The Ds of Cognitive Impairment

Let’s talk about the Triple Ds: Diners, Drive Ins and Dives it ain’t

If you are a fan of the Food Network and SBS3, you are sure to understand what I am talking about. Huge supersized burgers, fries, shakes and barbequed meat.

Mmm Mmmm!

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But this is not what we will be talking about in this blog.

We are talking about the medical triple D which consists of Delirium, Depression and Dementia, with a special emphasis on Delirium as this is a life threatening medical emergency that is common and often missed by novices.

Here is the introduction I got from a Guideline from my local health services [1].

Situation – Risk Statement: For many older people, hospitals can be dangerous places. Delirium is a medical emergency – requiring prompt assessment. Delirium may be the only indicator that an older person is acutely unwell. Rates of delirium on admission to hospital range from 10 – 24%. Incidence of delirium developing during hospitalization is estimated to be as much as 56% of all hospitalized older people. Post-operative delirium has been reported in up to 61% of older people having fractured hip/femur surgery. Delirium is associated with increased morbidity (rates of 25 – 33%) and mortality, functional decline, increased length of stay and increased rates of entry to residential aged care.

Delirium symptoms may resolve quickly (days) but can persist for six to twelve months. Many older people are discharged from hospital with a delirium, or symptoms of delirium, still being present. Delirium in older hospitalized people is largely preventable. The occurrence of delirium in hospital is often the harbinger of a dementing type illness and warrants follow up assessment.

So what is delirium?

Delirium is a syndrome characterized by the rapid onset of impaired attention that fluctuates, together with altered consciousness and cognition. It may be the only sign of a serious medical illness in an older person and therefore requires urgent medical and nursing assessment and management.

Delirium is usually a direct consequence of a new, or change in an existing medical condition, drug addition or withdrawal or intoxication.

My first encounter with a delirious person typically occurs with a phone call from a concerned intern from the medical or surgical team, baffled and perhaps at a loss about an older person sobbing inconsolably or talking incoherently about ‘pink furry animals running around the room’ or a cantankerous, combative elderly person who was previously pleasant.

The diagnosis of delirium represents an umbrella construct that was adopted to overcome definitional problems before DSM-III (1980) [2].  There were literally dozens of terms being used to indicate generalised brain dysfunction occurring in either the context of acute illness or drug intoxication. Its worth noting some of these as they are still in use.  They often reflect the setting or context in which the condition arises: `acute confusional state’, `encephalopathy’, `acute brain failure’, `ICU psychosis’, and even `subacute befuddlement’.

Prior to DSM-5 has been the requirement that alterations in attention and arousal of consciousness are core to the diagnosis of delirium. However, it has proven difficult to assess consciousness so in DSM-5 the term `consciousness’ is not used at all and delirium is now defined in terms of its cognitive features.  This has been a somewhat controversial move and it is probably best to view this change as an attempt to be more exact in diagnosis than a suggestion that problems with arousal and attention do not occur in delirium, they do, much of the time.

he pathophysiology behind delirium is not clearly understood. It is considered that delirium involves multiple changes to neurotransmitters (predominantly acetylcholine and dopamine) and inflammatory reactions (stress and hypoxia) which cause cytokines to stimulate the release of neurotoxins. It probably reflects a lack of cognitive reserve in a person. Delirium in older people is common and usually there is a multifactorial basis to the condition.   Delirium results when an older person who is predisposed, or at risk of, delirium is exposed to precipitating (or causal) factors. For example, an older person who has a pre-existing condition (such as dementia and/or chronic disease) is more likely to develop a delirium from a urinary tract infection. There are also different types of delirium.  There is Hyperactive Delirium which occurs in about 30% of cases. Behaviours are outwardly noticeable and include repetitive behaviours (for example, plucking at sheets), wandering, hallucinations or verbal and physical aggression. Not surprisingly this is the most commonly recognised form of delirium and one most likely to result in a referral to psychiatry.  Then there is Hypoactive Delirium which occurs in about 25% of cases. This form of delirium is characterised by lethargy and somnolence and is frequently not detected. It may only be when a family member comes in that they notice that “pops” is not his normal self.  Finally because most things in psychiatry are on a spectrum we also have Mixed Delirium which occurs in about 45% of cases and is basically periods of both hyperactive and hypoactive delirium.                                                                                                                                                        

My first encounter with a delirious person typically occurs with a phone call from a concerned intern from the medical or surgical team, baffled and perhaps at a loss about an older person sobbing inconsolably or talking incoherently about ‘pink furry animals running around the room’ or a cantankerous, combative elderly person who was previously pleasant.

This is where the first pitfall comes in: it may appear clear to the intern (or perhaps their Registrar or Consultant) that the patient is psychotic or there is something not quite right psychiatrically and the temptation is therefore to ask for a transfer to mental health.

So it is important to switch from Type 1 thinking to Type 2 here.

Consider the context, onset, acuity and duration of the symptoms. Ask yourself: what was the patient like before they were admitted. What was their baseline? What was their functioning like? What was their personality like? And more importantly: What did the patient present with on admission? What was done eg: surgery, medications etc… Lots of questions but trust me it will be worth it and this is only the beginning. And this is also the situation where collateral history from the nursing staff and relatives/carers are pure gold.

Along with physical examination and review of investigations, you should do a cognitive assessment.  Actually, you should do more than one of these. Most medical students are at least taught the Mini Mental Status Examination.  Although there are a range of other bedside cognitive assessments that you can perform.

In a person with delirium, you will often find it difficult for them to complete test due to the fluctuating level of consciousness and inattention (particularly evident in tasks such as serial sevens and spelling ‘WORLD’ backwards) but fear not and do not give up: just keep trying at different times of the day and when the person appears to be more lucid.

The key to differentiating delirium on cognitive assessment versus other conditions that can impair cognition is variations on performance over time.  Therefore it is critical that you perform more than one assessment.

So, the next step is what is the cause? It can come down to something simple and easy to treat like a urinary tract infection. But just beware that not all causes of a delirium can be detected on tests and investigations being negative especially the bloods does not mean there is no delirium.

Also remember that ‘Delirium symptoms may resolve quickly (days) but can persist for six to twelve months’[1]. The rule of thumb in managing delirium is a combination of common sense, simplicity and lots of patience.

Take it slowly, and using as little medication as possible and only as a last resort.

I like to remember the advice of a Psychiatrist who works with Older Adults and Consultation Liaison. Older: always approach the older person with a smile, be calm, do not argue, guide them (eg: hold their hands), take your time and maintain familiarity. Family is important so have them involved from the start. Make sure that patient is comfortable, clean and sleeping at the right time with no “nanna naps” during the day.

Last but not least: Follow a good guideline and encourage others to do so.  Guidelines are great in medicine when a condition is common (tick) and when the reality of practice is quite far from best practice (tick).

So what about the other D’s?

Depression and cognition: Just briefly, the cognitive deficit in depression is gradual in onset and fairly stable on repeat testing. The person usually appears really sluggish and slow (psychomotor retardation), which reflects itself in poor short term memory and recall. The person might even give up completing the MMSE. The good thing is cognitive impairment generally resolves with the treatment of the depressive illness.

Finally, dementia. This is again more gradual in onset, long term, mostly irreversible and progression depends on the type you have (eg: Alzheimer’s, Vascular, Frontal etc…). Early on the main effects are on short term memory hence the difficulty in learning new things but this does not mean no learning happening. Eventually, however, the whole brain will be involved and it will disrupt all other cognitive functions such as attention, executive function, inhibition and social skills. Again repeat testing of cognitive function over a few days will show generally similar results.  As the condition is long so the grieving for both person and family is long.  Remember you are not just looking after the person but the family and all the other important people in their lives.

I shall stop here. I really encourage you to read a guideline. If you want further information for dementia please do not hesitate to contact me or add a comment below.

Mini–Mental State Examination (MMSE) or Folstein test is a 30-point questionnaire that is used extensively in clinical and research settings to measure cognitive impairment.

 

Administration of the MMSE test takes between 5 and 10 minutes and examines a range of cognitive functions. It was originally introduced by Folstein et al. in 1975, in order to differentiate organic from functional psychiatric patients but is very similar to, or even directly incorporates, tests which were in use previous to its publication.

Advantages to the MMSE include requiring no specialized equipment or training for administration, and has both validity and reliability for the diagnosis and longitudinal assessment of Alzheimer’s Disease. Due to its short administration period and ease of use, it is useful for cognitive assessment in the clinician’s office space or at the bedside. Disadvantages to the utilization of the MMSE is that it is affected by demographic factors; age and education exert the greatest effect. The most frequently noted disadvantage of the MMSE relates to its lack of sensitivity to mild cognitive impairment and its failure to adequately discriminate patients with mild Alzheimer’s Disease from normal patients

Frontal Assessment Battery

The FAB is a brief tool that can be used at the bedside or in a clinic setting to assist in discriminating between dementias with a frontal dysexecutive phenotype and Dementia of Alzheimer‟s Type (DAT). The FAB has validity in distinguishing Fronto-temporal type dementia from DAT in mildly demented patients (MMSE > 24). Total score is from a maximum of 18, higher scores indicating better performance.

The FAB was developed in 2010 and takes about the same time as the MMSE to administer.

Addenbrooke’s cognitive examination

(ACE) is a brief neuropsychological assessment of cognitive functions and a development on the MMSE which it incorporates. The ACE is scored out of 100 possible points and takes significantly longer than the MMSE to administer.  Its was revised in 2010.

Rowland Universal Dementia Assessment Scale

The RUDAS was developed in Australia (Storey et al 2004) to overcome recognised cultural, educational and age-related constraints of other cognitive assessment tools. It also assesses a wider range of cognitive domains, particularly frontal lobe function, an early sign of dementia.  It takes about the same time as the MMSE to administer.

Montreal Cognitive Assessment (MoCA)

The MOCA was created in 1996 by Ziad Nasreddine in Montreal, Quebec. It was validated in the setting of mild cognitive impairment, and has subsequently been adopted in numerous other settings clinically.

The MoCA test is a one-page 30-point test administered in approximately 10 minutes (similar to MMSE). The test and administration instructions are also available for clinicians online. The test is available in 55 languages or dialects. There are alternate forms designed for use in longitudinal settings. There is also a basic form to test illiterate or subjects with lower education.

The MoCA assesses several cognitive domains and in some studies has been shown to be superior to the MMSE for detecting Alzheimer’s.

 

References:


1. Hunter New England Local Health District. Clinical Guidelines: Prevention, Recognition and Management of Delirium in the Older Person Version 2.0, 2015. Accessed from http://mylink.hnehealth.nsw.gov.au/pluginfile.php/83284/mod_resource/content/1/HNELHD%20CG%2013_04%20Delirium%20in%20older%20people.pdf on 30th March 2017.

2. European Delirium Association and American Delirium Society. The DSM-5 criteria, level of arousal and delirium diagnosis: inclusiveness is safer. BMC Medicine. 2014 (12):141. DOI: 10.1186/s12916-014-0141-2

Felicia Ng

Felicia Ng

Advanced trainee in general psychiatry and psychotherapies. Born and raised in Malaysia. Now an Australian with centre left leanings. Strong interest in social justice and human rights issues hence interest in psychotherapy and what it can do to facilitate healing in those who survived. I pay my respect to the traditional owners of lands I live and work on and elders past and present.
Felicia Ng

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