Revitalize Cognition: Near Infrared Stimulation in Parkinson Patients

The overall goal of this pilot, proof of concept study is to test a novel, relatively low cost, low risk and potentially high impact intervention for cognitive and motor symptoms associated with idiopathic Parkinson Disease. The intervention involves transcranial delivery of near infrared (NIR) light, aka as photobiomodulation (PBM). This pilot randomized controlled trial will examine whether NIR stimulation influences cognitive, mood, and motor symptoms in Parkinson patients relative to a sham treated group. The goal is to determine effect sizes for a potentially larger study.

Aims 1-3 of this study (Older Adult Specific) is registered separately under NCT02582593

There are few validated approaches for minimizing cognitive changes that frequently accompany Parkinson disease (PD). The goal of this study is to test a novel and potentially high impact brain stimulation approach for enhancing cognitive, mood, and motor symptoms in individuals with PD. This brain stimulation approach involves transcranial delivery of near infrared (NIR) light, which is painless and undetectable, and enhances brain metabolism. This NIR stimulation approach is also known as photobiomodulation (PMB).

The study builds on the following premises:

Mitochondrial dysfunction has been implicated in both familial and nonfamilial Parkinson disease.

NIR stimulation is a novel intervention for enhancing mitochondrial energy metabolism; Indeed, research in cellular and animal models suggests that application of light in red (630-700nm) and near infrared wavelengths (808-904nm) is neuroprotective and improves mitochondrial function by promoting increased production of intracellular adenosine triphosphate (ATP), important for cellular metabolism and oxygenation.

Findings of positive effects of NIR stimulation on motor and cognitive symptoms in animal models of PD, both rodent and macaques. In these animal studies, strong evidence supports neuroprotective and 'rescue' effects of NIR stimulation from MPTP-induced neurodegeneration, including preservation of locomotor activity and midbrain dopaminergic neurons. It is unclear whether similar beneficial effects might be afforded humans with idiopathic Parkinson disease (PD).

As such, the goal is to conduct a proof-of-concept randomized control pilot study to determine feasibility, acceptability and efficacy of a NIR stimulation protocol in individuals with Parkinson disease (PD). The intervention will involve six sessions over a 2-week period, in which active or sham stimulation is applied to the head using a delivery system that has been approved as a nonsignificant risk since 2003. The delivery system involves six MedX superluminous light emitting diode clusters positioned on the head in distinct configurations for a total of 40 minutes of stimulation. Dosing was based on a pilot study. The investigators plan to enroll 24 non-demented individuals with PD who will be randomized to active or sham groups. Cognitive, motor, and mood outcomes will be obtained before and after the intervention. An exploratory aim involves neuroimaging changes (1P MRS, resting state fMRI). Outcomes will be obtained during the off-dopamine medication state (i.e., standard overnight withdrawal from dopamine medications). The investigators hope to learn whether NIR stimulation has potential for influencing motor and cognitive symptoms in individuals with PD, with goal of determining effect sizes for a potentially larger randomized clinical trial.

Eligibility Criteria:
Inclusion Criteria:

* Diagnosis of idiopathic Parkinson disease by movement disorder neurologist using UK Brain Bank criteria
* Early-mid stage of disease severity
* Willingness to undergo baseline and post-intervention 'off' their normal dopamine medications
* Between 62 and 89 years of age
* Able to provide informed consent and perform cognitive and mood measures on a computer
* Willingness to be randomized to Sham or Real intervention
* Can devote 2 weeks to the intervention, and additional time for pre and post testing
* 8th grade education and ability to read on 8th grade level based on scores on the Wechsler Test of Adult Reading (WTAR) or the Wide Range Achievement Test-IV (WRAT-IV); ability to see 14 pt. text
* On stable doses of major medications for at least two months

Exclusion Criteria:

* History of brain abnormalities/ neurological disorders affecting cognition other than PD; No history of brain surgery
* Evidence of potential dementia based on cognitive screening (e.g., scores \< 5th %ile on the Montreal Cognitive Assessement (MoCA) or the Dementia Rating Scale-2 (DRS-2) based on appropriate age, education and sex norms.
* Use of psychotics, sedatives or other medications with anticholinergic properties;
* Unstable or uncontrolled medical conditions (e.g.,HIV, severe kidney disease)
* Diagnosis of active cancer
* Use of photosensitive medications within 15 days of intervention
* Sensory loss (vision, hearing) or motor deficits that would preclude participation in the experimental cognitive tasks or neuropsychological assessment
* Current or past history of major psychiatric disturbance including schizophrenia, or active psychosis, bipolar disorder, current major depressive episode, current alcohol or substance abuse or history thereof within the past six months. The investigators are not excluding individuals who are taking antidepressants or anti-anxiety medications, however, use of antidepressants and anxiolytics will be recorded and data will be analyzed in post-hoc analyses
* Previous participation in a cognitive training study within the last six months