Mohammed T. Abou-Saleh

Principles and Practice of Geriatric Psychiatry.Editors: Professor John R. M. Copeland, Dr Mohammed T. Abou-Saleh and Professor Dan G. BlazerCopyright & 2002 John Wiley & Sons LtdPrint ISBN 0-471-98197-4 Online ISBN 0-470-84641-045Clinical Features of Senile Dementiaand Alzheimer’s DiseaseBrice PittSt Mary’s Hospital, London, UKNot all dementias in the senium are forms of Alzheimer’s disease(AD), neither does AD always arise in the senium. However, thecommonest form of senile dementia and of AD is senile dementia ofthe Alzheimer type (SDAT). In most countries this alone is thoughtto account for 50–60% of the senile dementias and, in a formmixed with multi-infarct dementia (MID), for another 15–20% 1 .Alois Alzheimer originally described 2 a 51 year-old womanwhose morbid jealousy was followed by a rapidly progressingamnesia. She displayed paranoid delusions and, it seemed,auditory hallucinations as well as such cognitive defects asdisorientation, incomprehension, perseveration, dysphasia, dysgraphiaand dyspraxia. She died only 4.5 years after the onset ofher disorder, when Alzheimer was enabled to make theneuropathological observations that later caused his name to begiven to the disease. Thus ‘‘psychiatric’’ as well as cognitivesymptoms were part of the syndrome from the first. Personalitychange and behavioural disorder are also part of the condition,especially in those referred to psychiatrists.Most diagnostic criteria for dementia and AD, e.g. theAmerican Psychiatric Association’s Diagnostic and StatisticalManual, 3rd edn, Revised 3 and those of the Royal College ofPhysicians 4 , require some degree of disability. The operationaldiagnostic criteria for dementia in the Cambridge Examinationfor Mental Disorders of the Elderly 5 include ‘‘Progressive failurein performance at work and in the common activities of everydaylife—The decline in memory is sufficiently severe to impairfunctioning in daily life’’.Presumably there must be some period of minimal impairmentbefore the disorder becomes disabling, but it is still unclear whatare the very earliest features of AD, in its senile or presenile forms.Sufferers tend not to be brought to the notice of the medical orsocial services until problems arise that jeopardize self-care orstrain relationships, when the disease has usually been developingfor at least 2 years. Epidemiological surveys using such screeninginstruments as the Mini-Mental State Examination 6 have,however, identified some people with mild or borderline cognitiveimpairment, as have the memory clinics which have beendeveloped in recent years 7 , and some of these have been shownlater to have developed dementia. The distinction between thosesuffering from Kral’s 8 ‘‘benign senescent forgetfulness’’ (BSF) orCrook’s 9 ‘‘age-associated memory impairment’’ (AAMI), both ofwhich advance very gradually, if at all, and early AD is not veryclear. In a Cambridge field study 10 about half of those with mildmemory impairment later developed dementia, but it would havebeen hard to predict which. Among BSF subjects at the MaudsleyMemory Clinic 11 , however, there was a tendency for men andthose whose forgetfulness was noticed by others subsequently todevelop dementia.ORGANIC DISORDERSThe start of AD is usually manifest in memory impairment:1. Things are mislaid at home, cannot be found in their oncefamiliar places, or are left behind at home, in shops or in cars,buses and trains.2. There is an increasing need to check that things have beendone and reliance on aides-memoires; even so, appointmentsand plans are forgotten.3. The same remarks are made and the same questions askedagain and again, and conversation rambles on irrelevantly.4. Recent information and activities are forgotten and messagesare not passed on.5. The start of a story is forgotten before it is over, so it isdifficult to follow plays, films, books or news.6. New locations, as when on holiday, are not learnt easily, andthe patient may get lost.7. Some things may be done twice over, like feeding an animal orcleaning teeth, and others not at all, like paying bills or takingneeded medication for, say, heart-failure or diabetes.At a later stage:8. Once-familiar faces and places and locations seem lessfamiliar, and eventually the sufferer may be lost in his/herown neighbourhood or even in his/her own dwelling.9. The nearest and dearest may not be recognized, and treatedas strangers, while true strangers may be greeted warmly asold friends or family.10. The day, and the time of the day, are forgotten, and thepatient may go shopping in the middle of the night, and beunable to find his/her own home on returning.11. Sometimes the patient no longer knows his/her age orbirthday, or that his/her parents are no longer alive, and hasindeed entered upon a ‘‘second childhood’’.Language impairment is usually regarded as a later feature ofAD 12 . The sequence of deterioration begins with tasks, such asnaming, which use the semantic system, concerned with themeaning of words. There follow deviations and simplifications ofsyntax (grammar), and then phonemic breakdown (disordered useof sounds) 13 . One study 14 found more deficits on the BostonNaming Test than the Mini-Mental State Examination in earlyPrinciples and Practice of Geriatric Psychiatry, 2nd edn. Edited by J. R. M. Copeland, M. T. Abou-Saleh and D. G. Blazer&2002 John Wiley & Sons, Ltd