Trinity Researchers Shed New Light on Delirium Author: Trinity College Dublin

[xchrom]

http://atomiumculture.eu/content/trinity-researchers-shed-new-light-delirium

Trinity researchers studying the neuropsychiatric syndrome of delirium have uncovered important interactions between inflammation and brain chemistry that may contribute to its onset. The findings have been just published in the Journal of Neuroscience.

Delirium is a common psychiatric syndrome that manifests as sudden and profound disturbance of attention, memory, and behaviour. It is highly prevalent in the elderly and the long-term outcomes for these individuals are very poor, including long-term deterioration of cognitive function leading to permanent institutionalisation. Despite these economic and clinical imperatives there has been little basic research into delirium and the lack of animal models with which to study delirium has contributed to this. Delirium can arise in many situations, for example, after infection or surgery or as the result of changes in medication, particularly those medications targeting the chemical messenger acetylcholine. This has led to different theories of delirium, including the “cholinergic hypothesis”, which proposes that decreased levels or activity of acetylcholine are responsible for the deficits observed, and the “neuroinflammatory hypothesis”, which proposes that inflammation in the brain causes the disturbance of brain function.

Researchers in the School of Biochemistry and Immunology and the Trinity College Institute of Neuroscience, led by Wellcome Trust Senior Research Fellow Dr Colm Cunningham have now published findings that begin to reconcile these two theories of delirium. The findings, published this week in the Journal of Neuroscience, show that inflammation arising in the body as a result of an infection, trigger a robust disturbance of short-term memory but only in animals who already showed destruction of brain cells that normally synthesise the chemical messenger acetylcholine in cholinergic cells. Importantly, neither inflammation nor cholinergic cell loss individually were sufficient to cause this disturbance indicating that these two key factors must interact to produce the delirium-like state. Furthermore, the disturbance could be partially reversed by treatment with donepezil, a drug that slows down the breakdown of acetylcholine. Therefore, systemic inflammation can induce these cognitive impairments only in individuals with so called cholinergic vulnerability.

As well as throwing light on mechanisms relevant to delirium, this novel combination of prior pathology in the cholinergic area of the brain and subsequent systemic inflammation provides a valuable new animal model that can be used to study this distressing and damaging psychiatric condition.

[Warpy]

1. Distressing yes. Damaging, not necessarily.

While extreme post operative delirium can predict the development of dementia years down the road, most patients recover fully, especially when they go home to familiar surroundings.

In some cases, delirium can also be protective, the patient having no memory of trauma and the early recovery period.

Delirium makes for distressed families and challenging patient care, that's for certain. However, the study I'd like to see would be a comparison of post operative depression in delirious versus non delirious patients.

[cbayer]

2. Anything that can be done to decrease episodes of delirium would be a blessing for both patients and

hospital staff.

Delirium can be terrifying, disruptive and dangerous.

The most common cause is over-medication and polypharmacy prescribed by physicians who refuse to pay attention to the adverse effects of their orders. Psychiatrists who do consults in ICU's spend half their time taking patients off multiple drugs after delirium has set in.

This is, in fact, a neurological disorder. It is interesting that they call it a psychiatric disorder here. That is probably because the psychiatrists are the most likely to resolve it.