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inside Recognising dementia Excluding reversible pathology History and cognitive examination Determining the type of dementia Managing the disease and complications

The author DR BRUNO FRANCHI consultant, department of geriatric and rehabilitation medicine, Royal Adelaide Hospital, Hampstead Hospital and Calvary College Grove Rehabilitation Hospital, Adelaide; and lecturer in geriatrics to Spencer Gulf Rural Health School.

Dementia Background DEMENTIA is common. As the population ages, the incidence and prevalence of degenerative diseases increases. One in every 100 people over 65 will develop dementia, and the older the age group the higher the prevalence. At age 80, one in five people are affected. Some individuals will never develop dementia regardless of their age. There are several different causes

of dementia. The clinical expression of different dementias often overlaps, making a definitive diagnosis before death difficult. Most forms of dementia are relentlessly progressive neurodegenerative diseases that have no disease-modifying treatment. Available treatments aim to maintain the patient’s quality of life and the sanity of the carers. The difficulty in assessing and

managing dementia is highlighted by the fact that even the experts get it wrong. The clinical sensitivity for correctly diagnosing Alzheimer’s type dementia is about 70% and the specificity is also 70%. Dementia with Lewy bodies is much more difficult to diagnose, because it often masquerades as Alzheimer’s dementia. Clinically differentiating these syn-

dromes is important. Dementia with Lewy bodies tends to progress more rapidly and may be more sensitive to acetylcholine esterase therapy. However, only 25% of patients with dementia with Lewy bodies exhibit the characteristic clinical features, which leaves a significant proportion diagnosed and treated as Alzheimer’s dementia. At present, autopsy is the cont’d page 27

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References: 1. Prexige (lumiracoxib) Australian Product Information. 2. Tannenbaum H, et al. Ann Rheum Dis. 2004;63:1419-1426. 3. Fleishmann R et al. Clin Rheumatol. 2005;25:42-53. NOVPRE0204/PRX236807

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Figure 1: The clinical process surrounding the evaluation of a patient who may have dementia.

most accurate method of diagnosing dementia. Two other syndromes that are difficult to differentiate clinically are fronto-temporal dementia and Alzheimer’s dementia with frontal features. As therapy with acetylcholine esterase inhibitors (AChE-Is) tends to cause deterioration of function in patients with fronto-temporal dementia, it is important to exclude this diagnosis. There can be subtle differences in the presentation of these patients that may give clues to the diagnosis. Steps that can assist in diagnosing and managing dementia (figure 1) include: ■ Recognising the presence of dementia. ■ Excluding reversible pathology. ■ The clinical interaction — history and cognitive examination. ■ Determining the type of dementia. ■ Managing the underlying disease process. ■ Managing complications of the disease process. This article looks at each of these steps and also at possibilities for the future.

Recognition of the presence of dementia Exclusion of reversible pathology Clinical assessment Determine the type of dementia

Alzheimer’s dementia Eligibility for treatment with acetylcholine esterase inhibitors; supportive treatment as required

Vascular dementia Management of vascular risk factors

Other forms of dementia Supportive treatment as required

Contact with support services (eg, Alzheimer’s Australia, Metropolitan Domiciliary Care)

Recognising dementia THE first step in evaluating a patient with memory complaints is deciding whether or not there is cognitive impairment and whether this impacts on their function. It is important to recognise the features of ‘normal ageing’ and the spectrum that ranges from mild cognitive impairment to dementia.

Table 1: Normal changes in cognition with age ■

Decrease in episodic memory

— Learning and retention difficulties — No problems with retrieval ■

Preservation of implicit memory

— Ability to perform a previously learned skill without difficulty ■

Preservation of reading abilities

— May be mild changes in verbal fluency, naming and word comprehension

Normal ageing

of these changes with the onset of dementia.

Unfortunately our brains do not cope well with time. Expected normal agerelated changes in cognitive function are listed in table 1. There is no association

Mild cognitive impairment Mild cognitive impairment refers to a syndrome that

may pre-date the development of dementia. Other titles that have been given to this clinical entity include age-associated memory impairment and age-related cognitive decline. They describe a syndrome of objective memory impairment that does not significantly affect activities of daily living. On both history and examination it is clear there are problems with short-term recall, but no other cortical dysfunction can be elucidated. Recognising mild cognitive impairment is important, because a significant

proportion will progress to Alzheimer’s dementia (about 10-15% a year, cumulative for about five years). About 25% will not have developed dementia at the five-year mark. Studies have investigated the early use of AChE-Is in patients with mild cognitive impairment, but no differences in the progress of disease was found in treated or control groups.

Alzheimer’s dementia Alzheimer’s-type dementia is the most common cause of dementia. It is characterised pathologically by the

presence of amyloid plaques and neurofibrillary tangles, both of which are end products of defective amyloid processing. The diagnosis of Alzheimer’s dementia relies on one important fact — the condition affects more than memory alone. In addition to memory impairment affecting function, there must be another area of cortical dysfunction, or ‘domain’. Domains often explored during historytaking include impairments in calculation, language, visuospacial, sequencing, judgment or initiation.

Excluding reversible pathology 1

INSEL and Badger (2002) suggested the concept of “the four Ds of cognitive dysfunction” — depression, delirium, dementia and cognitive decline (normal agerelated changes as described above). This provides a simple framework to apply clinically when initially assessing a patient.

Delirium and the ‘dementia screen’ The features of delirium include short attention span, difficulty concentrating, hallucinations, delusions and a fluctuating con-

scious state. It can be difficult to differentiate delirium from dementia with Lewy bodies, as they can appear clinically very similar. If these symptoms are acute in onset, the diagnosis of a delirium is more likely. The classic teaching in a patient with memory impairment is to perform a dementia screen to exclude causes of an acute or subacute delirium. This includes a CT of the head (to exclude tumours, strokes and subdural haematomas, among other things), serum B12, folate, calcium, electrolytes, urea and creati-

Table 2: The dementia screen (subacute delirium screen) ■

Structural imaging: CT head scan



Blood tests: FBC, EUC, LFTs, B12, folate, calcium, thyroidstimulating hormone



Urine examination: midstream urine sample; microscopy, culture and sensitivity



High-risk patients: syphilis serology, HIV testing

nine levels, LFTs, thyroid function, FBC and urine examination (table 2). MRI may be used rather than CT for volumetric measuring of the hippocampus and vascular pathology. However, a CT alone is adequate.

Depression Depression (pseudo-dementia) is excluded by considering the quality of interactions, sleep and appetite, psychomotor retardation and the presence of a mood disorder.

Collateral history from family and friends and the mental state examination, along with the Geriatric Depression Scale and Foldstein’s Mini-Mental State Examination (MMSE) are useful to help exclude depression. Excluding depression is not an easy task. It is impossible to differentiate pseudo-dementia from dementia, as they commonly coexist. Reassessment after a trial of medication may be warranted. It is useful to obtain the opinion of a psychiatrist or psychogeriatrician, if available.

The clinical interaction — history and cognitive examination Assess the degree of cognitive impairment A USEFUL method to build rapport and begin to evaluate memory in a non-confronting manner, is to start by establishing where and when the patient was born, then work forward through their life to the present. Ask: ■ Which school they attended. ■ What work they performed. ■ When and where they were married. ■ When their first child was born. ■ How many children this child now has, how old they are at the moment

and what the grandchildren are doing. ■ Whether there are any great grandchildren.

Watching them access their memory banks for recent tasks gives clues to the presence of dysfunction. In those who maintain they watch the news or read the paper it is then useful to go on to test recent events. For example: ■ Who is the Prime Minister and the US president. ■ The death of Steve Irwin, what he did, how he died, how many children he had. ■ Changes to the Labor Party leadership. ■ The cricket or football results. If they watch television,

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it can be useful to ask what has been happening in their favourite programs. All questions must be asked within the social context. In most cases patients initially have some insight into the memory problems; however, it is usual to lose this insight as the disease progresses, resulting in a poor appreciation of the severity of their problems. It is useful to obtain history from family members and friends. History from others should ideally be taken without the patient present, as family’s concerns often will not be voiced in the

presence of the loved one. It is important to try to establish the relative’s view of the effect of memory impairment on a person’s function.

Functional assessment — the impact of cognitive impairment Functional problems include (from mild to severe impairment): ■ No longer being able to manage finances. ■ No longer sending out birthday or Christmas cards. ■ Disorientation as to which day it is. cont’d next page 6 April 2007 | Australian Doctor |

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How to treat – dementia from previous page

Forgetting appointments. ■ Disorganised cooking. ■ Disorientation when driving. ■ Problems with shopping. ■ Forgetting to lock the doors. ■ Problems with clothes washing. ■ Disorientation at night. ■ Muddling up medications. ■ Fear of leaving the home. ■ Delirium with operations or illness. ■ Problems finding the right words. ■ Withdrawal from conversations and social interactions. ■ Behavioural or personality changes. ■ Need for help with dressing. ■ Forgetting to shower ■

(Toward the severe end of the spectrum) Urinary and faecal incontinence and disorientation in the home environment. Finally, it is important to ask about physical or verbal aggression, as this is not often volunteered by the family when it occurs.



Objective evaluation — screening tests An objective assessment should follow the subjective assessment. By now it is usually clear whether cognitive dysfunction is present. Despite Foldstein’s initial design of the MMSE as a screen for the presence of Alzheimer’s dementia, it has attained roles beyond this. Primary language and edu-

cational level affect the results. Some feel it can objectively monitor the presence, severity and progress of dementia.

As the PBS requires an MMSE score for prescription of an AChE-I, the MMSE score has attained the status of a disease-severity marker. In practice, in most cases a person’s level of function can be extrapolated with clear differences when comparing scores of 25. However, there is little evidence behind this and it is merely a clinical observation. Typical early changes in the MMSE in Alzheimer’s dementia include recall and orientation difficulties. Depressed patients have trouble engaging, and a lack of desire to perform the task. This differentiates depression from dementia where patients will try but

not be able to perform the task. Delirious patients fail to engage because of short attention spans, and are very easily distracted by things happening in the background. Other cognitive tests that can be used if Foldstein’s is inappropriate include the Rowland universal dementia assessment scale (RUDAS, developed in NSW), the Alzheimer's disease assessment scale, cognitive sub-scale (ADASCog) and the clinician’s interview-based impression of change (CIBIC). The ADAS-Cog and CIBIC are the only tests besides the MMSE acceptable to the PBS for use in the monitoring of response to AChE-Is.

Determining the type of dementia WHEN dysfunction has been established it is important to identify the cause (table 3), as this provides some indication of prognosis. In general the rapidity of progression is unpredictable. However, in broad terms the time of diagnosis of Alzheimer’s to the time of death is about 10 years. Dementia with Lewy bodies tends to be more rapid, and fronto-temporal dementia more rapid again (with about five years from diagnosis to death). Vascular dementia is unpredictable and varies among individuals. The usual cause of death from a dementing process is from recurrent aspiration pneumonia, as swallowing dysfunction is common. It is not uncommon to see malnutrition toward the end of the disease process (see page 29). Recognising and treating malnutrition is important if it is related to access to food. When considering the rate of disease progression, it is always important to remember that rapidly progressive dementia (over the space of weeks) may represent idiopathic or acquired CreutzfeldJacob disease. Death in this disease may occur within three months of the diagnosis of dementia. CSF examination is useful in making this diagnosis.

Alzheimer’s dementia Alzheimer’s disease is the most common cause of dementia. The primary requirement for the diagnosis of Alzheimer’s dementia is memory impairment associated with at least one other domain affected. It has usually been present for 12-18 months before patients present for specialist opinion. Early on in Alzheimer’s disease there is a deficiency of acetylcholine production; however, multiple neurotransmitters are affected, which explains why increasing acetylcholine alone does not provide an answer. Inherited rare forms of Alzheimer’s dementia occur at younger ages (often in the 40s or 50s).

Dementia with Lewy bodies Dementia with Lewy bodies has several features in common with Alzheimer’s disease and delirium. The characteristic features are:

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with Parkinson’s disease than we recognise. Cognitive dysfunction occurring more than two years after the diagnosis of Parkinson’s disease is most likely related to the Parkinson’s disease rather than a separate process. Cognitive dysfunction before this time may be dementia with Lewy bodies or Alzheimer’s disease.

Table 3: Relative frequencies of the causes of dementia when diagnosed before death ■

Alzheimer’s disease 65%



Vascular dementia 15%



Dementia with Lewy bodies 10%



Fronto-temporal dementia 5%



Dementia of Parkinson’s disease