Autonomic dysregulation in headache patients

Heart rate variability and tension-type headache: A population-based cross-sectional study

Background

The relationship between tension-type headache (TTH) and autonomic functions is poorly understood, although TTH is one of the most prevalent disorders in the general population. The aim of this study was to investigate the direct and indirect effects of TTH on the autonomic functions measured by heart rate variability (HRV).

Methods

This population-based cross-sectional study was carried out in the general population of Ulaanbaatar between July and September in 2020. After physical examination, trained researchers applied structured interviews to examine the remote history of TTH and mental distress, followed by a recording of HRV to detect autonomic activity. Psychological factors and the quality of life were measured using Hospital Anxiety Depression Scale (HADS), Pittsburgh Sleep Quality Index (PSQI), and the World Health Organization Quality of Life-Brief (WHOQOL-BREF). Binary logistic regression and GLM mediation model analysis were used to examine the effects of risk factors on the associations between TTH and autonomic functions.

Results

Among participants (n = 217, mean age=41.8 ± 11.5 years), a total of 117 (53.9%) participants had a remote history of TTH. The age and sex-adjusted prevalence was 43%. Groups did not differ statistically in the HRV indices. LF/HF (ratio of low-frequency to high frequency), the index of sympathovagal balance, was correlated with the HADS anxiety. TTH was associated with mental distress. Binary logistic regression analysis confirms the relationship suggesting that TTH was associated with increased likelihood of mental distress, and decreasing RMSSD (root mean square of the sum of the squares of differences between adjacent NN intervals) and pNN50 (NN50 divided by the total number of NN intervals) were the independent predictors of TTH. GLM mediation model indicated that the relationship between TTH and RMSSD was mediated by mental distress.

Conclusions

The present study suggests that mental distress is a critical factor in the association between TTH and autonomic dysfunction. Additionally, our findings demonstrate the influence of age and gender on TTH. These results highlight the need to understand the mechanisms underlying pathophysiology to facilitate targeted and efficacious prevention and management approaches for TTH.

Dysautonomia, Hypermobility Spectrum Disorders and Mast Cell Activation Syndrome as Migraine Comorbidities

PURPOSE OF REVIEW

Dysautonomia refers to the dysfunction of the autonomic nervous system and encompasses a wide variety of autonomic symptoms and disorders. The most common autonomic disorders are postural orthostatic tachycardia syndrome (POTS), neurocardiogenic syncope (NCS), and orthostatic hypotension (OH), which may be encountered in clinical practice as part of a triad of dysautonomia, hypermobility spectrum disorders (HSD), and mast cell activation syndrome (MCAS). Migraine is one of the most common comorbidities of POTS, HSD, and MCAS; conversely, these conditions are also prevalent in patients with migraine, especially in those with multiple systemic symptoms, such as chronic dizziness, lightheadedness, orthostatic intolerance, joint pain, and allergic symptoms. Diagnostic criteria, pathophysiologic mechanisms, and therapeutic considerations in patients with migraine and comorbid dysautonomia, HSD, and MCAS are reviewed.

RECENT FINDINGS

Numerous studies indicate a significant overlap and shared pathophysiology in migraine, dysautonomia, HSD, and MCAS. In clinical setting, dysautonomia, HSD, and MCAS may present a diagnostic and therapeutic challenge in patients with migraine and require a high index of suspicion on the part of the neurologist. Diagnosis and treatment of these complex disorders in patients with migraine is essential to comprehensive patient-centric care, reduced symptom burden, and improved functional impairment secondary to both migraine and comorbidities.

Abnormal heart rate variability and its application in predicting treatment efficacy in patients with chronic migraine: An exploratory study

AIM

This study aimed to investigate the extent of autonomic nervous system dysfunction in patients with chronic migraine using heart rate variability analysis. In addition, we explored the potential association between heart rate variability and treatment outcomes in patients receiving preventive treatment.

METHODS

In this cross-sectional and prospective study, we compared heart rate variability profiles in 81 preventive-naïve chronic migraine patients and 58 healthy controls. In addition, treatment responses of patients, who received a 12-week treatment with flunarizine, were assessed in relation to baseline heart rate variability.

RESULTS

We observed that chronic migraine patients had a reduced heart rate variability, signifying autonomic dysfunction in comparison to healthy controls. Furthermore, patients presenting normal heart rate variability, characterized by a standard deviation exceeding 30 milliseconds in normal-to-normal RR intervals, experienced a superior response to flunarizine treatment. This improvement was exemplified by a significantly larger reduction in monthly headache days for patients with higher heart rate variability compared to those with lower heart rate variability: -9.7 (5.9) vs. -6.2 (6.0) days (p = .026).

CONCLUSIONS

Autonomic dysfunction occurs in chronic migraine as evaluated by heart rate variability. A preserved function is associated with a better treatment outcome to flunarizine.Trial registration: Neurologic Signatures of Chronic Pain Disorders, NCT02747940. Registered 22 April 2016, https://clinicaltrials.gov/ct2/show/NCT02747940.

Cognitive Behavioral Therapy for the Management of Episodic Migraine

PURPOSE OF REVIEW

This article provides an overview of the application of CBT in the management of episodic migraine while also providing context and insight into the underlying neurophysiological mechanisms of therapeutic change. It discusses the theoretical foundations of CBT and highlights key components including education, cognitive restructuring, behavioral interventions, relaxation techniques, and lifestyle changes.

RECENT FINDINGS

Cognitive behavioral therapy (CBT) is an empirically based treatment that is well suited for the management of episodic migraine. Although first-line treatments of migraine are typically pharmacological, a review of empirical literature suggests growing evidence for the use of CBT as a standard non-pharmacological treatment of headache conditions. In summary, this article explores evidence supporting the efficacy of CBT in reducing the frequency, intensity, and duration of migraine attacks as well as improving the quality of life and psychological well-being of those with episodic migraine.

A Multimodal Conservative Approach to Treating Migraine: A Physical Therapist's Perspective

PURPOSE OF REVIEW

Migraine is common and interventions to treat or manage it vary. Physical therapists possess a varied skill set that can assess and treat limitations related to migraine and its symptoms. Conservative and non-pharmacological examination and treatment techniques for migraine and headache management are reviewed in terms of efficacy and relevance in order to describe the physical therapist's abilities and clinical reasoning process when confronting a patient with migraine symptoms.

RECENT FINDINGS

A thorough examination is necessary to detect red flags and will reveal a person with migraine's biopsychosocial limitations to manage their symptoms. Strength, endurance, cervical mobility, and visual deficits are common in those reporting headaches and examination techniques, along with patient-reported outcome measures, can elicit objective data for re-assessment during an episode of care. Exercise interventions, manual therapy, biofeedback techniques, and vestibular therapy have become viable and efficacious non-pharmacological interventions in recent years to assist the patient with managing and mitigating their migraine symptoms, along with mindfulness-based exercises. A case study, with individualized treatment approaches based on examination findings, current evidence, and accrued expertise, demonstrates the clinical applicability of a physical therapist's multimodal approach to treating migraine. Psychologically- informed physical therapy with mindfulness-based approaches and biofeedback can help a patient gain more control over their symptoms and their body's response to head pain, while exercise and vestibular therapy can assist the system with recovery and adaptation from deficits related to migraine symptoms. A thorough examination, with an individually- tailored rehabilitation plan incorporating movement and mindfulness-based therapies, is recommended.

The Utility of a Novel, Combined Biofeedback-Virtual Reality Device as Add-on Treatment for Chronic Migraine: A Randomized Pilot Study

OBJECTIVES

To determine if the frequent use of a combined biofeedback-virtual reality device improves headache-related outcomes in chronic migraine.

MATERIALS AND METHODS

In this randomized, controlled pilot study, 50 adults with chronic migraine were randomized to the experimental group (frequent use of a heart rate variability biofeedback-virtual reality device plus standard medical care; n=25) or wait-list control group (standard medical care alone; n=25). The primary outcome was a reduction in mean monthly headache days between groups at 12 weeks. Secondary outcomes included mean change in acute analgesic use frequency, depression, migraine-related disability, stress, insomnia, and catastrophizing between groups at 12 weeks. Tertiary outcomes included change in heart rate variability and device-related user experience measures.

RESULTS

A statistically significant reduction in mean monthly headache days between groups was not demonstrated at 12 weeks. However, statistically significant decreases in the mean frequency of total acute analgesic use per month (65% decrease in the experimental group versus 35% decrease in the control group, P <0.01) and depression score (35% decrease in the experimental group versus 0.5% increase in the control group; P <0.05) were shown at 12 weeks. At study completion, more than 50% of participants reported device satisfaction on a 5-level Likert scale.

DISCUSSION

Frequent use of a portable biofeedback-virtual reality device was associated with decreases in the frequency of acute analgesic use and in depression in individuals with chronic migraine. This platform holds promise as an add-on treatment for chronic migraine, especially for individuals aiming to decrease acute analgesic use or interested in nonmedication approaches.

Acupuncture Based on Regulating Autonomic Nerves for the Prevention of Migraine Without Aura: A Prospective, Double-Dummy, Randomized Controlled Clinical Trial

Background

Migraine without aura (MWoA) is a nervous system disease, which is closely related to autonomic nerves dysfunction. As a popular non-pharmacological alternative treatment for preventing migraine, it remains unclear whether the acupuncture can prevent MWoA. Thus, this trial aims to evaluate the preventive effect and safety of the acupuncture method of stimulating acupoints that regulate autonomic nerves in MWoA patients.

Methods

This is a single-center, prospective, double-dummy, randomized controlled clinical trial. A total of ninety-six patients with MWoA are randomly allocated to acupuncture combined with the placebo group and sham acupuncture combined with the medication group in a 1:1 ratio. All subjects will receive intervention for 8 weeks and follow-up assessments three times (one month, three months, and six months in follow-up visiting). The frequency of acupuncture in both groups is three times a week for eight weeks. The primary outcome will be evaluated using a visual analog scale (VAS) and the number of migraine attacks per four weeks. The secondary outcome measures will include the migraine-specific quality of life (MSQOL) scale and headache needs assessment survey (HANA) questionnaire scale.

Results

The acupoint selection of this clinical trial is based on the combination of traditional Chinese medicine theory with modern medicine, thereby evaluating the efficacy and safety of the acupuncture method of stimulating acupoints that regulate autonomic nerves in the prevention of MWoA. The results may provide evidence of the beneficial effects of acupuncture on the prevention of MWoA by regulating autonomic nerves dysfunction.

Trial Registration

ClinicalTrials.gov NCT04766762.

The Responses to CGRP in the Territory of the Posterior Cerebral Artery in Migraine

Calcitonin gene-related peptide (CGRP) is important in trigeminovascular (TMV) sensitization with neurogenic inflammation which might be involved in CGRP-induced headache (CGRP-IH). Distribution of white matter lesions, migraine aura, and functional neuroimaging indicate that posterior circulation is especially exposed to TMV sensitization. The transcranial Doppler (TCD) is able to detect changes in the posterior cerebral artery (PCA) during CGRP stimulation. Thus, we studied CGRP-induced hemodynamic changes in PCA and frequency of CGRP-IH. Twenty healthy subjects and 20 patients with migraine participated in our study. TCD was used to monitor mean arterial velocity in posterior cerebral artery (v_mPCA). Simultaneously, end-tidal carbon dioxide (Et-CO₂), mean arterial pressure (MAP), and heart rate (HR) were measured. During the experiment, we monitored the frequency of CGRP-IH. We determined the values of v_mPCA, Et-CO₂, MAP, and HR and calculate the response of v_mPCA, Et-CO2, MAP, and HR to CGRP. To test the differences and relationships, statistical methods were applied using SSPS. We found significant decrease in v_mPCA in migraine and control groups and found the v_mPCA response to be significantly lower in migraine (p = 0.018). Et-CO₂ decreases in both groups, and it is significantly lower in migraine (p < 0.001). MAP is significantly higher in migraine (p = 0.001), while HR is not significantly higher in migraine (p = 0.570). CGRP-IH is significantly associated with v_mPCA responses (p = 0.003) and migraine (p < 0.001). We concluded that hemodynamic changes in PCA are significantly related to CGRP-IH. The TMV sensitization might be pronounced in posterior circulation explaining clinical and morphologic issues in migraine.

The Omnipresence of Autonomic Modulation in Health and Disease

The Autonomic Nervous System (ANS) is a critical part of the homeostatic machinery with both central and peripheral components. However, little is known about the integration of these components and their joint role in the maintenance of health and in allostatic derailments leading to somatic and/or neuropsychiatric (co)morbidity. Based on a comprehensive literature search on the ANS neuroanatomy we dissect the complex integration of the ANS: (1) First we summarize Stress and Homeostatic Equilibrium - elucidating the responsivity of the ANS to stressors; (2) Second we describe the overall process of how the ANS is involved in Adaptation and Maladaptation to Stress; (3) In the third section the ANS is hierarchically partitioned into the peripheral/spinal, brainstem, subcortical and cortical components of the nervous system. We utilize this anatomical basis to define a model of autonomic integration. (4) Finally, we deploy the model to describe human ANS involvement in (a) Hypofunctional and (b) Hyperfunctional states providing examples in the healthy state and in clinical conditions.

Longitudinal Assessment of Acute Concussion Outcomes Through SMS Text (ConText Study)

OBJECTIVE

Mild traumatic brain injury (mTBI), or concussion, is a common health problem that has seen a recent increase in US adolescents. This study uses SMS text messaging (a mobile health [mHealth] tool) to report patient symptoms. We aim to better characterize mTBI recovery and hypothesize that this mHealth tool will have high retention rates and correlate with a conventional means of assessing symptoms, the Post-Concussion Symptom Inventory (PCSI).

METHODS

A prospective observational cohort pilot study. Thirty-one pediatric patients with acute mTBI were recruited to characterize their injury and report their symptoms via text messaging. Patients reported symptoms once every 3 days for the first 21 days, then once a week for 6 weeks.

RESULTS

There was a strong and positive correlation between the PCSI and the mHealth tool (rs = 0.875, P < 0.000, n = 22). Retention was 74% until symptom resolution and 42% until study completion. Patients with balance deficits had a significantly higher somatization score than those with normal balance (6.53 ± 3.25 vs 2.56 ± 2.30, t(22) = 3.211, P < 0.01).

CONCLUSIONS

This pilot study demonstrates that this tool is a valid and easy-to-use method of reporting pediatric mTBI symptoms-it replicates and identifies novel findings. Our results suggest that there may be a relationship between balance and the manifestation of somatic symptoms. Retention rates were lower than predicted, indicating that text messaging may not be the ideal format in this population. Text messaging may still have other applications for short-term communication/symptom measurement.

Is there a causal relationship between stress and migraine? Current evidence and implications for management

Background

The purpose of this narrative review is to examine the literature investigating a causal relationship between stress and migraine and evaluate its implications for managing migraine.

Methods

PubMed, PsycINFO and CINAHL were searched from 1988 to August 2021, identifying 2223 records evaluating the relationship between stress and migraine. Records were systematically screened. All potentially relevant records were thematically categorized into six mechanistic groups. Within each group the most recent reports providing new insights were cited.

Results

First, studies have demonstrated an association of uncertain causality between high stress loads from stressful life events, daily hassles or other sources, and the incidence of new-onset migraine. Second, major stressful life events seem to precede the transformation from episodic to chronic migraine. Third, there is some evidence for changes in levels of stress as a risk factor for migraine attacks. Research also suggests there may be a reversed causality or that stress-trigger patterns are too individually heterogeneous for any generalized causality. Fourth, migraine symptom burden seems to increase in a setting of stress, partially driven by psychiatric comorbidity. Fifth, stress may induce sensitization and altered cortical excitability, partially explaining attack triggering, development of chronic migraine, and increased symptom burden including interictal symptom burden such as allodynia, photophobia or anxiety. Finally, behavioral interventions and forecasting models including stress variables seem to be useful in managing migraine.

Conclusion

The exact causal relationships in which stress causes incidence, chronification, migraine attacks, or increased burden of migraine remains unclear. Several individuals benefit from stress-oriented therapies, and such therapies should be offered as an adjuvant to conventional treatment and to those with a preference. Further understanding the relationship between stress, migraine and effective therapeutic options is likely to be improved by characterizing individual patterns of stress and migraine, and may in turn improve therapeutics.

Efficacy of cranial microcurrent stimulation in patients with tension-type headache: A prospective, randomised, double-blinded, sham-controlled clinical trial

OBJECTIVE

To investigate the therapeutic effect of cranial microcurrent stimulation (CMS) in patients with tension-type headaches (TTH).

METHODS

This study was designed as a prospective, randomised, double-blinded and sham-controlled trial. A total of 22 patients with tension-type headache were selected as our study participants and randomly assigned into two groups: CMS group (n = 11) and Sham group (n = 11). To each of the participants, a sham or a true portable CMS stimulation device (CMS; intensity, 25 μA; frequency, 8 Hz) to wear was distributed, and 20-minute daily treatment was provided using the device for 2 weeks. In CMS group, treatment was given by means of electrodes clipped to the ear, whereas, in Sham group, sham treatment was provided by CMS without current. The measurements of Visual Analogue Scale (VAS), Headache Impact Test-6 (HIT6), Patient Health Questionnaire-9 (PHQ9), Generalised Anxiety Disorder 7-item (GAD7) and Hospital Anxiety and Depression Scale (HADS) were performed at pre-treatment (baseline), week 1 and 2 of treatment and two weeks post-treatment.

RESULTS

In CMS group, VAS of maximal headache and VAS of current headache, HIT6, PHQ9 and GAD7 significantly decreased by two weeks post-CMS therapy, but not in Sham group (P < .05). Scores of HADS-A (anxiety), HADS-D (depression) and HADS-T (total) significantly decreased by 2 weeks post-CMS therapy in CMS group, but not in Sham group (P < .05). Changes in scores of PHQ9 and GAD7, HADS-A, HADS-D and HADS-T in CMS group were significantly greater than in Sham group by 2 weeks post-CMS therapy (P < .05).

CONCLUSION

The results indicate that CMS, as an adjunctive treatment for patients with TTH, is safe and analgesic as well as reducing depression or anxiety.

Heart Rate Variability Analysis in Episodic Migraine: A Cross-Sectional Study

Objective: It has been reported that autonomic nervous dysfunction is more prevalent in migraineurs. Heart rate variability (HRV) is a commonly used method to evaluate the cardiac autonomic nervous function modulation. However, HRV changes in migraine are still contradictory. The main objective of this study was to explore the potential HRV change patterns in episodic migraine (EM) and whether there were differences in HRV between EM ictal period and the interictal period.

Patients and Methods: We conducted a cross-sectional study including 18 patients with EM and 18 age- and sex-matched controls. The characteristics of demographics, some lifestyle factors, and psychological conditions were assessed at baseline. HRVs including time-domain analysis and frequency-domain analysis were performed in all participants. HRV analyses in migraine were recorded not only in the interictal period but also in the ictal period.

Results: All the HRV parameters showed a decreased trend in migraine than controls. Time-domain parameters standard deviation of all NN intervals in 24 h (SDNN) and triangular index were significantly lower in the migraine ictal period than controls separately (SDNN, 56.94 ± 22.09 ± 7.76 vs. 135.78 ± 35.16, p < 0.001; triangular index, 12.61 ± 3.20 vs. 22.11 ± 6.90, p < 0.001). Frequency-domain parameter low-frequency power was also lower in the migraine ictal period than controls (351.28 ± 206.71 vs. 559.61 ± 281.24, p = 0.02). SDNN was much lower in the migraine ictal period than migraine interictal period (56.94 ± 22.09 vs. 115.94 ± 46.88, p < 0.001). HRV changes during migraine interictal period did not differ from the control group. The correlation analysis revealed a negative correlation between visual analog scale and HRV parameters in the migraine ictal period (p = 0.04).

Conclusions: The present cross-sectional study indicates that HRV was significantly decreased in EM population especially during the migraine ictal period, which means unbalance of autonomic system in EM. Perhaps larger prospective cohort studies are wanted to validate these findings.

Craniofacial sensations induced by transient changes of barometric pressure in healthy subjects – A crossover pilot study

Background:

Changes in atmospheric pressure are suggested to trigger headaches. This pilot study was made to determine craniofacial sensations accompanying short phases of changing barometric pressure.

Methods:

In a crossover design, 15 adult healthy subjects were exposed in a climate chamber to 8 min phases of barometric pressure lowering by 0, 20 and 40 hPa. The subjects rated their sensations of ear pressure, head compression and the occurrence of headache every minute on a visual analogue scale (VAS, range 0–10). Pulse rate was recorded as a parameter for autonomic functions.

Results:

Nearly all subjects experienced ear pressure and half of them compression of their head at variable degrees. These sensations started in most subjects during the phase of lowering barometric pressure and increased to an average rating of about 3 VAS when returning to ambient atmospheric pressure. Heart rate slightly decreased during this phase. Three subjects reported mild to moderate headache for various durations within these phases.

Conclusions:

Changes in barometric pressure can be associated with sensations of ear pressure and head compression and may trigger headaches. The generation of these sensations is discussed with regard to convergent trigeminal innervation of the ear, the paranasal sinuses and the cranial meninges.

Wearable Sensors for Assessing the Role of Olfactory Training on the Autonomic Response to Olfactory Stimulation

Wearable sensors are nowadays largely employed to assess physiological signals derived from the human body without representing a burden in terms of obtrusiveness. One of the most intriguing fields of application for such systems include the assessment of physiological responses to sensory stimuli. In this specific regard, it is not yet known which are the main psychophysiological drivers of olfactory-related pleasantness, as the current literature has demonstrated the relationship between odor familiarity and odor valence, but has not clarified the consequentiality between the two domains. Here, we enrolled a group of university students to whom olfactory training lasting 3 months was administered. Thanks to the analysis of electrocardiogram (ECG) and galvanic skin response (GSR) signals at the beginning and at the end of the training period, we observed different autonomic responses, with higher parasympathetically-mediated response at the end of the period with respect to the first evaluation. This possibly suggests that an increased familiarity to the proposed stimuli would lead to a higher tendency towards relaxation. Such results could suggest potential applications to other domains, including personalized treatments based on odors and foods in neuropsychiatric and eating disorders.

Response of the autonomic activity to stress provocation in females with cervicogenic headache compared to asymptomatic controls: a cross-sectional study

BACKGROUND

Because abnormal activity of the autonomic nervous system is associated with chronification of pain, early detection of such dysfunction is important.

AIM

Although several studies highlight autonomic dysfunction in the chronification of headache, no study discussed its role in episodic cervicogenic headache.

DESIGN

Case-controlled cross-sectional single-blind comparative study between women with episodic cervicogenic headache and matched controls.

SETTING

Outpatient setting, Hasselt University.

POPULATION

Autonomic activity of 17 females with episodic cervicogenic headache (26.6±11.6 years) was compared with 17 age, gender and socio-economic matched asymptomatic controls (26.8±11.9 years).

METHODS

Autonomic activity was compared via repeated measures of the activity of the dermal sweat glands (µmho), peripheral circulation (%), electrical activity of the bilateral upper trapezius (μV) before, during and after cognitive stress provocation.

RESULTS

Whereas the autonomic parameters of the control group behaved as expected, participants in the headache group showed: 1) to stress provocation a significant lower dermal sweat gland activity (3.03±0.44 vs. 4.19±0.91 µmho, P<0.0001), higher vasodilatation (-5.56±1.45% vs. -5.61±1.85%, P=0.03), lower activity of the left upper trapezius (0.21±0.44 vs. 0.89±0.59 µV, P=0.03), significant less recuperation of the dermal sweat gland activity (-2.57±0.40 vs. -3.29±0.84 µmho, P<0.0001); 2) no recuperation of the activity (μV) of the left (P=0.83) and right (P=0.99) upper trapezius; 3) from stress provocation to recuperation a significant negative correlation (ρ=0.69, P=0.04) between dermal sweat gland and right upper trapezius activity.

CONCLUSIONS

Females with episodic cervicogenic headache reacted less to cognitive stress provocation. Recuperation after such provocation was absent. More research is needed to associate autonomous responses with a possible chronification process.

CLINICAL REHABILITATION IMPACT

A dysfunctional reaction to cognitive stress could be a threat to allostasis.

Effects of Respiratory Rate on Heart Rate Variability in Neurologic Outpatients with Epilepsies or Migraine: A Preliminary Study

BACKGROUND

Variation of spontaneous respiratory rates and influences of spontaneous and paced breathing rates on heart rate variability (HRV) were assessed in patients with epilepsy or migraine, and HRV parameters were compared between the groups.

MATERIALS AND METHODS

Thirty neurologic outpatients, 16 diagnosed with epilepsies and 14 with migraine, were included. Autonomic testing consisted of short-term HRV, the deep breathing test (DBT), and measurement of HRV at systematically changed breathing rates (paced breathing, 5-18 breaths per minute, bpm).

RESULTS

Spontaneous respiratory rate during short-term HRV varied from 9 to 23 bpm in the epileptic group and from 5 to 21 bpm in migraine patients and was significantly and negatively correlated with SD of all normal RR intervals (SDNN) and total power (TP) in epileptic patients but not in migraine patients. Paced breathing rate had a significant effect on all HRV parameters assessed in both groups. HRV (SD1, SDNN, TP) and DBT (E-I, SD1, SDNN) parameters were significantly lower in the epileptic group. Group differences were significantly greater during slow compared to fast breathing.

CONCLUSIONS

An important and new finding is the wide variation of spontaneous respiratory rate in both groups, along with the significant negative correlation with the assessed HRV parameters. The reduction of HRV during slow breathing in epileptic patients may indicate a diminished cardiorespiratory coupling caused by a probable loss of sensitivity within the cardiovagal brainstem circuitry.

Is There Support for the Paradigm 'Spinal Posture as a Trigger for Episodic Headache'? A Comprehensive Review

PURPOSE OF REVIEW

The International Classification of Headache Disorders provides an extensive framework to classify headaches. Physiotherapy is indicated if neuromusculoskeletal dysfunctions are involved in the pathophysiology. Maladaptive postures seem a dominant trigger in tension-type and cervicogenic headache. Yet, outcomes following physiotherapy vary. The absence of protocol studies to identify determinants concerning the role of spinal posture in headache might explain such variability. Hence, multi-dimensional profiling of patients with headache based on interactions between spinal posture, psychosocial and lifestyle factors might be essential. Therefore, the aim of this paper was to perform a comprehensive review to find support for the paradigm of spinal posture triggering episodic headache based on a multi-dimensional view on tension-type and cervicogenic headache including modern pain neuroscience.

RECENT FINDINGS

A review was conducted to support spinal posture-induced episodic headache. Pubmed, Web of Science, Pedro and the Cochrane database were explored based on the following 'Mesh' or 'Topics': 'Headache', 'Posture', 'Spine', 'Psychosocial', 'Lifestyle'. The contemporary review of neuroanatomical, biomechanical and non-nociceptive pathways, with integration of modern pain neuroscience in tension-type and cervicogenic headache, supports spinal posture as a trigger for episodic headache. Maladaptive postures can activate C1-C3 nociceptors. Convergence with trigeminal afferents at the trigeminocervical nucleus could explain spinal headache. Interactions with psychosocial and lifestyle factors might contribute to peripheral and central sensitisation. Neuroanatomical, biomechanical and non-nociceptive pathways seem to justify profiling patients based on a postural trigger. Further research is needed to determine the contribution of postural dysfunctions in headache and the effect of specific interventions.

Heart Rate Variability in Dental Science

Dentistry has made progress as a profession by integration with both medicine and other human sciences, especially when it uses empirical metrics to study process and outcome variables. Notably, progress in our understanding of genomic, biomic, and other molecular biological phenomena has been valuable. As has been identified by Drury (1, 2), it is proposed in this commentary that the inclusion of heart rate variability (HRV) as a biomarker of health may further this integrative progress. HRV is derived by various linear and non-linear statistical analyses of the R-R, beat-to-beat ECG interval in microseconds. Over twenty three thousand reports are identified in a recent PubMed search of the term heart rate variability, most of which demonstrate HRV's sensitivity to a wide diversity of physical and psychosocial pathologies. The small literature of dental use of HRV in both assessment and treatment will be selectively reviewed and relevant exemplars for other important health applications of HRV will be discussed. This will lead to a proposed agenda for researching HRV's value to professional dentistry as a human health and wellness profession.

Physiology learning for veterinary students: impact of guided practices on students' opinion and physiological parameters

Over recent decades, education has increasingly focused on student-centered learning. Guided practices represent a new way of learning for undergraduate students of physiology, whereby the students turn into teacher-students and become more deeply involved in the subject by preparing and teaching a practical (laboratory) class to their peers. The goal was to assess the students' opinions about guided practices and how physiological parameters change during the activity. For this objective, two experiments were performed. First, a voluntary questionnaire on guided practices was completed by the students during 2 academic years. Students could also write a free text commentary. The positive answers obtained in the questionnaire and the free commentary responses point to the effectiveness of this methodology in students' minds. Negative aspects included the time spent preparing the activity, and the stress that students experienced in the teaching role. Second, information about how the teacher-students felt before teaching the practical class was self-reported, and physiological parameters related to stress (heart rate, pulse rate, blood pressure, arterial oxygen saturation, respiratory rate, and electrocardiogram recorded to evaluate R-R interval and heart rate variability) were measured immediately before and while the practical class was taught. This evaluation reported an increase in stress during the execution of the practice. In conclusion, despite a new and stressful situation, guided practices are of interest for the students as a learning tool and for the acquisition of skills that may be of use in their later professional lives.

Pain Processing and Vegetative Dysfunction in Fibromyalgia: A Study by Sympathetic Skin Response and Laser Evoked Potentials

BACKGROUND

A dysfunction of pain processing at central and peripheral levels was reported in fibromyalgia (FM). We aimed to correlate laser evoked potentials (LEPs), Sympathetic Skin Response (SSR), and clinical features in FM patients.

METHODS

Fifty FM patients and 30 age-matched controls underwent LEPs and SSR by the right hand and foot. The clinical evaluation included FM disability (FIQ) and severity scores (WPI), anxiety (SAS) and depression (SDS) scales, and questionnaires for neuropathic pain (DN4).

RESULTS

The LEP P2 latency and amplitude and the SSR latency were increased in FM group. This latter feature was more evident in anxious patients. The LEPs habituation was reduced in FM patients and correlated to pain severity scores. In a significant number of patients (32%) with higher DN4 and FIQ scores, SSR or LEP responses were absent.

CONCLUSIONS

LEPs and SSR might contribute to clarifying the peripheral and central nervous system involvement in FM patients.

Individuals with tension and migraine headaches exhibit increased heart rate variability during post-stress mindfulness meditation practice but a decrease during a post-stress control condition - A randomized, controlled experiment

BACKGROUND

Current research suggests that associations between headache conditions (migraine, tension) and imbalances in the autonomic nervous system (ANS) are due to stress-related dysregulation in the activity of the parasympathetic-sympathetic branches. Mindfulness meditation has demonstrated effectiveness in reducing pain-related distress, and in enhancing heart rate variability-a vagal-mediated marker of ANS balance. This study examined HRV during cognitive stress and mindfulness meditation in individuals with migraine and tension headaches.

METHODS

Undergraduate students with tension and migraine headaches (n=36) and headache-free students (n=39) were recruited for an experiment involving HRV measurement during baseline, cognitive stress-induction, and after randomization to post-stress conditions of audio-guided mindfulness meditation practice (MMP) or mindfulness meditation description (MMD). HRV was derived using electrocardiograms as the absolute power in the high frequency bandwidth (ms²). A three-way ANOVA tested the effects of Group (headache vs. headache-free), Phase (baseline, stress, & post-stress), and Condition (MMP vs. MMD) on HRV.

RESULTS

ANOVA revealed a significant three-way interaction. Simple effects tests indicated: 1) HRV increased significantly from stress to MMP for headache and headache-free groups (p<0.001), 2) significantly greater HRV for headache (p<0.001) and headache-free (p<0.05) groups during MMP compared to MMD, and 3) significantly lower HRV in the headache vs. headache-free group during the post-stress MMD condition (p<0.05).

DISCUSSION

Results suggest mindfulness practice can promote effective heart rate regulation, and thereby promote effective recovery after a stressful event for individuals with headache conditions. Moreover, headache conditions may be associated with dysregulated stress recovery, thus more research is needed on the cardiovascular health and stress resilience of headache sufferers.

What the Gut Can Teach Us About Migraine

During gestation, cells of the brain and gut develop almost simultaneously into the central nervous system (CNS) and enteric nervous system (ENS), respectively. They remain connected via the vagal nerve lifelong. While it is well known that the brain sends signal to the gut, communication is in fact bidirectional. Just as the brain can modulate gut functioning, the gut, and likely what we ingest, can in fact influence our brain functioning. We will first review both gastrointestinal (GI) function and migraine pathophysiology and then discuss evidence linking the migraine brain to various GI disorders. Lastly, we discuss the effects of gut microbiota on brain functioning and speculate how the gut and particularly diet may affect migraine.

Influence of hydrotherapy on clinical and cardiac autonomic function in migraine patients

Background:

Migraine is associated with autonomic symptoms. The growing body of literature suggests that the dysfunctional autonomic nervous system might play a pivotal role in the pathogenesis of migraine. Thermal therapies have been hypothesized to modulate these changes and alleviate pain. However, data regarding the efficacy of hydrotherapy in migraine remain scant. We evaluated the effect of add on hydrotherapy procedure (a hot arm and foot bath with ice massage to head) in migraine patients.

Methods:

Forty chronic migraine patients fulfilling the International Classification of Headache Disorders II criteria were recruited from the neurology outpatient clinic. Patients were randomized to receive either hydrotherapy plus conventional pharmacological care (n = 20) or conventional medication only (n = 20). Hydrotherapy group received treatment with hot arm and foot bath (103°F to 110°F) and ice massage to head daily for 20 min for 45 days. Patients were assessed using headache impact test (HIT), visual analog scale for pain and cardiac autonomic function by heart rate variability (HRV) before and after intervention period.

Results:

There was a significant decrease in HIT score, frequency, and intensity of headaches following treatment in both the groups. However, it was more evident in add on hydrotherapy group compared to pharmacological treatment alone group. There was also significant improvement in the HRV parameters. In particular, there was a significant decrease in heart rate (P = 0.017), increase in high frequency (HF) (P = 0.014) and decrease in low frequency/HF ratio (P = 0.004) in add on hydrotherapy group.

Conclusion:

Our study shows that add on hydrotherapy enhanced the vagal tone in addition to reducing the frequency and intensity of headaches in migraine patients.

Aerobic Exercise for Reducing Migraine Burden: Mechanisms, Markers, and Models of Change Processes

BACKGROUND

Engagement in regular exercise routinely is recommended as an intervention for managing and preventing migraine, and yet empirical support is far from definitive. We possess at best a weak understanding of how aerobic exercise and resulting change in aerobic capacity influence migraine, let alone the optimal parameters for exercise regimens as migraine therapy (eg, who will benefit, when to prescribe, optimal types, and doses/intensities of exercise, level of anticipated benefit). These fundamental knowledge gaps critically limit our capacity to deploy exercise as an intervention for migraine.

OVERVIEW

Clear articulation of the markers and mechanisms through which aerobic exercise confers benefits for migraine would prove invaluable and could yield insights on migraine pathophysiology. Neurovascular and neuroinflammatory pathways, including an effect on obesity or adiposity, are obvious candidates for study given their role both in migraine as well as the changes known to accrue with regular exercise. In addition to these biological pathways, improvements in aerobic fitness and migraine alike also are mediated by changes in psychological and sociocognitive factors. Indeed a number of specific mechanisms and pathways likely are operational in the relationship between exercise and migraine improvement, and it remains to be established whether these pathways operate in parallel or synergistically. As heuristics that might conceptually benefit our research programs here forward, we: (1) provide an extensive listing of potential mechanisms and markers that could account for the effects of aerobic exercise on migraine and are worthy of empirical exploration and (2) present two exemplar conceptual models depicting pathways through which exercise may serve to reduce the burden of migraine.

CONCLUSION

Should the promise of aerobic exercise as a feasible and effective migraine therapy be realized, this line of endeavor stands to benefit migraineurs (including the many who presently remain suboptimally treated) by providing a new therapeutic avenue as an alternative or augmentative compliment to established interventions for migraine.

Responsiveness of the autonomic nervous system during paced breathing and mental stress in migraine patients

Background

Migraine is a stress-related disorder, suggesting that there may be sympathetic hyperactivity in migraine patients. However, there are contradictory results concerning general sympathetic activation in migraine patients. To shed more light on the involvement of the autonomic nervous system (ANS) in migraine pathophysiology, we investigated cardiac and cardiovascular reactions during vagal (paced breathing) and sympathetic activation (mental stress test).

Methods

Heart rate variability parameters and skin conductance responses were recorded interictally in 22 episodic migraine patients without aura and 25 matched controls during two different test conditions. The paced breathing test consisted of a five-minute baseline, followed by two minutes of paced breathing (6 breathing cycles per minute) and a five-minute recovery phase. The mental stress test consisted of a five-minute baseline, followed by one minute of stress anticipation, three and a half minutes of mental stress and a five-minute recovery phase. Furthermore we measured blood pressure and heart rate once daily over 2 weeks. Subjects rated their individual current stress level and their stress level during paced breathing and during the mental stress test.

Results

There were no significant differences between migraine patients and controls in any of the heart rate variability parameters in either time domain or frequency domain analysis. However, all parameters showed a non-significant tendency for larger sympathetic activation in migraine patients. Also, no significant differences could be observed in skin conductance responses and average blood pressure. Only heart rates during the 2-week period and stress ratings showed significantly higher values in migraine patients compared to controls.

Conclusions

Generally there were no significant differences between migraine patients and controls concerning the measured autonomic parameters. There was a slight but not significant tendency in the migraine patients to react with less vagal and more sympathetic activation in all these tests, indicating a slightly changed set point of the autonomic system. Heart rate variability and blood pressure in migraine patients should be investigated for longer periods and during more demanding sympathetic activation.

Neurobiology and sleep disorders in cluster headache

Cluster headache is characterized by unilateral attacks of severe pain accompanied by cranial autonomic features. Apart from these there are also sleep-related complaints and strong chronobiological features. The interaction between sleep and headache is complex at any level and evidence suggests that it may be of critical importance in our understanding of primary headache disorders. In cluster headache several interactions between sleep and the severe pain attacks have already been proposed. Supported by endocrinological and radiological findings as well as the chronobiological features, predominant theories revolve around central pathology of the hypothalamus. We aimed to investigate the clinical presentation of chronobiological features, the presence of concurrent sleep disorders and the relationship with particular sleep phases or phenomena, the possible role of hypocretin as well as the possible involvement of cardiac autonomic control. We conducted a questionnaire survey on 275 cluster headache patients and 145 controls as well an in-patient sleep study including 40 CH-patients and 25 healthy controls. The findings include: A distinct circannual connection between cluster occurrence and the amount of daylight, substantially poorer sleep quality in patients compared to controls which was present not only inside the clusters but also outside, affected REM-sleep in patients without a particular temporal connection to nocturnal attacks, equal prevalence of sleep apnea in both patient and control groups, reduced levels of hypocretin-1 in the cerebrospinal fluid of patients and finally a blunted response to the change from supine to tilted position in the head-up tilt table test indicating a weakened sympathoexcitatory or stronger parasympathetic drive. Overall, these findings support a theory of involvement of dysregulation in hypothalamic and brainstem nuclei in cluster headache pathology. Further, it is made plausible that the headache attacks are but one aspect of a more complex syndrome of central dysregulation manifesting as sleep-related complaints, sub-clinical autonomic dysregulation and of course the severe attacks of unilateral headache. Future endeavors should focus on pathological changes which persist in the attack-free periods but also heed the possibility of long-lived, cluster-induced pathology.

Vagally mediated heart rate variability in headache patients—a systematic review and meta-analysis

Objective

Vagal nerve activity—indexed by heart rate variability (HRV)—has been linked to altered pain processing and inflammation, both of which may underpin headache disorders and lead to cardiovascular disease (CVD). Here we examined the evidence for differences in parasympathetic (vagal) activity indexed by time- and frequency-domain measures of HRV in patients with headache disorders compared to healthy controls (HCs).

Methods

A systematic review and meta-analysis was conducted on studies investigating group differences in vagally mediated HRV (vmHRV) including time- (root-mean-square of successive R-R-interval differences (RMSSD)) and frequency- (high-frequency HRV) domain measures. Studies eligible for inclusion were identified by a systematic search of the literature, based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement.

Results

Seven studies reporting a total of 10 comparisons of patients with headache disorders (HF-HRV n = 67, RMSSD n = 122) and HCs (HF-HRV n = 64, RMSSD n = 125) were eligible for inclusion. Random-effects meta-analysis revealed a significant main effect on RMSSD ( Z = 2.03, p = 0.04; Hedges’ g = −0.63; 95% CI (−1.24, –0.02); k = 6) and similar pooled effect size estimates for HF-HRV when breathing was controlled ( g = −0.30; 95% CI (−0.69; 0.10)) but not when breathing was not controlled ( g = 0.02; 95% CI (−0.69; 0.74)). Controlling for breathing had no effect on RMSSD.

Conclusion

vmHRV is reduced in patients with headache disorders, findings associated with a medium effect size. Suggestions for future research in this area are provided, emphasizing a need to investigate the impact of headache disorders and commonly comorbid conditions—including mental disorders—as well as the investigation of the risk for CVD in migraine in particular. We further emphasize the need for large-scale studies to investigate HRV as a mechanism mediating the association of migraine and CVD.