Paola Piccini

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OBJECTIVE A small group of Parkinson's disease (PD) patients compulsively use dopaminergic drugs despite causing harmful social, psychological, and physical effects and fulfil core Diagnostic and Statistical Manual (of Mental Disorders) Fourth Edition criteria for substance dependence (dopamine dysregulation syndrome [DDS]). We aimed to evaluate(More)
Synaptic dopamine release from embryonic nigral transplants has been monitored in the striatum of a patient with Parkinson's disease using [11C]-raclopride positron emission tomography to measure dopamine D2 receptor occupancy by the endogenous transmitter. In this patient, who had received a transplant in the right putamen 10 years earlier, grafts had(More)
Impulsive-compulsive behaviours are a significant source of morbidity for patients with Parkinson's disease receiving dopaminergic therapy. The development of these behaviours may reflect sensitization of the neural response to non-drug rewards, similar to that proposed for sensitization to drug rewards in addiction. Here, by using (11)C-raclopride positron(More)
Troublesome involuntary movements in the absence of dopaminergic medication, so-called off-medication dyskinesias, are a serious adverse effect of fetal neural grafts that hinders the development of cell-based therapies for Parkinson's disease. The mechanisms underlying these dyskinesias are not well understood, and it is not known whether they are the same(More)
OBJECTIVE To evaluate the relationship between clinical improvement and in vivo synaptic dopamine (DA) release after a single oral dose of levodopa (LD) in patients with advanced Parkinson disease (PD). METHODS We studied 16 patients with advanced PD with [(11)C]raclopride (RAC) PET. Each patient had RAC PET twice: once when medication had been withdrawn(More)
Severe dyskinesias during the 'off' phases (periods of increased Parkinson's disease (PD) disability) have been observed following intrastriatal transplantation of human embryonic mesencephalic tissue. Here we retrospectively analyzed 14 patients who were followed for up to 11 years after grafting, and found that dyskinesias (abnormal involuntary movements(More)
We have established that the frequency of LRRK2 mutations in a series of 118 cases of familial Parkinson's disease is 5.1%. In the largest family with autosomal dominant, late-onset Parkinson's disease where affected subjects share a Y1699C missense mutation we provide a detailed clinical, pathological and imaging report. The phenotype in this large British(More)
Microglial activation may play a role in the pathogenesis of Huntington's disease (HD). Using 11C-(R)-PK11195 (PK) positron emission tomography (PET), we investigated microglial activation in HD presymptomatic gene carriers (PGCs), its relationship with striatal neuronal dysfunction measured with 11C-raclopride (RAC) PET, and the role of PK PET as a(More)
Intrastriatal grafts of embryonic mesencephalic tissue can survive in the brains of patients with Parkinson's disease, but the degree of symptomatic relief is highly variable and some cases develop troublesome dyskinesias. Here we explored, using clinical assessment and 18F-dopa and 11C-raclopride PET, factors which may influence the functional outcome(More)
The degeneration of nigrostriatal dopamine neurons in early Parkinson's disease (PD) is compensated in part by increased transmitter turnover in surviving neurons of the pathway. In this (18)F-dopa positron emission tomography study, we demonstrate compensatory changes in PD in another midbrain dopamine projection to the basal ganglia, the nigropallidal(More)