The potential of light therapy in Parkinson's disease

Abstract

Parkinson's disease is a movement disorder with cardinal signs of resting tremor, akinesia, and rigidity. These manifest after a progressive death of many dopaminergic neurons of the midbrain. Unfortunately, the progression of this neuronal death has proved difficult to slow and impossible to reverse despite an intense search for the specific causes and for treatments that address the causes. There is a corresponding need to develop approaches that regulate the self-repair mechanisms of neurons, independent of the specific causes of the damage that leads to their death. Red to infrared light therapy (λ=600-1,070 nm) is emerging as an effective, repair-oriented therapy that is capable of stabilizing dying neurons. Initially a space-age anecdote, light therapy has become a treatment for tissue stressed by the known causes of age-related diseases: hypoxia, toxic environments, and mitochondrial dysfunction. Here we focus on several issues relating to the use of light therapy for Parkinson's disease: 1) What is the evidence that it is neuroprotective? We consider the basic science and clinical evidence; 2) What are the mechanisms of neuroprotection? We suggest a primary mechanism acting directly on the neuron's mitochondria (direct effect) as well as a secondary, supportive mechanism acting indirectly through systemic systems (indirect effect); 3) Could this be effective in humans? We discuss the pros and cons of this treatment in humans, including the development of a new surgical method of delivery; and 4) What are the advantages of using light therapy? We explore the features that make this therapy a promising potential treatment. In summary, early evidence indicates that light regulates specific neuronal functions and is neuroprotective in animal models of Parkinson's disease. The stage is set for detailed and rigorous explorations into its use on Parkinson's disease patients, in particular, whether light slows the disease progression rather than simply mitigating signs.

Electromagnetic radiation therapy for Parkinson’s disease tremor reduction- systematic reviews and Bayesian meta-analyses for comparing the effectiveness of electric, magnetic and light stimulation methods

“…Light therapy may suppress melatonin [ 11 ] as an antioxidant against the pro-oxidant effects of L-dopa and dopamine. Furthermore, light therapy may influence PD through neuroprotective effects or by preventing oxidative stress inside the cells (see [ 59 ]). In light therapy, the weak penetration depth of the light prevents it from reaching deep brain areas which contain dopaminergic neurons, and in this regard, the impact of light therapy on PD symptoms may be restricted.…”

Photobiomodulation Therapy on Brain: Pioneering an Innovative Approach to Revolutionize Cognitive Dynamics

“…While most researchers have concentrated on transcranial and intracranial light delivery methods [ 33 , 34 ], there is also promising evidence that light radiation via the nasal and oral cavities can improve symptoms of dementia and PD [ 35 , 36 , 37 ] ( Figure 2 C,D). In the intranasal PBM approach, light is positioned within the nostril, allowing the direct irradiation of subcortical and cortical structures associated with the pathologies of AD and PD [ 38 ].…”