Examining the Impact of Photobiomodulation (PBM) on Brain Function in Dementia
Examining the Impact of Photobiomodulation (PBM) on Brain Function in Dementia
A recent study (Saltmarche et al., 21017) examined the effects of photobiomodulation (PBM), a kind of light therapy that uses red or near-infrared light to heal and protect tissue that has either been injured, is degenerating, or else is at risk of dying, in 5 older adults with dementia. After 12 weeks of PBM treatments, delivered with a commercially available, wearable device, the patients with mild to moderately severe dementia showed improvements on the Mini-mental State Exam (MMSE, p<0.003) and Alzheimer's Disease Assessment Scale-cognitive, ADAS-cog, p<0.03). The caregivers, who kept daily journals of their experiences during the 12 weeks of PBM treatment, reported better sleep, fewer angry outbursts, decreased anxiety and wandering in their loved-ones with dementia. The goals of this trial are to: (1) replicate this finding in a larger group of individuals with dementia and (2) to examine the underling brain mechanisms behind the changes in cognitive function.
Photobiomodulation (PBM) describes a kind of light therapy that uses red or near-infrared light to stimulate, heal, regenerate, and protect tissue that has either been injured, is degenerating, or else is at risk of dying. Human cadaver studies have shown near-infrared wavelengths can penetrate 40-50 mm through the scalp and skull. Saltmarche et al. (2017) recently reported that 12-weeks of transcranial treatment with a commercially available PBM device (i.e., the Vielight "Neuro ") benefits cognitive function in patients with mild-to-moderately severe dementia. Specifically, Saltmarche et al. reported improvements on the Mini Mental State Examination (MMSE, p< 0.003) and Alzheimer's Disease Assessment Scale-cognitive subscale (ADAS-cog, p< 0.03) in 5 dementia patients after 12-weeks of PBM treatment.
The first aim of this trial is to replicate Saltmarche et al' s findings that the effects of 12-weeks of PBM treatment can improve cognitive function in older adults with dementia. Because the Vielight Neuro device targets nodes of the default mode network (DMN), which is dysregulated in Alzheimer's disease (AD), the second aim of this pilot study is to investigate whether 12 weeks of PBM therapy with the Vielight Neuro device improves DMN connectivity in older adults with dementia. Finally, because there is suggestive evidence that PBM therapy enhances blood flow, the third aim of the trial is to examine whether 12-weeks of PBM therapy improves cerebral blood flow (CBF) in older adults with dementia. The trial will also explore the effects of PBM treatment on quality of life in older adults with dementia and on caregiver burden.
Ten older adults with dementia (i.e., the primary study participants, PP) and their caregivers (CG) will be enrolled in a randomized, wait-list control trial. Five PPs will be randomized to the "immediate" PBM treatment group after the baseline psychometric and MRI assessments. Five PP will be randomized to a "delayed" PBM treatment group that will not receive PBM treatment with the Vielight Neuro device until after the 12 week psychometric and MRI assessments.
Neuroimaging measures will be assessed in all PPs at baseline and week 12. Cognitive function and quality of life will be assessed in all PPs at baseline, weeks 6 and 12. Caregivers (CGs) will be asked to fill out questionnaires Caregivers (CGs) will be asked to fill out questionnaires about caregiver burden, positive aspects of care giving, depressive symptomology, and dementia-related behaviors in the PP at baseline, weeks 6 and 12.
PPs randomized to the "immediate" PBM treatment group will receive PBM with the Vielight Neuro device once a day, every other day (e.g., Mon, Wed, Fri) for 12 weeks. PPs randomized to the "delayed" PBM treatment group will keep doing their usual activities for 12 weeks. After the 12 week psychometric and MRI assessments, PPs randomized to the "delayed" PBM treatment group will receive PBM with the Vielight Neuro device once a day, every other day (e.g., Mon, Wed, Fri) for 12 weeks. PPs randomized to the "delayed" PBM treatment group will undergo additional psychometric assessment at weeks 18 and 24. CGs of PPs randomized to the "delayed" PBM treatment group will be asked to fill out additional questionnaires about caregiver burden, positive aspects of care giving, depressive symptomology, and dementia-related behaviors in the PP at baseline, weeks 18 and 24.
Inclusion Criteria:
For primary study participants (i.e., individuals with dementia):
age > 50 years a diagnosis of dementia (preferably AD) by their neurologist English language fluency, legally authorized representative consent no contraindications for MRI MMSE > 11
Inclusion criteria for caregivers:
current provision of care to primary participant with dementia ability to answer questions about the primary participant's behaviors, quality of life, and their own level of stress.
Exclusion Criteria:
For primary study participants (i.e., individuals with dementia):
lack of assent to study procedures contraindications for MRI (i.e., pacemakers, metal implants, claustrophobia) terminal illness (i.e., life expectancy < 1 year) started dementia medication (i.e., cholinesterase inhibitor or memantine) in the past 3 months or planning to start new dementia medication current participation in another research study that could potentially confound current study (e.g., medication or behavioral intervention) MMSE < 11.
Exclusion criteria for caregivers:
major neurological or psychiatric condition terminal illness evidence of cognitive impairment inability to consent to study procedures