Gaetano Barbagallo1, Rita Nisticò2, Basilio Vescio3, Antonio Cerasa4, Giuseppe Olivadese5, Salvatore Nigro6, Marianna Crasà7, Andrea Quattrone8, Maria Giovanna Bianco9, Maurizio Morelli10, Antonio Augimeri11, Maria Salsone12, Fabiana Novellino13, Giuseppe Nicoletti14, Gennarina Arabia15, Aldo Quattrone16. 1. Institute of Neurology, University "Magna Graecia", Catanzaro, Italy. Electronic address: gaebarbagallo@gmail.com. 2. Neuroimaging Unit, IBFM, National Research Council, Catanzaro, Italy. Electronic address: r.nistico@unicz.it. 3. Biotecnomed, S.C.aR.L, Catanzaro, Italy. Electronic address: basilio.vescio@biotecnomed.it. 4. Neuroimaging Unit, IBFM, National Research Council, Catanzaro, Italy; S. Anna Institute and Research in Advanced Neurorehabilitation (RAN) Crotone, Italy. Electronic address: a.cerasa@unicz.it. 5. Neuroimaging Unit, IBFM, National Research Council, Catanzaro, Italy. Electronic address: olivadese.giuseppe@gmail.com. 6. Neuroimaging Unit, IBFM, National Research Council, Catanzaro, Italy. Electronic address: salvatoreangelo.nigro@gmail.com. 7. Neuroimaging Unit, IBFM, National Research Council, Catanzaro, Italy. Electronic address: mariannacrasa@yahoo.it. 8. Institute of Neurology, University "Magna Graecia", Catanzaro, Italy. Electronic address: an.quattrone@hotmail.it. 9. Neuroimaging Unit, IBFM, National Research Council, Catanzaro, Italy. Electronic address: maria.giovanna.bianco@gmail.com. 10. Institute of Neurology, University "Magna Graecia", Catanzaro, Italy. Electronic address: m.morelli@unicz.it. 11. Biotecnomed, S.C.aR.L, Catanzaro, Italy. Electronic address: antonio.augimeri@biotecnomed.it. 12. Neuroimaging Unit, IBFM, National Research Council, Catanzaro, Italy. Electronic address: salsonemaria@gmail.com. 13. Neuroimaging Unit, IBFM, National Research Council, Catanzaro, Italy. Electronic address: fabiananovellino@gmail.com. 14. Neuroimaging Unit, IBFM, National Research Council, Catanzaro, Italy. Electronic address: g.nicoletti@unicz.it. 15. Institute of Neurology, University "Magna Graecia", Catanzaro, Italy. Electronic address: g.arabia@unicz.it. 16. Neuroimaging Unit, IBFM, National Research Council, Catanzaro, Italy; Neuroscience Research Centre, University "Magna Graecia", Catanzaro, Italy. Electronic address: quattrone@unicz.it.
Abstract
INTRODUCTION: The aim of our study was to investigate the effect of apomorphine and placebo on resting tremor in tremor-dominant Parkinson's disease (tPD) patients. METHODS:Fifteen tPD patients were enrolled. Each patient underwent two treatments on two consecutive days: on day one the patients received a subcutaneous injection of placebo, while on day two they received apomorphine. On each day, the patients underwent three electrophysiological recording sessions: T0, T1, and T2: before, 30 min, and 60 min after the treatment respectively. Electrophysiological changes in tremor amplitude were evaluated using a triaxial accelerometer. RESULTS:Placebo was effective in improving resting tremor in all tPD patients (p = 0.009) at T1, but not at T2. Eight out of 15 tPD patients (53.3%) responded to placebo with an at least 70% reduction in tremor amplitude compared to the basal condition (responders). By contrast, seven out of 15 tPD patients (46.7%) did not show any variation in tremor amplitude after placebo administration (non-responders). Apomorphine induced a marked reduction in tremor amplitude at 30 min and 60 min in all investigated tPD patients. Of note, the decrease in tremor amplitude in placebo responders was similar to that achieved with dopaminergic stimulation induced by apomorphine. CONCLUSIONS: Our study demonstrates that placebo was very effective in reducing resting tremor in about half of patients with tPD. The decrease in tremor amplitude in placebo responders was similar to that induced by apomorphine. The cerebral mechanisms underlying the placebo effect on resting tremor need further investigations.
RCT Entities:
INTRODUCTION: The aim of our study was to investigate the effect of apomorphine and placebo on resting tremor in tremor-dominant Parkinson's disease (tPD) patients. METHODS: Fifteen tPD patients were enrolled. Each patient underwent two treatments on two consecutive days: on day one the patients received a subcutaneous injection of placebo, while on day two they received apomorphine. On each day, the patients underwent three electrophysiological recording sessions: T0, T1, and T2: before, 30 min, and 60 min after the treatment respectively. Electrophysiological changes in tremor amplitude were evaluated using a triaxial accelerometer. RESULTS: Placebo was effective in improving resting tremor in all tPD patients (p = 0.009) at T1, but not at T2. Eight out of 15 tPDpatients (53.3%) responded to placebo with an at least 70% reduction in tremor amplitude compared to the basal condition (responders). By contrast, seven out of 15 tPDpatients (46.7%) did not show any variation in tremor amplitude after placebo administration (non-responders). Apomorphine induced a marked reduction in tremor amplitude at 30 min and 60 min in all investigated tPD patients. Of note, the decrease in tremor amplitude in placebo responders was similar to that achieved with dopaminergic stimulation induced by apomorphine. CONCLUSIONS: Our study demonstrates that placebo was very effective in reducing resting tremor in about half of patients with tPD. The decrease in tremor amplitude in placebo responders was similar to that induced by apomorphine. The cerebral mechanisms underlying the placebo effect on resting tremor need further investigations.