Screening for REM sleep behaviour disorder to improve consideration of dementia with Lewy bodies

By Dr Rachel Moir, Dr Ruth-Pye Jones, Dr Amit Sindhi, and Dr Boben Benjamin

A quality improvement project conducted in Trafford (Greater Manchester Mental Health Trust), as part of the Dementia Academy 'Mild cognitive impairment virtual course' which ran from March-September 2021.


Lewy Body Dementia (LBD) is believed to be underdiagnosed in the general population. Since differential diagnosis of dementia subtypes is important for patient support and disease-targeted treatment, we believe that it’s important to address this deficit.

Our recent pilot study has highlighted a method by which memory assessments may improve differential diagnosis of LBD, without placing significant extra time commitments on staff. We would like to share our methodology and findings here, in the hope that this intervention may be adopted more widely. If you have any questions please contact or

Clinical Deficit

Lewy Body Dementia (LBD) is predicted to be underdiagnosed in the general population. There is a large disparity between prevalence rates in clinical population based studies (4%) of LBD and neuropathological studies (15-20%).

Aims of intervention

REM sleep behaviour disorder (RBD) is one of the 4 core clinical criteria for diagnosis of LBD. Longitudinal studies of RBD show strong association with LBD, potentially present up to 8 years prior to identification of LBD.

Adding a screening question can potentially alert the clinician to consider a diagnosis of LBD.


  • A validated screening question was added to the initial assessment proforma for memory assessments; 'Have you ever been told that you “act out your dreams” while sleeping (punched or flailed arms in the air, shouted or screamed)?' (Postuma, et al. Mov Disord. 2012)

  • Delivery of an RBD and LBD educational package to the memory team who administer the initial assessments.

  • Reminders to use the new proforma.


  • The initial baseline data showed that 0% of initial assessments screened for RBD. This increased to 100% at the end of the last plan-do-study-act cycle.

  • Main reason for non-completion was nurses using the old proforma.

  • 4/152 patients screened positive for RBD
    • These patients were subsequently diagnosed with delirium, late-onset Alzheimer’s disease, vascular dementia and mixed dementia (Alzheimer’s disease and vascular dementia)

Further work

The authors:

  • are in the process of disseminating the project findings locally within Greater Manchester with intentions to also share these nationally.

  • intend to submit an abstract to the Royal College of Psychiatrists International Congress 2022.

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