Study results were based on a change in the Insomnia Severity Index (ISI) which measures the severity of sleep disruption using a zero-to-28 point scale; the median ISI for study participants was between 18.7 and 18.9, which is considered moderate-to-severe insomnia. Researchers found that the HIRREM group had a 10.3 point drop in ISI, improved insomnia symptoms and, clinically moved into a category of ‘no insomnia’ or ‘sub-threshold insomnia’. The control subjects, who continued their existing insomnia treatment without HIRREM, showed no change in ISI. However, when the crossover control group received HIRREM therapy, the results were indistinguishable from those of the original HIRREM group.
This unblinded, wait-list control, crossover study enrolled 20 participants (14 women and 6 men). Ten people were randomized to receive HIRREM sessions, plus usual care; the remaining 10 were assigned to the wait-list control group. An initial assessment determined the symmetry, or balance, in amplitude and frequencies between the brain hemispheres and data collection included a subject’s ISI and other measures including blood pressure and neurocognitive function tests.
Study participants randomized to HIRREM underwent eight to 12 sessions that each lasted between 60-90 minutes. The sessions involved reclining in a zero gravity chair and placing sensors over numerous locations on both sides of the scalp. A musical tone, determined by a mathematic algorithm and based on the dominant frequency in a floating middle range of the participant’s EEG frequencies, was played back to the participant through ear buds. Resonance between musical tones and oscillating brain circuits is designed to allow the brain to auto-calibrate, moving towards better balance, with associated improvement in symptoms.
The limitations of the study include the small number of study participants and the absence of a sham-placebo control group which prevented blinding. This means it is possible that the changes observed with HIRREM, could be due to a placebo effect. In addition, because HIRREM therapy involves social interaction and relaxation, there may be other non-specific mechanisms for improvement, in addition to the tonal mirroring. Although the researchers believe that the degree of improvement and length of time it persisted (for four weeks after the last session) suggests real change through HIRREM, Tegeler is planning a larger clinical trial using a sham placebo, to confirm the HIRREM effect and further explore the technology.
SOURCE Wake Forest Baptist Medical Center