Delirium
Delirium, or acute confusional state, is an organically-caused decline from a previously attained baseline level of cognitive function. It is typified by fluctuating course, attentional deficits and generalized severe disorganization of behavior. It typically involves other cognitive deficits, changes in arousal (hyperactive, hypoactive, or mixed), perceptual deficits, altered sleep-wake cycle, and psychotic features such as hallucinations and delusions.
Etiology
With Cocaine initial CNS stimulation that first manifests as a sense of well-being and euphoria. Sometimes dysphoric agitation results, occasionally with delirium.
Thallium: may produce tremors, leg pains, paresthesias in the hands and feet, polyneuritis in the LE, psychosis, delirium, seizures, encephalopathy.
Delirium tremens
Postoperative Delirium
Alcohol withdrawal seizures
see Alcohol withdrawal seizures.
Diagnosis
Early neutrophil-to-lymphocyte ratio (NLR) elevation may also predict delayed-onset delirium, potentially implicating systemic inflammation as a contributory delirium mechanism 1).
Delirium is an acute disorder affecting up to 80% of intensive care unit (ICU) patients. It is associated with a 10-fold increase in cognitive impairment, triples the rate of in-hospital mortality, and costs $164 billion annually. Delirium acutely affects attention and global cognitive function with fluctuating symptoms caused by underlying organic etiologies. Early detection is crucial because the longer a patient experiences delirium the worse it becomes and the harder it is to treat. Currently, identification is through intermittent clinical assessment using standardized tools, like the Confusion Assessment Method for ICU. Such tools work well in clinical research but do not translate well into clinical practice because they are subjective, intermittent and have low sensitivity. As such, healthcare providers using these tools fail to recognize delirium symptoms as much as 80% of the time. Delirium-related biochemical derangement leads to electrical changes in electroencephalographic (EEG) patterns followed by behavioral signs and symptoms. However, continuous EEG monitoring is not feasible due to cost and need for skilled interpretation. Studies using limited-lead EEG show large differences between patients with and without delirium while discriminating delirium from other causes. The Ceribell is a limited-lead device that analyzes EEG. If it is capable of detecting delirium, it would provide an objective physiological monitor to identify delirium before symptom onset. This pilot study was designed to explore relationships between Ceribell and delirium status. Completion of this study will provide a foundation for further research regarding delirium status using the Ceribell data 2).
Unlike dementia, delirium has an acute onset, motor signs (tremor, myoclonus, asterixis), slurred speech, altered consciousness (hyperalert/agitated or lethargic, or fluctuations), hallucinations may be florid. EEG shows pronounced diffuse slowing.
Delirium itself is not a disease, but rather a clinical syndrome (a set of symptoms). It may result from an underlying disease, from drugs administered during treatment of that disease in a critical phase, withdrawal from drugs, from a new problem with mentation, or from varying combinations of two or more of these factors. It is a corollary of the criteria that a diagnosis of delirium usually cannot be made without a previous assessment, or knowledge, of the affected person’s baseline level of cognitive function. In other words, a mentally disabled person who is suffering from this will be operating at their own baseline level of mental ability and would be expected to appear delirious without a baseline mental functional status against which to compare.
Hut SC, Dijkstra-Kersten SM, Numan T, Henriquez NR, Teunissen NW, van den Boogaard M, Leijten FS, Slooter AJ. EEG and clinical assessment in delirium and acute encephalopathy. Psychiatry Clin Neurosci. 2021 May 16. doi: 10.1111/pcn.13225. Epub ahead of print. PMID: 33993579.
Differential diagnosis
Delirium vs. dementia (critical distinction). Delirium AKA acute confusional state. Distinct from dementia; however, patients with dementia are at increased risk of developing delirium.
A primary disorder of attention that subsequently affects all other aspects of cognition.
Often represents life-threatening illness, e.g.hypoxia, sepsis, uremic encephalopathy, electrolyte abnormality, drug intoxication, MI. 50% of patients die within 2 yrs of this diagnosis.
Unlike dementia, delirium has acute onset, motor signs (tremor, myoclonus, asterixis), slurred speech, altered consciousness (hyperalert/agitated or lethargic, or fluctuations), hallucinations may be florid. EEG shows pronounced diffuse slowing.
Outcome
Delirium during critical illness is associated with nearly a 3-fold increased risk of death the following day for patients in the hospital but is not associated withmortality after hospital discharge. This finding appears primarily driven by the hypoactive motoric subtype. The independent relationship between delirium and mortality occurs early during critical illness but does not persist after hospital discharge 3)