Autonomous control of cardiovascular reactivity in patients with episodic and chronic forms of migraine

Reconceptualizing autonomic function testing in migraine: a systematic review and meta-analysis

BACKGROUND

Autonomic nervous system (ANS) testing has aided in our ability to evaluate autonomic dysfunction in migraine patients. We reviewed the literature in multiple databases which investigate ANS function in migraine patients and healthy subjects.

METHODS

This systematic review and meta-analysis examined the respective deep breathing, Valsalva manoeuvre, orthostatic and isometric challenge results, using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and Meta-analyses of Observational Studies in Epidemiology (MOOSE) statements.

RESULTS

Seven articles met all inclusion criteria. Fixed-effects meta-analysis showed migraine patients (n = 424), collectively, had lower interictal autonomic test results compared with healthy controls (n = 268). In detail, this was true for the standardized mean difference (g) of deep breathing (g= -0.32; 95% confidence interval (CI) -0.48, -0.16), orthostatic challenge (g= -0.28; 95% CI -0.44, -0.13) and isometric challenge (g= -0.55; 95% CI -0.71, -0.39) and for the difference of means (MD) of the Valsalva ratio (MD = -0.17; 95% CI -0.23, -0.10).

CONCLUSIONS

Interictal ANS dysfunction can be identified in migraine patients when compared to healthy controls. These findings indicate the importance to evaluate ANS function in migraine patients - especially, as migraine-specific prophylactic therapies (such as anti-calcitonin gene-related peptide (CGRP) antibodies) may affect the function of the ANS.

Episodic Migraine and POTS

PURPOSE OF REVIEW

Migraine is prevalent in patients with postural orthostatic tachycardia syndrome (POTS). The purpose of this review is to summarize and interpret studies that examine stress response systems in patients with migraine, focusing on their relevance to the pathologies associated with POTS. Important structural and functional components of the stress response network are also reviewed.

RECENT FINDINGS

In patients with migraine, studies examining the autonomic nervous system have demonstrated interictal sympathetic hypofunction and ictal sympathetic hyperfunction, while those focusing on the hypothalamic-pituitary-adrenal axis have demonstrated elevated responsivity. There is evidence that activation of these stress response systems during a migraine episode may exacerbate vascular dysfunction and play a role in the development of central sensitization. Activation of the stress response systems during an episode of migraine has the potential to exacerbate the pathology of POTS. Treatment approaches for the patient with comorbid episodic migraine and POTS should consider the etiology of POTS.

Reduced cardiovagal baroreflex sensitivity is associated with postural orthostatic tachycardia syndrome (POTS) and pain chronification in patients with headache

Background

Non-cephalgic symptoms including orthostatic intolerance, fatigue, and cognitive impairment, are common in patients with chronic headache disorders and may result from alterations in the autonomic nervous system. However, little is known about the function of autonomic reflexes, which regulate cardiovascular homeostasis and cerebral perfusion in patients with headache.

Methods

Autonomic function testing data from patients with headache collected between January 2018 and April 2022 was retrospectively analyzed. Through review of EMR we determined headache pain chronicity and patient self-report of orthostatic intolerance, fatigue, and cognitive impairment. Composite Autonomic Severity Score (CASS), CASS subscale scores, and cardiovagal and adrenergic baroreflex sensitivities were used to quantify autonomic reflex dysfunction. Descriptive analyses (Mann-Whitney-U or χ2, as appropriate) determined associations between autonomic reflex dysfunction and POTS as well as chronic headache. Binomial logistic regression adjusted for age and sex. Spearman’s rank correlation determined the association between the total CASS score and the number of painless symptoms reported by each participant.

Results

We identified 34 patients meeting inclusion criteria, of whom there were 16 (47.0%) with orthostatic intolerance, 17 (50.0%) with fatigue, 11 (32.4%) with cognitive complaints, and 11 (32.4%) with Postural Orthostatic Tachycardia Syndrome (POTS). The majority of participants had migraine (n = 24, 70.6%), were female (n = 23, 67.6%) and had a chronic (>15 headache days in a month) headache disorder (n = 26, 76.5%). Reduced cardiovagal baroreflex sensitivity (BRS-V) independently predicted chronic headache [aOR: 18.59 (1.16, 297.05), p = 0.039] and POTS [aOR: 5.78 (1.0, 32.5), p = 0.047]. The total CASS was correlated with the total number of non-painful features in the expected direction (r = 0.46, p = 0.007).

Conclusion

Abnormal autonomic reflexes may play an important role in pain chronification and the development of POTS in patients with headache.

Impairment on Cardiovascular Autonomic Modulation in Women with Migraine

Autonomic dysfunction, such as reduced vagally mediated heart rate variability, has been suggested in headache patients but is still uncertain when considering primary headache disorders. This study aims to compare the heart rate and blood pressure variability and baroreflex sensitivity between women with migraine and controls. A migraine (n = 20) and a control group (n = 20) of age-matched women without headache were evaluated. Heart rate variability was analyzed through frequency-domain using spectral analysis presenting variance, low-frequency (LF; 0.04-0.15 Hz) and high-frequency (HF; 0.15-0.4 Hz) bands and by time domain (root mean square of successive R-R interval differences, RMSSD). Blood pressure variability was analyzed with spectral analysis and baroreflex sensitivity with the sequence method. Migraine group had lower heart rate variability characterized by a reduction in total variance, LF oscillations (sympathetic/vagal modulation) and HF oscillations (vagal modulation), and a reduction in SD and RMSSD compared to control group. No difference was found in the blood pressure variability analysis. Regarding baroreflex sensitivity, migraine group had decreased values of total gain, gain down and up compared to control group. Women with migraine exhibited autonomic modulation alterations, expressed by decreased values of heart rate variability and baroreflex sensitivity, but not by differences in blood pressure variability.

Do catastrophizing and autonomic-reduced flexibility mediate pain outcomes in chronic headache?

OBJECTIVES

Maladaptive cognitive strategies and reduced autonomic flexibility have been reported in chronic pain conditions. No study to date addressed the effects of maladaptive coping and reduced autonomic flexibility, as indexed by heart rate variability (HRV), in chronic headaches. The present study aimed to assess the mediating role of pain catastrophizing and HRV on pain outcomes in patients with chronic headache.

METHODS

Thirty-two chronic headache patients and 28 healthy controls were recruited. Self-reported pain severity, pain interference on daily activity, and pain catastrophizing were assessed through the Multidimensional Pain Inventory and the Pain-Related Self Statements Scale. HRV was recorded at rest. Correlations and mediation analysis between self-report, HRV, and pain outcomes were run.

RESULTS

Patients with chronic headache reported significantly higher pain severity (p < .001; d =  - 1.98), pain interference on daily activity (p < .001; d =  - 1.81), and pain catastrophizing (p < .001; d =  - 0.96) compared to controls. They also presented significantly lower HRV (p < .05; d = 0.57). Both pain catastrophizing and HRV were associated with pain interference on daily activity. However, from mediation analysis, pain catastrophizing only emerged as the mediator for pain severity (p < .001; b = 0.30) and pain interference (p < .001; b = 0.14).

CONCLUSION

Present results showed that chronic headache patients are characterized by high catastrophizing and lower physiological adaptability. Pain catastrophizing emerged as the only mediator of pain outcomes, suggesting that cognitive factors might have a major influence on the severity of pain and its interference on daily activities. Further studies are needed to evaluate these autonomic-cognitive interactions in chronic pain.

The Function of the Autonomic Nervous System in Asian Patients With Chronic Migraine

Background

The pathogenic mechanisms underlying the autonomic nervous system (ANS) dysfunction in patients with chronic migraine (CM) remain unclear. This study investigated the pathogenesis of ANS dysfunction in this population.

Methods

A total of 60 patients diagnosed with CM and 60 healthy subjects were recruited to participate in this study. The pupil diameter, pupil contraction velocity, latency, amplitude, and the maximum gradient recovery time were examined before, at 2 min and at 5 min after the cold pressor test, which was combined with the pupillary light reflex method. A brain 3D T1-weighted structural imaging scan, resting-state functional magnetic resonance imaging scan, and diffusion tensor imaging (DTI) scan were also acquired.

Results

Patients with CM exhibited a longer recovery time to the maximum gradient at 2 min and at 5 min after cold pressing compared with the control group (P < 0.01 and P < 0.05, respectively). There was no significant difference in the pupil diameter, pupillary contraction velocity, latency, amplitude, blood pressure, or heart rate between the two groups (all P > 0.05). In the CM group, the regional homogeneity (ReHo) values of the left amygdala and left lateral hypothalamic area were significantly higher than those of other brain areas (P < 0.001, Alphasim corrected). The DTI scan of the whole brain area showed a lack of significant difference in DTI indices, including FA, MD, AD, and RD values between the two groups (P > 0.05, Alphasim corrected).

Conclusion

The dysfunction of the left amygdala and left lateral hypothalamic area may be related to ANS dysfunction in patients with CM.

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.

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.

Impairment of microvascular blood flow in patients with type 2 diabetes and cardiovascular autonomic neuropathy

BACKGROUND: Diabetic autonomic neuropathy is the reason for early morbidity and mortality on diabetic patients. The pathology not only cardiac innervation but microvascular is presented.

AIMS: We estimated the parameters of skin microvascular blood flow in accordance with cardiovascular autonomic neuropathy (CAN) staging in diabetic patients. We also assessed other risk factors of CAN in patients with diabetes.

MATERIALS AND METHODS: We included 76 patients with type 2 diabetes in the study (24 patients with resent-onset diabetes and/or diabetes without microvascular complications, 26 with diabetic sensorimotor neuropathy (SMN) and 26 with SMN and previous history of diabetic foot amputation). The SMN was diagnosed on the basis of patients complaints, anamnesis and data of clinical neurological examinations. CAN was detected using several cardiovascular autonomic reflex tests (CART) as a gold standard of diagnosis: the tilt-table test, a deepbreathing and Valsalva Maneuver, handgrip test, cold-stress vasoconstriction. According to the Toronto Diabetic Neuropathy Expert Group Recommendation all patients was separated on the groups: CAN 0 (all CARTs were normal), CAN 1 (possible/early CAN — one abnormal CART was presented), CAN 2 (definite/confirmed CAN –at least two abnormal CARTs were found), CAN 3 (severe/advanced CAN — in the cases of orthostatic hypotension in addition to CARTs abnormalities). Microvascular blood flow of skin at the nail roller of fingers skin was valuated at rest as well as in functional cold test by the method of High-frequency Ultrasonic Dopplerography using the “Minimax Doppler K” device (LLC JV “Minimax”, St. Petersburg, Russia).

RESULTS: CAN 1 was found in 8% diabetic patients without microvascular complications, 42 and 21% patients with SMN and diabetic foot amputations respectively. CAN 2 was diagnosed in 27% patients with SMN and 58% patients history of diabetic foot amputations. CAN 3 in 8% and 19% cases in patients with SMN and history of diabetic foot amputations respectively. The parameters of microvascular blood flow at rest were significantly decreased in patients with confirmed/severe CAN in comparison with early staging of CAN and patients without CAN (Vm=2.5±0.66 sm/sec vs. 4.4±0.54 sm/sec and 5.1±1.01 sm/sec respectively; p=0.0033). The abnormal result of cold test was detected in 94% patients with confirmed/ severe CAN and 26% patients with CAN 1.

CONCLUSIONS: This investigation has demonstrated in a cohort with type 2 diabetes patients with/without SMN and with/ without history of previously foot amputations that decrease the Vm (the variable of microvascular blood flow assessed by High-frequency Ultrasonic Dopplerography) lower than 2.4 sm/sec is associated with 6.4 times increased likelihood of confirmed/severe CAN as well as positive cold test result. That the patients with positive cold test results were 28.6 times more likely have confirmed/severe CAN.

Ambulatory blood pressure abnormalities in children with migraine

BACKGROUND

Although there are data showing that the frequency of hypertension increases in adults with migraine, there has been no study on this subject in children. In this study, we aimed to evaluate the presence of hypertension in children with migraine by performing ambulatory blood pressure monitoring (ABPM).

METHODS

Thirty-seven children diagnosed with migraine and 30 healthy controls were evaluated between January 2015 and March 2016. Demographic data, clinical and laboratory features, and physical examination findings were recorded for both groups. Office blood pressure was measured for all children, and each also underwent ABPM. The two groups were compared in terms of ambulatory blood pressure parameters.

RESULTS

The mean age was 13.3 and 13.1 years and the proportion of females was 73% and 60% in the migraine and control groups, respectively. Although the frequency of hypertension was not higher, abnormal ABPM patterns were found to be significantly more frequent in the migraine group (migraine, 45.9%; control, 16.7%; p, 0.018). Nighttime mean arterial blood pressure, nighttime diastolic blood pressure, and non-dipping pattern were higher in children with migraine than those in the control group (p < 0.05).

CONCLUSIONS

These results suggest that ambulatory blood pressure abnormalities may be present in almost half of patients with migraine. Therefore, we suggest that ABPM should be performed even if the office blood pressure measurements of children diagnosed with migraine are normal.

Low-frequency facial hemodynamic oscillations distinguish migraineurs from non-headache controls

Background

Surface imaging is a promising, noninvasive approach to assess regional perfusion in craniovascular disorders such as migraine.

Methods

We used optical imaging to examine differences in facial blood volume at baseline and in response to ammonia inhalation (a noxious stimulus), as well as standardized measures of cardiovascular autonomic function, in healthy, non-headache controls (n = 43) and in interictal migraine subjects (n = 22).

Results

Resting facial cutaneous oscillation (FCO) frequency was significantly different in migraine compared to healthy controls. Following ammonia inhalation, healthy controls showed a significant increase in resting FCO frequency, whereas this response was not significant in the migraine group. Standardized autonomic reflex parameters did not differ significantly between study groups, and facial cutaneous activity did not correlate with standardized cardiovascular autonomic reflex parameters, suggesting potentially different regulation.

Conclusions

This approach to the assessment of craniofacial hemodynamic function appears to exhibit differing mechanisms from previously available techniques, and represents a promising new physiological biomarker for the study of craniofacial vascular function in migraine and potentially other craniovascular disorders.

Electrographic indices in migraine patients: A systematic review and meta-analysis

BACKGROUND AND AIM

Migraine patients can exhibit autonomic dysregulation, in turn leading to cardiac conduction and repolarization abnormalities. This systematic review and meta-analysis evaluated the electrocardiographic changes in migraineurs.

METHOD

PubMed and Embase databases were searched for human studies using the search terms 'migraine' and 'electrocardiogram' until 15th December 2018, identifying 108 and 131 studies.

RESULTS

Thirteen studies involving 667 migraineurs and 208 normal subjects included (mean age=30.7, total male percentage=19.8%) were included. A longer mean QTc interval (standard mean difference=7.89, 95% confidence interval=[3.29, 12.49], p=0.0008) and higher frequency of QTc prolongation (risk ratio [RR]=6.23, [2.86-13.58], p<0.00001), but no difference in PR-interval (SMD=4.33, [-3.90-12.56], p=0.30) were observed during migraine attacks compared to pain-free periods. P-wave dispersion was higher in migraine patients compared to controls (mean difference=3.62, [1.03-6.21], p=0.006). RR-interval were statistically indistinguishable between migraine patients and controls (SMD=0.08, [-0.65-0.81], p=0.83), or between migraineurs with and without aura (SMD=-0.03, [-0.44-0.38], p=0.89). Deep breathing ratio was significantly lower in migraineurs compared to controls (SMD=-0.27, 95% CI=[-0.46, -0.08], p=0.006) but similar between migraineurs with and without aura (SMD=-0.04, [-0.27-0.19], p=0.74). No significant difference in Valsalva ratio is found between migraineurs and controls (SMD=0.10, [-0.32-0.53], p=0.63) or between migraineurs with and without aura (SMD=-0.17, [-0.40-0.06], p=0.14). Root mean square of successive differences (RMSSD) (SMD=-0.07, [-1.10-0.95], p=0.89) and standard deviation of NN intervals (SDNN) (SMD=-0.10, [-0.61-0.41], p=0.71) did not significantly differ between migraine patients and controls.

CONCLUSION

Electrocardiographic alterations are observed in migraine patients compared to controls, especially during migraine attacks.

Body Mass Index and Primary Headache: A Hospital-Based Study in China

OBJECTIVE

Primary headache and obesity are highly prevalent disorders in the general population. Although many studies have reported an association between the two, there is still no overall comprehension about this relationship. To gain a more accurate understanding in this regard, we analyzed data from a 2011 cross-sectional study in Chongqing, China.

METHODS

Patients with a chief complaint of headache were administered a headache questionnaire and diagnosed by neurology doctors in accordance with the International Classification of Headache Disorders 2nd Edition (ICHD-II) criteria. Patients aged < 18 years or diagnosed with secondary headache were excluded.

RESULTS

Of 1327 patients who cited headache as the chief complaint, 16 were excluded for missing data, while 396 were diagnosed with chronic headache (177 chronic migraine [CM], 186 chronic tension-type headache [CTTH], and 33 other chronic headache) and 915 with episodic headache (369 episodic migraine [EM], 319 episodic tension-type headache [ETTH], and 227 other episodic headache). Chronic headache patients had a higher number of headache days per month, longer duration of headache history, and greater tendency to overuse analgesics than episodic headache patients. The CM and ETTH patients were more apt to be overweight and had a significantly greater body mass index (BMI; p < 0.05) than the EM and CTTH patients. Overweight (odds ratio [OR] = 3.64; 95% confidence interval (CI), 1.19-8.81) and obesity (OR = 28.63; 95% CI, 2.96-276.6) were independently associated with CM but not with other headaches, and this association was not influenced by other factors such as medication overuse.

CONCLUSIONS

The relationship between headache and overweight/obesity varies depending on the type of primary headache. CM patients are more likely to have a higher body mass index than EM patients, while ETTH patients are more likely to be overweight/obese than CTTH patients.

Novel capsaicin-induced parameters of microcirculation in migraine patients revealed by imaging photoplethysmography

Background

The non-invasive biomarkers of migraine can help to develop the personalized medication of this disorder. In testing of the antimigraine drugs the capsaicin-induced skin redness with activated TRPV1 receptors in sensory neurons associated with the release of the migraine mediator CGRP has already been widely used.

Methods

Fourteen migraine patients (mean age 34.6 ± 10.2 years) and 14 healthy volunteers (mean age 29.9 ± 9.7 years) participated in the experiment. A new arrangement of imaging photoplethysmography recently developed by us was used here to discover novel sensitive parameters of dermal blood flow during capsaicin applications in migraine patients.

Results

Blood pulsation amplitude (BPA) observed as optical-intensity waveform varying synchronously with heartbeat was used for detailed exploration of microcirculatory perfusion induced by capsicum patch application. The BPA signals, once having appeared after certain latent period, were progressively rising until being saturated. Capsaicin-induced high BPA areas were distributed unevenly under the patch, forming “hot spots.” Interestingly the hot spots were much more variable in migraine patients than in the control group. In contrast to BPA, a slow component of waveforms related to the skin redness changed significantly less than BPA highlighting the latter parameter as the potential sensitive biomarker of capsaicin-induced activation of the blood flow. Thus, in migraine patients, there is a non-uniform (both in space and in time) reaction to capsaicin, resulting in highly variable openings of skin capillaries.

Conclusion

BPA dynamics measured by imaging photoplethysmography could serve as a novel sensitive non-invasive biomarker of migraine-associated changes in microcirculation.

Association between Body Mass Index and Migraine: A Survey of Adult Population in China

Both migraine and obesity are prevalent disorders in the general population, which are characterized by disability and impaired quality of life. Although so many researches had studied the association between migraine and obesity, there are still no full knowledge of the relationship between body mass index (BMI) and migraine, especially chronic migraine (CM). In this study, we analyzed a previous epidemiological survey data of primary headache patients in Chongqing, which surveyed consecutive neurological outpatients through face-to-face interview with physicians using a headache questionnaire. 166 episodic migraine (EM) patients and 134 chronic migraine (CM) patients were included in the study out of 1327 primary headache patients. And 200 healthy adults from the physical examination center were included as a control group. Finally, we found that the patients with migraine (EM and CM) were more likely to be overweight, obese, or morbidly obese compared to those in the healthy group. Significant difference was found between BMI and frequency of migraine attacks but not severity or duration of headache onset. And no significant difference was found in severity and duration of headache onset between episodic and chronic migraine among different BMI classifications. Such may update our knowledge about the clinical features of migraine and BMI, revealing that the frequency of attacks may be associated with being overweight, obese, or morbidly obese in patients with migraine and that the extent of being overweight, obese, or morbidly obese in CM patients was lower than that in EM patients.

Migraine and Autonomic Dysfunction: Which Is the Horse and Which Is the Jockey?

PURPOSE OF REVIEW

Symptoms of autonomic dysfunction are common in patients with migraine, both during and between migraine attacks. Studies evaluating objective autonomic testing in patients have found significant, though somewhat conflicting results. The purposes of this review are to summarize and interpret the key findings of these studies, including those evaluating heart rate variability, autonomic reflex testing, and functional imaging in patients with migraine. The neuroanatomy of the central autonomic network as it relates to migraine is also reviewed.

RECENT FINDINGS

Several studies have evaluated autonomic balance in migraineurs, with conflicting results on the magnitude of sympathetic versus parasympathetic dysfunction. Most studies demonstrate sympathetic impairment, with a lesser degree of parasympathetic impairment. Three trends have emerged: (1) migraine with aura tends to produce more significant autonomic dysfunction than migraine without aura, (2) sympathetic impairment is more common than parasympathetic impairment, and (3) sympathetic impairment is common in the interictal period, with increased sympathetic responsiveness during the ictal period, suggesting adrenoreceptor hypersensitivity.

Novel contactless approach for assessment of venous occlusion plethysmography by video recordings at the green illumination

Occlusion plethysmography is an important method for assessment of the status of the cardiovascular system, which provides valuable information concerning arterial and venous blood flow, including mechanisms of their regulation. All up-to-date systems estimate change of the limb's volume during occlusion by contact-type sensors. The objective of the research is demonstration of feasibility of the novel approach to measuring the blood flow during venous occlusion by using imaging photoplethysmography (PPG). Twenty healthy individuals participated in the experiment. We used four synchronized video cameras to record all-around view of the forearm illuminated by the green light. After the recording, the PPG waveform was calculated in more than 4000 non-overlapping Regions of Interest (ROI). In the most of the ROIs, the waveform shape was typical for classical plethysmography with the distinctive linear growth of the signal. Speed of the signal change was the same along the forearm but it varied along the forearm's circumference. These findings allows us to hypothesize that the PPG waveform is the direct consequence of the forearm blood flow. Therefore, the novel technique could be applied to the same medical examinations as the classical plethysmography, but it is more advantageous because of non-contact nature and easiness in implementation.

Arterial hypertension in migraine: Role of familial history and cardiovascular phenotype

Recent studies indicate that migraine is associated with increased risk of cardiovascular diseases. However, links between autonomic cardiovascular regulation, arterial hypertension (AH) and migraine are still little explored. In this study, we evaluated autonomic regulation in migraine patients with and without hypertension. We studied 104 patients with migraine, aged 34±10 y, including 28 with and 76 without hypertension (M+AH and M-AH groups, respectively). The control group consisted of 88 healthy volunteers matched by age and sex. The autonomic regulation of circulation was examined with the tilt-table test, deep-breathing and Valsalva Maneuver, handgrip test, cold-stress induced vasoconstriction, arterial baroreflex, and blood pressure variability measurements. We found that migraine patients with concomitant hypertension demonstrated reduced arterial baroreflex, whereas other parameters of cardiac autonomic regulation were unchanged. In contrast, most indicators of vasomotor reactivity (blood pressure response to the hand-grip, Valsalva maneuver and cold vasoconstriction) were enhanced in migraine patients with no significant differences between migraine patients with and without hypertension. Patients from both M+AH and M-AH groups more commonly had a family history of cardiovascular disorders. Our data revealed increased vasomotor reactivity in migraine patients, with or without concomitant hypertension. This was associated with the family history of cardiovascular diseases.

Mamontov O, A. Kamshilin A, Giniatullin R. Parasympathetic Cholinergic and Neuropeptide Mechanisms of Migraine

Context

Migraine mechanisms remain largely uncovered for various reasons including a very high complexity of the neurophysiological mechanisms implicated in this disorder and a plethora of endogenous biologically active compounds involved in the pathological process. The functional role of parasympathetic innervation of meninges and cholinergic mechanisms of migraine are among little explored issues despite multiple evidence indirectly indicating the role of acetylcholine (ACh) and its analogues in migraine and other types of headache. In the current short review, we discuss morphological, functional, and clinical issues related to the role of ACh and its analogues such as carbachol and nicotine in this most common neurological disorder.

Evidence Acquisition

In the present work, studies published from 1953 to 2016 were investigated. Literature was searched with following keywords: acetylcholine (ACh), carbachol, nicotine, parasympathetic, mast cells, vasoactive intestinal polypeptide (VIP), and pituitary adenylate cyclase-activating polypeptide (PACAP).

Results

Parasympathetic fibers originated from SPG and trigeminal nerves can interact at the level of meninges which is considered to be the origin site of migraine pain. Here, in dura mater, ACh, VIP, and PACAP released by parasympathetic afferents can both affect mast cells provoking its degranulation and additional release of neurotransmitters, or they can directly affect trigeminal nerves inducing nociception.

Conclusions

In summary, cholinergic mechanisms in migraine and other types of headache remain little elucidated and future studies should clarify the role of parasympathetic nerves and molecular mechanisms of cholinergic modulation within the nociceptive system.

Accurate measurement of the pulse wave delay with imaging photoplethysmography

Assessment of the cardiovascular parameters using noncontact video-based or imaging photoplethysmography (IPPG) is usually considered as inaccurate because of strong influence of motion artefacts. To optimize this technique we performed a simultaneous recording of electrocardiogram and video frames of the face for 36 healthy volunteers. We found that signal disturbances originate mainly from the stochastically enhanced dichroic notch caused by endogenous cardiovascular mechanisms, with smaller contribution of the motion artefacts. Our properly designed algorithm allowed us to increase accuracy of the pulse-transit-time measurement and visualize propagation of the pulse wave in the facial region. Thus, the accurate measurement of the pulse wave parameters with this technique suggests a sensitive approach to assess local regulation of microcirculation in various physiological and pathological states.