EEG biofeedback, or neurofeedback, involves real-time display of brain electrical activity provided to the individual as visual or auditory information. Use of this feedback approach was studied in patients with cancer for its effect on cognitive impairment, sleep-wake disturbances, and fatigue.
Effectiveness Not Established
Research Evidence Summaries
Alvarez, J., Meyer, F. L., Granoff, D. L., & Lundy, A. (2013). The effect of EEG biofeedback on reducing postcancer cognitive impairment. Integrative Cancer Therapies, 12, 475–487.doi: 10.1177/1534735413477192
To determine the feasibility of using electroencephalography (EEG) biofeedback (neurofeedback) and identify its potential effects on cognitive impairment, sleep quality, fatigue, and psychological symptoms.
Intervention Characteristics/Basic Study Process:
Neurofeedback was provided using an EEG system that detects and alerts the brain of phase changes to increase brain flexibility and resilience. Single EEG sensors, placed at the left C3 and right C4 for each brain hemisphere, analyze EEG activity for identification of phase state changes in the brain. During the session, the patient listened to music while sitting quietly; brief interruptions of the music signal alerted the patient that the software detected phase changes and was providing the brain feedback. No patient response or action was required because it is believed that the brain uses the feedback for its own self-organization without conscious action. Patients had twice weekly sessions for 10 weeks. Assessments were performed prior to beginning the sessions and during the fourth, seventh, and tenth week of sessions.
- The study included 23 Caucasian women with a median age of 56 years (range 43–70).
- All patients were breast cancer survivors with self-reported cognitive impairment since diagnosis.
- Median time since last chemotherapy was 24 months (range 9–59).
- Of the patients, 26% were taking antidepressants and 39% were taking sleep medication.
The study was conducted at a single outpatient site in Ohio.
Phase of Care and Clinical Applications:
The study has clinical applicability for late effects and survivorship.
The study used a feasibility quasiexperimental design.
- Functional Assessment of Cancer Therapy–Cognitive Function (FACT-C)
- Functional Assessment of Chronic Illness Therapy–Fatigue (FACIT-F)
- Pittsburgh Sleep Quality Index (PSQI)
- Brief Symptom Inventory (BSI)
Significant symptom presence and dysfunction were reported by this sample at baseline, as compared to normative data. Baseline comparisons to normative sample showed significant differences from the norms in all measures, indicating significant dysfunction. FACT, FACIT, and PSQI scores improved over time, although not at a constant rate over longitudinal time points. At study conclusion, symptom report of dysfunction no longer differed significantly from normative populations on three of four FACT-C subscales, FACIT, and PSQI. The proportion of patients using sleep medications declined from 39% to 17% by study conclusion. No adverse effects of the intervention were identified.
EEG neurofeedback was shown to be feasible and potentially beneficial for improving cognitive function, sleep, and fatigue in breast cancer survivors.
- The study had a small sample size, with less than 30 patients.
- The study had risks of bias due to no control group, no blinding, and no random assignment.
- Unintended interventions or applicable interventions were not described that would influence the results.
- The intervention was expensive, impractical, or required training.
- Findings were not generalizable.
- This intervention requires specialized equipment, training, and setting to provide EEG feedback sessions.
- It was not stated whether patients were receiving any other interventions aimed at these symptoms.
- Cognitive function was measured only with self-report instruments with repeated measures design; thus, self-reported improvements may be because of testing effects.
- No objective cognitive function instruments were used to determine cognitive impairment at time of baseline or improvement in cognitive function over time.
- The sample was a homogenous group of patients, potentially limiting generalizability to other patient groups.
This study reported a potentially promising intervention that may have a positive effect on several symptoms experienced by breast cancer survivors. Additional well-designed clinical trials are needed to assess the efficacy of this approach.