Care of the elderly - Special interest

Lewy body dementia is a heterogeneous condition that is often difficult to treat. It is associated with higher rates of neuropsychiatric symptoms, inpatient admission and carer stress, as well as shorter survival, than other dementia subtypes. Core clinical features are: fluctuating cognition with pronounced variations in attention and alertness; recurrent visual hallucinations; REM sleep behaviour disorder; one or more features of spontaneous parkinsonism. Recurrent visual hallucinations occur in up to 80% of patients.

In older adults, the prevalence of anxiety disorders is higher among those with other health problems, and those in hospital and care settings. A primary depressive disorder should be excluded whenever an older person presents with anxiety symptoms for the first time, and comorbid anxiety often indicates a more severe presentation of depression. Around four in five patients have a comorbid physical disorder. Medical conditions can mimic symptoms of, predispose to, or even directly precipitate an anxiety disorder, and may colour its symptomatology or limit treatment options.

Late life psychosis may be caused by organic conditions including: delirium, dementia, drug intoxication or withdrawal, or a general medical condition. In these situations there should be evidence of a temporal relationship between the psychosis and the underlying condition. Around 60% of older adults presenting with new onset psychosis have an identifiable underlying organic cause. If an underlying medical condition can be excluded, and there is no evidence to support a diagnosis of delirium or dementia, then the cause of psychosis may be functional. This is more likely if there is a family or personal history of mental illness.

Depression in older adults is common. Depressive symptoms may be part of a recurrent depressive disorder or experienced for the first time in later life as a result of changes in risk and resilience factors. There is an association between cerebrovascular pathology, vascular risk factors and depression. Physical illnesses, particularly those associated with frailty, are also important risk factors for depression. Depression has a distinct presentation in late life and low mood may not be the predominant presenting symptom. Older patients may present with physical symptoms, apathy, cognitive symptoms, agitation, retardation, fatigue or weight loss.

Vascular dementia is the second most common type of dementia, after Alzheimer’s disease, and accounts for 15% of cases. The core diagnostic features include cognitive impairment in at least two domains (orientation, attention, language, visuospatial function, executive function, motor control and praxis), which affect social or occupational function, together with evidence of cerebrovascular disease (focal neurological signs or neuroimaging). Crucially there should be a temporal relationship between cerebrovascular disease and the onset of cognitive changes.

Depression and dementia are both common conditions in older people, and they frequently occur together. Rather than a risk factor, depression with onset in later life is more likely to be either prodromal to dementia or a condition that unmasks pre-existing cognitive impairment by compromising cognitive reserve. The distinction between depression and early dementia may be particularly difficult. Detailed histories obtained from patients and their relatives as well as longitudinal follow-up are important.