Mohammed T. Abou-Saleh

130 PRINCIPLES AND PRACTICE OF GERIATRIC PSYCHIATRYincluding some superficially unlikely offenders such as digoxin,non-steroidal anti-inflammatories and cimetidine. The anticholinergiceffects of phenothiazines, tricyclic antidepressantsand anti-Parkinsonism drugs commonly cause problems. Longeractingsulphonylureas may produce a state of chronic befuddlementin elderly patients, contrasting with the acute hypoglycaemicepisodes and prominent adrenergic symptoms usually seen inyounger diabetics. Stomach remedies, laxatives and diuretics maybring about mental changes through electrolyte disturbances andother mechanisms.Physical examination is rarely helpful if the patient is ‘‘well’’ butlocalized neurological signs should obviously raise suspicions of aspace-occupying lesion. The association of incontinence andataxia or gait apraxia with mental disturbance may suggestnormal pressure hydrocephalus, but there is considerable overlapwith cerebrovascular disease 51 . Similarly, signs of Parkinsonismmay be observed in patients with multi-infarct disease or diffuseLewy body disease, who are unlikely to benefit much from L-dopa. On the other hand, patients with the characteristic extendedposture and vertical gaze failure of progressive supranuclear palsymay respond to high doses of dopamine agonists 58 . If the mentaldeterioration was preceded by a fall or there is evidence of headtrauma, no matter how minor, suspicion of subdural haematomashould be aroused.Some investigations, such as serum B 12 folate, calcium, thyroidfunction and screening for syphilis, are cheap to perform and leadto simple, if not always effective, medical treatment if anabnormality is found. It should be remembered that neuropsychiatricdisorders caused by cobalamin deficiency 59 or folatedeficiency 60,61 can occur in the absence of haematological changes.On the other hand, the scientific evidence on which to base aneffective and economically realistic policy for the use of expensivebrain imaging techniques in people with dementia is still lacking.Since the ‘‘treatable syndrome’’ of normal pressure hydrocephaluswas first described by Adams et al. 62 in 1965, there hasbeen little agreement about the precise definition of the conditionor the indications for treatment. Ventricular enlargement, with orwithout periventricular leukoaraiosis and various degrees ofcortical atrophy, is a common CT finding in mentally normalold people, as well as those with dementia and other neuropsychiatricabnormalities. Clearly, it is not practical to monitor CSFpressure or to perform a lumbar infusion test in all cases,especially as such investigations do not always predict theresponse to internal shunting 63 . Common sense would suggestthat the response to repeated removal of CSF by lumbar puncturemight be the best predictor of long-term benefit from surgery, butthere again no systematic prospective study, let alone arandomized controlled trial, seems to have been done.Similar, although less profound, uncertainty surrounds thetreatment of subdural haematoma in the elderly. Here at least theCT scan should show a definite abnormality, but the relativemerits of surgical and medical treatment (or none at all) are notprecisely known. At the time of writing it is not possible to makelogical recommendations for the clinical assessment and investigationof elderly people with dementia, since the issues are stillsurrounded by a fog of confusion and prejudice. The costs ofinvestigation for all may be high, but they must be weighedagainst the enormous costs of institutional care and thepsychological, social and indirect costs of the burden on carers,a substantial part of which might be avoidable. Large-scale,pragmatic outcome trials are urgently needed.Depression and Functional IllnessIn operational terms, if not according to strict definition, thecommonest of the reversible dementias is so-called ‘‘depressivepseudo-dementia’’. Here the psychiatrist has more to offer, but thephysician is often involved because of the frequency of somaticsymptoms and physical disabilities manifested by elderlydepressed people. Indeed, when neither physicians nor psychiatristsare involved, people with potentially treatable illness canbecome heavy consumers of social services 64 or even residentialcare 65 . In this situation the psychiatric history and mental stateexamination are of paramount importance, although yet again thepossibility of adverse drug effects must be borne in mind. b-Blockers, methyldopa and benzodiazepine are often implicated 66 .Alcohol may be a cause or contributory factor and a simplescreening questionnaire, such as the CAGE, should be included inany medical or psychiatric assessment 67 . Physical examination islikely to be less rewarding. Although depression is a commoncomplication of many physical illnesses, the proportion of caseswhere it is the sole presenting feature is quite small. Nevertheless,the chances of finding physical disease in elderly depressedpatients are far higher than in their younger counterparts and itspresence has a substantial adverse effect on prognosis: indeed,severe intractable depression in old age is nearly always associatedwith chronic physical ill-health 68 . Secondary complications ofdepression, such as dehydration, nutritional deficiencies andconstipation, must be identified and treated. It is unlikely thatmetabolic disturbances such as diabetes or hypothyroidism will bediagnosed clinically, so the appropriate blood tests should be donein all cases. A high ESR or C-reactive protein level should warn ofthe possibility of tuberculosis, other infection or cancer. Anintensive search for occult neoplasia is rarely justified, although achest X-ray should be done in any patient whose symptoms do notrespond rapidly to treatment. Once again, the role of CT scanningwill remain unclear until prospective studies of representativegroups of old people presenting with clearly defined psychosyndromeshave been reported. Finally, it should be rememberedthat the goal of clinical assessment in elderly patients is rarely tomake a single unifying diagnosis. Multiple pathology is the rulerather than the exception and unusual combinations of symptomsor signs are more likely to be due to the combined effects ofseveral common diseases rather than one rare one. The reducedhomeostatic reserves of old age also means that a single initialinsult (or treatment) often begins a chain of metabolic disturbancesthat multiply, leading to a cascade of complications.Thus, whatever the primary event, the clinician is often faced witha range of problems as well as pathophysiological diagnoses.Mental disturbance may therefore be seen as just one aspect of acomplex multi-system disorder, but few would dispute that it isone of the most interesting and challenging of all.REFERENCES1. Lipowski ZJ. In Delirium: Acute Confusional States. New York:Oxford University Press, 1990; Ch 1.2. Engel GL, Romano. Delirium, a syndrome of cerebral insufficiency. JChron Dis 1999; 9: 60–77.3. American Psychiatric Association. 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