Is light therapy a potential treatment modality in Parkinson’s disease?

You can find out more about NPF's National Medical Director, Dr. Michael S. Okun, by also visiting the NPF Center of Excellence, University of Florida Center for Movement Disorders & Neurorestoration. Dr. Okun is also the author of the Amazon #1 Parkinson's Best Seller 10 Secrets to a Happier Life.

Recent research has indicated that there may be unexplored symptomatic benefits by using light therapy to treat Parkinson’s disease patients.  This “light” approach is particularly appealing in Parkinson’s disease because patients commonly suffer from excessive daytime sleepiness, fatigue, sleep disorders, as well as depression—and all have been reported to potentially improve.  In this month’s What’s Hot Column, we explore the scientific underpinnings of the brain’s natural sleep-wake cycle; called the circadian rhythm.  The scientific term circadian rhythm is derived from the Latin words circa which means approximately, and diem which means day. The human sleep wake cycle has this been referred to as a circadian rhythm as it occurs everyday. Melatonin has been heavily implicated in the human sleep-wake cycle, and we will review both melantonin and light therapy, as potential symptomatic approaches for Parkinson’s disease.

Many investigators have focused on melatonin as an important chemical in the human sleep-wake circadian rhythm.  Melatonin is manufactured in the center of the brain in a structure called the pineal gland.  René Descartes referred to the pineal gland as the “seat of the soul.”  Melatonin from the pineal gland can trigger sleepiness, and can also lower body temperature.  The manufacture of melantonin is disrupted by exposure to light.  Researchers have postulated that by intervening in the melatonin pathways by exposing people to bright light could have a therapeutic benefit.
Videnovic and colleagues at the National Parkinson Foundation Center of Excellence in Northwestern University recently explored blood melatonin tests sampled over 24 hours.  The tests were designed to uncover some of the mysteries of fatigue, and the sleep-wake disturbances in Parkinson’s disease.  The researchers studied twenty Parkinson’s patients and twenty control patients without Parkinson’s. Melatonin blood levels were checked every thirty minutes for twenty-four straight hours.  Parkinson’s patients were observed not to secrete melatonin in a normal pattern.  Parkinson’s disease patients in the study who suffered from excessive daytime sleepiness or fatigue had more dysfunction in the patterns of melatonin than those without excessive daytime sleepiness or fatigue. How long you had Parkinson’s disease, how severe your motor symptoms were, and what medications you were taking, were not related to the circadian rhythm.  The author’s postulated that sleep-wake circadian function could be improved by timed exposure to bright light, and also potentially by exercise.  There have been several other small studies that have also suggested Parkinson’s disease motor, as well as non-motor symptoms, may improve with light therapy.

In May 2014, at the 66th Annual Meeting of the American Academy of Neurology (AAN), Videnovic and colleagues presented another study on the preliminary results of light therapy for excessive daytime sleepiness or fatigue. There were thirty patients included with an average duration of disease of approximately seven years. The study intervention was bright light therapy (5000 lux) or dim red-light therapy (300 lux) delivered for two hours a day for fourteen days.  The results did not reveal a difference between the groups, however a closer look at the scores in this small study revealed that the Epworth Excessive Sleepiness Scale improved by 2.3 points in the dim red light group, and 4.3 points in the bright light therapy group.  Though these results were not robust, they suggested, at least the possibility, that light therapy could be optimized for better results in Parkinson’s disease.  Some researchers have suggested that better penetrance of light therapy could be delivered through other techniques including deep brain electrodes, but this remains highly investigational and has only been attempted in animals.

If melatonin release is blocked by exposure to light, and exposing patients to light may improve Parkinson’s disease symptoms, why would patients intentionally take melatonin?  Melatonin (N-acetyl-5-methoxy-tryptamine) is also an antioxidant. Neurodegenerative disorders such as Parkinson’s disease have been linked to oxidative damage and free radical generation, and some people believe that melatonin may help in blocking neurodegeneration.  There are however no human studies to support the notion that melatonin slows or blocks neurodegeneration.  Some patients also use melatonin for sleep issues, though again there are no large well-controlled studies to support this notion, and in many cases reports have surfaced that melatonin replacement may actually worsen sleep in Parkinson’s disease.  I have personally listened to several patients who have tried melatonin, and reported worsening in sleep.  If you decide to try melatonin (which is over the counter) for sleep, you should do it under the guidance of a physician.  Until more data is published, we cannot make a recommendation as to the usefulness of melatonin replacement for sleep issues.

The bottom line is that there is accumulating evidence that melatonin is important to sleep and to excessive daytime sleepiness in Parkinson’s disease.  Melatonin can possibly be powerfully modulated by light therapy and also possibly by exercise.  Melatonin pills may not be the answer for many patients with Parkinson’s disease and could potentially worsen symptoms.  More research will be needed to clarify how shining a light on Parkinson’s disease may provide a new option for patients, especially those with excessive daytime sleepiness.

Selected References:

1: Videnovic A, Noble C, Reid KJ, Peng J, Turek FW, Marconi A, Rademaker AW, Simuni T, Zadikoff C, Zee PC. Circadian melatonin rhythm and excessive daytime sleepiness in Parkinson disease. JAMA Neurol. 2014 Apr;71(4):463-9. doi: 10.1001/jamaneurol.2013.6239. PubMed PMID: 24566763.

2: Bolitho SJ, Naismith SL, Rajaratnam SM, Grunstein RR, Hodges JR, Terpening Z, Rogers N, Lewis SJ. Disturbances in melatonin secretion and circadian sleep-wake regulation in Parkinson disease. Sleep Med. 2014 Mar;15(3):342-7. doi: 10.1016/j.sleep.2013.10.016. Epub 2014 Jan 21. PubMed PMID: 24529544.

3: Cardinali DP, Pagano ES, Scacchi Bernasconi PA, Reynoso R, Scacchi P. Melatonin and mitochondrial dysfunction in the central nervous system. Horm Behav. 2013 Feb;63(2):322-30. doi: 10.1016/j.yhbeh.2012.02.020. Epub 2012 Feb 25. Review. PubMed PMID: 22391273.

4: Ortiz GG, Benítez-King GA, Rosales-Corral SA, Pacheco-Moisés FP,Velázquez-Brizuela IE. Cellular and biochemical actions of melatonin which protect against free radicals: role in neurodegenerative disorders. Curr Neuropharmacol. 2008 Sep;6(3):203-14. doi: 10.2174/157015908785777201. PubMed PMID: 19506721; PubMed Central PMCID: PMC2687933.

Posted: 6/2/2014 1:07:27 PM by Cathy Whitlock

Browse current and archived What's Hot in PD? articles, the National Parkinson Foundation's monthly blog for people with Parkinson's written by our National Medical Director, Dr. Michael S. Okun. 

June 2015
Short and Long-Term Problems with Anticholinergic Drugs used for Sleep, Bladder, and Tremor Symptoms

May 2015
Leaps in Deep Brain Stimulation Technology

April 2015
What to tell Parkinson’s patients about diet and taking statin drugs

March 2015
Everything a Parkinson’s Disease Patient Needs to Know About the New Dopamine Pump

February 2015
Tips for Parkinson’s Disease Patients Switching from Sinemet or Madopar to Rytary (IPX066)

January 2015
More Evidence Linking Gut Bacteria to Parkinson’s Disease: A Guide for Patients

December 2014
Two New Therapies for Parkinson’s Disease Patients to get Excited About: Vaccines and Monoclonal Antibodies

November 2014
The Importance of a Monitoring Strategy When Prescribing Dopamine Agonists: Lessons from the National Parkinson Foundation Data

October 2014
Is Midlife Migraine Related to Late Life Parkinson’s Disease?

September 2014
Deep Brain Stimulation for Parkinson’s Disease: NPF Congratulates Mahlon DeLong and Alim-Louis Benabid and Looks to a Bright Future in Human Neural-Network Modulation

August 2014
Everything You Need to Know About Medical Marijuana and Parkinson’s Disease

July 2014
The End for Levodopa Phobia: New Study Shows Sinemet is a Safe Initial Therapy for Treatment of Parkinson's Disease

June 2014
Is light therapy a potential treatment modality in Parkinson’s disease?

May 2014
How does the most common genetic cause of Parkinson’s Disease (LRRK2) cause Parkinson’s disease and could it be used to help develop a better therapy?

April 2014
An Update on DAT Scanning for Parkinson’s Disease Diagnosis

March 2014
Could Northera (Droxidopa) Be an Alternative Treatment for Low Blood Pressure and Passing Out Symptoms?

February 2014
The Dream of a Pill Free Existence and the Continuous Dopaminergic Pump for the Treatment of Parkinson's Disease

January 2014
Should I take Inosine to Raise my Uric Acid Levels and Treat my Parkinson’s Disease?

December 2013
Could Fungus and Mold be an Important Contributor to Parkinson’s Disease?

November 2013
Pimavanserin and the Hope for a Better Drug for Hallucinations and Psychosis in Parkinson’s Disease

October 2013
Halting of the Creatine Study

September 2013
The Importance of Identifying and Treating Caregiver Strain

August 2013
Putting Parkinson’s Disease Information into the Palm of Your Hand: Parkinson’s Enters the Smartphon

July 2013
What Parkinson’s Disease Patients Need to Know about H. Pylori Gastrointestinal Infections

June 2013
A2A Receptor Antagonists and Parkinson’s Disease Treatment

May 2013
Another Setback for Trophic Factor Treatment in Parkinson's Disease

April 2013
IPX066 and What Patients Really Want in New Carbidopa/Levodopa (Sinemet) Formulations

March 2013
The Weather Forecast for Parkinson’s Disease Calls for Worldwide Economic Storm

February 2013
Defeating the Barriers to Implementing Exercise Regimens in Parkinson’s Disease Patients

January 2013
When should you start medication therapy for Parkinson’s disease?

December 2012
Neurologist Care Reduces Hospitalizations in Parkinson's Disease

November 2012
A Victory in Court for Parkinson's Disease Patients who Require Ongoing Rehabilitative Therapies

October 2012
Given the recent FDA announcement about Mirapex (pramipexole), should I be worried about dopamine agonists?

September 2012
What about the new Parkinson’s Disease Vaccine? What should I know?

August 2012
Caffeine as a Potential Treatment for Parkinson’s Disease

July 2012
Time to Consider GPi DBS for Parkinson’s Disease: A Shift in the Practice of Patient Selection for DBS

June 2012
A New Treatment for Parkinson’s Disease-Related Constipation

May 2012
Too Many Pills: Improving Delivery Systems for Parkinson’s Disease Drugs

April 2012
Measuring Quality and Assessing Depression in Parkinson's Disease

March 2012
Watch out for Unexpected Obstacles if You Use a Cueing Strategy to Break Freezing of Gait in Parkinson’s Disease

February 2012
Pill Color, Generic Medications and Insurance Issues: Important Medication-Related Tips for the Parkinson’s Disease Patient

January 2012
Are Blood Tests for Parkinson’s Disease on the Horizon?

December 2011
Placing Stem Cells in Animal Models of Parkinson’s Disease: Another Important Step

November 2011
Important News for the Parkinson’s Disease Community: More Evidence that Sinemet and Madopar are Not Toxic and do Not Accelerate Disease Progression

October 2011
The Case for All Parkinson’s Disease Patients to be Co-managed by a Primary Care-Neurologist Team

September 2011
Scientists say Research on Brain Proteins Involved in Parkinson’s Disease is “Shaping” Up

August 2011
Who Actually Takes Care of Most of the Parkinson’s Patients Worldwide: The Need for Education and the Parkinson’s Toolkit

July 2011
If you are Dizzy or Passing Out, it could be Your Parkinson’s Disease or Parkinson’s Disease Medications

June 2011
How Will Group Visits for Parkinson’s Disease Fit into the Future of Parkinson’s Disease Care?

May 2011
Why Patients Should be Wary of Chelation Therapy for Parkinson’s Disease

April 2011
Opening the Door to Gene Therapy in Parkinson’s Disease: The Need for Refinement of the Technology and Approach

March 2011
Does it Matter if I Can’t Get Brand Sinemet?

February 2011
Should I get a DaTscan or PET scan to confirm my diagnosis of Parkinson’s disease?

January 2011
A Critical Reappraisal of the Worst Drugs in Parkinson’s Disease

December 2010
Environmental Risks for PD: Manganese, Welding, Mining, and Parkinsonism

November 2010
Calling for the FDA to Revise the Eight Sinemet a Day Rule

October 2010
Dry Cleaning Solvents and Potential Environmental Risks for Developing Parkinson’s Disease

September 2010
Maintaining the Balance: Why Parkinson’s Disease Patients Need to Understand Drug Recalls, Withdrawals, and Safety Alerts

August 2010
Shining a Light on Parkinson’s Disease: Optogenetics Has a Bright Future in Research

July 2010
Poor Medication Management of Parkinson's Disease During Hospital Admissions: Patients and Families Can Improve Their Hospital-Based Management

June 2010
Why Are Patches and Continuous Release Technology a Big Deal to Parkinson's?

May 2010
Is the PD SURG Trial Another Surge Forward for DBS Therapy?

April 2010
Cycling in PD in Those Who Can’t Walk: Is it Possible?

March 2010
New iPS Stem Cells for PD: What Does it Mean?

February 2010
Time for Comprehensive Care Networks for PD

January 2010
Is Parkinson's Disease a Prion Disease?

December 2009
Parkinson's Disease Linked to Gaucher's Disease

November 2009
Brain Cells Keep Time Stamps: Implications for Parkinson's Disease Therapies

October 2009
Is it Safe to Have an MRI with a DBS in Place?

September 2009
Take Care of Your Bones as They Are Affected in Parkinson's Disease (Even in Men)

August 2009
Is it Time to Start Paying Attention to Pain Symptoms in Parkinson's Disease Patients?

July 2009
Glutathione Fails to Demonstrate Significant Improvement in PD Symptoms

June 2009
Keeping an Eye on Trials Important to the Parkinson's Disease Patient

May 2009
Increased Risk of Melanoma in Parkinson's Disease

April 2009
Finally a DBS Expert Consensus Statement Aimed at Their True Customers: The Patients

March 2009
Pesticides and Environmental Exposure in Parkinson's disease: Should We Stay Away From the Stink Truck?

February 2009
Is Exercise Effective Treatment and Protection Against PD?

January 2009
Why are Transplant Trials Struggling to Succeed in the Treatment of PD?

December 2008
Are Monoamine Oxidase Inhibitors Disease Modifying or Neuroprotective in PD?

November 2008
Update on Gene Therapy for Parkinson's Disease

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Each month, we will feature a new column by NPF's National Medical Director, Dr. Michael Okun, on the latest developments in Parkinson's disease research. Read the latest "What's Hot in PD?" below.

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