Acoustic Stimulation May Significantly Impact Adults Who Have Persistent Symptoms Following Concussion

Concussion, or mild traumatic brain injury (mTBI), is not an uncommon occurrence among service members (SMs) of the United States military. While patients usually recover within a month, many suffer from persistent or permanent symptomatic and functional sequelae post-concussion.

There is new research that has identified acoustic stimulation as a means of improving post-concussive symptoms, according to authors of research published in the Annals of Clinical and Translational Neurology. While linking tones to a person’s brainwaves was not shown tonecessarily be more effective, the authors noted that more research needs to be done.

“The brain is complex,” wrote study authors in the article. “No intervention has yet proven efficacious in addressing the full sequelae of postconcussive symptoms, making this one of the more challenging medical conditions to try to address.”

While social support, sex, and socioeconomic status can influence recovery, the study showed that computer-generated acoustic stimulation is a tolerable therapeutic that may clinically and statistically improve symptoms associated with persistent concussion.

This double-blind, 2-arm, randomized controlled clinical trial (rCCT) included 106 SM, veterans, or spouses with history of mTBI and persistent symptoms (Neurobehavioral Symptom Inventory [NSI] Score of 23 or greater). The aim of the study was to evaluate a closed-loop acoustic stimulation neurotechnology called Cereset Research (CR).

The CR technology, which uses computer algorithm standard operating procedure (CR-SOP), works by echoing brainwaves and reflecting them as engineered tones in a closed-loop fashion toinduce relaxation and wellbeing.

Patients in the intervention went through 10 cumulative hours of comfortable rest in a zero-gravity chair in the dark with eyes closed. Patients were either randomized to receive computer-generated acoustic stimulation with tones that linked to brainwaves (LB) or receive acoustic stimulation with tones not linked to brainwaves (NL; control).

Woman with headache | Image credit: Sebra - stock.adobe.com

The primary outcome of the study was change in score on the NSI, a 22-item questionnaire of neurobehavioral symptoms, ranked from 0 to 4 (very severe symptoms), from baseline to 3-months post-intervention.

All study patients had a significant drop in average score (41.0 to 27.2 [P < 0.0001]). Patients in the intervention arm experienced an NSI score reduction of 39.9 to 28.2 from baseline to post-intervention, and patients in the NL arm experienced a reduction of 41.5 to 26.2. At 3 months, NSI scores were 31.5 (BL) and 29.9 (NL), and at 6 months, scores were 29.4 (BL) and 27.3(NL). These findings suggest the brainwave-matching tones were not significantly more effective for symptoms than tones not linked to patient brainwaves.

Participants also rated the severity of symptoms related to post-traumatic stress disorder (PTSD) and depression on the PTSD Checklist for DSM-5 (PCL5) and Patient Health Questionnaire (PHQ9), respectively. Acoustic stimulation modestly improved PTSD symptom severity from baseline to post-intervention, but it was not clinically significant; there was also no significant improvement in depression severity.

Study limitations include a wide inclusion criterion, whereby participants could have had a concussion 10 years or 3 months prior to the intervention. In addition, there was not a static intervention duration, there was no complete autonomic data, and NSI may relate to PTSD severity more than concussion history.

Additionally, there is new research being conducted that highlights the possible benefits of acoustic stimulation combined with micro electrical stimulation of the scalp. According to the authors, more investigation should be done to address this difficult-to-treat condition.

“There might also be an unexplored relationship between TBI and other neurodegenerative mechanisms [and] scientists continue to evaluate if neuroplasticity, inflammation, resonance, or other factors could be influencing the treatment of TBI,” authors write in the article.

Reference

Cole WR, Tegeler CL, Choi SY, et al. Randomized, controlled clinical trial of acoustic stimulation to reduce postconcussive symptoms. Ann Clin Transl Neurol.2023;doi:10.1002/acn3.51937