Light Therapy Treatment in Parkinson's Disease Patients With Daytime Somnolence

Effects of Bright Light Treatment on Daytime Sleepiness and Nocturnal Sleep in Patients With Parkinson's Disease

Study objectives are to determine the efficacy, safety and tolerability of bright light treatment in Parkinson's Disease (PD) patients with daytime sleepiness. Thirty PD patients will be enrolled and equally randomized to bright light or dim-red light treatment. Objective (actigraphy) and subjective (sleep logs/scales) sleep measures will be collected through the baseline and intervention phases of the study. The primary outcome measure will be the change in the Epworth Sleepiness Scale (ESS) comparing the bright light treatment with dim-red light treatment. Secondary outcome measures will include the Multiple Sleep Latency Test (MSLT), global Pittsburgh Sleep Quality Index (PSQI) score, Parkinson's Disease Sleep Scale (PDSS) score, and actigraphy measures. A variety of exploratory analyses will examine the effects of bright light treatment on fatigue, depression, quality of life, cognition, and motor disability.

Hypothesis: Bright light exposure will diminish daytime sleepiness and improve night-time sleep in PD patients with daytime sleepiness.

See above.

Inclusion Criteria:

1. Diagnosis of idiopathic PD as defined by the United Kingdom Parkinson's Disease Society Brain Bank Criteria
2. Hoehn and Yahr stage of 2 to 4 in the "on" state
3. Excessive daytime sleepiness as defined by the Epworth Sleepiness Scale (ESS) score of greater than or equal to 12 points
4. Stable PD medication regimen for at least 4 weeks prior to study screening
5. Willing and able to give written informed consent

Exclusion Criteria:

1. Atypical parkinsonian syndromes
2. Significant sleep disordered breathing (defined as an apnea-hypopnea index >15 events/hr of sleep on screening PSG)
3. Significant periodic limb movement disorder (defined as a PLM arousal index>10 events/hr of sleep on screening PSG) and REM sleep behavior disorder (based on the presence of both clinical symptomatology as well as intermittent loss of REM atonia on screening PSG)
4. Cognitive impairment indicated by the mini-mental status examination (MMSE) score of less than 24
5. Presence of depression defined as the Beck Depression Inventory (BDI) score >14
6. Untreated hallucinations or psychosis (drug-induced or spontaneous)
7. Use of hypno-sedative drugs for sleep or stimulants during the daytime
8. Use of antidepressants unless the patient has been on a stable dose for at least three months
9. Visual abnormalities that may interfere with light therapy, such as significant cataracts, narrow angle glaucoma or blindness
10. Travel through 2 time zones within 90 days prior to study screening