Dementia with Lewy bodies (DLB) is a type of dementia that is characterized by cognitive impairments in the areas of visuo-constructive and executive function, as well as attention and processing speed. These impairments can significantly impact the daily lives of those living with DLB, and they are often accompanied by memory problems that can make it difficult for patients to retain new information or recall previously learned information.
In this study, we tried to understand better the neuro-anatomical substrates of attention and processing speed in DLB. Specifically, we wanted to examine the correlations between behavioral scores measuring processing speed and the degree of cerebral atrophy in patients with prodromal to moderate DLB.
To do this, we selected 93 prodromal to moderate DLB patients (mean MMSE = 25.5) to participate in the study and 28 healthy elderly subjects (mean MMSE = 28.9) who were matched in terms of age and educational level. These subjects were then given tests to assess their attention and processing speed, including the Trail Making Test A (TMTA) and the Digit Symbol Substitution Test (DSST).
The results of these tests revealed that the DLB patients had significantly impaired performances on both the TMTA (p = .026) and the DSST (p < .001) when compared to the healthy control subjects. Additionally, we used a technique called voxel-based morphometry (VBM) to perform correlational analyses in the patient group, which revealed negative correlations in the caudate nucleus, the putamen, the left thalamus, and the subthalamic nuclei for the TMTA (p < .05 FDR corrected). Some positive correlations associated with the DSST were found in the right inferior frontal gyrus, the left thalamus, and the left cerebellum (p < .001 uncorrected).
These results provide important insights into the neural mechanisms underlying attention and processing speed impairments in DLB. Specifically, the involvement of the basal ganglia, particularly the left caudate nucleus, suggests that this structure plays an essential role in attentional processing speed. This also indicates the clinical implication of damage in this region relatively early in the disease.
Overall, this study highlights the importance of understanding the underlying neural mechanisms of DLB and the need for further research in this area. This research can help us better understand the impact of DLB on patients’ daily lives and provide insights into developing new treatments and therapies for DLB.
It is important to note that this research is not conclusive and is subject to further studies and replication. The sample size used in the study is relatively small, and the study design is cross-sectional, which limits the ability to infer causality from the findings. Further studies with larger sample sizes, longitudinal designs, and other imaging techniques are needed to confirm the results and understand the mechanisms of attention and processing speed impairments in DLB.
In conclusion, the study provides important insights into the neural mechanisms underlying attention and processing speed impairments in DLB and opens the door for further research in this area. This research can help improve the lives of those living with DLB and provide valuable information for developing new treatments and therapies.
https://alzres.biomedcentral.com/articles/10.1186/s13195-019-0568-y