Traditional treatment options in drug-resistant epilepsy cases may include surgery or neurostimulation devices. However, a promising non-invasive approach is emerging: neurofeedback training
Epilepsy is a chronic neurological condition characterised by recurrent seizures. These can be a one-time event, or happen repeatedly without a trigger. While the cause of epilepsy, as well as the localisation of the seizures (Figure 1), may be undetermined, it is linked to abnormal brain activity and damage, possibly from head injuries, strokes, or substance abuse (Fisher et al., 2005). Epilepsy can be lifelong or temporary. When medication fails to control seizures, it becomes intractable or severe, known as drug-resistant epilepsy. Traditional treatment options for such cases may include surgery or neurostimulation devices. However, a promising non-invasive approach is emerging: neurofeedback training.
How Could Neurofeedback Help with Epilepsy?
Imagine being able to see your brain activity in real-time and learn to control it. That is the basic idea behind neurofeedback. It uses tools like electroencephalography (EEG) to measure brainwave patterns. Patients receive feedback on this activity, often visually or through sound. With repeated training sessions, they learn to adjust their brain activity towards a desired state, potentially leading to symptom improvement.
In epilepsy, abnormal electrical activity in the brain triggers seizures. Therefore, neurofeedback aims to target these abnormal patterns. In other words, it ‘teaches the brain to regulate its own activity’. This may be achieved through two main ways:
· Reducing focal slow wave activity: epileptic activity often involves increased slow wave activity (delta and theta waves) in specific brain regions. Neurofeedback can train patients to decrease this activity, potentially reducing seizure frequency (Lubar et al., 1986).
· Normalising brain activity: neurofeedback might promote a more balanced and regulated brain state, potentially making it less susceptible to seizure initiation (Tan et al., 2009).
Efficacy Research on Neurofeedback for Epilepsy.
Efficacy research on neurofeedback training for Epilepsy has been carried out since the 70s, showing promising results. In a meta-analysis by Sterman (2000), most studies (82%) showed significant seizure reduction (over 30%), with an average improvement exceeding 50%. Even complete seizure freedom was achieved in a small number of cases (around 5%) for up to a year. This was achieved through SMR neurofeedback training, and/or neurofeedback training targeted to coherence abnormalities.
Effectiveness of SMR Neurofeedback Training on Epilepsy.
The Sensory Motor Rhythm (SMR) is a specific frequency range of brainwave activity (12-15 Hz) that occurs over the sensorimotor cortex, which is involved in motor control and sensory processing. SMR activity is typically observed during states of quiet wakefulness and relaxation, and it plays a role in maintaining a calm and focused mental state (Arroyo et al., 1993). In individuals with epilepsy, there is often an imbalance in brainwave activity, including excessive slow-wave activity and reduced SMR activity.
SMR neurofeedback aims to rebalance these brainwave patterns by rewarding the individual for increasing SMR activity while decreasing slow-wave activity, particularly in regions associated with seizure generation. Through repeated sessions of SMR neurofeedback training, the brain undergoes neuroplastic changes, leading to improved self-regulation of brainwave activity and enhanced seizure control (Sterman & Egner, 2006).
Additionally, benefits of SMR neurofeedback training have been also reported in the context of improved cognitive functioning (Morales-Quzada et al., 2019). In short, then, by increasing SMR activity and reducing slow-wave activity, the brain becomes less prone to hyperexcitability and seizure generation as a result of an improved brain’s ability to self-regulate. Table 1 below offers a summary of the evidence in support of SMR neurofeedback training for reducing seizures in epilepsy.
Overall, it has been suggested that neurofeedback impacts seizure susceptibility by enhancing functional connectivity across the brain. Through neurofeedback sessions, the brain gradually adapts to minimise seizure occurrence, refining its electrical activity primarily within epileptic regions.
Neurofeedback Training Targeted to Coherence Abnormalities Associated with Epilepsy.
Brain coherence refers to the degree of similarity in the electrical activity of different brain regions. It essentially tells us how well different parts of the brain are communicating with each other. When different brain regions communicate effectively, their electrical activity will show a certain level of similarity or ‘coherence’. This means their rhythms and frequencies tend to be aligned. In epilepsy, this communication between brain regions can become excessively synchronised (creating buildup of electrical activity that triggers seizure) or disconnected (affecting various cognitive functions like memory, attention or emotional regulation).
Advanced brain scans (for example, qEEG) now allow to pinpoint specific imbalances in brainwave activity (coherence abnormalities) for people with epilepsy who don't respond to medication. By using neurofeedback training, it is possible to target these imbalances. Accordingly, when communication between brain regions is too weak (decreased coherence), it can be up-trained. Conversely, overly strong connections (increased coherence) can be down-trained. Table 2 offers a summary of a study by Walker & Kozlowski (2005) training coherence in epilepsy patients. Importantly, results show that, in some cases, it even allowed patients to go off medication completely.
In summary, these studies suggest that neurofeedback, by normalising brainwave coherence, might help prevent seizures. More precisely, neurofeedback training could potentially address the increased synchronisation observed before seizures, thereby reducing their propagation (Chavez et al., 2003).
Neurofeedback as a Supportive, Adjunctive Tool for Epilepsy Management.
Despite showing great promise, it is important to note that research is still developing, and neurofeedback should not be considered a sole treatment for epilepsy - neurofeedback training is not meant to replace seizure medication. Instead, it functions as an adjunctive therapy, working alongside medication to enhance patient's seizure resistance by addressing the underlying imbalances in brainwave activity. More recently, other neurofeedback (Slow Cortical Potentiation, SCP) and peripheral biofeedback techniques (galvanic skin response; GSR) have also been included on the periphery of epilepsy management protocols, yet additional research and increased availability of biofeedback interventions are crucial for its wider adoption.
For optimal epilepsy management, a multi-faceted approach is recommended. This might include dietary adjustments, improved sleep hygiene, reducing substance use, stress management techniques and coping mechanisms (Ventola, 2014). By incorporating these strategies alongside medication and potentially neurofeedback training, patients with epilepsy can explore a comprehensive approach to managing their condition.
This article has been written by Goretti Hurtado Barbeito.
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References:
· Arroyo, S.; Lesser, RP.; Gordon, B; Uematsu, S; Jackson, D; Webber, R (1993). "Functional significance of the mu rhythm of human cortex: an electrophysiologic study with subdural electrodes". Electroencephalography and Clinical Neurophysiology. 87 (3): 76–87.
· Chavez M, Quyen M, Navarro V, Baulac M, Martinerie J. Spatiotemporal dynamics prior to neocortical seizures: amplitude vs. phase couplings. IEEE Trans 2003;50:571–83.
· Fisher RS, van Emde Boas W, Blume W, Elger C, Genton P, Lee P, Engel J Jr. Epileptic seizures and epilepsy: definitions proposed by the International League Against Epilepsy (ILAE) and the International Bureau for Epilepsy (IBE). Epilepsia. 2005 Apr;46(4):470-2. doi: 10.1111/j.0013-9580.2005.66104.x. PMID: 15816939.
· Lubar, J.F., et al., EEG operant conditioning in intractable epileptics. Arch Neurol, 1981. 38(11): p. 700-4.
· Sterman MB, Egner T. Foundation and practice of neurofeedback for the treatment of epilepsy. Appl Psychophysiol Biofeedback. 2006 Mar;31(1):21-35. doi: 10.1007/s10484-006-9002-x. PMID: 16614940.
· Sterman MB. Basic concepts and clinical findings in the treatment of seizure disorders with EEG operant conditioning. Clin Electroencephalogr 2000;32(1):45–55.
· Ventola CL. Epilepsy management: newer agents, unmet needs, and future treatment strategies. P T. 2014 Nov;39(11):776-92. PMID: 25395820; PMCID: PMC4218673.
· Morales-Quezada, L., Martinez, D., El-Hagrassy, M. M., Kaptchuk, T. J., Sterman, M. B., & Yeh, G. Y. (2019). Neurofeedback impacts cognition and quality of life in pediatric focal epilepsy: An exploratory randomized double-blinded sham-controlled trial. Epilepsy & behavior : E&B, 101(Pt A), 106570.
· Tan G, Thornby J, Hammond DC, Strehl U, Canady B, Arnemann K, Kaiser DA. Meta-analysis of EEG biofeedback in treating epilepsy. Clin EEG Neurosci. 2009 Jul;40(3):173-9. doi: 10.1177/155005940904000310. PMID: 19715180.
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