Abstract:

Parkinson’s disease is a neurological disorder with distinct motor signs of resting tremor, akinesia and/or lead-pipe rigidity, together with non-motor symptoms of impaired smell, cognition and autonomic function. These manifest after a major degeneration of neurones mainly within the brainstem, particularly among the dopaminergic neurones in the substantia nigra pars compacta, together with their terminations in the striatum. A number of recent studies have shown that photobiomodulation, the use of red to infrared light (λ = 600–1070 nm) on body tissues, has beneficial effects in many animal models of Parkinson’s disease, from flies to monkeys.These benefits include, a restoration of the abnormal neuronal activity in the basal ganglia, an improvement in locomotive behaviour and reduction in clinical signs, as well as an increase in the survival patterns of neurones damaged by either the parkinsonian toxin or the genetic mutation of the model used. This latter neuroprotective disease-modifying effect is particularly relevant because it is the key process in Parkinson’s disease and is currently not addressed by drug and surgical therapies. In this perspective, we will explore several issues associated with the use of photobiomodulation in patients. First,we will consider the early evidence indicating that this therapy is effective in improving the signs and symptoms of the disease, as well as the mechanisms that may underpin these improvements. Second, we discuss how these preliminary reports (and experimental findings) can be developed into a viable treatment option for patients, together with some of the potential issues and/or problems associated with this process.