motor findings, autonomic instability, clonus), disparate definitions of encephalopathy within the literature, precipitating risk factors, lack of clearly defined diagnostic tests or laboratory findings, and shared secondary complications when diagnosis is delayed or missed. Agitation is often the most readily identifiable presenting symptom of neuropsychiatric syndromes in critically ill patients, largely due to its disruptive impact on patient care, both patient and staff safety, potential to delay in time to extubation, and risk of worsening patient outcomes.In this analytic review, neuropsychiatric syndromes that can present with agitation were identified and further appraised upon reviewing randomized controlled trials, meta-analyses, and systematic reviews from the PubMed database spanning from 1995 to 2024. In total 507 articles were identified using relevant search terminology, article titles were subsequently screened for relevance, followed by screening of abstracts. Neuropsychiatric syndromes included within this review were selected based upon diagnostic complexity, overlapping clinical features, and highlighted based upon prevalence within the literature: Serotonin syndrome, neuroleptic malignant syndrome, catatonia, and paroxysmal sympathetic hyperactivity. We highlight these distinct syndromes and propose a clinical heuristic-based decision tree to accompany clinical decision making for the intensivist from a psychiatrist's lens.