Motion sickness and migraine: optokinetic stimulation increases scalp tenderness, pain sensitivity in the fingers and photophobia

The aim of this study was to determine whether scalp tenderness and photophobia, two well-recognized symptoms of migraine, develop during the motion sickness induced by optokinetic stimulation. To investigate whether motion sickness has a general influence on pain perception, pain was also assessed in the fingertips. After optokinetic stimulation, nausea increased more and headache persisted longer in 21 migraine sufferers than in 15 non-headache controls. Scalp tenderness increased during optokinetic stimulation in nauseated subjects, and pain in the fingertips increased more and photophobia persisted longer in migraine sufferers than controls. These findings suggest that the disturbance responsible for nausea also sensitizes trigeminal nociceptive neurones or releases inhibitory controls on their discharge. A low nausea threshold and a propensity for sensitization to develop rapidly in nociceptive pathways may increase susceptibility to migraine

Sample representation in a psychological treatment study after single event paediatric trauma

Children and their families who attended an emergency department following a single traumatic incident and who agreed to participate in a psychological treatment study (N = 211) were compared with nonparticipants (N = 2333) on several measures of trauma and injury severity: duration of admission and heart rate in the emergency department, emergency transport and admission to hospital, injury severity score, and triage code. Within the nonparticipant population, those who requested further information about the study (N = 573) were exposed to more severe trauma or injury than other nonparticipants (N = 1760). In addition, participants were exposed to more severe trauma or injury than either group of nonparticipants. These observations indicate that those exposed to more severe trauma or injury do not avoid participation in psychological treatment studies. Findings can therefore be generalized to those with more severe exposure, but not to the population as a whole

Migraine and motion sickness: what is the link?

The brainstem is a structurally complex region, containing numerous ascending and descending fibres that converge on centres that regulate bodily functions essential to life. Afferent input from the cranial tissues and the special senses is processed, in part, in brainstem nuclei. In addition, brainstem centres modulate the flow of pain messages and other forms of sensory information to higher regions of the brain, and influence the general excitability of these cortical regions. Thus, disruptions in brainstem processing might evoke a complex range of unpleasant symptoms, vegetative changes and neurovascular disturbances and that, together, form attacks of migraine. Migraine is linked with various co-morbid conditions, the most prominent being motion sickness. Symptoms such as nausea, dizziness and headache are common to motion sickness and migraine; moreover, migraine sufferers have a heightened vulnerability to motion sickness. As both maladies involve reflexes that relay in the brainstem, symptoms may share the same neural circuitry. In consequence, subclinical interictal persistence of disturbances in these brainstem pathways could not only increase vulnerability to recurrent attacks of migraine but also increase susceptibility to motion sickness. Mechanisms that mediate symptoms of motion sickness and migraine are explored in this paper. The physiology of motion sickness and migraine is discussed, and neurotransmitters that may be involved in the manifestation of symptoms are reviewed. Recent findings have shed light on the relationship between migraine and motion sickness, and provide insights into the generation of migraine attacks

Stochastic gauges in quantum dynamics for many-body simulations

Quantum dynamics simulations can be improved using novel quasiprobability distributions based on non-orthogonal hermitian kernel operators. This introduces arbitrary functions (gauges) into the stochastic equations, which can be used to tailor them for improved calculations. A possible application to full quantum dynamic simulations of BEC's is presented.Comment: 4 pages, 2 figure

Quantum phase-space simulations of fermions and bosons

We introduce a unified Gaussian quantum operator representation for fermions and bosons. The representation extends existing phase-space methods to Fermi systems as well as the important case of Fermi-Bose mixtures. It enables simulations of the dynamics and thermal equilibrium states of many-body quantum systems from first principles. As an example, we numerically calculate finite-temperature correlation functions for the Fermi Hubbard model, with no evidence of the Fermi sign problem.Comment: 4 pages, 2 figures, to appear in Comp. Phys. Com

Topical treatment in pain medicine: From ancient remedies to modern usage

Over several millennia, substances have been applied to the skin for treatment of pain. Some ingredients are in current use; others have been discontinued. Mechanisms of action include interactions with nociceptive neural networks and inflammatory processes. Substances must penetrate the stratum corneum barrier and vehicles that enhance penetration have been developed. Topical drugs with links to the past include menthol, capsaicin, some opioids, local anesthetic agents and NSAIDs. Mandragora is also described as an example of a herbal remedy that has been discontinued due to its toxicity. The future for topical drugs is promising, with the advent of new drugs tailored for specific pain mechanisms and the development of both penetration enhancers and sterile preparation methods

Topically applied capsaicin inhibits sensitivity to touch but not to warmth or heat-pain in the region of secondary mechanical hyperalgesia

The aim of this study was to investigate tactile sensitivity near the site of primary hyperalgesia evoked by capsaicin applied topically to the dorsolateral aspect of the hand. In the first experiment (N = 15), touch thresholds increased in the fifth finger ipsilateral to the topically applied capsaicin, but remained unchanged at greater distances from the site of capsaicin treatment. In a second experiment (N = 12), the effect of the capsaicin treatment on sensations evoked not only by light touch but also by warmth, heat-pain, and pressure-pain to a 2-mm diameter steel probe was investigated in the fifth finger. Again, tactile sensitivity was inhibited at the fifth finger, even though stimulation with a cotton bud evoked no discomfort; moreover, sensitivity to warmth and heat-pain were unimpaired. However, sensitivity to pressure-pain increased in the fifth finger after the capsaicin treatment, possibly due to activation of nociceptors sandwiched between the probe tip and bone that normally responded to sharp stimuli. These findings suggest that the central mechanisms that mediate secondary mechanical hyperalgesia suppress sensitivity to innocuous tactile sensations. This effect may contribute to tactile hypoesthesia in chronic pain conditions

Efficacy of curcumin, and a saffron/curcumin combination for the treatment of major depression: A randomised, double-blind, placebo-controlled study

Background Several studies have supported the antidepressant effects of curcumin (from the spice turmeric) and saffron for people with major depressive disorder. However, these studies have been hampered by poor designs, small sample sizes, short treatment duration, and similar intervention dosages. Furthermore, the antidepressant effects of combined curcumin and saffron administration are unknown. Methods In a randomised, double-blind, placebo-controlled study, 123 individuals with major depressive disorder were allocated to one of four treatment conditions, comprising placebo, low-dose curcumin extract (250 mg b.i.d.), high-dose curcumin extract (500 mg b.i.d.), or combined low-dose curcumin extract plus saffron (15 mg b.i.d.) for 12 weeks. The outcome measures were the Inventory of Depressive Symptomatology self-rated version (IDS-SR30) and Spielberger State-Trait Anxiety Inventory (STAI). Results The active drug treatments (combined) were associated with significantly greater improvements in depressive symptoms compared to placebo (p=.031), and superior improvements in STAI-state (p<.001) and STAI-trait scores (p=.001). Active drug treatments also had greater efficacy in people with atypical depression compared to the remainder of patients (response rates of 65% versus 35% respectively, p=.012). No differences were found between the differing doses of curcumin or the curcumin/saffron combination. Limitations Investigations with larger sample sizes are required to examine the efficacy of differing doses of curcumin and saffron/curcumin combination. Its effects in people with atypical depression also require examination in larger scale studies. Conclusions Active drug treatments comprising differing doses of curcumin and combined curcumin/saffron were effective in reducing depressive and anxiolytic symptoms in people with major depressive disorder

Visual function impairment in migraine: Cerebral versus retinal deficit

Letters to the Edito

Increases in psychological stress precede flares of rosacea: A prospective study

Objective: Psychological stress is thought to exacerbate symptoms of rosacea. However, this view is based largely on cross-sectional surveys and retrospective clinical reports. Thus, the aim of this study was to determine prospectively whether psychological stress precedes increases in symptom severity in patients with rosacea. Method: Twelve women and four men aged between 35 and 70 years who had been diagnosed with rosacea by a general practitioner or dermatologist filled out a rosacea symptom checklist and rated psychological stress daily for up to two months (mean ± SD, 59 ± 14 days). Each day, they recorded the presence of papules and pustules and rated the average intensity of facial redness, stinging or burning, and psychological stress between 0 (“none”) and 10 (“extreme”). Results: In 12 of the 16 patients, higher levels of stress were associated with more severe symptoms. This association was similar in summer and winter, and in medicated and un-medicated patients. In the group as a whole, stress ratings increased the day before facial flushing increased, and remained high when symptoms were severe. In addition, stress ratings were higher when stinging was severe than when stinging was mild. Conclusion: These findings support the view that psychological stress exacerbates symptoms of rosacea. Further studies are required to determine whether a surge of cutaneous blood flow associated with stress-linked flushing aggravates inflammation in vulnerable facial vessels, or whether stress hormones such as corticotropin releasing factor activate cutaneous mast cells which, in turn, release vasoactive and pro-inflammatory mediators into the skin. Neurogenic inflammation (characterized by stinging pain) might further intensify the inflammatory process when symptoms are severe, so that symptoms and distress escalate in a vicious circle. If so, psychological treatments such as cognitive-behavioural therapy might not only help to alleviate symptom-related distress but could also decrease the frequency and/or intensity of rosacea flares