Assessment and Differential Diagnosis
These are the approved guidelines published by the South African Society of Psychiatrists to provide an overview on treatment and management of commonly diagnosed psychiatric illnesses. The guidelines include consensus recommendations, based on peer contribution and using the international evidence based guidelines that are suitable for the local South African health service.
Please note that parts of this guideline may be out of date, an update will be published as soon as it is available.
Assessment of neuropsychiatric symptoms
Mild cognitive impairment
Of note is that up to one-quarter of elderly present as ‘doddery’, falling into the realm of mild cognitive impairment (MCI), also known as age-associated cognitive decline. Here the MMSE score is around 27/30. Cognitive function is not impaired to the point where it interferes significantly with daily social or occupational functioning, but may well do so over the next 2 - 5 years, when an estimated 30% of this category are known to go on to exhibit dementia. These patients need to be re-evaluated at regular intervals.
Depression and delirium
At this stage of diagnostic screening dementia must be distinguished from depression (primarily a mood disorder with very little disturbance in cognition), and delirium (a transient organic disorder hallmarked by a global cognitive impairment as well as disturbance in consciousness and attention/concentration deficit). In addition there is a reversal of the sleep-wake cycle. In the elderly, depression and delirium may frequently coexist with AD or herald its presence, and both require management in their own right. Delirium constitutes a medical emergency.
Good collateral information from a reliable family member, friend or caregiver is crucial. A detailed history and thorough physical examination including blood (‘organic work-up’) and urine tests not only distinguish AD from depression and delirium, but also help to differentiate AD from other types of dementia. A review of all current prescribed medications and over-the-counter preparations, with particular emphasis on those impacting on central nervous system functions, is essential.
Assessment of neuropsychiatric symptoms
This is discussed below.
COGNITIVE ASSESSMENT: THE MINI MENTAL STATE EXAMINATION
Ascertain the degree of cognitive impairment by administering the MMSE,[12] which was designed to distinguish dementia from depressive pseudo dementia. While one or two mistakes are allowed, the nature of these mistakes is of importance (e.g. an accountant failing to do the serial sevens). An MMSE score of 27 generally indicates MCI. In mild AD (MMSE range 21 - 26) there is short-term memory impairment, often accompanied by symptoms of anxiety and depression. Moderate AD (MMSE range 11 - 20) is characterised by neuropsychiatric phenomena such as visual hallucinations, false beliefs, restlessness and disturbed sleep patterns. Severe AD (MMSE range 0 - 10) is characterised by prominent cognitive decline, motor signs and the onset of loss of sphincter control.
While depressed patients will still obtain a high MMSE score, an MMSE score of 26 or less out of 30 is strongly indicative of dementia, where the patient has had at least 7 years of schooling. AD patients lose on average some 2 - 3 points on the MMSE per year, and progress can thus be tracked by re-administration of the test at 3 - 6-monthly intervals. There is no time limit for the completion of the test.
Note that a person with dementia may achieve an MMSE score of 30 out of 30 with some difficulty, while still holding a high position in working life. This function is support-staff dependent.
FUNCTIONAL ASSESSMENT: ACTIVITIES OF DAILY LIVING
Cognition and behaviour also impact on the patient’s level of function.[13] This determines whether patients can still perform more complicated tasks such as taking their medication, difficult household chores, shopping, cooking and finances (instrumental activities of daily living (IADL)) or only wash, dress, feed and toilet themselves (basic activities of daily living (BADL)).[14] The watershed between IADL and BADL usually occurs at an MMSE of 16 out of 30,[15] while urinary incontinence occurs at a score of around 8.
Driving
Driving a car relies on implicit memory, praxis and executive functioning. In the early stages of the illness patients can still drive a car because these abilities are still relatively intact. With time, however, they are unable to pay attention to all aspects of driving and often become impulsive or exercise the wrong options. Note that if the dementia renders the person incapable of driving and controlling a vehicle safely, he/she is medico-legally disqualified from driving. Doctors have a legal obligation under the National Road Traffic Act 1996 (Act 93 of 1996) to report such individuals to the traffic authorities.[16]
In general:
- Assess all cases on individual merit.
- Patients must drive in conditions affording good visibility and then in day time only, on non-busy suburban roads and always accompanied by a caregiver.
- Their MMSE should be at least 20-22/30 or above and they must still be able to do the pentagon test (which tests for visuospatial ability) or trail-making B.
- Re-assess at 3-monthly intervals.
Firearms
Similarly gun licenses should be revoked for the same reasons.
Financial affairs and wills
Should the patient be incapable of handling her/his own financial affairs, urge a reliable and trustworthy member of the family to take control of the situation. Transfer of authority by means of power of attorney works well in early dementia where competency is still preserved. Failing this, or where no family members are available, curatorship should be sought. The forms are obtainable from the court who will appoint a curator bonis to attend to the patient’s affairs based on the recommendations of a psychiatrist and medical officer/general practitioner. Social workers and occupational therapists who are well-versed in these matters may have to be called in for advice and help with these cases. A patient who has not yet written a will or testament but now wishes to do so should be referred to a psychiatrist in order to establish testamentary capacity.[16]
Social assessment
A thorough social evaluation is of the utmost importance when assessing a dementia patient. The social assessment includes information regarding where the person lives, living circumstances, relevant family members and caregivers, and the extent of coping of both patient and caregivers, employment (if relevant) and economic resources, and degree of additional social support, as well as medicolegal matters.
Elder abuse
Awareness of abuse in the area of financial resources and the administration of the patient’s affairs is of paramount importance. It should be determined who draws, administers and dispenses the patient’s financial resources and pension.
Elder abuse includes physical abuse as well as ‘acts of omission’ or negligence leading to the detriment of the health and well-being of the person. This would include physical, psychological, financial and material aspects. Examples would be the denial of food, visits, medication, clothing and other essentials. Note that sexual abuse and incest also occur.
Cases must be reported to Halt Elder Abuse Line (toll free 0800003081) for investigation and management.
Comorbid medical conditions
Patients with dementia commonly have comorbid medical conditions such as depression, cardiovascular and pulmonary diseases, infections, arthritis, sleep disturbances, falls, incontinence and drug-related adverse events, among others. There is a strong association between medical conditions and impaired cognition in AD.[17]
People with dementia, particularly those who live alone, are at risk of inadequate nutrition and dehydration. Both of these factors can contribute to the development of neuropsychiatric symptoms (NPS). The propensity to develop subsequent bronchopneumonia or urinary tract infection is very high.
Comorbid medical conditions need to be optimally managed, especially vascular risk factors which may be contributing to the dementia by exacerbating any vascular disease. Regular medication review is mandatory as is the supervision of medication by a responsible caregiver.
Investigations
Cost restraints and other practicalities often dictate the number of investigations that can be performed. Generally, in a typical or advanced case of dementia, investigations have little to offer towards treatment. A ‘positive’ result is more likely to be obtained when:
• The patient is less than 65 years of age
• Onset has been recent and the course rapid
• Course of disease fluctuates markedly
• Physical examination reveals a neurological deficit.
Special investigations help to improve or rule out treatable contributory and exacerbating causes of dementia. The full ‘organic work-up’ entails a full blood count, plasma viscosity, urea and electrolytes; thyroid, liver and parathyroid function tests, random blood sugar, niacin, vitamin B12, red cell folate and lipogram. C-reactive protein (CRP) levels may be indicated. Additional tests include syphilis serology, HIV and urine dipstick (this also helps to exclude a concurrent urinary tract infection).
More specialised investigations encompass a CT or MRI scan (with measurements of the medial temporal lobes) as well as psychometric testing. Single photon-emission CT results often settle diagnostic speculation.
Assessment by a trained neuropsychologist may be required when the cognitive impairment is very mild or does not conform to an expected pattern.
The trimmed-down version of the ‘organic work-up’ consists of the following only: haemoglobin, mean cell volume, white cell count and platelets; glucose; potassium, sodium and urea/creatinine; thyroid-stimulating hormone; albumin and gamma-glutamyl transferase (γGT); calcium; vitamin B12; total cholesterol; syphilis serology and urine dipsticks.[10]