Hippocampal and insula volume in mild cognitive impairment with Lewy bodies
Michael J Firbank1, Rory Durcan1, John T O'Brien2
1Translational and Clinical Research Institute, Newcastle University, UK.
Introduction:
Diagnostic criteria for prodromal dementia with Lewy bodies have recently been published. These include the use of imaging biomarkers to distinguish mild cognitive impairment with Lewy bodies (MCI-LB) from MCI due to other causes. Two potential biomarkers listed, though not formally included in the diagnostic criteria, due to insufficient evidence, are relatively preserved hippocampi, and atrophy of the insula cortex on structural brain imaging.
Methods:
In this report, we sought to investigate these imaging biomarkers in 105 research subjects, including well characterised groups of patients with MCI-LB (n = 38), MCI with no core features of Lewy body disease (MCI-AD; n = 36) and healthy controls (N = 31). Hippocampal and insula volumes were determined from T1 weighted structural MRI scans, using grey matter segmentation performed with SPM software.
Results:
Adjusting for age, sex and intracranial volume, there were no differences in hippocampal or insula volume between MCI-AD and MCI-LB, although in both conditions volumes were significantly reduced relative to controls.
Conclusion:
Our results do not support the use of either hippocampal or insula volume to identify prodromal dementia with Lewy bodies.
Insights
Preserved hippocampi and insula atrophy were investigated as biomarkers for prodromal dementia with Lewy bodies (DLB). This study found no significant differences in these brain regions between mild cognitive impairment with Lewy bodies (MCI-LB) and other MCI types, suggesting they are not reliable indicators for early DLB detection.
Area of Science:
- Neuroimaging
- Neurology
- Dementia Research
Background:
- Diagnostic criteria for prodromal dementia with Lewy bodies (DLB) are emerging.
- Imaging biomarkers are crucial for differentiating subtypes of mild cognitive impairment (MCI).
- Relatively preserved hippocampi and insula atrophy are potential, though unproven, biomarkers for MCI with Lewy bodies (MCI-LB).
Purpose of the Study:
- To investigate the utility of hippocampal and insula volumes as imaging biomarkers for prodromal dementia with Lewy bodies.
- To compare these volumes in patients with MCI-LB, MCI due to other causes (MCI-AD), and healthy controls.
Main Methods:
- Structural MRI scans (T1-weighted) were analyzed for hippocampal and insula volumes in 105 participants.
- Participants included well-characterized groups of MCI-LB (n=38), MCI-AD (n=36), and healthy controls (n=31).
- Grey matter segmentation was performed using SPM software, with adjustments for age, sex, and intracranial volume.
Main Results:
- No significant differences in hippocampal or insula volume were found between MCI-AD and MCI-LB groups.
- Both MCI groups exhibited significantly reduced hippocampal and insula volumes compared to healthy controls.
- The findings did not support the use of hippocampal or insula volume for distinguishing MCI-LB from MCI-AD.
Conclusions:
- Hippocampal and insula volumes are not reliable biomarkers for identifying prodromal dementia with Lewy bodies.
- Further research is needed to identify validated imaging biomarkers for early DLB detection.
