Small vessel disease contributions to acute delirium: a pilot feasibility MRI study
Una Clancy1,2,3, Yajun Cheng4, Charlotte Jardine5
1Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK.
Background And Aims:
Delirium carries an eight-fold risk of future dementia. Small vessel disease (SVD), best seen on magnetic resonance imaging (MRI), increases delirium risk, yet delirium is understudied in MRI research. We aimed to determine MRI feasibility, tolerability, image usability and prevalence of SVD lesions in delirium.
Methods:
This case-control feasibility study performed MRI (3D T1/T2-weighted), fluid-attenuated inversion recovery, susceptibility-weighted and diffusion-weighted imaging (DWI) on 20 medical inpatients >65 years: 10 with delirium ≥3 weeks and 10 without delirium, matched for vascular risk, Clinical Frailty Scale (CFS) and cognition. We excluded acute stroke, agitation necessitating sedation, mobility assistance of >2 and MRI contraindications. We measured scan duration, tolerability, image usability, acute infarcts and SVD features. Six months later, we recorded CFS and cognitive diagnoses.
Results:
Mean age was 83.5 years (delirium 78.7 vs non-delirium 88.4); 13/20 were female; 17/20 had premorbid cognitive decline/impairment or dementia. Acquisition took mean 26.8 min. MRI was well tolerated in 16/20 (7/10 in delirium arm; 9/10 in non-delirium arm). Also, 4/20 had early scan termination, but 20/20 had clinically interpretable images. We detected DWI-hyperintense lesions in 3/10 (30%) with delirium (2/10 small subcortical and 1/10 cortical) and in 3/10 (30%) without delirium (2/10 small subcortical; 1/10 cortical). Mean white matter hyperintensity Fazekas score was 6 in delirium versus 4.5 without.
Conclusions:
MRI is feasible, usable and tolerable in delirium, and we detected DWI-hyperintense lesions in one-third of all study participants, regardless of delirium status. This study indicates acute vascular contributions, including SVD, to both delirium- and non-delirium-related presentations, supporting the need for larger studies.
Insights
Magnetic resonance imaging (MRI) is feasible for studying delirium and small vessel disease (SVD). This research found SVD lesions in one-third of participants, suggesting vascular factors contribute to delirium.
Area of Science:
- Geriatric Medicine
- Neurology
- Radiology
Background:
- Delirium significantly increases the risk of future dementia.
- Small vessel disease (SVD), detectable via MRI, is a known risk factor for delirium.
- Delirium remains understudied in the context of MRI research.
Purpose of the Study:
- To assess the feasibility, tolerability, and image usability of MRI in older patients with delirium.
- To determine the prevalence of SVD lesions in patients experiencing delirium.
Main Methods:
- A case-control feasibility study involving 20 inpatients over 65 years old (10 with delirium, 10 without).
- Utilized various MRI sequences including DWI, T1/T2-weighted, FLAIR, and SWI.
- Excluded patients with acute stroke, severe agitation, or MRI contraindications; assessed scan duration, tolerability, and image interpretability.
Main Results:
- MRI scans were feasible and yielded clinically interpretable images in all participants.
- Diffusion-weighted imaging (DWI)-hyperintense lesions were found in 30% of patients with delirium and 30% without.
- Higher mean white matter hyperintensity Fazekas scores were observed in the delirium group.
Conclusions:
- MRI is a feasible, usable, and tolerable imaging modality for patients with delirium.
- The presence of DWI lesions in a significant proportion of participants suggests acute vascular contributions to delirium.
- Further large-scale studies are warranted to explore the link between SVD and delirium.
