title: Apomorphine reduces BOLD signal in fMRI during voluntary movement in Parkinsonian patients.
abstract: Our group investigated modulatory effects of apomorphine on cerebral activation patterns during finger tapping movements in seven Parkinson's disease (PD) patients off medication. Cerebral activation was measured according to an established fMRI protocol. Apomorphine application disclosed a reduction of cerebral activation patterns to the contralateral precentral gyrus affecting both clinically affected and unaffected sides; tapping with the unaffected hand additionally revealed activation in the contralateral postcentral gyrus. These findings contradict those of similar functional imaging studies performed in PD to date, which variously found augmentation of cerebral activation patterns in Parkinsonian patients after dopaminergic stimulation. One conceivable explanation for our singular results would be preferred binding of apomorphine to presynaptic dopaminergic receptors, leading to inhibition of endogenous dopamine release and resultant diminished dopaminergic stimulation, reflected in diminished cerebral activation patterns. These findings warrant future consideration and further investigation of possible central inhibitory effects of dopaminergic therapy in functional imaging studies in PD.
authors.affiliation: Department of Neurology, St. Josef Hospital, Ruhr-University Bochum, Gudrunstr. 56, 44791 Bochum, Germany. neuromatrx@aol.com
authors.forename: Sören
authors.initials: S
authors.lastname: Peters
authors.forename: Boris
authors.initials: B
authors.lastname: Suchan
authors.forename: Joanna
authors.initials: J
authors.lastname: Rusin
authors.forename: Irene
authors.initials: I
authors.lastname: Daum
authors.forename: Odo
authors.initials: O
authors.lastname: Köster
authors.forename: Horst
authors.initials: H
authors.lastname: Przuntek
authors.forename: Thomas
authors.initials: T
authors.lastname: Müller
authors.forename: Gebhard
authors.initials: G
authors.lastname: Schmid
mesh_terms: D000978:Antiparkinson Agents / Q000494:pharmacology* / Q000627:therapeutic use; D001058:Apomorphine / Q000494:pharmacology* / Q000627:therapeutic use; D001921:Brain / Q000187:drug effects* / Q000503:physiopathology; D018491:Dopamine Agonists / Q000494:pharmacology* / Q000627:therapeutic use; D005385:Fingers; D006801:Humans; D008279:Magnetic Resonance Imaging; D009068:Movement; D010300:Parkinson Disease / Q000188:drug therapy* / Q000503:physiopathology
chemical_list: D000978:Antiparkinson Agents; D018491:Dopamine Agonists; D001058:Apomorphine