Prevalence and characteristics of headache attributed to ingestion or inhalation of a cold stimulus (HICS): A cross-sectional study

Menthol dural application alters meningeal arteries tone and enhances excitability of trigeminocervical neurons in rats

Headaches, including migraines, can have a causal relationship to exposure to cold, and this relationship may be both positive and negative, as cold can both provoke and alleviate cephalgia. The role of thermoreceptors responsible for transduction of low temperatures belongs to the transient receptor potential cation channel subfamily melastatin member 8 (TRPM8). These channels mediate normal cooling sensation and have a role in both cold pain and cooling-mediated analgesia; they are seen as a potential target for principally new anti-migraine pharmaceuticals. Using a validated animal migraine models, we evaluated effects of menthol, the TRPM8-agonist, on trigeminovascular nociception. In acute experiments on male rats, effects of applied durally menthol solution in various concentrations on the neurogenic dural vasodilatation (NDV) and firing rate of dura-sensitive neurons of the trigeminocervical complex (TCC) were assessed. Application of menthol solution in concentrations of 5 % and 10 % was associated with NDV suppression, however amplitude reduction of the dilatation response caused not by the vascular dilatation degree decrease, but rather due to the significant increase of the meningeal arterioles' basal tone. In electrophysiological experiments the 1 % and 30 % menthol solutions intensified TCC neuron responses to the dural electrical stimulation while not changing their background activity. Revealed in our study excitatory effects of menthol related to the vascular as well as neuronal branches of the trigeminovascular system indicate pro-cephalalgic effects of TRPM8-activation and suggest feasibility of further search for new anti-migraine substances among TRPM8-antagonists.

Cold-Stimulus Headache in Children and Adolescents

The literature on cold-stimulus headache (CSH) is relatively sparse compared to other primary headache disorders and the studies on the pediatric population are very limited. This systematic review aims to analyze the evidence on CSH in children and adolescents focusing on epidemiology, clinical features, pathogenic mechanisms, and treatments. Our review included 25 studies, among which 9 papers include pediatric cases (4 pediatric samples, 5 mixed samples of children and adults). The aim of this work is to highlight the features of CSH in children and adolescents. In children, the prevalence of CSH is higher than in adults and it is not gender-specific. There is a relevant family history for CSH and the comorbidity with migraine is significant. The triggers and clinical features of CSH due to ingesting a cold stimulus in children overlap with those in adults. CSH due to external application of a cold stimulus (or to environmentally low temperatures) is not studied in children and adolescents. We describe in detail a new pediatric case of CSH triggered by low ambient temperatures; to the best of our knowledge, this represents the first description in the literature. In conclusion, CSH in children is probably underestimated and has peculiar features compared to adults; further studies are needed to better understand its clinical features and pathophysiology.

Transient receptor potential melastatin 8 is required for nitroglycerin- and calcitonin gene-related peptide-induced migraine-like pain behaviors in mice

ABSTRACT

Migraine is a complex neurovascular disorder that is one of the leading causes of disability and a reduced quality of life. Even with such a high societal impact, our understanding of the cellular and molecular mechanisms that contribute to migraine headaches is limited. To address this complex disorder, several groups have performed genome-wide association studies to elucidate migraine susceptibility genes, with many identifying transient receptor potential melastatin 8 (TRPM8), a cold-sensitive cation channel expressed in peripheral afferents innervating the trigeminovascular system, and the principal mediator of cold and cold pain associated with injury and disease. Interestingly, these migraine-associated single-nucleotide polymorphisms reside in noncoding regions of TRPM8, with those correlated with reduced migraine risk exhibiting lower TRPM8 expression and decreased cold sensitivity. Nonetheless, as a role for TRPM8 in migraine has yet to be defined, we sought to address this gap in our knowledge using mouse genetics and TRPM8 antagonism to determine whether TRPM8 channels or neurons are required for migraine-like pain (mechanical allodynia and facial grimace) in inducible migraine models. Our results show that both evoked and spontaneous pain behaviors are dependent on both TRPM8 channels and neurons, as well as required in both acute and chronic migraine models. Moreover, inhibition of TRPM8 channels prevented acute but not established chronic migraine-like pain. These results are consistent with its association with migraine in genetic analyses and establish that TRPM8 channels are a component of the underlying mechanisms of migraine.

Headache and migraine in mitochondrial disease and its impact on life-results from a cross-sectional, questionnaire-based study

Headache is frequent in patients with mitochondrial disorders. Previous studies point to a higher prevalence of headache in these patients than in the general population. As mitochondrial disorders often present a variety of other symptoms, the question arises how much the presence of headache really influences daily life. We performed a cross-sectional, questionnaire-based study investigation with 61 patients with a genetically proved mitochondrial disease mainly composed of CPEO phenotype. Headache was examined using a standardized questionnaire, and classified according to ICHD-2. Headache-related disability was evaluated by the Headache-Impact-Test-6 (HIT-6). Additionally, depression and anxiety were examined using the Hospital Anxiety and Depression Scale (HADS) and Short-Form-Health Survey (SF-12) was used to investigate the health-related quality of life. Headache was reported by 43/61 (70.5%) of the patients. 35/61 patients (57.4%) described a Tension-type headache (TTH) and 26 patients (42.6%) a migraine. Patients reporting headache had a significantly higher HIT-6 score than those without (mean: 54.47 vs. 38.47, p < 0.001). The HIT-6 score was significantly higher in patients reporting a migraine compared to those with a tension-type headache (mean: 62.13 vs. 46.18, p < 0.001). In the HADS score and in the SF-12 were not significantly influenced by the occurrence of headache. This study confirms the previously reported frequent occurrence of headache in a large cohort of patients with a confirmed mitochondrial disease. Migraine had the greatest impact on daily living, which appeared not to be confounded by depression and anxiety. Thus, we conclude that Migraine may be a substantial contributor for burden of disease in patients with mitochondrial diseases.