EEG neurofeedback research: A fertile ground for psychiatry?

The clinical efficacy of neurofeedback is still a matter of debate. This paper analyzes the factors that should be taken into account in a transdisciplinary approach to evaluate the use of EEG NFB as a therapeutic tool in psychiatry. Neurofeedback is a neurocognitive therapy based on human-computer interaction that enables subjects to train voluntarily and modify functional biomarkers that are related to a defined mental disorder. We investigate three kinds of factors related to this definition of neurofeedback. We focus this article on EEG NFB. The first part of the paper investigates neurophysiological factors underlying the brain mechanisms driving NFB training and learning to modify a functional biomarker voluntarily. Two kinds of neuroplasticity involved in neurofeedback are analyzed: Hebbian neuroplasticity, i.e. long-term modification of neural membrane excitability and/or synaptic potentiation, and homeostatic neuroplasticity, i.e. homeostasis attempts to stabilize network activity. The second part investigates psychophysiological factors related to the targeted biomarker. It is demonstrated that neurofeedback involves clearly defining which kind of relationship between EEG biomarkers and clinical dimensions (symptoms or cognitive processes) is to be targeted. A nomenclature of accurate EEG biomarkers is proposed in the form of a short EEG encyclopedia (EEGcopia). The third part investigates human-computer interaction factors for optimizing NFB training and learning during the closed loop interaction. A model is proposed to summarize the different features that should be controlled to optimize learning. The need for accurate and reliable metrics of training and learning in line with human-computer interaction is also emphasized, including targeted biomarkers and neuroplasticity. All these factors related to neurofeedback show that it can be considered as a fertile ground for innovative research in psychiatry.

Efficacy of second-line chemotherapy after a first-line triplet in patients with metastatic colorectal cancer.

Background: Exposing patients with metastatic colorectal cancer (mcrc) to all three active chemotherapeutic agents (oxaliplatin, irinotecan, fluorouracil) has improved survival. The benefit of second-line chemotherapy after a first-line triplet is not clearly defined. We evaluated the efficacy of second-line chemotherapy in patients who had received first-line triplet therapy. Methods: The medical records of patients treated on a prospective trial of first-line triplet therapy were reviewed for second-line treatment. Univariate and multivariate analyses were performed to establish factors of prognostic significance. Results: Of the 53 patients who received first-line triplet therapy, 28 (53%) received second-line chemotherapy [13 men; 8 with a colon primary; mutant KRAS in 10, wild-type in 15, and unknown status in 3; Eastern Cooperative Oncology Group performance status (ps) of 1 in 16 patients, ps 2 in 3, ps 3 in 2, and unknown in 7; involved organs: liver in 17 patients, lung in 16, and peritoneum in 8]. Second-line chemotherapy consisted of xelox or folfox in 13 patients, xeliri or folfiri in 12, and single-agent irinotecan in 3. Concurrent bevacizumab was given in 16 patients (57%), and cetuximab, in 2 (7%). Median survival was 28.0 months [95% confidence interval (ci): 22.8 months to 33.2 months] for patients receiving second-line therapy and 23.0 months (95% ci: 13.2 months to 32.8 months) for those not receiving it. Best response was partial in 6 patients (21%), stable disease in 11 (39%), and progressive disease in 11 (39%). Median progression-free survival was 4.8 months (95% ci: 2.4 months to 9.6 months), and overall survival was 15 months (95% ci: 9.6 months to 20.4 months). Conclusions: Second-line chemotherapy after first-line triplet therapy in mcrc is feasible and suggests efficacy comparable to that reported for second-line therapy after a doublet, regardless of the agent used.