Loss of Dopamine Transporter Binding and Clinical Symptoms in Dementia With Lewy Bodies

Abstract

Background: Little is known about the underlying mechanisms of clinical symptoms in dementia with Lewy bodies. The aim of this study was to explore the association between loss of striatal dopamine transporter binding and symptoms in dementia with Lewy bodies.

Methods: Thirty-five patients with dementia with Lewy bodies underwent single-photon emission computerized tomography brain imaging with N-ω-fluoropropyl-2β-carbomethoxy-3β-(4-iodophenyl)nortropane ([(123) I]FP-CIT). Associations between striatal binding ratios and motor (UPDRS), psychiatric (Neuropsychiatric Inventory; [NPI]), and cognitive (Mini-Mental State Examination [MMSE] and neuropsychological tests) symptoms were assessed by linear regression analysis.

Results: The explorative analysis showed that the motor UPDRS was negatively associated with putamen dopamine transporter binding, whereas no association with striatal dopamine transporter binding was found for total NPI, hallucinations, apathy, depression, anxiety, and MMSE scores. However, in post-hoc analysis, executive impairment was positively associated with dopamine transporter loss after adjustment of age and gender.

Conclusions: Dopamine deficiency in patients with dementia with Lewy bodies was associated with severity of motor symptoms, but did not correlate significantly with ratings of neurobehavioral disturbances or overall cognition.

Keywords: Lewy body; SPECT; [123I]FP-CIT; dementia; dopamine transporter.