Predictors and correlates of emotionalism across acquired and progressive neurological conditions: A systematic review.

Emotionalism can develop following a range of neurological disorders; however the aetiology of emotionalism is still unclear. To identify anatomical, neuropsychological and psychological predictors and correlates of emotionalism across neurological disorders: stroke, Parkinson's disease, multiple sclerosis, traumatic brain injury, Alzheimer's disease, vascular dementia and amyotrophic lateral sclerosis. To explore if these predictors and correlates of emotionalism differ across neurological disorders. A comprehensive systematic search was completed of four databases: MEDLINE, CINAHL Complete, PsycINFO and EMBASE. Methodological quality was assessed using the Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies and each study was graded according to the level of evidence using the Scottish Intercollegiate Guidelines Network. Fifty papers (participants N  = 1922) were included. 25 studies were rated as "Fair," 21 "Good" and 4 "Poor." The review identified predictors and correlates found in several neurological disorder such as bulbar networks, serotonergic pathways, genetics and female gender. Multiple studies across diseases (stroke, MS, ALS) indicate emotionalism is associated with cognitive impairment, especially frontal deficits. Due to the disproportionate number of studies identified across neurological disorders, it is difficult to draw definitive answers. Further research is required across neurological disorders to explore similarities and differences in anatomical, neuropsychological and psychological predictors and correlates.