The effect of transcranial photobiomodulation on cognitive function and attentional performance of older women with mild cognitive impairment: a randomized controlled trial

Shahab Papi; Hamid Allahverdipour; Ali Jahan; Iman Dianat; Mohammad Asghari Jafarabadi; Maryam Moghadam Salimi

doi:10.5114/pm.2022.119794

The effect of transcranial photobiomodulation on cognitive function and attentional performance of older women with mild cognitive impairment: a randomized controlled trial

Prz Menopauzalny. 2022 Sep;21(3):157-164. doi: 10.5114/pm.2022.119794. Epub 2022 Sep 28.

Authors

Shahab Papi¹, Hamid Allahverdipour², Ali Jahan³, Iman Dianat⁴, Mohammad Asghari Jafarabadi⁵, Maryam Moghadam Salimi⁶

Affiliations

¹ Department of Public Health, School of Health, Mazandaran University of Medical Sciences, Sari, Iran.
² Department of Health Education and Promotion, Faculty of Health Sciences, Tabriz University of Medical Sciences, Tabriz, Iran.
³ Department of Speech Therapy, Faculty of Rehabilitation Sciences, Tabriz University of Medical Sciences, Tabriz, Iran.
⁴ Department of Occupational Health and Ergonomics, Faculty of Health, Tabriz University of Medical Sciences, Tabriz, Iran.
⁵ Department of Statistic and Epidemiology, Tabriz University of Medical Sciences, Tabriz, Iran.
⁶ Department of Physical Therapy, Faculty of Rehabilitation Sciences, Tabriz University of Medical Sciences, Tabriz, Iran.

Abstract

Introduction: Mild cognitive impairment (MCI) is a progressive age-related condition caused by physiological and structural changes in the brain, such as neurodegeneration and hypometabolism. Transcranial photobiomodulation (tPBM) is a neuromodulation technique that improves brain metabolism and oxygenation by irradiating red to near-infrared light on a specific area of the head. This study aimed to investigate the effect of multi-session tPBM on the cognitive capacities and attentional function of older women with MCI.

Material and methods: In this randomized controlled trial, 42 older women with MCI were randomly assigned to 2 equal groups: real and sham. The mini-mental state examination (MMSE) and the attentional Go/No-Go task were used to examine the patients. On the right frontal-pole of the cortex, 5 sessions of 850 nm tPBM were given. Re-examinations were conducted on the participants. For the Go/No-Go task, the reaction time to the target (RTT), the percentage of correct trials (PCT), and the efficiency score (ES) were measured.

Results: The findings revealed a significant interaction between group × time for MMSE (F (1, 40) = 20, p < 0.001, h² = 0.33), and the post-hoc paired-samples t-tests revealed a substantial rise in the mean MMSE in the real group (t = 15.9; p = 0.001; d = 9.3). Additionally, for ES (F (1, 40) = 19, p < 0.001, h² = 0.32), RTT (F (1, 40) = 17, p < 0.001, h² = 0.38), and PCT (F (1, 40) = 13, p < 0.001, h² = 0.31), a significant group × time interaction was discovered, and post-hoc paired-samples t-tests revealed a significant improvement in attention performance of the real group for increases in the mean of ES (F (1,40) = 20, p < 0.001, h² = 0.33), (t = 5.3, p < 0.001, d = 0.034), decreases in the mean of RTT (t = 4.8; p = 0.001; d = -37.4), and increases in the mean of PCT (t = 2.67; p = 0.015; d = 6.3).

Conclusions: According to the findings of this study, tPBM had a positive effect on older people's attention and cognitive abilities.

Keywords: mild cognitive impairment; older adults; sustained attention; transcranial photobiomodulation; women.