A ten-year study on the effects of strategic light exposure on the primary and secondary features of Parkinson's disease. - Trial ANZCTR12623000147684

Timeline & Enrollment

Primary Outcome

Primary Outcome 1: Change in the time to sleep and time to awaken as a result of 1 hour of light exposure. The instrument employed will be a sleep diary kept by the patient and by structured interview. ;; Primary Outcome 2: Change in sleep features including the total amount of sleep, the number of awakenings, and how readily the patient falls back to sleep as a result of 1 hour of light exposure. All sleep features will be analyzed together. The instrument employed will be a sleep diary kept by the patient and by structured interview. ;; Primary Outcome 3: Change in REM sleep behaviour disorder (RSBD) as a result of 1 hour of light exposure. The instrument employed will be a sleep diary kept by the patient and by structured interview.

Summary

The involvement of the circadian system is becoming an increasingly important topic in respect to the aetiology and treatment of Parkinson’s disease (PD). PD is traditionally described as, a disorder predominantly of motor impairment, mediated by nigro-striatal DA (NSD) function. However, the secondary symptoms that proceed and accompany the disease during its course tell a different story. Insomnia, fatigue, depression and sleep disturbance are four of the most troublesome symptoms of PD that not only herald disease onset but also exacerbate primary symptoms and rob patients of their quality of life. Realigning circadian phase is the mechanism by which we can intervene in circadian function and phototherapy is the most effective method for doing so. Unfortunately, only a few studies have examined the efficacy of phototherapy as it relates to the protracted, ongoing nature of the disease itself. The present study examines the effect of light treatment for as long as ten years during the course of PD by monitoring primary and secondary symptoms at regular intervals. Improvement in circadian based symptoms observed including insomnia, fatigue, sleep architecture and depression may occur, and it is hypothesized that motor function will be subtle and occur incrementally. It is hypothesized that Improvement in both motor and secondary symptoms will occur for the duration of the study as long as patients used the treatment daily. The sequence of symptom recovery from secondary symptoms to motor impairment is expected to be slow suggesting that an incremental process of improvement is in tow, representing an inverse of the degenerative sequelae that continues over decades. Such a process would emulate the slow incremental process that characterizes the reparative process seen with pure disorders of circadian function. Recent findings suggesting that weakened circadian rhythmicity is associated with increased risk of PD thereby corroborating the possibility that “tweaking” the circadian system with a potent Zeitgeber may interfere with internal timing to slow the degenerative process of PD.

ICD-10 Classifications