Dementia with Lewy bodies

Abstract

Clinical Medicine. 1 In my own practice I have seen a similar case. A diagnosis of dementia with Lewy bodies (DLB) was suspected based on clinical history, collateral history and clinical examination, previous episodes of delirium, lack of response to treatment of identified causes of delirium and the protracted nature of the delirium. The patient was too unwell to undergo a dopamine transporter scan and the patient was trialled on rivastigmine with an excellent response. The patient was discharged home. The published case highlights various aspects of the management of delirium. It is worth referring to the recently published Scottish Intercollegiate Guidelines Network (SIGN) guideline for risk reduction and the management of delirium. 2 The recommended tool for detection of delirium is the 4AT based on a comparison of different tools, and the National Institute for Health and Care Excellence (NICE) quality standards for delirium recommend assessing all those at risk newly admitted to hospital or long-term care. 2,3 It is worth noting that the investigation of acute and chronic cognitive impairment differ. For delirium the SIGN guidelines recommend good history, collateral history, clinical examination (including neurological) followed by basic and targeted investigations. The recommendation for computed tomography brain relates to various ‘red flags’ in the acute situation and for further consideration of brain imaging in the case of non-resolving delirium or where there are features to suggest primary nervous system pathology. Similarly, the NICE guidelines for dementia have clear guidance on assessment and investigation strategy in suspected dementia, which includes recommendations around imaging. 4 Some of the investigations listed in the approach to investigation by Akintade and Pierres, for example, autoantibodies would be appropriate only when a cause for delirium has not been found, the presentation is unusual or when not resolving as was the case for the patient presented. It is also worth emphasising that anti-psychotics would not be recommended first line in the management of delirium unless there is intractable distress, risk of harm to the patient or others and when benefits of these medications outweigh potential harms. Non-pharmacological treatment options should always be implemented first, use of more than one pharmacological agent would not be recommended, and it should be noted that only haloperidol is licensed for use in delirium when used without other drugs that prolong QT interval on electrocardiogram. 2 I would also like to highlight that it has been increasingly recognised in the literature that in some cases of delirium there may be a diagnostic opportunity for DLB. 5,6 It has been suggested that a delirium-like illness may be a prodrome to a diagnosis of DLB. 7 This presentation by Akintade and Pierres is welcome in that DLB as a differential diagnosis for delirium that fails to resolve or is recurrent is highlighted. ■