EEG changes during forced alternate nostril breathing

Non-invasive sensory neuromodulation in epilepsy: Updates and future perspectives

Epilepsy, one of the most common neurological disorders, often is not well controlled by current pharmacological and surgical treatments. Sensory neuromodulation, including multi-sensory stimulation, auditory stimulation, olfactory stimulation, is a kind of novel noninvasive mind-body intervention and receives continued attention as complementary safe treatment of epilepsy. In this review, we summarize the recent advances of sensory neuromodulation, including enriched environment therapy, music therapy, olfactory therapy, other mind-body interventions, for the treatment of epilepsy based on the evidence from both clinical and preclinical studies. We also discuss their possible anti-epileptic mechanisms on neural circuit level and propose perspectives on possible research directions for future studies.

Analysis of Respiratory Sinus Arrhythmia and Directed Information Flow between Brain and Body Indicate Different Management Strategies of fMRI-Related Anxiety

Background: Respiratory sinus arrhythmia (RSA) denotes decrease of cardiac beat-to-beat intervals (RRI) during inspiration and RRI increase during expiration, but an inverse pattern (termed negative RSA) was also found in healthy humans with elevated anxiety. It was detected using wave-by-wave analysis of cardiorespiratory rhythms and was considered to reflect a strategy of anxiety management involving the activation of a neural pacemaker. Results were consistent with slow breathing, but contained uncertainty at normal breathing rates (0.2–0.4 Hz). Objectives and methods: We combined wave-by-wave analysis and directed information flow analysis to obtain information on anxiety management at higher breathing rates. We analyzed cardiorespiratory rhythms and blood oxygen level-dependent (BOLD) signals from the brainstem and cortex in 10 healthy fMRI participants with elevated anxiety. Results: Three subjects with slow respiratory, RRI, and neural BOLD oscillations showed 57 ± 26% negative RSA and significant anxiety reduction by 54 ± 9%. Six participants with breathing rate of ~0.3 Hz showed 41 ± 16% negative RSA and weaker anxiety reduction. They presented significant information flow from RRI to respiration and from the middle frontal cortex to the brainstem, which may result from respiration-entrained brain oscillations, indicating another anxiety management strategy. Conclusion: The two analytical approaches applied here indicate at least two different anxiety management strategies in healthy subjects.

EEG signatures change during unilateral Yogi nasal breathing

Airflow through the left-and-right nostrils is said to be entrained by an endogenous nasal cycle paced by both poles of the hypothalamus. Yogic practices suggest, and scientific evidence demonstrates, that right-nostril breathing is involved with relatively higher sympathetic activity (arousal states), while left-nostril breathing is associated with a relatively more parasympathetic activity (stress alleviating state). The objective of this study was to further explore this laterality by controlling nasal airflow and observing patterns of cortical activity through encephalographic (EEG) recordings. Thirty subjects participated in this crossover study. The experimental session consisted of a resting phase (baseline), then a period of unilateral nostril breathing (UNB) using the dominant nasal airway, followed by UNB using the non-dominant nasal airway. A 64-channel EEG was recorded throughout the whole session. The effects of nostril-dominance, and nostril-lateralization were assessed using the power spectral density of the neural activity. The differences in power-spectra and source localization were calculated between EEG recorded during UNB and baseline for delta, theta, alpha, beta and gamma bands. Cluster-based permutation tests showed that compared to baseline, EEG spectral power was significantly (1) decreased in all frequency bands for non-dominant nostril UNB, (2) decreased in alpha, beta and gamma bands for dominant nostril UNB, (3) decreased in all bands for left nostril UNB, and (4) decreased in all bands except delta for right nostril UNB. The beta band showed the most widely distributed changes across the scalp. our source localisation results show that breathing with the dominant nostril breathing increases EEG power in the left inferior frontal (alpha band) and left parietal lobule (beta band), whereas non-dominant nostril breathing is related to more diffuse and bilateral effects in posterior areas of the brain.These preliminary findings may stimulate further research in the area, with potential applications to tailored treatment of brain disorders associated with disruption of sympathetic and parasympathetic activity.

The breathing brain: The potential of neural oscillations for the understanding of respiratory perception in health and disease

Dyspnea or breathlessness is a symptom occurring in multiple acute and chronic illnesses, however, the understanding of the neural mechanisms underlying its subjective experience is limited. In this topical review, we propose neural oscillatory dynamics and cross-frequency coupling as viable candidates for a neural mechanism underlying respiratory perception, and a technique warranting more attention in respiration research. With the evidence for the potential of neural oscillations in the study of normal and disordered breathing coming from disparate research fields with a limited history of interdisciplinary collaboration, the main objective of the review was to converge the existing research and suggest future directions. The existing findings show that distinct limbic and cortical activations, as measured by hemodynamic responses, underlie dyspnea, however, the time-scale of these activations is not well understood. The recent findings of oscillatory neural activity coupled with the respiratory rhythm could provide the solution to this problem, however, more research with a focus on dyspnea is needed. We also touch on the findings of distinct spectral patterns underlying the changes in breathing due to experimental manipulations, meditation and disease. Subsequently, we suggest general research directions and specific research designs to supplement the current knowledge using neural oscillation techniques. We argue for the benefits of interdisciplinary collaboration and the converging of neuroimaging and behavioral methods to best explain the emergence of the subjective and aversive individual experience of dyspnea.

The neuronal associations of respiratory-volume variability in the resting state

The desire to enhance the sensitivity and specificity of resting-state (rs-fMRI) measures has prompted substantial recent research into removing noise components. Chief among contributions to noise in rs-fMRI are physiological processes, and the neuronal implications of respiratory-volume variability (RVT), a main rs-fMRI-relevant physiological process, is incompletely understood. The potential implications of RVT in modulating and being modulated by autonomic nervous regulation, has yet to be fully understood by the rs-fMRI community. In this work, we use high-density electroencephalography (EEG) along with simultaneously acquired RVT recordings to help address this question. We hypothesize that (1) there is a significant relationship between EEG and RVT in multiple EEG bands, and (2) that this relationship varies by brain region. Our results confirm our first hypothesis, although all brain regions are shown to be equally implicated in RVT-related EEG-signal fluctuations. The lag between RVT and EEG is consistent with previously reported values. However, an interesting finding is related to the polarity of the correlation between RVT and EEG. Our results reveal potentially two main regimes of EEG-RVT association, one in which EEG leads RVT with a positive association between the two, and one in which RVT leads EEG but with a negative association between the two. We propose that these two patterns can be interpreted differently in terms of the involvement of higher cognition. These results further suggest that treating RVT simply as noise is likely a questionable practice, and that more work is needed to avoid discarding cognitively relevant information when performing physiological correction rs-fMRI.

Role of Yoga and Meditation as Complimentary Therapeutic Regime for Stress-Related Neuropsychiatric Disorders: Utilization of Brain Waves Activity as Novel Tool

During recent decades, stress-related neuropsychiatric disorders such as anxiety, depression, chronic tension headache, and migraine have established their stronghold in the lives of a vast number of people worldwide. In order to address this global phenomenon, intensive studies have been carried out leading to the advancement of drugs like anti-depressants, anxiolytics, and analgesics which although help in combating the symptoms of such disorders but also create long-term side effects. Thus, as an alternative to such clinical practices, various complementary therapies such as yoga and meditation have been proved to be effective in alleviating the causes and symptoms of different neuropsychiatric disorders. The role of altered brain waves in this context has been recognized and needs to be pursued at the highest level. Thus, the current study provides a review focused on describing the effects of yoga and meditation on anxiety and depression as well as exploring brain waves as a tool for assessing the potential of these complementary therapies for such disorders.

Effect of Alternate Nostril Breathing Exercise on Experimentally Induced Anxiety in Healthy Volunteers Using the Simulated Public Speaking Model: A Randomized Controlled Pilot Study

A randomized controlled pilot study was carried out to determine the effect of a 15-minute practice of ANB exercise on experimentally induced anxiety using the simulated public speaking model in yoga-naïve healthy young adults. Thirty consenting medical students were equally divided into test and control groups. The test group performed alternate nostril breathing exercise for 15 minutes, while the control group sat in a quiet room before participating in the simulated public speaking test (SPST). Visual Analog Mood Scale and Self-Statements during Public Speaking scale were used to measure the mood state at different phases of the SPST. The psychometric scores of both groups were comparable at baseline. Repeated-measures ANOVA showed a significant effect of phase (p < 0.05), but group and gender did not have statistically significant influence on the mean anxiety scores. However, the test group showed a trend towards lower mean scores for the anxiety factor when compared with the control group. Considering the limitations of this pilot study and the trend seen towards lower anxiety in the test group, alternate nostril breathing may have potential anxiolytic effect in acute stressful situations. A study with larger sample size is therefore warranted. This trial is registered with CTRI/2014/03/004460.

Rhythms of the body, rhythms of the brain: Respiration, neural oscillations, and embodied cognition

In spite of its importance as a life-defining rhythmic movement and its constant rhythmic contraction and relaxation of the body, respiration has not received attention in Embodied Cognition (EC) literature. Our paper aims to show that (1) respiration exerts significant and unexpected influence on cognitive processes, and (2) it does so by modulating neural synchronization that underlies specific cognitive processes. Then, (3) we suggest that the particular example of respiration may function as a model for a general mechanism through which the body influences cognitive functioning. Finally, (4) we work out the implications for EC, draw a parallel to the role of gesture, and argue that respiration sometimes plays a double, pragmatic and epistemic, role, which reduces the cognitive load. In such cases, consistent with EC, the overall cognitive activity includes a loop-like interaction between neural and non-neural elements.

Yoga for epilepsy

BACKGROUND

This is an updated version of the original Cochrane Review published in the Cochrane Library, Issue 5, 2015.Yoga may induce relaxation and stress reduction, and influence the electroencephalogram and the autonomic nervous system, thereby controlling seizures. Yoga would be an attractive therapeutic option for epilepsy if proved effective.

OBJECTIVES

To assess whether people with epilepsy treated with yoga:(a) have a greater probability of becoming seizure free;(b) have a significant reduction in the frequency or duration of seizures, or both; and(c) have a better quality of life.

SEARCH METHODS

For this update, we searched the Cochrane Epilepsy Group Specialized Register (3 January 2017), the Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 12) in the Cochrane Library (searched 3 January 2017), MEDLINE (Ovid, 1946 to 3 January 2017), SCOPUS (1823 to 3 January 2017), ClinicalTrials.gov (searched 3 January 2017), the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (searched 3 January 2017), and also registries of the Yoga Biomedical Trust and the Research Council for Complementary Medicine. In addition, we searched the references of all the identified studies. No language restrictions were imposed.

SELECTION CRITERIA

The following study designs were eligible for inclusion: randomised controlled trials (RCT) of treatment of epilepsy with yoga. The studies could be double-, single- or unblinded. Eligible participants were adults with uncontrolled epilepsy comparing yoga with no treatment or different behavioural treatments.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the trials for inclusion and extracted data. The following outcomes were assessed: (a) percentage of people rendered seizure free; (b) seizure frequency and duration; (c) quality of life. Analyses were on an intention-to-treat basis. Odds ratio (OR) with 95% confidence intervals (95% Cls) were estimated for the outcomes.

MAIN RESULTS

We did not identify any new studies for this update, therefore the results are unchanged.For the previous version of the review, the authors found two unblinded trials in people with refractory epilepsy. In total these two studies included 50 people (18 treated with yoga and 32 to control interventions). Antiepileptic drugs were continued in all the participants. Baseline phase lasted three months in both studies and treatment phase from five weeks to six months in the two trials. Randomisation was by roll of a die in one study and using a computerised randomisation table in the other one but neither study provided details of concealment of allocation and were rated as unclear risk of bias. Overall, the two studies were rated as low risk of bias (all participants were included in the analysis; all expected and pre-expected outcomes were reported; no other sources of bias).The overall ORs with 95% CI were as follows: (i) seizure free for six months - for yoga versus sham yoga the OR was 14.54 (95% CI 0.67 to 316.69) and for yoga versus 'no treatment' group it was 17.31 (95% CI 0.80 to 373.45); for Acceptance and Commitment Therapy (ACT) versus yoga the OR was 1.00 (95% Cl 0.16 to 6.42); (ii) reduction in seizure frequency - the mean difference between yoga versus sham yoga group was -2.10 (95% CI -3.15 to -1.05) and for yoga versus 'no treatment' group it was -1.10 (95% CI -1.80 to -0.40); (iii) more than 50% reduction in seizure frequency - for yoga versus sham yoga group, OR was 81.00 (95% CI 4.36 to 1504.46) and for the yoga versus 'no treatment' group it was 158.33 (95% CI 5.78 to 4335.63); ACT versus yoga OR was 0.78 (95% Cl 0.04 to 14.75); (iv) more than 50% reduction in seizure duration - for yoga versus sham yoga group OR was 45.00 (95% CI 2.01 to 1006.75) and for yoga versus 'no treatment' group it was 53.57 (95% CI 2.42 to 1187.26); ACT versus yoga OR was 0.67 (95% Cl 0.10 to 4.35).In addition in Panjwani 1996 the authors reported that the one-way analysis of variance revealed no statistically significant differences between the three groups. A P-Lambda test taking into account the P values between the three groups also indicated that the duration of epilepsy in the three groups was not comparable. No data were available regarding quality of life. In Lundgren 2008 the authors reported that there was no significant difference between the yoga and ACT groups in seizure-free rates, 50% or greater reduction in seizure frequency or seizure duration at one-year follow-up. The yoga group showed significant improvement in their quality of life according to the Satisfaction With Life Scale (SWLS) (P < 0.05), while the ACT group had significant improvement in the World Health Organization Quality of Life-BREF (WHOQOL-BREF) scale (P < 0.01).Overall, we assessed the quality of evidence as low; no reliable conclusions can be drawn at present regarding the efficacy of yoga as a treatment for epilepsy.

AUTHORS' CONCLUSIONS

A study of 50 subjects with epilepsy from two trials reveals a possible beneficial effect in control of seizures. Results of the overall efficacy analysis show that yoga treatment was better when compared with no intervention or interventions other than yoga (postural exercises mimicking yoga). There was no difference between yoga and Acceptance and Commitment Therapy. However no reliable conclusions can be drawn regarding the efficacy of yoga as a treatment for uncontrolled epilepsy, in view of methodological deficiencies such as limited number of studies, limited number of participants randomised to yoga, lack of blinding and limited data on quality-of-life outcome. Physician blinding would normally be taken to be the person delivering the intervention, whereas we think the 'physician' would in fact be the outcome assessor (who could be blinded), so that would be a reduction in detection bias rather than performance bias. In addition, evidence to inform outcomes is limited and of low quality. Further high-quality research is needed to fully evaluate the efficacy of yoga for refractory epilepsy.Since we did not find any new studies, our conclusions remain unchanged.

Hippocampal sharp-wave ripples in awake mice are entrained by respiration

Several recent studies have shown that respiration modulates oscillatory neuronal activity in the neocortex and hippocampus on a cycle-by-cycle basis. It was suggested that this respiratory influence on neuronal activity affects cognitive functions, including memory. Sharp-wave ripples (SWRs) are high-frequency local field potential activity patterns characteristic for the hippocampus and implicated in memory consolidation and recall. Here we show that the timing of SWR events is modulated by the respiratory cycle, with a significantly increased probability of SWRs during the early expiration phase. This influence of respiration on SWR occurrence was eliminated when olfactory bulb activity was inhibited. Our findings represent a possible neuronal mechanism for a direct influence of the respiratory cycle on memory function.

Hemisphere specific EEG related to alternate nostril yoga breathing

BACKGROUND

Previously, forced unilateral nostril breathing was associated with ipsilateral, or contralateral cerebral hemisphere changes, or no change. Hence it was inconclusive. The present study was conducted on 13 normal healthy participants to determine the effects of alternate nostril yoga breathing on (a) cerebral hemisphere asymmetry, and (b) changes in the standard EEG bands.

METHODS

Participants were randomly allocated to three sessions (a) alternate nostril yoga breathing (ANYB), (b) breath awareness and (c) quiet sitting, on separate days. EEG was recorded from bilaterally symmetrical sites (FP1, FP2, C3, C4, O1 and O2). All sites were referenced to the ipsilateral ear lobe.

RESULTS

There was no change in cerebral hemisphere symmetry. The relative power in the theta band was decreased during alternate nostril yoga breathing (ANYB) and the beta amplitude was lower after ANYB. During quiet sitting the relative power in the beta band increased, while the amplitude of the alpha band reduced.

CONCLUSION

The results suggest that ANYB was associated with greater calmness, whereas quiet sitting without specific directions was associated with arousal. The results imply a possible use of ANYB for stress and anxiety reduction.

Breathing as a Fundamental Rhythm of Brain Function

Ongoing fluctuations of neuronal activity have long been considered intrinsic noise that introduces unavoidable and unwanted variability into neuronal processing, which the brain eliminates by averaging across population activity (Georgopoulos et al., 1986; Lee et al., 1988; Shadlen and Newsome, 1994; Maynard et al., 1999). It is now understood, that the seemingly random fluctuations of cortical activity form highly structured patterns, including oscillations at various frequencies, that modulate evoked neuronal responses (Arieli et al., 1996; Poulet and Petersen, 2008; He, 2013) and affect sensory perception (Linkenkaer-Hansen et al., 2004; Boly et al., 2007; Sadaghiani et al., 2009; Vinnik et al., 2012; Palva et al., 2013). Ongoing cortical activity is driven by proprioceptive and interoceptive inputs. In addition, it is partially intrinsically generated in which case it may be related to mental processes (Fox and Raichle, 2007; Deco et al., 2011). Here we argue that respiration, via multiple sensory pathways, contributes a rhythmic component to the ongoing cortical activity. We suggest that this rhythmic activity modulates the temporal organization of cortical neurodynamics, thereby linking higher cortical functions to the process of breathing.

Measuring and Characterizing the Human Nasal Cycle

Nasal airflow is greater in one nostril than in the other because of transient asymmetric nasal passage obstruction by erectile tissue. The extent of obstruction alternates across nostrils with periodicity referred to as the nasal cycle. The nasal cycle is related to autonomic arousal and is indicative of asymmetry in brain function. Moreover, alterations in nasal cycle periodicity have been linked to various diseases. There is therefore need for a tool allowing continuous accurate measurement and recording of airflow in each nostril separately. Here we provide detailed instructions for constructing such a tool at minimal cost and effort. We demonstrate application of the tool in 33 right-handed healthy subjects, and derive several statistical measures for nasal cycle characterization. Using these measures applied to 24-hour recordings we observed that: 1: subjects spent slightly longer in left over right nostril dominance (left = 2.63 ± 0.89 hours, right = 2.17 ± 0.89 hours, t(32) = 2.07, p < 0.05), 2: cycle duration was shorter in wake than in sleep (wake = 2.02 ± 1.7 hours, sleep = 4.5 ± 1.7 hours, (t(30) = 5.73, p < 0.0001). 3: slower breathing was associated with a more powerful cycle (the extent of difference across nostrils) (r = 0.4, p < 0.0001), and 4: the cycle was influenced by body posture such that lying on one side was associated with greater flow in the contralateral nostril (p < 0.002). Finally, we provide evidence for an airflow cycle in each nostril alone. These results provide characterization of an easily obtained measure that may have diagnostic implications for neurological disease and cognitive state.

Effects of Various Prāṇāyāma on Cardiovascular and Autonomic Variables

Cardiovascular functions are controlled by neural factors, temperature, hormones, etc., Of these, neural factors primarily concern the autonomic nervous system, which plays a major role in maintaining and regulating cardiac functions, e.g., blood pressure and heart rate. Prāṇāyāma is one of the most important yogic practices. There are various review articles on Yoga and its effects but, though Prāṇāyāma is a part of yoga, there is lack of review articles. To the best of our knowledge there is no known review article on effect of various Prāṇāyāma on cardiovascular and autonomic variables. To provide a general overview about the effect of various prāṇāyāma (breathing techniques) on cardiovascular and autonomic variables. A narrative review was performed based on the available scientific literature. An electronic data search was performed in Medline/PubMed database to review relevant articles, using keywords such as "Prāṇāyāma, Yogic breathing techniques, Unilateral nostril breathing, Alternate nostril breathing, Kapalbhati, Bhastrika and Bhramari Pranayama". All the relevant articles published from 1988 to 06-04-2016 were included in this review. Slow type of yogic breathing technique was reported to produce beneficial effect on cardiovascular and autonomic variables while fast breathing techniques do not produce such effects. There is lack of consistency in the results of specific nostril yogic breathing techniques and the mechanisms behind the effects of various prāṇāyāma. This review suggests that different types of Prāṇāyāma techniques produce different effects and the mechanisms behind these effects are not fully understood.

A brief qualitative survey on the utilization of Yoga research resources by Yoga teachers

Introduction:

Yoga has become popular worldwide with increasing research done on its therapeutic potential. However, it remains to be determined whether such findings actually percolate down into teaching and practice of Yoga teachers/therapists.

Materials and Methods:

The aim of this survey was to document awareness of Yoga research findings in the Yoga community and find out how these were utilized. It was undertaken with a select group of 34 international Yoga teachers and therapists utilizing email and social media between August and December 2015. Majority of responders had well-established reputation in Yoga and were from diverse lineages with 30 of them having more than 5 years of experience in the field. A set of eight questions were sent to them related to essentiality of Yoga research, how they updated themselves on research findings and whether such studies influenced their teaching and practice. Responses were compiled and appropriate statistics determined for quantitative aspects while feedback, comments and suggestions were noted in detail.

Results and Discussion:

About 89% agreed that it was essential to be up-to-date on Yoga research but only 70% updated themselves regularly with average papers read fully per year being <10. Most accessed information through general news reports, emails from contacts, and articles on internet sites whereas only 7% were through PubMed. About 60% felt these studies helped them in general teaching whereas 20% said that such studies had not really influenced it in any way.

Conclusion:

This survey provides a basic picture of a general lack of awareness of Yoga research amongst practicing Yoga teachers and therapists. Though a majority agree research is important, few seriously update themselves on this through scientific channels. With regard to future studies, most wanted “proof” that could be used to convince potential clients and felt that more qualitative methods should be applied.

Yoga for epilepsy

BACKGROUND

This is an updated version of the original Cochrane review published in The Cochrane Library, Issue 1, 2002.Yoga may induce relaxation and stress reduction, and influence the electroencephalogram and the autonomic nervous system, thereby controlling seizures. Yoga would be an attractive therapeutic option for epilepsy if proved effective.

OBJECTIVES

To assess whether people with epilepsy treated with yoga:(a) have a greater probability of becoming seizure free;(b) have a significant reduction in the frequency or duration of seizures, or both; and(c) have a better quality of life.

SEARCH METHODS

We searched the Cochrane Epilepsy Group Specialized Register (26 March 2015), the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, 26 March 2015), MEDLINE (Ovid, 1946 to 26 March 2015), SCOPUS (1823 to 9 January 2014), ClinicalTrials.gov (26 March 2015), the World Health Organization (WHO) International Clinical Trials Registry Platform ICTRP (26 March 2015), and also registries of the Yoga Biomedical Trust and the Research Council for Complementary Medicine. In addition, we searched the references of all the identified studies. No language restrictions were imposed.

SELECTION CRITERIA

The following study designs were eligible for inclusion: randomised controlled trials (RCT) of treatment of epilepsy with yoga. Eligible participants were adults with uncontrolled epilepsy comparing yoga with no treatment or different behavioural treatments.

DATA COLLECTION AND ANALYSIS

Three review authors independently selected trials for inclusion and extracted data. The following outcomes were assessed: (a) percentage of people rendered seizure free; (b) seizure frequency and duration; (c) quality of life. Analyses were on an intention-to-treat basis. Odds ratio (OR) with 95% confidence intervals (95% Cl) were estimated for the outcomes.

MAIN RESULTS

Two unblinded trials recruited a total of 50 people (18 treated with yoga and 32 to control interventions). Antiepileptic drugs were continued in all the participants. Baseline phase lasted 3 months in both studies and treatment phase from 5 weeks to 6 months in the two trials. Randomisation was by roll of a die in one study and using a computerised randomisation table in the other one but neither study provided details of concealment of allocation and were rated as unclear risk of bias. Overall, the two studies were rated as low risk of bias (all participants were included in the analysis; all expected and pre-expected outcomes were reported; no other sources of bias). The overall OR with 95% confidence interval (CI) was: (i) seizure free for six months - for yoga versus sham yoga ORs of 14.54 (95% CI 0.67 to 316.69) and for yoga versus no treatment group 17.31 (95% CI 0.80 to 373.45); for Acceptance and Commitment Therapy (ACT) versus yoga ORs of 1.00 (95% Cl 0.16 to 6.42; (ii) reduction in seizure frequency - the Mean Difference between yoga versus sham yoga group was -2.10 (95% CI -3.15 to -1.05) and for yoga versus no treatment group -1.10 (95% CI -1.80 to -0.40); (iii) more than 50% reduction in seizure frequency - for yoga versus sham yoga group ORs of 81.00 (95% CI 4.36 to 1504.46) and for the yoga versus no treatment group 158.33 (95% CI 5.78 to 4335.63); ACT versus yoga ORs of 0.78 (95% Cl 0.04 to 14.75); (iv) more than 50% reduction in seizure duration - for yoga versus sham yoga group ORs of 45.00 (95% CI 2.01 to 1006.75) and for yoga versus no treatment group 53.57 (95% CI 2.42 to 1187.26); ACT versus yoga ORs of 0.67 (95% Cl 0.10 to 4.35). In addition in Panjwani 1996 the authors reported that the one-way analysis of variance revealed no statistically significant differences between the three groups. A P-Lambda test taking into account the P values between the three groups also indicated that the duration of epilepsy in the three groups was not comparable. No data were available regarding quality of life. In Lundgren 2008 the authors reported that there was no significant difference between the yoga and ACT groups in seizure free rates, 50% or greater reduction in seizure frequency or seizure duration at one year follow-up. The yoga group showed significant improvement in their quality of life according to the Satisfaction With Life Scale (SWLS) (P < 0.05), while the ACT group had significant improvement in the World Health Organization Quality of Life-BREF (WHOQOL-BREF) scale (P < 0.01).

AUTHORS' CONCLUSIONS

Study of 50 subjects with epilepsy from two trials reveals possible beneficial effect in control of seizures. Results of the overall efficacy analysis show that yoga treatment was better when compared with no intervention or interventions other than yoga (postural exercises mimicking yoga). There was no difference between yoga and Acceptance and Commitment Therapy. However no reliable conclusions can be drawn regarding the efficacy of yoga as a treatment for uncontrolled epilepsy, in view of methodological deficiencies such as limited number of studies, limited number of participants randomised to yoga, lack of blinding and limited data on quality-of-life outcome. Physician blinding would normally be taken to be the person delivering the intervention, whereas we think the 'physician' would in fact be the outcome assessor (who could be blinded), so that would be a reduction in detection bias rather than performance bias. In addition, evidence to inform outcomes is limited and of low quality. Further high-quality research is needed to fully evaluate the efficacy of yoga for refractory epilepsy.

Respiratory cycle-related electroencephalographic changes during sleep in healthy children and in children with sleep disordered breathing

STUDY OBJECTIVE

To investigate respiratory cycle-related electroencephalographic changes (RCREC) in healthy children and in children with sleep disordered breathing (SDB) during scored event-free (SEF) breathing periods of sleep.

DESIGN

Interventional case-control repeated measurements design.

SETTING

Paediatric sleep laboratory in a hospital setting.

PARTICIPANTS

Forty children with SDB and 40 healthy, age- and sex-matched children.

INTERVENTIONS

Adenotonsillectomy in children with SDB and no intervention in controls.

MEASUREMENTS AND RESULTS

Overnight polysomnography; electroencephalography (EEG) power variations within SEF respiratory cycles in the overall and frequency band-specific EEG within stage 2 nonrapid eye movement (NREM) sleep, slow wave sleep (SWS), and rapid eye movement (REM) sleep. Within both groups there was a decrease in EEG power during inspiration compared to expiration across all sleep stages. Compared to controls, RCREC in children with SDB in the overall EEG were significantly higher during REM and frequency band specific RCRECs were higher in the theta band of stage 2 and REM sleep, alpha band of SWS and REM sleep, and sigma band of REM sleep. This between-group difference was not significant postadenotonsillectomy.

CONCLUSION

The presence of nonrandom respiratory cycle-related electroencephalographic changes (RCREC) in both healthy children and in children with sleep disordered breathing (SDB) during NREM and REM sleep has been demonstrated. The RCREC values were higher in children with SDB, predominantly in REM sleep and this difference reduced after adenotonsillectomy.

CITATION

Immanuel SA, Pamula Y, Kohler M, Martin J, Kennedy D, Saint DA, Baumert M. Respiratory cycle-related electroencephalographic changes during sleep in healthy children and in children with sleep disordered breathing.

Increased oxygen load in the prefrontal cortex from mouth breathing: a vector-based near-infrared spectroscopy study

Individuals who habitually breathe through the mouth are more likely than nasal breathers to have sleep disorders and attention deficit hyperactive disorder. We hypothesized that brain hemodynamic responses in the prefrontal cortex might be different for mouth and nasal breathing. To test this hypothesis, we measured changes in oxyhemoglobin and deoxyhemoglobin in the prefrontal cortex during mouth breathing and nasal breathing in healthy adults (n=9) using vector-based near-infrared spectroscopy. The angle k, calculated from changes in oxyhemoglobin and deoxyhemoglobin and indicating the degree of oxygen exchange, was significantly higher during mouth breathing (P<0.05), indicating an increased oxygen load. Mouth breathing also caused a significant increase in deoxyhemoglobin, but oxyhemoglobin did not increase. This difference in oxygen load in the brain arising from different breathing routes can be evaluated quantitatively using vector-based near-infrared spectroscopy. Phase responses could help to provide an earlier and more reliable diagnosis of a patient’s habitual breathing route than a patient interview.

Changes in P300 following alternate nostril yoga breathing and breath awareness

This study assessed the effect of alternate nostril yoga breathing (nadisuddhi pranayama) on P300 auditory evoked potentials compared to a session of breath awareness of equal duration, in 20 male adult volunteers who had an experience of yoga breathing practices for more than three months. Peak amplitudes and peak latencies of the P300 were assessed before and after the respective sessions. There was a significant increase in the P300 peak amplitudes at Fz, Cz, and Pz and a significant decrease in the peak latency at Fz alone following alternate nostril yoga breathing. Following breath awareness there was a significant increase in the peak amplitude of P300 at Cz. This suggests that alternate nostril yoga breathing positively influences cognitive processes which are required for sustained attention at different scalp sites (frontal, vertex and parietal), whereas breath awareness brings about changes at the vertex alone.

Breathing practices for treatment of psychiatric and stress-related medical conditions

Neurophysiological studies may explain how breathing techniques normalize stress response, emotion regulation, and autonomic and neuroendocrine system function. Breath practices have been shown to reduce symptoms of stress, anxiety, insomnia, post-traumatic stress disorder, mass disasters, depression, and attention deficit disorder. Technology-assisted breathing interventions facilitate therapeutic breathing by using either static cues such as a breath pacer or real-time feedback based on physiological parameters such as heart rate variability. The empirical literature indicates that technology-assisted breathing can be beneficial in mental health treatment, though it may not be appropriate for all individuals. Initial in-person training and evaluation can improve results.

Yoga for epilepsy

BACKGROUND

Stress is considered an important precipitating factor for seizures. Yoga is believed to induce relaxation and stress reduction. The effect of yoga on the EEG and the autonomic nervous system have been reported. Yoga would be an attractive therapeutic option for epilepsy (if proved effective), in view of its nonpharmacological nature, minimal side effects and international acceptance.

OBJECTIVES

To assess the efficacy of yoga in the treatment of patients with epilepsy.

SEARCH STRATEGY

We searched the Cochrane Epilepsy Group trial register, the Cochrane Controlled Trials Register (The Cochrane Library Issue 4, 1998), MEDLINE for articles published up to the middle of 1998, and also registries of the research council for complimentary medicine were searched. In addition, we searched the references of all the identified studies. Finally, we contacted the members of the Neurological Society of India, several neurophysiology institutions and yoga institutes to seek any ongoing studies or studies published in nonindexed journals or unpublished studies.

SELECTION CRITERIA

Randomized control trials and controlled clinical trials of treatment of epilepsy with yoga.

DATA COLLECTION AND ANALYSIS

The data were extracted independently by both reviewers and any discrepancies were resolved by discussion. The main outcomes assessed were percentage of patients rendered seizure free, number of patients with more than 50% reduction in seizure frequency or seizure duration and the overall reduction in seizure frequency. Analyses were on an intention to treat basis.

MAIN RESULTS

Only one study met the selection criteria, and recruited a total of 32 patients, 10 to sahaja yoga and 22 to control treatments. Antiepileptic drugs were continued in all. Randomization was by roll of a dice. The results of this study are as follows: (i) Four patients treated with yoga were seizure free for six months compared to none in the control groups. The Odds Ratio (OR) (95% Confidence Interval (CI)) for yoga versus sham yoga group was 14.5 (0.7, 316.7) and for yoga versus no treatment group 17.3 (0.8, 373.5). (ii) Nine patients in the yoga group had more than 50% reduction in seizure frequency compared to only one among the controls. The OR (95% CI) for yoga versus sham yoga group was 81 (4.4, 1504.5) and for the yoga versus no treatment group was 158.3 (5.8, 4335.9). (iii) There was a decline in the average number of attacks per month compared to the baseline frequency among the patients treated with yoga. The weighted mean difference ( 95% CI) between yoga versus sham yoga group was -2.1 (-3.1, -1.0) and for the yoga versus no treatment group -1.1 (-1.8, -0.4). (iv) More than 50% reduction in seizure duration was found in seven of the 10 patients treated with yoga, compared to none among the 22 controls. The OR (95%CI) for yoga versus sham yoga group was 45 (2.0, 1006.8) and for yoga versus no treatment group 53.57 (2.4, 1187.3).

REVIEWER'S CONCLUSIONS

No reliable conclusions can be drawn regarding the efficacy of yoga as a treatment for epilepsy. Further studies are necessary to evaluate the efficacy of yoga in the treatment of epilepsy.

Yoga: intuition, preventive medicine, and treatment

Mind-body fitness programs use a combination of muscular activity and mindful focus on awareness of the self, breath, and energy to promote health. The ancient discipline of yoga includes physical postures and breathing and meditation techniques. Scientific evidence exists about the physiologic effects of yoga. Mind-body fitness programs may offer therapeutic effects different from those offered by traditional body fitness programs.

Responses of the nervous system to low frequency stimulation and EEG rhythms: clinical implications

The present paper reviews literature data on the role of the non-specific central nervous system response mechanisms on the therapeutic effects of relatively weak external stimulations used in clinical practice. The factors affecting the stimulation efficiency and increased sensitiveness of living things to extra-low-frequency periodic stimulations (in the range of from less than 1 Hz to tens of Hz) are discussed. Among the factors determining such effects, the non-specific response mechanisms of the nervous system, the resonance phenomena in different organism systems, and the interaction of external stimulation with endogenous rhythmic processes are analyzed. Most attention is given to endogenous rhythms of the electrical brain activity reflected in the EEG rhythms. A high resolution EEG processing approach that is used to reveal the intrinsic oscillators in the individual EEG spectrum is described. Synchronization of sensory stimulation parameters with the frequencies of intrinsic EEG oscillators is supposed to be an appropriate way to enhance the therapeutic effects of various sensory stimulation treatments. Specific methods for utilizing resonance therapy via sensory stimulation with intrinsic EEG frequencies, and for automatic modulation of stimulation parameters by endogenous organism rhythms are delineated; some preliminary results are described.