Mohammed T. Abou-Saleh

CLINICAL ASSESSMENT AND DIFFERENTIAL DIAGNOSIS 499confidant(e) as another’s presence may equally inhibit orencourage the disclosure of sensitive material. For similar reasonsan informant may wish to speak privately though discussionsshould never appear clandestine.Deafness and communication problems should be openlyacknowledged, hearing aids worn and working, and extraneousnoise eliminated, otherwise false impressions of cognitive statemay be formed 41 . If a patient is seen in a hospital setting, insist ona separate, quiet interview room, otherwise conversation will beinhibited and information lost. Posture and attitude conveysincerity, concern and how seriously problems are considered. Thepatient needs to form a trusting relationship, and a respectful,honest but never patronizing approach is normally accepted. Asympathetic hand can reassure and encourage an anxious orsuspicious patient.The importance of establishing a positive therapeutic relationshipat this early stage cannot be overstated, as it can have farreachingeffects, not only for the openness of discussion but alsofor future compliance and prognosis 12 .HistoryThe nature of psychotic symptoms, their form, content and coursemust be detailed. Late-onset schizophrenia may develop insidiouslyover months or a year or more 2,3 , delusional depressionover a few months, delirium over days and dementia over 1–2years. The intensity of paranoid ideas and their effect onbehaviour assist diagnosis and the evaluation of risk. Associatedsymptoms, particularly affective and cognitive, should then beelicited.Current and past medical problems and their temporalrelationship to the onset of paranoid symptoms must be clearlyestablished, including visual or auditory failure. Aetiologicallysignificant hearing loss in late-onset schizophrenia is typically oflong duration, severe and due to bilateral middle ear disease, oftenoriginating in early life 42–45 . Details of prescribed and nonprescribeddrugs, dosages and recent alterations are essential.Previous episodes of mental disorder should be confirmed frommedical records, when past diagnoses and response to treatmentmay quickly clarify a diagnostic dilemma. Careful enquiry mightuncover past episodes of untreated, self-limiting illness 3,31 andchanges in behaviour may date the onset of current problems.Premorbid personality and behaviour are important becausedepartures from these in old age usually signify the onset of amorbid process. Forty to fifty per cent of late-onset schizophrenicshave schizoid or paranoid premorbid traits 2,3 and the diagnosis ofpersonality disorder depends on establishing a life-long attitude,Brenes Jette and Winnett 46 emphasized the interaction ofnarcissistic personality traits and the psychosocial consequencesof ageing in their psychodynamic formulation of late-onsetparanoid disorder.The genetic loading of schizophrenia in old age is less markedthan with younger patients but a positive family history isoften found 2,7,20,47 . Odd behaviour or suicide among familymembers may be discovered when formal psychiatric treatmentis absent.Current social circumstances and recent change are of relevanceto aetiology and management. The schizophrenias of late life areparticularly associated with social isolation, but rarely withprecipitating life events 2,3 . Paranoid patients frequently havepoor socioeconomic status and multiple difficulties 13 and socialsupport has prognostic implications 12 . Enquiring about alcoholand drug abuse must not be avoided for fear of offending arespectable elderly person. The elderly are not without vice andmay be less inclined to confess it.Mental State ExaminationThe detailed psychopathology of these conditions is describedelsewhere and only points relevant to the process of mental stateexamination will be mentioned here.It is important to ensure that the patient understands theterminology used to elicit abnormal experiences and that acommon language is being used. Eliciting paranoid and psychoticsymptoms can be difficult, but with tact and careful choice ofwords most patients will participate in an exchange of ideas abouttheir experiences. This must be an unthreatening process for thepatient and it is unwise to challenge or trivialize complaints at anearly stage. A neutral position is advisable until a firm relationshipis established, when complaints may be gradually reframed so thatthey can be viewed by the patient as problems that can be relieved,rather than immovable realities that are not amenable totherapeutic intervention. Suggesting that ‘‘it’s all imagination’’will be considered insulting and the patient’s confidence will belost.Insight is rarely retained and patients may not volunteerexperiences if they interpret questions as purely an enquiry intothe state of their health. Patients have limited ability to accept thepresence of illness or recognize psychiatric experiences aspathological 48 . Needless to say, the mental state examinationmust be thorough.Physical ExaminationA complete physical examination should be performed routinely,with particular emphasis on neurological status and sensoryfunction. The association between sensory impairment and lateonsetschizophrenia 44,49 makes attention to this area importantand remediable conditions may be found. Visual impairment,particularly due to cataracts, is often found in association withdelusions and deafness 43,50 and visual hallucinations may be asmuch to do with ocular pathology as psychiatric diagnosis 51 .Aparticular form of acute, elaborate visual hallucinosis, theCharles–Bonnet syndrome, is usually related to eye disease orcerebral organic disorder 52 . Simple clinical interview and selfreportingseriously underestimate sensory impairment and moredetailed ophthalmic and audiometric examination may benecessary 53–55 . A simple battery of laboratory investigations isrequired for all patients, including haematology, biochemistry,thyroid function, urinalysis and chest radiography.Advanced neuroradiological techniques promise much for thefuture but have limited clinical application at the present time.Some authors recommend the routine use of computedtomography (CT) and MRI. These procedures frequently revealstructural cerebral abnormalities, including increased ventricularsize and periventricular and deep white matter hyperintensities56,57 , although their clinical significance is uncertain 58,59 andthey appear to bear little relationship to clinical state oroutcome 60,61 . These findings have no diagnostic value and therole of neuroimaging in clinical practice, at present, is toexclude specific intracranial pathology, particularly spaceoccupyinglesions suggested by clinical examination. Similarly,non-specific electrophysiological abnormalities are common 5and the EEG will only be of value in a minority of cases.Psychometric testing may provide a useful baseline measurethat can be serially repeated when the possibility of dementiaarises 62 . Psychometric testing certainly reveals cognitive deficits inlate-onset schizophrenic patients, particularly affecting frontallobe and memory function 56 . These rarely signify dementia 60 andare more like the deficits found with early-onset schizophreniathan Alzheimer’s disease 56 . They do not correlate with severity ofpsychosis or other clinical parameters 60,62 .