Impairment of parasympathetic baroreflex responses in migraine patients

Vagus nerve stimulation inhibits cortical spreading depression via glutamate-dependent TrkB activation mechanism in the nucleus tractus solitarius

BACKGROUND

Vagus nerve stimulation (VNS) was recently found to inhibit cortical spreading depression (CSD), the underlying mechanism of migraine aura, through activation of the nucleus tractus solitarius (NTS), locus coeruleus (LC) and dorsal raphe nucleus (DRN). The molecular mechanisms underlying the effect of VNS on CSD in these nuclei remain to be explored. We hypothesized that VNS may activate glutamate receptor-mediated tropomyosin kinase B (TrkB) signaling in the NTS, thereby facilitating the noradrenergic and serotonergic neurotransmission to inhibit CSD.

METHODS

To investigate the role of TrkB and glutamate receptors in non-invasive VNS efficacy on CSD, a validated KCl-evoked CSD rat model coupled with intra-NTS microinjection of selective antagonists, immunoblot and immunohistochemistry was employed.

RESULTS

VNS increased TrkB phosphorylation in the NTS. Inhibition of intra-NTS TrkB abrogated the suppressive effect of VNS on CSD and CSD-induced cortical neuroinflammation. TrkB was found colocalized with glutamate receptors in NTS neurons. Inhibition of glutamate receptors in the NTS abrogated VNS-induced TrkB activation. Moreover, the blockade of TrkB in the NTS attenuated VNS-induced activation of the LC and DRN.

CONCLUSIONS

VNS induces the activation of glutamate receptor-mediated TrkB signaling in the NTS, which might modulate serotonergic and norepinephrinergic innervation to the cerebral cortex to inhibit CSD and cortical inflammation.

Autonomic Function Tests, Heart Rate Variability, and Electrophysiological Evaluation in Patients With a Primary Episodic Headache: An Observational Study

PURPOSE

Cranial autonomic symptoms are typically associated with the trigeminal autonomic cephalalgias and also present in substantial cases of migraine. Autonomic nervous system dysfunctions are also been reported in headache disorders and postulated to promote headache attacks. This study was aimed to evaluate the parasympathetic and sympathetic autonomic functions tests in patients with a episodic primary headache and to investigate, if any, electrophysiological abnormalities in the blink reflex test and sympathetic skin response test in these patients.

METHODS

In this cross-sectional study, a total of 100 patients, 50 patients each of migraine and tension-type headache attending the neurology OPD and fulfilling the diagnostic criteria of headache disorders were enrolled. Autonomic functions tests were performed in the Department of Physiology, whereas electrophysiological tests were powered by the Editorial Manager and ProduXion Manager from Aries Systems Corporation performed in the Department of Neurology.

RESULTS

Significant association ( P < 0.05) was observed in "blood pressure response to sustained handgrip" (sympathetic activity) and "heart rate response to Valsalva maneuver" (parasympathetic activity) among patients with migraine. Although the mean sympathetic skin response latency of patients with migraine was within the normal range, it was significantly prolonged in comparison with the control group. "Blood pressure response to sustained handgrip" and "heart rate variability" were found to be significantly ( P < 0.05) different in patients with a tension-type headache. The blink reflex test was observed to be normal in all patients with a headache. Patients with migraine showed a significant dysautonomia in category three of the Ewing battery for autonomic functional disability.

CONCLUSIONS

Autonomic functional abnormality, both sympathetic and parasympathetic, does exist in patients with a primary episodic headache.

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.

Sex and stress hormone dysregulation as clinical manifestations of hypothalamic function in migraine disorder: A meta-analysis

Migraine is a leading cause of disability in young adults. It occurs more frequently in females, often comorbidly with stress disorders, suggesting an association with hypothalamic sex and stress hormonal function and a likely interaction with autonomic nervous system activation. Thus, this study aimed to meta-analyse current literature pertaining to female and male sex hormones (estrogen, progesterone and testosterone concentration), hypothalamic-pituitary-adrenal axis (HPA axis) cortisol responses and heart rate variability (HRV) in migraineurs and controls aged 13-65 years. A systematic search of MEDLINE, Embase, PsycINFO, PubMed, CINAHL and Web of Science databases on 29/08/2022 identified 29 studies for meta-analysis (encompassing 719 migraineur and 592 control participants) that met inclusion and NHLBI risk of bias criteria. Results demonstrated that estrogen concentrations of female migraineurs were reduced (g = -.60, 95% CI [-.91, -.29], p < .001) in the luteal phase of the menstrual cycle, compared to controls. No differences were found in progesterone levels overall in female migraineurs, nor in testosterone levels in male migraineurs compared to controls. Further, early diurnal cortisol concentrations were elevated (g = .32, 95% CI [.00, .63], p = .036) in female and male migraineurs compared to controls, though no differences were found in HRV of female or male migraineurs compared to controls. These findings of dysregulation of estrogen in females and cortisol dysregulation in female and male migraineurs indicate perturbed hypothalamic function and highlight the association of migraine with stress and the need for further rigorous investigation of hypothalamic neuroendocrine functions in migraineurs of both sexes.

"The Pupillary (Hippus) Nystagmus": A Possible Clinical Hallmark to Support the Diagnosis of Vestibular Migraine

(1) Background: Hippus (which in this paper will be called "Pupillary nystagmus") is a well-known phenomenon which has never been related to any specific pathology, so much so that it can be considered physiological even in the normal subject, and is characterized by cycles of dilation and narrowing of the pupil under constant lighting conditions. The aim of this study is to verify the presence of pupillary nystagmus in a series of patients suffering from vestibular migraine. (2) Methods: 30 patients with dizziness suffering from vestibular migraine (VM), diagnosed according to the international criteria, were evaluated for the presence of pupillary nystagmus and compared with the results obtained in a group of 50 patients complaining of dizziness that was not migraine-related. (3) Results: Among the 30 VM patients, only two cases were found to be negative for pupillary nystagmus. Among the 50 non-migraineurs dizzy patients, three had pupillary nystagmus, while the remaining 47 did not. This resulted in a test sensitivity of 0.93% and a specificity of 0.94%. (4) Conclusion: we propose the consideration of the presence of pupillary nystagmus as an objective sign (present in the inter-critical phase) to be associated with the international diagnostic criteria for the diagnosis of vestibular migraine.

Heart rate variability in patients with low back pain: a systematic review

OBJECTIVES

Heart rate variability (HRV) is an important physiological measure of the capacity for neurogenic homeostatic regulation, and an indirect measure of emotional processing. We aimed to investigate whether HRV parameters are altered in people with chronic low back pain when compared to healthy controls.

METHODS

We searched on PubMed, Scopus, CINAHL, Web of Science, Cochrane Library, and PsycINFO from inception to January 2018. The inclusion criteria were: patients with non-specific chronic low back pain, absence of radiculopathy, age from 18 to 65 years, and comparison with healthy controls. Data extraction was performed by two independent review authors. The methodological quality of the studies was assessed using the appraisal tool for cross-sectional studies.

RESULTS

After screening 2,873 potential articles, two studies met the inclusion criteria. Studies were composed of 153 patients with chronic low back pain and 62 healthy controls. An electrocardiogram was used to record HRV and linear methods (time and frequency) were used to analyze the results. The main findings indicate that patients with chronic low back pain have a significant reduction in HRV, with sympathetic predominance compared to healthy controls.

CONCLUSIONS

There is limited evidence suggesting that chronic low back pain patients presented a lower vagal activity evidenced by HRV, when compared to healthy controls. The results of this systematic review should be interpreted with caution due to the restricted number of included studies, small sample sizes and different protocols used to measure HRV. The limited evidence about HRV alterations in low back pain also suggests the need of future studies to investigate if HRV parameters can be a useful measure in chronic pain samples or even if it can be used as an outcome in clinical trials aiming to investigate the effectiveness of interventions based on emotion regulation.

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.

Fabrication of polyvinyl alcohol based fast dissolving oral strips of sumatriptan succinate and metoclopramide HCL

Migraine is a throbbing condition, usually associated with nausea and vomiting and requires concurrent administration of anti-migraine along with anti-emetic therapy. The current study was undertaken with an aim to fabricate fast dissolving oral strips (FDOSs) containing Sumatriptan succinate (anti-migraine) and Metoclopramide HCl (anti-emetic) in combination without involving any superdisintegrant. Hydrophilic polymer polyvinyl alcohol (PVA) was used alone with three concentrations of 100, 125, and 150 mg using variable concentrations of glycerol. The solvent casting technique was employed to formulate FDOSs and were evaluated for surface morphology, mechanical properties, surface pH, % moisture content, disintegration time (DT), total dissolving time (TDT), drug contents, and dissolution profile. PVA (150 mg) with 5% glycerol concentration gave best formulation results. FDOSs have exhibited good tensile strength with smooth and uniform surface morphology. DT was ranged from 7.7 to 28 s; while TDT was from 26.4 to 77.6 s. Both polymer and plasticizer concentrations were found to be influencing the characteristics of the strips. Dissolution studies were carried out in distilled water for 15 min and all the formulations have shown released more than 50% drug within first 2 min thereby highlighting the usefulness of FDOSs for the delivery of both drugs in combination significantly. Optimized combination of ingredients was found to be suitable for the formulation of FDOSs for simultaneous delivery of Metoclopramide HCl and Sumatriptan succinate.

Targeting the Autonomic Nervous System Balance in Patients with Chronic Low Back Pain Using Transcranial Alternating Current Stimulation: A Randomized, Crossover, Double-Blind, Placebo-Controlled Pilot Study

Background

Chronic low back pain (CLBP) is characterized by an alteration in pain processing by the central nervous system that may affect autonomic nervous system (ANS) balance. Heart rate variability (HRV) reflects the balance of parasympathetic and sympathetic ANS activation. In particular, respiratory sinus arrhythmia (RSA) solely reflects parasympathetic input and is reduced in CLBP patients. Yet, it remains unknown if non-invasive brain stimulation can alter ANS balance in CLBP patients.

Objective

To evaluate if non-invasive brain stimulation modulates the ANS, we analyzed HRV metrics collected in a previously published study of transcranial alternating current stimulation (tACS) for the modulation of CLBP through enhancing alpha oscillations. We hypothesized that tACS would increase RSA.

Methods

A randomized, crossover, double-blind, sham-controlled pilot study was conducted to investigate the effects of 10Hz-tACS on metrics of ANS balance calculated from electrocardiogram (ECG). ECG data were collected for 2 mins before and after 40 mins of 10Hz-tACS or sham stimulation.

Results

There were no significant changes in RSA or other frequency-domain HRV components from 10Hz-tACS. However, exploratory time-domain HRV analyses revealed a significant increase in the standard deviation of normal intervals between R-peaks (SDNN), a measure of ANS balance, for 10Hz-tACS relative to sham.

Conclusion

Although tACS did not significantly increase RSA, we found in an exploratory analysis that tACS modulated an integrated HRV measure of both ANS branches. These findings support the further study of how the ANS and alpha oscillations interact and are modulated by tACS.

ClinicalTrials.gov

Transcranial Alternating Current Stimulation in Back Pain – Pilot Study, NCT03243084.

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.

Cardiorespiratory Regulation in Migraine. Results in Children and Adolescents and Review of the Literature

To investigate autonomic regulation in juvenile migraine we studied 70 children and adolescents with migraine during the headache-free period and 81 healthy controls by cardiorespiratory function tests. Heart rate variability was analysed with time and frequency domain indices during spontaneous breathing at rest and during metronomic breathing. Changes of heart rate and blood pressure were studied during tilt-table test, active standing, Valsalva manoeuvre and sustained handgrip. We found significant differences in metronomic breathing, tilt-table test and Valsalva manoeuvre. We interpret our findings and results reported in the literature as pointing to a restricted ability of the system to rest, which supports therapies intending to further this ability. In autonomic tests, hyperreactivity in juvenile migraineurs changes to hyporeactivity and passive coping in adults. This might be explained by disturbances of raphe nuclei and the periaqueductal grey. It corresponds to psychological findings in juvenile migraineurs reporting hypersensitivity and repressed aggression and claiming learned helplessness.

Neuroimaging brainstem circuitry supporting cardiovagal response to pain: a combined heart rate variability/ultrahigh-field (7 T) functional magnetic resonance imaging study

Central autonomic control nuclei in the brainstem have been difficult to evaluate non-invasively in humans. We applied ultrahigh-field (7 T) functional magnetic resonance imaging (fMRI), and the improved spatial resolution it affords (1.2 mm isotropic), to evaluate putative brainstem nuclei that control and/or sense pain-evoked cardiovagal modulation (high-frequency heart rate variability (HF-HRV) instantaneously estimated through a point-process approach). The time-variant HF-HRV signal was used to guide the general linear model analysis of neuroimaging data. Sustained (6 min) pain stimulation reduced cardiovagal modulation, with the most prominent reduction evident in the first 2 min. Brainstem nuclei associated with pain-evoked HF-HRV reduction were previously implicated in both autonomic regulation and pain processing. Specifically, clusters consistent with the rostral ventromedial medulla, ventral nucleus reticularis (Rt)/nucleus ambiguus (NAmb) and pontine nuclei (Pn) were found when contrasting sustained pain versus rest. Analysis of the initial 2-min period identified Rt/NAmb and Pn, in addition to clusters consistent with the dorsal motor nucleus of the vagus/nucleus of the solitary tract and locus coeruleus. Combining high spatial resolution fMRI and high temporal resolution HF-HRV allowed for a non-invasive characterization of brainstem nuclei, suggesting that nociceptive afference induces pain-processing brainstem nuclei to function in concert with known premotor autonomic nuclei in order to affect the cardiovagal response to pain.

Allergic Rhinitis and Chronic Daily Headaches: Is There a Link?

Allergic rhinitis and migraine remain on the list of the most common diseases affecting adults. Migraines and headaches due to allergic rhinitis are easily confused because the symptoms of both conditions often overlap. Both may occur with sinus headache, nasal congestion, and lacrimation and may worsen with weather changes and exposure to allergens. No precise clinical definition exists for what constitutes a sinus headache, which has always been a diagnostic dilemma. Contrary to popular belief, headache is not a typical symptom of rhinitis. Some studies have shown that up to 90 % of sinus headaches are actually migraines. Nevertheless, patients with self-diagnosed sinus headache self-treat or are treated by primary care physicians and/or otolaryngologists with medications for rhinosinusitis, ignoring the neurogenic causes of the symptoms when most of these patients fulfill diagnostic criteria for chronic migraine. Chronic migraine affects 2 % of the general population and has a significant socioeconomic impact on society, incurring health care costs and diminishing quality of life; therefore, the proper diagnosis and treatment of these headache patients should be a priority.

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.

Sphenopalatine ganglion neuromodulation in migraine: what is the rationale?

OBJECTIVE

The objective of this article is to review the prospect of treating migraine with sphenopalatine ganglion (SPG) neurostimulation.

BACKGROUND

Fuelled by preliminary studies showing a beneficial effect in cluster headache patients, the potential of treating migraine with neurostimulation has gained increasing interest within recent years, as current treatment strategies often fail to provide adequate relief from this debilitating headache. Common migraine symptoms include lacrimation, nasal congestion, and conjunctival injection, all parasympathetic manifestations. In addition, studies have suggested that parasympathetic activity may also contribute to the pain of migraineurs. The SPG is the largest extracranial parasympathetic ganglion of the head, innervating the meninges, lacrimal gland, nasal mucosa, and conjunctiva, all structures involved in migraine with cephalic autonomic symptoms.

CONCLUSION

We propose two possible mechanisms of action: 1) interrupting the post-ganglionic parasympathetic outflow to inhibit the pain and cephalic autonomic symptoms, and 2) modulating the sensory processing in the trigeminal nucleus caudalis. To further explore SPG stimulation in migraineurs as regards therapeutic potential and mode of action, randomized clinical trials are warranted.

Ventricular tachycardia during basilar-type migraine attack

Autonomic dysfunction is a characteristic of migraine attacks, rarely, even cardiac repolarization abnormalities have been associated with migraine. We report a case of documented ventricular tachycardia during basilar-type migraine attack. The therapeutic implications of such a co-occurrence as well as a possible relationship between ventricular tachycardia and the underlying biology of basilar-type migraine are discussed.

Increased baroreflex sensitivity and heart rate variability in migraine patients

OBJECTIVES

We investigated whether spontaneous baroreflex sensitivity and heart rate variability (HRV) are different in migraine patients compared to healthy controls.

MATERIAL AND METHODS

Sixteen female migraine patients without aura aged 18-30 years and 14 age-matched healthy female controls were included. Continuous finger blood pressure and ECG were measured supine during paced breathing in the laboratory. Continuous finger blood pressure was measured the following 24-h period. Spontaneous baroreflex sensitivity (time-domain cross correlation baroreflex sensitivity) as well as HRV parameters were calculated.

RESULTS

Spontaneous baroreflex sensitivity measured in the 24-h period was increased in patients (20.6 ms/mmHg) compared to controls (15.7 ms/mmHg, P = 0.031). HRV parameters were increased during paced breathing in patients (P < 0.045).

CONCLUSIONS

The results suggest that central hypersensitivity in migraine also includes cardiovascular reactivity and may be important for the understanding of the mechanisms for the effect of antihypertensive drugs for migraine prophylaxis.

Hypertension-associated hypalgesia: a clue to the comorbidity of headache and other pain disorders

BACKGROUND

Primary headaches and chronic musculoskeletal pain are prevalent disorders with incompletely known causes.

AIMS

To review the data from the HUNT studies on the comorbidity of these pain disorders, and their relation to blood pressure levels.

MATERIALS & METHODS

Cross-sectional and prospective data from more than 50,000 persons participating in the HUNT studies, a large Norwegian population-based health survey

RESULTS

Headache and chronic musculoskeletal complaints in all parts of the body were comorbid, and the prevalence of pain in all locations was inversely related to blood pressure levels.

DISCUSSION

A likely cause for this is hypertension-associated hypalgesia, described in both animal and human experimental models, involving interactions between cardiovascular and pain modulating centres at the brainstem level, and probably also peripheral baroreceptor mechanisms.

CONCLUSION

Better understanding of these mechanisms may be crucial for enabling better prevention and treatment of these very prevalent, costly and disabling disorders.

Carotid baroreflex testing using the neck collar device

A neck chamber device for stimulation of carotid sinus baroreceptors by changing carotid transmural pressure was first described in 1957 by Ernsting and Parry and, with several modifications, has been extensively used in a number of physiological and clinical studies. This article outlines the evolution of neck chamber devices and describes some of the advantages and limitations of the technique. We also describe the responses in healthy subjects and the changes observed in patients with some disorders affecting the autonomic nervous system.

Heart rate recovery in migraine and tension-type headache

OBJECTIVE

There are reports proposing that migraine and tension-type headache (TTH) may affect the autonomic nervous system (ANS). Abnormalities in both sympathetic and parasympathetic nervous system have been suggested in migraineurs. However, in TTH, reports on the ANS function are limited and only associated with sympathetic system. Techniques for evaluating parasympathetic activity are more limited when compared with sympathetic function. Hence, the aim of the study was to measure heart rate recovery (HRR), an index of vagal activity, in migraine, TTH, and control subjects.

METHODS

Forty-seven episodic migraine, 10 episodic TTH, 11 chronic TTH, and 25 control subjects underwent exercise tolerance test according to modified Bruce protocol, and HRR at 1 minute and 3 minutes (HRR1 and HRR3) were calculated.

RESULTS

The HRR 1 and 3 were found to be similar in 3 groups of subjects. However, resting heart rate of migraine and chronic TTH were found to be higher than episodic TTH, but not different from the control group.

CONCLUSION

These results suggest that parasympathetic function has not been affected in migraine and TTH patients. However, sympathetic tonus, which is evaluated by resting heart rate, is higher in migraine and chronic TTH than in episodic TTH.

Autonomic abnormalities in cyclic vomiting syndrome

BACKGROUND

Although cyclic vomiting syndrome (CVS) is associated with migraine, and migraine in turn is associated with orthostatic tachycardia, few studies have explored the association of CVS and autonomic dysfunction. We describe the results of autonomic testing in 6 children with characteristic CVS.

PATIENTS AND METHODS

All patients fully met the established criteria for the diagnosis of CVS, were well hydrated, and were beyond their episode of vomiting. We performed 3 tests of cardiovascular function and 1 sudomotor test, using standard previously published methods.

RESULTS

The findings were surprisingly uniform, with normal cardiovascular responses to deep breathing and to the Valsalva maneuver in all patients, a significant increase in heart rate (>30 beats per minute) with tilt testing, and a vasodepressor tendency in 2 patients. Interestingly, abdominal pain occurred at blood pressure nadir in both these patients and in a third patient without the vasodepressor findings but who described syncope clinically. Sudomotor test results were abnormal in all 6 patients, with reduced responses in 5 of 6 and exaggerated responses in the 6th. All 6 patients reported a personal or family history of migraine headaches.

CONCLUSIONS

CVS is associated with remarkably uniform primarily sympathetic autonomic dysfunction, affecting mainly the vasomotor and sudomotor systems, and compatible with an underlying autonomic neuropathy. The occurrence of symptoms during tilt testing in half the patients suggests that these findings may play a true pathophysiologic role. A vagally modulated sympathetic effect is postulated as the best mechanistic model to account for all current physiologic data on cyclic vomiting and gastroparesis.

Dysautonomia rhinitis: associated otolaryngologic manifestations and characterization based on autonomic function tests

CONCLUSIONS

Dysautonomia is a multisystem disorder. Beside the nasal symptoms, some otolaryngological disorders may be explained on the basis of autonomic dysfunction. Testing of the autonomic nervous system (ANS) complements the clinical findings and provides objective measurements to substantiate the presence of ANS dysfunction. The term dysautonomia rhinitis may be used to specify this autonomic-related rhinitis.

OBJECTIVES

Nonallergic, noninfectious perennial rhinitis is a heterogeneous disorder comprising several pathophysiological entities. This study was designed to objectively investigate the relation of idiopathic perennial rhinitis to ANS dysfunction.

PATIENTS AND METHODS

This was a prospective controlled clinical study; 78 patients, carefully diagnosed as having idiopathic perennial rhinitis, were enrolled. Workshop protocol included diagnostic measures for exclusion of other causes of rhinitis and autonomic function assessment at a clinical cardiology laboratory. Results were compared with those of 20 age- and sex-matched normal control subjects.

RESULTS

In addition to their nasal symptoms, all patients reported more than one regional and multisystem complaint. Each patient had at least one autonomic function test that displayed a hypervagal response and the overall response score was as follows: 46 (59%) had hypervagal response, 32 (41%) had mixed response and none had a normal or hyperadrenergic response.

Migraine: a review and future directions for treatment

Migraine is a chronic, neurological disorder generally manifesting itself in attacks with severe headache, nausea and an increased reactivity to sensory stimuli. A low migraine threshold is set by genetic factors, although the phenotype also modulates the manifestations. The 1-year prevalence is approximately 13% and is higher among women. Patients usually experience neuropsychological dysfunction, and sometimes also reversible focal neurological symptoms. The trajectories of the characteristic symptoms of acute migraine usually follow a similar time course, indicating a reciprocal underlying mechanism. A central nervous system hyperexcitability has been demonstrated in neurophysiological studies. The dibilitating effects of migraine are not confined to the attacks per se. Many individuals do not recover completely between the attacks and most report a negative impact on the most important life domains, and an interest in testing other treatments. Young persons have a higher frequency of attacks. Acute treatment should routinely be initiated with an analgesic plus a prokinetic anti-emetic. Triptans must not be provided early during the attack to ensure their efficacy. The natural course of attacks is commonly only temporarily altered by acute treatment. Non-pharmacological treatment and drugs may be equally viable in prophylaxis for migraine. In more complicated cases, conjoint therapy should be considered. New strategies to improve adherence with existing therapeutic regimens might yield greater benefits than will new pharmacological agents.

Psychophysiological response patterns of migraine patients in two habituation tests

OBJECTIVE

To investigate the habituation response pattern of patients with migraine to a simple standard stressor and to a more complex performance-dependent (achievement) stressor in three peripheral systems (electrodermal, vasomotor, and cardiovascular). We hypothesized that the migraine patients would show abnormal habituation in these peripheral systems, especially in response to achievement stimuli.

BACKGROUND

Abnormal central habituation to repetitive stimuli has been reported frequently in patients with migraine. But little is known about habituation of the peripheral autonomic nervous system to stressors in these patients.

METHODS

A total of 30 female migraineurs and 30 physically and mentally healthy women matched for age and social status participated in a simple habituation test (auditory stimuli) and an achievement habituation test (mental arithmetic).

RESULTS

Habituation was impaired in the electrodermal (skin conductance response), vasomotor (pulse volume amplitude), and cardiovascular (heart rate response) systems during the mental arithmetic test (achievement stimuli) in the migraineurs as compared to the healthy controls. With the simple stressor (auditory stimuli), however, habituation was impaired in the vasomotor system only. Consistent with these findings were the participants' verbal reports, which indicated significantly more subjective tension in the migraine group than in the control group during the calculation test.

CONCLUSION

Our results suggest that the mental arithmetic (achievement) habituation paradigm is an important tool for demonstrating reduced habituation in several specific components of the autonomic nervous system. Further research is needed to target the covariance of central and autonomic nervous system habituation phenomena in migraine.