Background: Dementia with Lewy bodies (DLB) is one of the main differential diagnoses of Alzheimer's disease (AD). Key pathological features of patients with DLB are not only the presence of cerebral cortical neuronal loss, with Lewy bodies in surviving neurones, but also loss of nigrostriatal dopaminergic neurones, similar to that of Parkinson's disease (PD). In DLB there is 40-70% loss of striatal dopamine. Objective: To determine if detection of this dopaminergic degeneration can help to distinguish DLB from AD during life. Methods: The integrity of the nigrostriatal metabolism in 27 patients with DLB, 17 with AD, 19 drug naive patients with PD, and 16 controls was assessed using a dopaminergic presynaptic ligand, 123 Ilabelled 2β-carbomethoxy-3β-(4-iodophenyl)-N-(3-fluoropropyl)nortropane (FP-CIT), and single photon emission tomography (SPET). A SPET scan was carried out with a single slice, brain dedicated tomograph (SME 810) 3.5 hours after intravenous injection of 185 MBq FP-CIT. With occipital cortex used as a radioactivity uptake reference, ratios for the caudate nucleus and the anterior and posterior putamen of both hemispheres were calculated. All scans were also rated by a simple visual method. Results: Both DLB and PD patients had significantly lower uptake of radioactivity than patients with AD (p<0.001) and controls (p<0.001) in the caudate nucleus and the anterior and posterior putamen. Conclusion: FP-CIT SPET provides a means of distinguishing DLB from AD during life.

Alzheimer's disease is confirmed as the most common cause of dementia in older people, followed by vascular dementia. However, DLB and FLD occur sufficiently often to be seen frequently in clinical practice and should be incorporated into future editions of standard diagnostic criteria.

Patients with dementia with lewy bodies (DLB) have progressive deficits in cognition, parkinsonism, and neuropsychiatric symptoms. Cholinesterase inhibitors have been used to ameliorate cognitive decline and neuropsychiatric symptoms in short-term trials. In this study, patients with DLB were treated with rivastigmine up to 96 weeks. Improvement from baseline was seen in cognitive function as measured by the Mini-Mental State Examination (MMSE), and neuropsychiatric symptoms as measured by the Neuropsychiatric Inventory (NPI) over the first 24 weeks of treatment. By 96 weeks, neither the MMSE scores nor the NPI scores were significantly worse than at baseline.