Recurrent extratrigeminal stabbing and burning sensation with allodynia in a migraine patient

Migraine and Its Equivalents: What Do They Share? A Narrative Review on Common Pathophysiological Patterns

Migraine is the first in order of frequency of the neurological disorders, affecting both adult and paediatric populations. It is also the first cause of primary headaches in children. Migraine equivalents are periodic disorders that can be associated with migraine or considered as prognostic features of a future migraine manifestation. Despite the mechanisms underlying migraine and its equivalents are not entirely clear, several elements support the hypothesis of common pathophysiological patterns shared by these conditions. The aim of this review is thus to analyze the literature in order to highlight which currently known mechanisms may be common between migraine and its equivalents.

Neurovascular contributions to migraine: Moving beyond vasodilation

Migraine is the third most common disease worldwide, the most common neurological disorder, and one of the most common pain conditions. Despite its prevalence, the basic physiology and underlying mechanisms contributing to the development of migraine are still poorly understood and development of new therapeutic targets is long overdue. Until recently, the major contributing pathophysiological event thought to initiate migraine was cerebral and meningeal arterial vasodilation. However, the role of vasodilation in migraine is unclear and recent findings challenge its necessity. While vasodilation itself may not contribute to migraine, it remains possible that vessels play a role in migraine pathophysiology in the absence of vasodilation. Blood vessels consist of a variety of cell types that both release and respond to numerous mediators including growth factors, cytokines, adenosine triphosphate (ATP), and nitric oxide (NO). Many of these mediators have actions on neurons that can contribute to migraine. Conversely, neurons release factors such as norepinephrine and calcitonin gene-related peptide (CGRP) that act on cells native to blood vessels. Both normal and pathological events occurring within and between vascular cells could thus mediate bi-directional communication between vessels and the nervous system, without the need for changes in vascular tone. This review will discuss the potential contribution of the vasculature, specifically endothelial cells, to current neuronal mechanisms hypothesized to play a role in migraine. Hypothalamic activity, cortical spreading depression (CSD), and dural afferent input from the cranial meninges will be reviewed with a focus on how these mechanisms can influence or be impacted by blood vessels. Together, the data discussed will provide a framework by which vessels can be viewed as important potential contributors to migraine pathophysiology, even in light of the current uncertainty over the role of vasodilation in this disorder.

Recurrent limb pain and migraine: case reports and a clinical review

Recurrent limb pain (RLP) is a well-known entity in childhood. It is considered a precursor of migraine. The temporal relationship of RLP with headache in childhood is lacking in the literature. However, there are many cases with limb pain in a close temporal relationship with migraine headache in adults. We report six female patients with RLP and migraine and delineate the temporal relationship between the two. Three patients had a history of RLP in childhood and developed migraine headache after many years. Conversely, two patients had a long history of migraine headache and later developed RLP. One patient developed RLP and migraine headache at the same age. Isolated limb pain was frequent in all six patients. It was mild to severe, for a few minutes to a few days, and predominantly located in the upper extremities. Only one patient reported allodynia. The patients showed response to preventive measures (all six patients) and abortive therapies (four patients), even in those attacks of RLP that were not associated with headache episodes. We also review the clinical profiles of the patients in whom RLP and migraine were related to each other, and speculate on the possible mechanisms for RLP in the patients with migraine.

Symptomatic cluster-like headache triggered by forehead lipoma: a case report and review of the literature

We describe the case of a patient with symptomatic strictly unilateral paroxysmal headache mimicking cluster headache related to an ipsilateral forehead lipoma. Interestingly, immediately after the surgical excision of the lipoma pain attacks disappeared with no recurrence during a follow-up period of 18 months. Like other descriptions of cluster-like headaches secondary to extracranial lesions, this case report focuses on the hypothetical role of a peripheral trigger factor for trigeminal autonomic cephalgias (TACs). To our knowledge, this is the first well-described cluster-like headache case secondary to an extracerebral lipoma. This case offered the opportunity to discuss the possible pathophysiological mechanisms underlying probable TACs and the relationship with peripheral extracerebral activation of the trigeminal-autonomic reflex.

Migrainous Corpalgia: Body Pain and Allodynia Associated with Migraine Attacks

Cephalic and extracephalic allodynia are recognized as a common sign of sensory sensitization during migraine episodes. However, the occurrence of body pain in migraine has not been thoroughly explored. Here we report three patients presenting with spontaneous body pain in association with migraine attacks. A 41-year-old woman experienced face and limb pain along with migraine headaches; it started before, during or after headache, was usually ipsilateral to head pain, and could last from minutes to days. A 39-year-old woman had pain in her right limbs, back and neck for 30-60 min prior to right-sided migraine headaches. A 30-year-old woman perceived pain in her left upper limb for 24-48 h prior to left-sided migraine headaches. All patients had allodynia to mechanical stimuli over the painful areas. Spontaneous body pain may be associated with migraine attacks. Together with allodynia, this might be a consequence of central sensitization.

Episodic dural stimulation in awake rats: a model for recurrent headache

OBJECTIVES

To model, in rats, the development of chronic trigeminal nociceptive hypersensitivity seen in patients with recurrent headache.

BACKGROUND

Pathophysiology studies suggest that patients with recurrent migraine headache experience repeated bouts of dural nociceptor activation. In some patients, the severity and frequency of headache attacks increase over time. Patients with recurrent headache are hypersensitive to nitric oxide donors, such as glyceryl trinitrate (GTN). Current trigeminal pain models do not reflect the repeated episodic nature of dural nociceptor activation in patients with recurrent headache. Repeated nociceptor activation creates long-lasting changes in the periphery and brain due to activity-dependent neuronal plasticity. An animal model of repeated activation of dural nociceptors will facilitate the study of the physiological changes caused by repeated, episodic pain and the factors important for the transition of episodic to chronic migraine.

METHODS

We induced dural inflammation by infusing an inflammatory soup (IS) through a cannula on the dura in awake behaving rats. This was repeated 3 times per week for up to 4 weeks. Periorbital pressure sensory testing was used to monitor the change in trigeminal sensitivity. Rats were challenged with GTN to test the hypothesis that many dural stimulations are required to model the hypersensitivity of migraine patients. Quantitative trigeminal sensory testing and microdialysis in the trigeminal nucleus caudalis (TNC) were used to measure GTN hypersensitivity.

RESULTS

Multiple infusions of IS (>8), over weeks, induced a long-lasting decrease in periorbital pressure thresholds that lasted >3 weeks after the last infusion. In contrast, IS infusion in IS-naive rats and those that received 3 IS infusions produced only short-lasting decreases in periorbital pressure thresholds. Rats that received more than 8 IS infusions showed a marked increase in their neurochemical and behavioral responses to GTN. In these rats, GTN induced a decrease in periorbital von Frey thresholds that lasted >5 hours. In contrast, in rats that received only 3 IS infusions, GTN caused a threshold decrease for 1.5 hour. In vivo microdialysis in the TNC showed that GTN increased extracellular glutamate levels in rats with more than 8 IS infusions to 7.7 times the basal levels. In IS-naive rats and those that received only 3 IS infusions, the extracellular glutamate levels rose to only 1.7 and 1.9 times the basal level, respectively.

CONCLUSIONS

Repeated IS stimulation of the dura produces a chronic state of trigeminal hypersensitivity and potentiates the response to GTN. This hyperresponsiveness outlasts the last IS infusion and is the basis of our rat model of recurrent headache. This model can be used to study the changes in the brain and periphery induced by repeated trigeminovascular nociceptor activation and has the potential to elucidate the mechanisms for the transition of episodic to chronic headache.

Paroxysmal stabbing headache in the multiple dermatomes of the head and neck: a variant of primary stabbing headache or occipital neuralgia?

A paroxysmal stabbing or icepick-like headache in the multiple nerve dermatomes, especially involving both trigeminal and cervical nerves, has not been fully explained or classified by the International Classification of Headache Disorder, 2(nd) Edition (ICHD-II). Of patients with acute-onset paroxysmal stabbing headache who had visited the Hallym University Medical Center during the last four years, 28 subjects with a repeated stabbing headache involving multiple dermatomes at the initial presentation or during the course were prospectively enrolled. All patients were neurologically and otologically symptom free. A coincidental involvement of both trigeminal and cervical nerve dermatomes included seven cases. Six cases involved initially the trigeminal and then cervical nerve dermatomes. Five cases showed an involvement of the cervical and then trigeminal nerve dermatomes. The remaining patients involved multiple cervical nerve branches (the lesser occipital, greater occipital and greater auricular). Pain lasted very shortly and a previous history of headache with the same nature was reported in 13 cases. Preceding symptom of an infection and physical and/or mental stress were manifested in seven and six subjects, respectively. All patients showed a self-limited benign course and completely recovered within a few hours to 30 days. Interestingly, a seasonal gradient in occurrence of a stabbing headache was found in this study. A paroxysmal stabbing headache manifested on multiple dermatomes can be explained by the characteristics of pain referral, and may be considered to be a variant of primary stabbing headache or occipital neuralgia.

Extracephalic Stabbing Pain Temporally Related to Cephalic Ones

A 23-year-old woman consulted with the complaint of short-lasting, severe stabbing headaches and mild-to-moderate degree near-daily migrainous headaches. Further questioning revealed that she also had stabbing pain on both ipsilateral hand and calf. Stabs on the hand were time-locked to cephalic ones and stabs in the calf were alternating with the ones in the hand. Dizziness and scotomas were accompanying symptoms to cephalic ones and paresthesia was the accompanying symptom in the hand. Patient's cephalic and extracephalic stabbing pains responded to indomethacine and daily headaches responded to prophylactic sodium valproate therapy. The stabs were felt in the head; hand and calf are considered as the parts of a whole. Along with its accompanying symptoms, stabbing pain may be the result of complex interactions in central nervous system.

Convergence of cervical and trigeminal sensory afferents

Cranial nociceptive perception shows a distinct topographic distribution, with the trigeminal nerve receiving sensory information from the anterior portions of the head, the greater occipital nerve, and branches of the upper cervical roots in the posterior regions. However, this distribution is not respected during headache attacks, even if the etiology of the headache is specific for only one nerve. Nociceptive information from the trigeminal and cervical territories activates the neurons in the trigeminal nucleus caudalis that extend to the C2 spinal segment and lateral cervical nucleus in the dorsolateral cervical area. These neurons are classified as multimodal because they receive sensory information from more than one afferent type. Clinically, trigeminal activation produces symptoms in the trigeminal and cervical territory and cervical activation produces symptoms in the cervical and trigeminal territory. The overlap between the trigeminal nerve and cervical is known as a convergence mechanism. For some time, convergence mechanisms were thought to be secondary to clinical observations. However, animal studies and clinical evidence have expanded our knowledge of convergence mechanisms. In this paper, the role of convergence mechanisms in nociceptive physiology, physiopathology of the headaches, clinical diagnosis, and therapeutic conduct are reviewed.