The role of migraine headache severity, associated features and interactions with overweight/obesity in inhibitory control

Reduced oxygen supply to the prefrontal cortex during the Stroop task in migraine patients with aura: A preliminary functional near-infrared spectroscopy study

The role of the cerebrovascular system in migraine pathogenesis is critical. Several studies have demonstrated alterations in the regional cerebral blood flow that persist during headache-free intervals. In the present study, we aimed to measure the prefrontal hemodynamic responses to the cognitive task in interictal episodic migraineurs. We enrolled eight migraine patients with aura (mean age 25.75 ± 4.39 years), twelve migraine patients without aura (mean age 28.25 ± 6.59 years), and eleven age- and education-matched healthy subjects. We employed the Victoria Stroop task to assess executive functions, specifically selective attention and inhibitory control. The mean changes in the oxy-Hb, deoxy-Hb and total Hb concentrations during the Stroop interference (incongruent minus neutral) were recorded by functional near-infrared spectroscopy (fNIRS). Our preliminary results indicated that migraine patients with aura had higher reaction time (p = 0.033) and lower prefrontal oxy-Hb activity (p = 0.036) during the Stroop interference compared to healthy subjects. For the left lateral prefrontal cortex, migraine with aura group showed lower oxy-Hb activity than the healthy subjects during the Stroop interference (p = 0.009). However, there were no such differences in the right lateral prefrontal cortex. Additionally, we found a relationship between prefrontal oxygenation and the severity of headaches, the frequency of attacks, and the number of monthly migraine days. We noticed a decrease in prefrontal blood flow in migraine patients with aura, even during the interictal periods. This may indicate that migraine with aura could be a persistent neurovascular uncoupling disorder. Moreover, the reduced oxygen supply to the prefrontal cortex may be associated with impaired frontal lobe functions.

The effect of pain conditioning on experimentally evoked cough: evidence of impaired endogenous inhibitory control mechanisms in refractory chronic cough

The pathophysiology of refractory chronic cough (RCC) is unclear. We hypothesised that endogenous inhibitory control mechanisms, such as those activated by noxious stimuli inducing pain (conditioned pain modulation) may be capable of inhibiting coughing and urge to cough evoked by inhaled capsaicin. Furthermore, these mechanisms may be impaired in patients with RCC.The objective was to investigate the effects of pain on cough and urge to cough in healthy volunteers and RCC patients. Healthy volunteers and RCC patients underwent a randomised, controlled, four-way crossover study comparing the effect of four interventions on capsaicin-evoked coughing and urge to cough. The interventions comprised immersing a hand in 1) noxious cold water; 2) warm water; 3) warm water, but subjects were instructed to voluntarily supress coughing; and 4) no intervention. The co-primary outcomes were numbers of evoked coughs and urge to cough scores.20 healthy volunteers (mean±sd age 50.1±14.2 years, male:female 10:10) and 20 RCC patients (age 60.1±7.9 years, male:female 9:11) participated. Overall, noxious cold water reduced capsaicin-evoked urge-to-cough scores and cough numbers compared with warm water (1.6 (95% CI 1.3-2.0) versus 2.2 (1.8-2.6), p<0.001 and 4.8 (3.7-6.2) coughs versus 7.9 (6.7-9.5) coughs, p<0.001, respectively). Healthy volunteers and RCC patients demonstrated similar reductions in the urge to cough during noxious cold-water immersion, but noxious cold water and voluntary suppression interventions were less effective at reducing capsaicin-evoked cough in RCC patients than in healthy volunteers (p=0.041).Endogenous inhibitory control mechanisms, specifically those activated by pain, can reduce both coughing and the urge to cough. Impairment of endogenous inhibitory control mechanisms may contribute to excessive coughing in RCC.

Effect of cinnamon on migraine attacks and inflammatory markers: A randomized double-blind placebo-controlled trial

Migraine is the most common type of primary headaches. Increased levels of interleukin-6 (IL-6), calcitonin-gene-related peptide (CGRP) and nitric oxide (NO) lead to inflammation and neurogenic pain. Cinnamon has anti-inflammatory and neuroprotective properties. Thus, the aim of this study was to assess the effect of cinnamon on migraine attacks and inflammatory status. Fifty patients with migraine were randomized to receive either cinnamon powder (three capsules/day each containing 600 mg of cinnamon) or three placebo capsules/day each containing 100 mg of corn starch (control group) for 2 months. Serum levels of IL-6, CGRP and NO were measured at baseline and at the end of the study. The frequency, severity and duration of pain attacks were also recorded using questionnaire. Serum concentrations of IL-6 and NO were significantly reduced in the cinnamon group compared with the control group (p < .05). However, serum levels of CGRP remained unchanged in both groups. The frequency, severity and duration of migraine attacks were significantly decreased in the cinnamon group compared with the control group. Cinnamon supplementation reduced inflammation as well as frequency, severity and duration of headache in patients with migraine. Cinnamon could be regarded as a safe supplement to relieve pain and other complications of migraine.

Executive Functions and Pain

Abstract. A growing body of literature suggests that chronic-pain patients suffer from problems in various neuropsychological domains, including executive functioning. In order to better understand which components of executive functioning (inhibition, shifting and/or updating) might be especially affected by pain and which mechanisms might underlie this association, we conducted a systematic review, including both chronic-pain studies as well as experimental-pain studies. The chronic-pain studies (N = 57) show that pain is associated with poorer executive functioning. The findings of experimental-pain studies (N = 28) suggest that this might be a bidirectional relationship: Pain can disrupt executive functioning, but poorer executive functioning might also be a risk factor for higher vulnerability to pain.