Clinical Trial: Imaging of Vesicular Acetylcholine and Dopamine Transporters in Dementia With Lewy Bodies
Study Status: Completed
Recruit Status: Completed
Study Type: Interventional
Official Title: In Vivo SPECT Imaging of Vesicular Acetylcholine and Dopamine Transporters in Dementia With Lewy Bodies: Applying in Diagnostic and Identification of Pathological Subtypes
Brief Summary:
The general aim of this research project is to determine the relationships between alterations of central cholinergic (ACh) and dopaminergic (DA) systems and neurobehavioral features of dementias with Lewy bodies (DLB).
Both clinical and neurochemical data support the view that DLB is not a homogeneous entity and it can be hypothesized that differential alterations of central ACh systems (i.e. anterior vs posterior vs striatal interneurons) in association or not with a DA nigrostriatal dysfunction could partly support the clinical heterogeneity observed in this disease. ACh in vivo imaging has been relatively underutilized to date and to our knowledge only on the postsynaptic side. Furthermore, ACh/DA interactions and their relationships with the symptomatology of DLB and related pathologies (PDD) had never been investigated.
Detailed Summary:
Neurochemical investigations and observations suggest a crucial physiopathological role of central ACh systems in dementias with Lewy bodies (DLB). Alterations of cholinergic neurons could be involved in the general cognitive decline (central feature) but also in fluctuating attentional performances and rapid eye movement sleep disorder as it was shown in thalamus.
Post synaptic in vivo SPECT imaging recently demonstrated an increase in muscarinic receptors in DLB patients in the occipital cortex that could be associated with the visuospatial dysfunction often reported in DLB or even in visual hallucinations.From a pharmacological point of view, the involvement of ACh systems in DLB is confirmed by the consistently reported efficacy of cholinesterase inhibitor therapy, considered as greater than in AD.
Concerning DA systems, presynaptic in vivo SPECT imaging studies of DA transporter have shown a decreased striatal uptake in DLB patients, different when compared with Parkinson's disease patients or Alzheimer's disease patients.
Strategy, procedure In this project we will use for the first time in vivo molecular imaging of presynaptic molecular target of ACh systems (VAChT) with [123I]-iodobenzovesamicol and of DA systems (DAT) with DATSCAN in order to better analyse the link between neurobehavioral profiles of patients and a differential alteration of ACh/DA systems in DLB.
Sponsor: University Hospital, Bordeaux
Current Primary Outcome: Binding Potential (BP) quantification of each radioligand [ Time Frame: Day 1 ; Day 1 and between day 14 to 28 ]
Original Primary Outcome: Same as current
Current Secondary Outcome: Ratio dopaminergic system/cholinergic system Binding Potential [ Time Frame: Day 1 and between day 14 to 28 ]
Original Secondary Outcome: Same as current
Information By: University Hospital, Bordeaux
Dates:
Date Received: June 5, 2009
Date Started: May 2009
Date Completion:
Last Updated: August 20, 2014
Last Verified: August 2014
