Aim of study

While, Lewy body diseases (LBDs, comprising Parkinson's disease, dementia with Lewy bodies) and white matter diseases (WMD) coexist pathologically, it is uncertain to what extent each disease and the combination of the two manifests clinically, particularly regarding gait disorders. To answer this question, we performed neuroimaging-assisted analysis.

Methods

This was a retrospective cohort study (215 patients with gait, cognitive, or sleep- autonomic disorders who were referred to our department within a 2-year period). The inclusion criteria were: apparent gait disorder; age > 65 years; WMD observed on MRI; and LBD observed on both DAT and MIBG for clarity.

Results

We had 39 patients with LBD; 31 with WMD; and 52 with dual diseases. The types of motor disorder in LBD varied (purely akinetic, akineto-rigid, and tremor forms) whereas in WMD it was purely akinetic with a wide-based gait. Those with dual diseases showed a clinical combination of the two. Cognitive disorders of LBD only and of dual diseases were more severe than WMD only. Sleep disorder and postural hypotension occurred only in LBD only and in dual diseases; constipation was common in LBD and dual groups. However, none of the differences reached statistical significance.

Conclusion

Among the patients, 23-50% of LBD and those of dual diseases had the purely akinetic form, which might be indistinguishable from WMD. In such cases, additional motor (subtle upper-half akinesia, abnormal posture) and nonmotor (cognitive-sleep-autonomic) signatures may help in diagnosing (comorbid) LBD cases that require treatment.