Hostname: page-component-cd9895bd7-lnqnp Total loading time: 0 Render date: 2024-12-25T05:06:54.471Z Has data issue: false hasContentIssue false

Commentary on Richardson et al. detecting delirium superimposed on dementia: diagnostic accuracy of a simple combined arousal and attention testing procedure

Published online by Cambridge University Press:  29 August 2017

Ravi Bhat*
Affiliation:
Department of Rural Health, Melbourne Medical School, The University of Melbourne, Shepparton, Australia
Nicola T. Lautenschlager
Affiliation:
Academic Unit for Psychiatry of Old Age, Department of Psychiatry, The University of Melbourne, Melbourne, Victoria, Australia NorthWestern Mental Health, Melbourne Health, Melbourne, Victoria, Australia
Rosie Watson
Affiliation:
Royal Melbourne Hospital, Melbourne, Australia The Florey Institute of Neuroscience and Mental Health, Melbourne, Australia
Get access

Extract

Consciousness consists of two components: arousal and awareness of the environment and self. Arousal refers to the behavioral continuum that occurs between sleep and wakefulness, while awareness to the content of consciousness (Laureys, 2014). In normal physiological states, with the exception of REM sleep, the level of arousal is positively correlated with awareness (Laureys, 2014) such that arousal is graded and measured by the degree to which it is diminished. This conceptualization appears to have led experts, including the DSM-5, to consider delirium as a condition to not associated with impairments in arousal (Schiff and Plum, 2000, American Psychiatric Association, 2013). However, arousal can be both diminished and heightened, not unlike the performance of an old-fashioned incandescent bulb at different voltages, giving barely sufficient light at low voltages and brightening up unbearably at high voltages (MacIsaac et al., 1999). Delirium is associated with both hypo-arousal and hyper-arousal (Han et al., 2017). A small but significant proportion of delirious older patients (10%; n = 155) in the emergency department in this study had normal arousal at the time of the short arousal assessment (Han et al., 2014).

Type
Commentary
Copyright
Copyright © International Psychogeriatric Association 2017 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

American Psychiatric Association (2013). Diagnostic and Statistical Manual of Mental Disorders, 5th edn, (DSM-5). Washington, DC: American Psychiatric Association.Google Scholar
Bhat, R. and Rockwood, K. (2007). Delirium as a disorder of consciousness. Journal of Neurology Neurosurgery and Psychiatry, 78, 11671170.Google Scholar
Chester, J. G., Beth Harrington, M., Rudolph, J. L., VA Delirium Working Group (2012). Serial administration of a modified richmond agitation and sedation scale for delirium screening. Journal of Hospital Medicine, 7, 450453. doi: 10.1002/jhm.1003. Epub 2011 Dec 15.CrossRefGoogle ScholarPubMed
European Delirium Association; American Delirium Society (2014). The DSM-5 criteria, level of arousal and delirium diagnosis: inclusiveness is safer. BMC Medicine, 12, 141. doi: 10.1186/s12916-014-0141-2.Google Scholar
Han, J. H. et al. (2014). Impaired arousal at initial presentation predicts 6-month mortality: an analysis of 1084 acutely ill older patients. Journal of Hospital Medicine, 9, 772778. doi: 10.1002/jhm.2276. Epub 2014 Oct 29.Google Scholar
Han, J. H. et al. (2015). The diagnostic performance of the richmond agitation sedation scale for detecting delirium in older emergency department patients. Academic Emergency Medicine, 22, 878882. doi: 10.1111/acem.12706. Epub 2015 Jun 25.Google Scholar
Han, J. H. et al. (2017). Exploring Delirium's heterogeneity: association between arousal subtypes at initial presentation and 6-month mortality in older emergency department patients. American Journal of Geriatric Psychiatry, 25, 233242. doi: 10.1016/j.jagp.2016.05.016. Epub 2016 Jul 4.CrossRefGoogle ScholarPubMed
Laureys, S. (2014). Arousal versus awareness. In Bayne, T., Cleeremans, A. and Wilken, P. (eds.), The Oxford Companion to Consciousness (pp. 5860). Oxford: Oxford University Press.Google Scholar
MacIsaac, D., Kanner, G. and Anderson, G. (1999). Basic physics of the incandescent lamp (lightbulb). The Physics Teacher, 37, 520525.Google Scholar
Morandi, A. et al. (2016). Detecting delirium superimposed on dementia: evaluation of the diagnostic performance of the richmond agitation and sedation scale. Journal of the American Medical Directors Association, 17, 828833. doi: 10.1016/j.jamda.2016.05.010. Epub 2016 Jun 23.Google Scholar
Neufeld, K. J. et al. (2014). Delirium diagnosis methodology used in research: a survey-based study. American Journal Geriatric Psychiatry, 22, 15131521. doi: 10.1016/j.jagp.2014.03.003.CrossRefGoogle ScholarPubMed
Richardson, S. J. et al. (2017). Detecting delirium superimposed on dementia: diagnostic accuracy of a simple combined arousal and attention testing procedure. International Psychogeriatrics. Published online May 31, 19. doi: 10.1017/S1041610217000916.Google Scholar
Schiff, N. D. and Plum, F. (2000). The role of arousal and “gating” systems in the neurology of impaired consciousness. Journal of Clinical Neurophysiology, 17, 438452.CrossRefGoogle ScholarPubMed
Tieges, Z., McGrath, A., Hall, R. J. and Maclullich, A. M. (2013). Abnormal level of arousal as a predictor of delirium and inattention: an exploratory study. American Journal of Geriatric Psychiatry, 21, 12441253. doi: 10.1016/j.jagp.2013.05.003.CrossRefGoogle ScholarPubMed