Brain imaging after neural transplantation.
Functional imaging has provided objective evidence that human fetal ventral mesencephalic tissue implanted in the striatum of Parkinson's disease patients can survive, grow, release dopamine, normalize brain metabolism, and restore striatal-cortical connections. Open-label clinical trials have shown robust clinical improvement in several PD patients but these results were not replicated in two double-blind sham-surgery controlled clinical trials. Graft-induced dyskinesias are serious adverse effects and a major roadblock for the further development of cell therapies, and functional imaging can help investigate the mechanisms underlying their cause. Functional imaging can also aid future trials by improving patient selection, assessing restoration of brain connectivity, and monitor inflammatory processes. Although functional imaging cannot currently be used as a primary endpoint in clinical transplantation trials, it can provide additional valuable information alongside clinical observations.
Politis
Marios
M
Centre for Neuroscience and MRC Clinical Sciences Centre, Faculty of Medicine, Hammersmith Hospital, Imperial College London, UK.
Piccini
Paola
P
D000818:Animals; D001921:Brain / Q000000981:diagnostic imaging / Q000473:pathology*; D016380:Brain Tissue Transplantation / Q000009:adverse effects*; D002540:Cerebral Cortex / Q000473:pathology; D002986:Clinical Trials as Topic; D003342:Corpus Striatum / Q000473:pathology; D004295:Dihydroxyphenylalanine / Q000031:analogs & derivatives; D004298:Dopamine / Q000502:physiology; D020820:Dyskinesias / Q000209:etiology / Q000473:pathology; D016332:Fetal Tissue Transplantation; D006085:Graft Survival; D006801:Humans; D009415:Nerve Net / Q000000981:diagnostic imaging / Q000473:pathology; D010300:Parkinson Disease / Q000000981:diagnostic imaging / Q000473:pathology* / Q000628:therapy*; D049268:Positron-Emission Tomography; D017661:Receptors, Presynaptic / Q000502:physiology; D015899:Tomography, Emission-Computed, Single-Photon
D017661:Receptors, Presynaptic; C029112:5-fluorodopa; D004295:Dihydroxyphenylalanine; D004298:Dopamine