Impaired olfaction may be a biomarker for early Lewy body disease, but its value in mild cognitive impairment with Lewy bodies (MCI-LB) is unknown. We compared olfaction in MCI-LB with MCI due to Alzheimer’s disease (MCI-AD) and healthy older adults. We hypothesized that olfactory function would be worse in probable MCI-LB than in both MCI-AD and healthy comparison subjects (HC).

Cross-sectional study assessing olfaction using Sniffin’ Sticks 16 (SS-16) in MCI-LB, MCI-AD, and HC with longitudinal follow-up. Differences were adjusted for age, and receiver operating characteristic (ROC) curves were used for discriminating MCI-LB from MCI-AD and HC.

Participants were recruited from Memory Services in the North East of England.

Thirty-eight probable MCI-LB, 33 MCI-AD, 19 possible MCI-LB, and 32HC.

Olfaction was assessed using SS-16 and a questionnaire.

Participants with probable MCI-LB had worse olfaction than both MCI-AD (age-adjusted mean difference (B) = 2.05, 95% CI: 0.62–3.49, p = 0.005) and HC (B = 3.96, 95% CI: 2.51–5.40, p < 0.001). The previously identified cutoff score for the SS-16 of ≤ 10 had 84% sensitivity for probable MCI-LB (95% CI: 69–94%), but 30% specificity versus MCI-AD. ROC analysis found a lower cutoff of ≤ 7 was better (63% sensitivity for MCI-LB, with 73% specificity vs MCI-AD and 97% vs HC). Asking about olfactory impairments was not useful in identifying them.

MCI-LB had worse olfaction than MCI-AD and normal aging. A lower cutoff score of ≤ 7 is required when using SS-16 in such patients. Olfactory testing may have value in identifying early LB disease in memory services.

Lewy Bodie Dementia (LBD) is the second more common progressive dementia caused by the deposition of proteins at the neocortical level, producing motor and psychotic symptoms (parkinsonism and visual hallucinations) which typically get worse with antipsychotics.

Find the best antipsychotic treatment in a real patient with LBD balancing control of motor and psychotic symptoms.

A clinical trial about a real case based on an updated bibliographical review. Received a 70 years old man with more than ten years LBD diagnosis, treated with clozapine (25mg / 12h). According to his wife (principal keeper), it stills a paranoid speech with fluctuant delusional ideas conditioned by visual hallucinations, predominantly in the evening, with no amelioration in four years clozapine treatment, adding a progressive parkinsonism impairment despite neurological drugs (carbidopa:levodopa). Doing a bibliographical review, we found a 2019 article (with 3 Systematic review/Metanalysis and 3 Clinical Practice Guidance, including in NICE), where point olanzapine 5mg well effective but worse tolerated and light up quetiapine as choice that should be considered (no doses specified).

One month later of therapeutic trial following the review in our clinical case, changing clozapine for quetiapine (50mg / 12h), we found an improvement of motor control and a reduction of psychotic manifestation that allows a less disruptive behavior in our patient, also objectified by his principal keeper.

While bibliography doesn’t point a specific dose drug guide for antipsychotic treatment in LBD, in our clinical trial we detected a better control of symptoms using low dose quetiapine, nevertheless more studies are needed.

Dementia with Lewy bodies (DLB) and Alzheimer's disease (AD) are common forms of dementia, yet diagnosis is often difficult. Diffusion tensor imaging (DTI) is an MR technique used to assess neuronal microstructural integrity that may help develop a better understanding of the differences between the conditions.

We recruited subjects with DLB (n = 35), AD (n = 36), and similar aged healthy controls (n = 35). T1 weighted anatomical and diffusion MR images were acquired at 3 Tesla. Region of interest (ROI) analysis was used to measure fractional anisotropy (FA) and mean diffusivity (MD) in five structures: precuneus, thalamus, pons, midbrain, and amygdala. Where appropriate diffusivity measures (FA, MD) were correlated with selected clinical measures.

Compared to controls, DLB subjects were characterized by reduced FA (p = 0.016) and increased MD (p = 0.007) in the precuneus. Amygdala diffusivity was positively correlated with UPDRS-III score in DLB (p = 0.003). In AD, reduced FA in the precuneus was also observed compared to controls (p = 0.026), and was associated with impaired global cognition (MMSE score) (p = 0.03).

Our findings highlight the potential importance of the precuneus in the pathogenesis of DLB as well as AD. Diffusion tensor MRI may shed new light on the different neurobiological changes underpinning the key clinical features of DLB and AD.