Emerging Targets for Migraine Treatment.

BACKGROUND: While understanding the pathophysiology of migraine has led to CGRP-based treatments, other potential targets have also been implicated in migraine. OBJECTIVES: To catalog new promising targets for the treatment of migraine. METHODS: We completed a literature review focusing on 5HT1F, PACAP, melatonin, and orexins. RESULTS: The 5HT1F receptor agonist lasmiditan, following two positive randomized placebo-controlled trials, was FDA-approved for the acute treatment of migraine. PACAP-38 has shown analogous evidence to what was obtained for CGRP with its localization in key structures, provocation tests, and positive studies when antagonizing its receptor in animal models, although a PAC-1 receptor monoclonal antibody study was negative. Melatonin has undergone several randomized controlled trials showing a positive trend. Filorexant is the only dual orexin receptor antagonist, which was tested in humans with negative results. CONCLUSIONS: Further and ongoing studies will determine the utility of these new therapies with lasmiditan and melatonin having demonstrated efficacy for the treatment of migraine.

Cluster Headache: Epidemiology, Pathophysiology, Clinical Features, and Diagnosis.

Cluster headache is a primary headache disorder affecting up to 0.1% of the population. Patients suffer from cluster headache attacks lasting from 15 to 180 min up to 8 times a day. The attacks are characterized by the severe unilateral pain mainly in the first division of the trigeminal nerve, with associated prominent unilateral cranial autonomic symptoms and a sense of agitation and restlessness during the attacks. The male-to-female ratio is approximately 2.5:1. Experimental, clinical, and neuroimaging studies have advanced our understanding of the pathogenesis of cluster headache. The pathophysiology involves activation of the trigeminovascular complex and the trigeminal-autonomic reflex and accounts for the unilateral severe headache, the prominent ipsilateral cranial autonomic symptoms. In addition, the circadian and circannual rhythmicity unique to this condition is postulated to involve the hypothalamus and suprachiasmatic nucleus. Although the clinical features are distinct, it may be misdiagnosed, with patients often presenting to the otolaryngologist or dentist with symptoms. The prognosis of cluster headache remains difficult to predict. Patients with episodic cluster headache can shift to chronic cluster headache and vice versa. Longitudinally, cluster headache tends to remit with age with less frequent bouts and more prolonged periods of remission in between bouts.

Overview of Trigeminal Autonomic Cephalalgias: Nosologic Evolution, Diagnosis, and Management.

The term trigeminal autonomic cephalalgias (TACs) encompasses four primary headache disorders - cluster headache, paroxysmal hemicrania (PH), hemicrania continua (HC), short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT)/short-lasting unilateral neuralgiform headache attacks with cranial autonomic symptoms (SUNA). All of these except HC are characterized by short-lasting headaches. HC is characterized by a continuous unilateral headache that waxes and wanes in its intensity without complete resolution. It is included in the TACs group given the overlap in the activation of the posterior hypothalamic grey, and the shared clinical feature of unilateral head pain with ipsilateral cranial autonomic symptoms. The present review gives an overview of the nosologic evolution, diagnosis, and management of TACs.

Experts' opinion about the primary headache diagnostic criteria of the ICHD-3rd edition beta in children and adolescents.

BACKGROUND: The 2013 International Classification of Headache Disorders-3 (ICHD-3) was published in a beta version to allow the clinicians to confirm the validity of the criteria or to suggest improvements based on field studies. The aim of this work was to review the Primary Headache Disorders Section of ICHD-3 beta data on children and adolescents (age 0-18 years), and to suggest changes, additions, and amendments. METHODS: Several experts in childhood headache across the world applied different aspects of ICHD-3 beta in their normal clinical practice. Based on their personal experience and the literature available on pediatric headache, they made observations and proposed suggestions for the primary headache disorders section of ICHD-3 beta data on children and adolescents. RESULTS: Some headache disorders in children have specific features which are different from those seen in adults and which should be acknowledged and considered. Some features in children were found to be age-dependent: clinical characteristics, risks factors and etiologies have a strong bio psycho-social basis in children and adolescents making primary headache disorders in children distinct from those in adults. CONCLUSIONS: Several recommendations are presented in order to make ICHD-3 more appropriate for use with children.

Experts' opinion about the pediatric secondary headaches diagnostic criteria of the ICHD-3 beta.

BACKGROUND: The 2013 International Classification of Headache Disorders-3 was published in a beta version to allow clinicians to confirm the validity of the criteria or suggest improvements based on field studies. The aim of this work was to review the Secondary Headache Disorders and Cranial Neuralgias and Other Headache Disorders sections of ICHD-3 beta data on children and adolescents (age 0-18 years) and to suggest changes, additions, and amendments. METHODS: Several experts in childhood headache across the world applied different aspects of ICHD-3 beta in their normal clinical practice. Based on their personal experience and the available literature on pediatric headache, they made observations and proposed suggestions for the mentioned headache disorders on children and adolescents. RESULTS: Some headache disorders in children have specific features, which are different from adults that should be acknowledged and considered. Some features in children were found to be age-dependent: clinical characteristics, risks factors and etiologies have a strong bio psychosocial basis in children and adolescents making primary headache disorders in children distinct from those in adults. CONCLUSIONS: Several recommendations are presented in order to make ICHD-3 more appropriate for use in children.

Brain activations in the premonitory phase of nitroglycerin-triggered migraine attacks.

Our aim was identify brain areas involved in the premonitory phase of migraine using functional neuroimaging. To this end, we performed positron emission tomography scans with H2(15)O to measure cerebral blood flow as a marker of neuronal activity. We conducted positron emission tomography scans at baseline, in the premonitory phase without pain and during migraine headache in eight patients. We used glyceryl trinitrate (nitroglycerin) to trigger premonitory symptoms and migraine headache in patients with episodic migraine without aura who habitually experienced premonitory symptoms during spontaneous attacks. The main outcome was comparing the first premonitory scans in all patients to baseline scans in all patients. We found activations in the posterolateral hypothalamus, midbrain tegmental area, periaqueductal grey, dorsal pons and various cortical areas including occipital, temporal and prefrontal cortex. Brain activations, in particular of the hypothalamus, seen in the premonitory phase of glyceryl trinitrate-triggered migraine attacks can explain many of the premonitory symptoms and may provide some insight into why migraine is commonly activated by a change in homeostasis.