P300 Following Four Voluntarily Regulated Yoga Breathing Practices and Breath Awareness.

Attention was influenced by yoga breathing in previously published research. Each yoga breathing practice uniquely modifies specific breath characteristics. Differences in the study designs, assessment methods and interventions resulted in difficulty in comparing effects between yoga breathing practices. This study aimed (i) to compare four yoga breathing practices on attention using an auditory oddball task and (ii) to determine cardiac autonomic activity associated with attention using heart rate variability. P300 event related potential was recorded simultaneously with heart rate variability before and after 18-minute periods each of (i) high frequency yoga breathing (with increased breath frequency), (ii) bellows yoga breathing (with increased depth of respiration), (iii) alternate nostril yoga breathing (with alternate nostril patency), (iv) bumblebee yoga breathing (with prolonged exhale), (v) breath awareness (with attention to the breath) and (vi) quiet seated rest as control in 38 yoga experienced males (average age ± SD; 24.08 ± 4.01 years). The six sessions were on separate, randomly allocated days. The P300 peak amplitude recorded at Pz was significantly increased after four yoga breathing practices (Bonferroni adjusted post-hoc tests, repeated measures ANOVA). No significant changes were noted in heart rate variability following yoga breathing or control sessions. These findings suggest that the four yoga breathing practices increase the attentional neural resources engaged for this auditory oddball task, irrespective of the characteristic of breath uniquely regulated in the four yoga breathing practices.

Effects of alternate nostril breathing exercise on cardiorespiratory functions in healthy young adults.

Introduction: Alternate nostril breathing (ANB) is an effective breathing exercise with therapeutic benefits on cardiorespiratory functions for healthy and diseased individuals. This study was conducted to assess the effects of ANB exercise on cardiorespiratory tasks in healthy adults. Materials and Methods: This randomized experimental study was conducted in the Department of Physiology, Chittagong Medical College, Chattogram, from July 2017 to June 2018. A total of 100 1st-year students, aged between 18 and 20 years, were included by a random sampling method. Fifty participants (25 males and 25 females) were enrolled in the experimental group, while age- and body mass index-matched another 50 participants (25 males and 25 females) served as the control group. Experimental group participants performed ANB exercise for 4 weeks. Cardiorespiratory parameters (pulse rate, blood pressure, forced vital capacity, forced expiratory volume in 1st s [FEV1], and peak expiratory flow rate [PEFR] were measured. Data were taken at the start and after 4 weeks in both groups. Results: Independent t-test showed no significant differences in the cardiorespiratory functions between the experimental and control groups among the male and female participants, except for the females' PEFR which showed small differences. On the other hand, repeated measure ANOVA shows significant improvement in the experimental groups among males (P < 0.001-0.028) and females (P < 0.001-0.001) in all the cardiorespiratory functions measured, except for the FEV1 and PEFR among males. Conclusion: The results of this study suggest that cardiorespiratory functions were improved after breathing exercise, and therefore, ANB can be recommended for increasing cardiorespiratory efficiency.

RésuméIntroduction: La respiration nasale alternée (ANB) est un exercice de respiration efficace avec des avantages thérapeutiques sur les fonctions cardiorespiratoires pour les individus sains et malades. Cette étude a été menée pour évaluer les effets de l'exercice ANB sur les tâches cardiorespiratoires chez des adultes en bonne santé. Matériels et méthodes: Cette étude expérimentale randomisée a été menée au Département de physiologie, Chittagong Medical College, Chattogram, de juillet 2017 à juin 2018. Un total de 100 étudiants de 1ère année, âgés de 18 à 20 ans, ont été inclus par un échantillonnage aléatoire. méthode. Cinquante participants (25 hommes et 25 femmes) ont été inscrits dans le groupe expérimental, tandis que l'âge et l'indice de masse corporelle correspondaient à 50 autres participants (25 hommes et 25 femmes) servant de groupe témoin. Les participants du groupe expérimental ont effectué des exercices ANB pendant 4 semaines. Les paramètres cardiorespiratoires (fréquence du pouls, pression artérielle, capacité vitale forcée, volume expiratoire forcé en 1ère s [VEMS] et débit expiratoire de pointe [PEFR] ont été mesurés. Les données ont été recueillies au début et après 4 semaines dans les deux groupes. Résultats: Le test t indépendant n'a montré aucune différence significative dans les fonctions cardiorespiratoires entre les groupes expérimentaux et témoins parmi les participants masculins et féminins, à l'exception du PEFR des femmes qui présentait de petites différences.D'autre part, l'ANOVA à mesures répétées montre une amélioration significative dans les groupes expérimentaux chez les hommes (P < 0,001 à 0,028) et les femmes (P < 0,001 à 0,001) dans toutes les fonctions cardiorespiratoires mesurées, à l'exception du VEMS et du DEP chez les hommes Conclusion: Les résultats de cette étude suggèrent que les fonctions cardiorespiratoires ont été améliorées après un exercice respiratoire , et par conséquent, l'ANB peut être recommandé pour augmenter l'efficacité cardiorespiratoire.

Nasal saline irrigation - A review of current anatomical, clinical and computational modelling approaches.

Nasal saline irrigation is frequently utilised in allergic rhinitis and rhinosinusitis management, and after nasal and sinus surgery. Anatomical modelling, clinical and computational studies guide treatment optimisation. This review offers a comprehensive summary of the modelling methodologies used in previous nasal irrigation studies by undertaking a systematic analysis of anatomical, clinical and computational investigations that assessed nasal saline irrigation using Medline, EMBASE, and Cochrane Review databases. Both procedural and assessment methods were reviewed. It was found that all twenty-four publications reviewed did not discuss the influence of the nasal cycle on internasal geometry and nasal resistance. Cadaver studies misrepresent in vivo nasal geometry. Irrigation pressure and shear forces, which could influence mucociliary transport and postoperative cleaning, were not evaluated. Previous studies focus on irrigation coverage and have not considered the nasal cycle which influences unilateral nasal resistance and thus pressure/ flow relationships and may also increase nasal air-locking. New computational fluid dynamic models could better inform nasal irrigation clinical practice.

Characterization of nasal irrigation flow from a squeeze bottle using computational fluid dynamics.

BACKGROUND: Nasal saline irrigation has become standard of care in various sinonasal conditions, including allergic and nonallergic rhinitis, chronic rhinosinusitis, and in the postoperative patient. Evidence regarding the mechanisms and dynamics of liquid flow through the sinonasal cavity remains limited due to inadequate experimental models (cadaveric, 3-dimensional [3D] printed, imaging of labeled dyes and radioisotopes). We aimed to develop a computational fluid dynamics (CFD) model of nasal irrigation to demonstrate sinonasal surface coverage, residence times across the mucosal surfaces, and shearing force of irrigation. METHODS: A nasal cavity geometry derived from high-resolution paranasal sinus computed tomography (CT) scans of a healthy, unoperated, 25-year-old patient was created. CFD analysis was performed to assess the distribution of nasal irrigation from a tapered nozzle bottle at a forward head-tilt position of 45 degrees with a 2-second burst at 35 mL/second. RESULTS: The model demonstrates nasal irrigation from ipsilateral to contralateral with precise measures of velocity, pressure, wall shear stress, and mapping of surface coverage and residence times at specific locations and times. The nasal cavity experiences almost complete coverage of irrigation, while overflow from the nasal cavity facilitates moderate coverage of the ipsilateral maxillary (40%) and anterior ethmoid sinuses (30%). Negligible coverage of the sphenoid and frontal sinuses was noted. CONCLUSION: Detailed physical mechanisms of liquid irrigation injected from a commonly used squeeze bottle were shown. Ipsilateral maxillary and ethmoid sinus penetration are primarily due to overflow rather than direct jet entry, confirming the recommendation of larger volumes of irrigation to "flood" the sinus ostia.

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.

A model for the central control of airflow patterns within the human nasal cycle.

BACKGROUND: The nasal cycle exhibits mainly reciprocal changes in nasal airflow that may be controlled from centres in the hypothalamus and brainstem. This study aims to gather new knowledge about the nasal cycle to help develop a control model. METHOD: Right and left nasal airflow was measured in healthy human subjects by rhinomanometry. This was performed over 7-hour periods on 2 study days separated by approximately 1 week. The correlation coefficient for nasal airflow was calculated for day 1 and day 2. RESULTS: Thirty subjects (mean age, 22.7 years) completed the study. The correlation coefficient for nasal airflow varied between r = 0.97 with in-phase changes in airflow and r = -0.89 with reciprocal changes in airflow. The majority of r values were negative, indicating reciprocal changes in airflow (50 out of 60). There was a tendency for r values to become more negative between day 1 and day 2 (p < 0.001). CONCLUSION: A control model involving a hypothalamic centre and two brainstem half centres is proposed to explain both the in-phase and reciprocal changes in airflow associated with the nasal cycle.

Nasal cycle dominance and hallucinations in an adult schizophrenic female.

Nasal dominance, at the onset of hallucinations, was studied as a marker of both the lateralized ultradian rhythm of the autonomic nervous system and the tightly coupled ultradian rhythm of alternating cerebral hemispheric dominance in a single case study of a schizophrenic female. Over 1086 days, 145 hallucination episodes occurred with left nostril dominance significantly greater than the right nostril dominant phase of the nasal cycle. A right nostril breathing exercise, that primarily stimulates the left hemisphere, reduces symptoms more quickly for hallucinations.

Blood pressure and Purdue pegboard scores in individuals with hypertension after alternate nostril breathing, breath awareness, and no intervention.

BACKGROUND: Previously alternate nostril yoga breathing (anuloma-viloma pranayama) was shown to reduce the blood pressure (BP) in people with hypertension. An elevated BP has been associated with poor performance in certain tasks requiring attention and co-ordination. The Purdue pegboard task assesses manual dexterity and eye-hand co-ordination. MATERIAL/METHODS: In the present study there were ninety participants with essential hypertension. Their ages ranged from 20 to 59 years (group average age ±S.D., 49.7±9.5 years; sixty males). Participants were randomized as three groups, with thirty participants in each group. One group practiced alternate nostril yoga breathing for 10 minutes, the second group practiced breath awareness for the same duration and the third group was given a control intervention (i.e., reading a magazine with neutral content). Assessments were taken before and after the interventions for participants of the three groups. Assessments included the blood pressure and performance in the Purdue pegboard task. Data were analyzed with a repeated measures ANOVA and post-hoc analyses were Bonferroni adjusted. RESULTS: Following alternate nostril breathing (ANYB) there was a significant decrease in systolic and diastolic blood pressure (p<0.001 and p<0.05), and an improvement in Purdue pegboard task scores for both hands (p<0.05), and for the right hand (p<.001). Breath awareness (the control session) also showed a significant decrease in systolic blood pressure (p<0.05). The right hand scores improved in the group reading a magazine (p<0.05). CONCLUSIONS: The results suggest that the immediate effect of ANYB is to reduce the BP while improving the performing in a task requiring attention, bimanual dexterity and visuo-motor co-ordination.

Immediate effect of specific nostril manipulating yoga breathing practices on autonomic and respiratory variables.

The effect of right, left, and alternate nostril yoga breathing (i.e., RNYB, LNYB, and ANYB, respectively) were compared with breath awareness (BAW) and normal breathing (CTL). Autonomic and respiratory variables were studied in 21 male volunteers with ages between 18 and 45 years and experience in the yoga breathing practices between 3 and 48 months. Subjects were assessed in five experimental sessions on five separate days. The sessions were in fixed possible sequences and subjects were assigned to a sequence randomly. Each session was for 40 min; 30 min for the breathing practice, preceded and followed by 5 min of quiet sitting. Assessments included heart rate variability, skin conductance, finger plethysmogram amplitude, breath rate, and blood pressure. Following RNYB there was a significant increase in systolic, diastolic and mean pressure. In contrast, the systolic and diastolic pressure decreased after ANYB and the systolic and mean pressure were lower after LNYB. Hence, unilateral nostril yoga breathing practices appear to influence the blood pressure in different ways. These effects suggest possible therapeutic applications.

Epistaxis: consideraciones generales y manejo clínico / Epistaxis: general considerations and clinical management

La epistaxis es un signo clínico extremadamente frecuente y una preocupación constante para el médico en los servicios de urgencia, pudiendo presentarse tanto en niños como en adultos, con una mayor incidencia entre los 10 y 13 años, y en la población mayor de 50. La importancia deriva de su frecuencia y de su potencial gravedad, ya que puede llevar a alteraciones hemodinámicas, que requieren incluso hospitalización. De ahí, la necesidad de conocer la irrigación nasal y los diferentes métodos para cohibir todo tipo de hemorragia, siendo además importante tratar de buscar la causa que la produce, para asegurar un tratamiento eficaz. En este artículo se presenta su clasificación y se explican algunos procedimientos para solucionar el problema, no olvidando que se trata de un signo y no de una enfermedad.

Sensory regulation of swallowing and airway protection: a role for the internal superior laryngeal nerve in humans.

During swallowing, the airway is protected from aspiration of ingested material by brief closure of the larynx and cessation of breathing. Mechanoreceptors innervated by the internal branch of the superior laryngeal nerve (ISLN) are activated by swallowing, and connect to central neurones that generate swallowing, laryngeal closure and respiratory rhythm. This study was designed to evaluate the hypothesis that the ISLN afferent signal is necessary for normal deglutition and airway protection in humans. In 21 healthy adults, we recorded submental electromyograms, videofluoroscopic images of the upper airway, oronasal airflow and respiratory inductance plethysmography. In six subjects we also recorded pressures in the hypopharynx and upper oesophagus. We analysed swallows that followed a brief infusion (4-5 ml) of liquid barium onto the tongue, or a sip (1-18 ml) from a cup. In 16 subjects, the ISLN was anaesthetised by transcutaneous injection of bupivacaine into the paraglottic compartment. Saline injections using the identical procedure were performed in six subjects. Endoscopy was used to evaluate upper airway anatomy, to confirm ISLN anaesthesia, and to visualise vocal cord movement and laryngeal closure. Comparisons of swallowing and breathing were made within subjects (anaesthetic or saline injection vs. control, i.e. no injection) and between subjects (anaesthetic injection vs. saline injection). In the non-anaesthetised condition (saline injection, 174 swallows in six subjects; no injection, 522 swallows in 20 subjects), laryngeal penetration during swallowing was rare (1.4 %) and tracheal aspiration was never observed. During ISLN anaesthesia (16 subjects, 396 swallows), all subjects experienced effortful swallowing and an illusory globus sensation in the throat, and 15 subjects exhibited penetration of fluid into the larynx during swallowing. The incidence of laryngeal penetration in the anaesthetised condition was 43 % (P < 0.01, compared with either saline or no injection) and of these penetrations, 56 % led to tracheal aspiration (without adverse effects). We further analysed the swallow cycle to evaluate the mechanism(s) by which fluid entered the larynx. Laryngeal penetration was not caused by premature spillage of oral fluid into the hypopharynx, delayed clearance of fluid from the hypopharynx, or excessive hypopharyngeal pressure generated by swallowing. Furthermore, there was no impairment in the ability of swallowing to halt respiratory airflow during the period of pharyngeal bolus flow. Rather, our observations suggest that loss of airway protection was due to incomplete closure of the larynx during the pharyngeal phase of swallowing. In contrast to the insufficient closure during swallowing, laryngeal closure was robust during voluntary challenges with the Valsalva, Müller and cough manoeuvres under ISLN anaesthesia. We suggest that an afferent signal arising from the ISLN receptor field is necessary for normal deglutition, especially for providing feedback to central neural circuits that facilitate laryngeal closure during swallowing. The ISLN afferent signal is not essential for initiating and sequencing the swallow cycle, for co-ordinating swallowing with breathing, or for closing the larynx during voluntary manoeuvres.

Segmental analysis of nasal cavity compliance by acoustic rhinometry.

To explore the determinants of possible collapse of the nasal valve region, a common cause of nasal obstruction, we evaluated the mechanical properties of the nasal wall. In this study, we determined the nasal cross-sectional area-to-negative pressure ratio (nasal wall compliance) in the anterior part of the nose in six healthy subjects by measuring nasal area by acoustic rhinometry at pressures ranging from atmospheric pressure to a negative pressure of -10 cmH(2)O. Measurements were performed at baseline and after nasal mucosal decongestion (oxymetazoline). At baseline, nasal wall compliance increased progressively from the nasal valve (0.031 +/- 0.016 cm2/cmH(2)O, mean +/- SD) to the anterior and medial part of the inferior turbinate (0.045 +/- 0.024 cm2/cmH(2)O) and to the middle meatus region (0.056 +/- 0.029 cm2/cmH(2)O). After decongestant, compliances decreased and became similar in the three regions. On the basis of these results, we hypothesize that compliance of the nasal wall is partly related to mucosal blood volume and quantity of vascular tissue, which differ in the three regions, increasing from the nasal valve to the middle meatus.

Acoustic reflections during rhinometry: spatial resolution and sound loss.

The accuracy of the acoustic reflections method for the evaluation of human nasal airway geometry is determined by the physical limitations of the technique and also by the in vivo deviations from the assumptions of the technique. The present study 1) examines the sound loss caused by nonrigidity of the nasal mucosa and viscous loss caused by complex geometry and its influence on the estimation of the acoustic area-distance function; 2) examines the optimal relation between sampling frequency and low-pass filtering, and 3) evaluates advantages of breathing He-O2 during the measurements on accuracy. Measurements made in eight plastic models, with cavities exactly identical to the "living" nasal cavities, revealed only minor effects of nonrigidity of the nasal mucosa. This was confirmed by an electrical analog model, based on laser vibrometry admittance measurements of the nasal mucosa, which indicated that the error in the acoustic measurements caused by wall motion is insignificant. The complex geometry of the nasal cavity per se (i.e., departure from circular) showed no significant effects on the measurements. Low-pass filtering of the signal is necessary to cut off cross modes arising in the nasal cavity. Computer simulations and measurements in models showed that the sampling frequency should be approximately four times the low-pass filtering frequency (i.e., twice the Nyquist frequency) to avoid influence on the result. No advantage was found for the the use of He-O2 vs. air in the nasal cavity.

[Relationship between nasal airflow sensation and nasal patency].

The relationship between nasal airflow sensation and nasal patency was evaluated by means of visual analogue test and anterior rhinomanometry. It was demonstrated that there is no significant correlation between the subjective sensation of nasal airflow and objective assessment of nasal airflow resistance. The site responsible for sensing airflow is located in the nasal vestibule. The volatile agents used in traditional Chinese medicine for nasal obstruction, such as camphor and menthol, could only improve the nasal sensation of airflow without alteration of nasal airway resistance. Our results suggested that the nasal sensation of airflow could not reflect real patency completely. Therefore, assessment of subjective sensation of airflow and measurement of nasal airway resistance combined must be used in the diagnosis and treatment of nasally obstructed patients.

[The effects of menthol, borneolum and moschus on nasal airflow sensation and nasal resistance].

Menthol and borneolum have been used widely in traditional Chinese medicine for the treatment of nasal obstruction, but the mechanism has been still unknown. The effects of inhalation of menthol, borneolum, moschus on nasal resistance and airflow sensation were investigated in 52 subjects. All of these medicines could cause a highly significant enhancement of nasal airflow sensation but had no effect on nasal resistance. Therefore this sort of medicine is regarded as pseudo nasal decongestant.

Svara (nostril dominance) and bilateral volar GSR.

The Svara yoga concept of Ida, Pingala and Susumna svara representing rest, active and turbulent states was examined in this study by recording nostril dominance (svara) and bilateral volar GSR (galvanic skin resistance) as an indicator of sympathetic activity under field and laboratory conditions. The sympathetic activity was low in Ida svara, followed by Pingala svara and was maximum in Susumna svara group of subjects under both field and laboratory conditions which agreed with the traditional Svara yoga description. The volar GSR on the right side more readily varied with svara, particularly so in the physically relaxed subjects of laboratory condition than the left volar GSR. The latter observation was worth noting because the subjects were right handed. The right side could be recommended as the standard site for recording volar GSR to closely reflect the sympathetic activity, particularly so when physical rest was given to subjects.

Nasal pressure-volume relationships determined with acoustic rhinometry.

Partitioning of ventilation has been hypothesized to be related to nasal pressure-volume relationships, relationships that have been difficult to measure. Regional differences in nasal passage pressure-volume relationships are likely because the nasal valve and anterior turbinate are structurally different, but both are altered by agents that alter vascular tone. This study determined nasal volume-to-pressure ratio (NVPR) on six healthy nonsmoking subjects by measuring nasal volume by using acoustic rhinometry at pressures ranging between -14 and +14 cmH2O on 3 days: baseline, after intranasal decongestion (oxymetazoline), and congestion (histamine). NVPR was lower in the nasal valve (0.07 +/- 0.01 cm3/cmH2O) than in the anterior portion of the turbinates (0.29 +/- 0.05 cm3/cmH2O; P < 0.005). Oxymetazoline decongestion decreased NVPR in the nasal valve by 23% and NVPR in the anterior portion of the turbinates by 47%. Histamine did not alter NVPR at either site. Nasal resistance changes correlated with changes in nasal valve and anterior turbinate volume. In summary, regional differences in nasal pressure-volume relationships exist and changes occur with pharmacologically induced vascular decongestion.

Lesions in the medial posterior region of the BST impair sexual behavior in sexually experienced and inexperienced male rats.

Previous studies have showed that lesions in the bed nucleus of the stria terminalis of experienced male rats impair some parameters of sexual behavior. The aim of this study was to examine the contribution of the medial posterior region of the bed nucleus of the stria terminalis (BSTMP), a sexually dimorphic region of this nucleus that pertains to the vomeronasal system, to the modulation of sexual behavior of the male rat. Small electrolytic bilateral lesions in the BSTMP were made in male heterosexual experienced and inexperienced rats. Sham lesioned animals were also tested as a control of the effects of the general surgical procedures. Behavioral tests were then performed to obtain standard measures of masculine sexual behavior. Our results indicate that the sexually experienced male rats with lesioned BSTMPs showed increases in the number of mounts and the number of intromissions and, consequently, in ejaculation latency. In contrast, the sexually naive male rats showed increases in first mount and intromission latencies and in ejaculation latency, but the latter occurred due to increases in the interintromission intervals. This group also showed low correlations between olfactory investigation of the anogenital area of the female and initiation and maintenance of copulatory behavior. The results suggest that sexual experience obtained in the very artificial conditions of laboratory tests could supply some of the cues provided by the BSTMP in the process of sensorial integration, which we hypothesize modulates the initiation and pacing of copulation. However, sexual experience does not apparently supply any other kinds of cues provided or processed in the BSTMP that are involved in modulating the elicitation of intromissions and ejaculations.