Trigeminal autonomic cephalalgias: diagnostic and therapeutic developments

Phenotype of Cluster Headache: Clinical Variability, Persisting Pain Between Attacks, and Comorbidities-An Observational Cohort Study in 825 Patients

INTRODUCTION

Cluster headaches can occur with considerable clinical variability. The inter- and intra-individual variability could contribute to the fact that the clinical headache phenotype is not captured by too strict diagnostic criteria, and that the diagnosis and the effective therapy are thereby delayed. The aim of the study was to analyze the severity and extent of the clinical symptoms of episodic and chronic cluster headaches with regard to their variability and to compare them with the requirements of the International Classification of Headache Disorders 3rd edition (ICHD-3) diagnostic criteria.

METHODS

The study was carried out as a cross-sectional analysis of 825 patients who had been diagnosed with cluster headaches by their physician. Using an online questionnaire, standardized questions on sociodemographic variables, clinical features of the cluster headache according to ICHD-3, and accompanying clinical symptoms were recorded.

RESULTS

The majority of patients with cluster headaches have clinical features that are mapped by the diagnostic criteria of ICHD-3. However, due to the variability of the symptoms, there is a significant proportion of clinical phenotypes that are not captured by the ICHD-3 criteria for cluster headaches. In addition, change in the side of the pain between the cluster episodes, pain location, as well as persisting pain between the attacks is not addressed in the ICHD-3 criteria. In the foreground of the comorbidities are psychological consequences in the form of depression, sleep disorders, and anxiety.

CONCLUSIONS

The variability of the phenotype of cluster headaches can preclude some patients from receiving an appropriate diagnosis and effective therapy if the diagnostic criteria applied are too strict. The occurrence of persisting pain between attacks should also be diagnostically evaluated due to its high prevalence and severity as well as psychological strain. When treating patients with cluster headaches, accompanying psychological illnesses should carefully be taken into account.

SUNCT/SUNA in Pediatric Age: A Review of Pathophysiology and Therapeutic Options

The International Classification of Headache Disorders, 3rd edition (ICHD3) defines Short-lasting Unilateral Neuralgiform Headache Attacks (SUNHA) as attacks of moderate or severe, strictly unilateral head pain lasting from seconds to minutes, occurring at least once a day and usually associated with prominent lacrimation and redness of the ipsilateral eye. Two subtypes of SUNHA are identified: Short-lasting Unilateral Neuralgiform headache attacks with Conjunctival injection and Tearing (SUNCT) and Short-lasting Unilateral Neuralgiform headache attacks with cranial Autonomic symptoms (SUNA). These pathologies are infrequent in children and difficult to diagnose. The authors reviewed the existing literature on SUNCT and SUNA, especially in the developmental age, which describes the pathophysiology in detail and focuses on the therapeutic options available to date. SUNHA-type headaches must be considered on the one hand, for the possibility of the onset of forms secondary to underlying pathologies even of a neoplastic nature, and on the other hand, for the negative impact they can have on an individual’s quality of life, particularly in young patients. Until now, published cases suggest that no chronic variants occur in childhood and adolescents. In light of this evidence, the authors offer a review that may serve as a source to be drawn upon in the implementation of suitable treatments in children and adolescents suffering from these headaches, focusing on therapies that are non-invasive and as risk-free as possible for pediatric patients.

Hemicrania Continua With Scintillating Scotoma: A Rare Presentation

Headache can be a primary or secondary disorder. The characteristics of headache and its associated features, especially the presence of red flag signs, are important in distinguishing secondary from primary causes. Hemicrania continua is a type of primary headache disorder characterized by a continuous unilateral headache with episodes of exacerbations and association with cranial autonomic symptoms, which include several ocular symptoms. The absolute response to indomethacin remains the hallmark of this disease. We would like to report a rare case of hemicrania continua with scintillating scotoma during exacerbations apart from the typical autonomic features of conjunctival injection, ptosis, eyelid edema, and lacrimation.

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.

Cost-effectiveness analysis of non-invasive vagus nerve stimulation for the treatment of chronic cluster headache

Background

Cluster headache (CH) is a debilitating condition that is generally associated with substantial health care costs. Few therapies are approved for abortive or prophylactic treatment. Results from the prospective, randomised, open-label PREVA study suggested that adjunctive treatment with a novel non-invasive vagus nerve stimulation (nVNS) device led to decreased attack frequency and abortive medication use in patients with chronic CH (cCH). Herein, we evaluate whether nVNS is cost-effective compared with the current standard of care (SoC) for cCH.

Methods

A pharmacoeconomic model from the German statutory health insurance perspective was developed to estimate the 1-year cost-effectiveness of nVNS + SoC (versus SoC alone) using data from PREVA. Short-term treatment response data were taken from the clinical trial; longer-term response was modelled under scenarios of response maintenance, constant rate of response loss, and diminishing rate of response loss. Health-related quality of life was estimated by modelling EQ-5D™ data from PREVA; benefits were defined as quality-adjusted life-years (QALY). Abortive medication use data from PREVA, along with costs for the nVNS device and abortive therapies (i.e. intranasal zolmitriptan, subcutaneous sumatriptan, and inhaled oxygen), were used to assess health care costs in the German setting.

Results

The analysis resulted in mean expected yearly costs of €7096.69 for nVNS + SoC and €7511.35 for SoC alone and mean QALY of 0.607 for nVNS + SoC and 0.522 for SoC alone, suggesting that nVNS generates greater health benefits for lower overall cost. Abortive medication costs were 23 % lower with nVNS + SoC than with SoC alone. In the alternative scenarios (i.e. constant rate of response loss and diminishing rate of response loss), nVNS + SoC was more effective and cost saving than SoC alone.

Conclusions

In all scenarios modelled from a German perspective, nVNS was cost-effective compared with current SoC, which suggests that adjunctive nVNS therapy provides economic benefits in the treatment of cCH. Notably, the current analysis included only costs associated with abortive treatments. Treatment with nVNS will likely promote further economic benefit when other potential sources of cost savings (e.g. reduced frequency of clinic visits) are considered.

Trial registration

Clinicaltrials.gov identifier NCT01701245, 03OCT2012.

A novel translational animal model of trigeminal autonomic cephalalgias

OVERVIEW

Trigeminal autonomic cephalalgias (TACs) are highly disabling primary headache disorders that involve severe unilateral head pain coupled with significant lateralized cranial autonomic features. Our understanding of these disorders and the development of novel and more effective treatments has been limited by the lack of a suitable animal model to explore their pathophysiology and screen prospective treatments.

DISCUSSION

This review details the development of a novel preclinical model that demonstrates activation of both the trigeminovascular system and parasympathetic projections, thought to be responsible for the severe head pain and autonomic symptoms.

CONCLUSION

This model demonstrates a unique response to TAC specific treatments and highlights the importance of the cranial parasympathetic pathway to the pathophysiology of TACs and as a potential locus of action for treatments. The development of this model opens up opportunities to understand the pathophysiology of these disorders further, the likely involvement of the hypothalamus, as well as providing a preclinical model with which to screen novel compounds.

The Neuropharmacology of Cluster Headache and other Trigeminal Autonomic Cephalalgias

Trigeminal autonomic cephalalgias (TACs) are a group of primary headaches including cluster headache (CH), paroxysmal hemicrania (PH) and short-lasting unilateral neuralgiform headache with conjunctival injection and tearing (SUNCT). Another form, hemicrania continua (HC), is also included this group due to its clinical and pathophysiological similarities. CH is the most common of these syndromes, the others being infrequent in the general population. The pathophysiology of the TACs has been partly elucidated by a number of recent neuroimaging studies, which implicate brain regions associated with nociception (pain matrix). In addition, the hypothalamic activation observed in the course of TAC attacks and the observed efficacy of hypothalamic neurostimulation in CH patients suggest that the hypothalamus is another key structure. Hypothalamic activation may indeed be involved in attack initiation, but it may also lead to a condition of central facilitation underlying the recurrence of pain episodes. The TACs share many pathophysiological features, but are characterised by differences in attack duration and frequency, and to some extent treatment response. Although alternative strategies for the TACs, especially CH, are now emerging (such as neurostimulation techniques), this review focuses on the available pharmacological treatments complying with the most recent guidelines. We discuss the clinical efficacy and tolerability of the currently used drugs. Due to the low frequency of most TACs, few randomised controlled trials have been conducted. The therapies of choice in CH continue to be the triptans and oxygen for acute treatment, and verapamil and lithium for prevention, but promising results have recently been obtained with novel modes of administration of the triptans and other agents, and several other treatments are currently under study. Indomethacin is extremely effective in PH and HC, while antiepileptic drugs (especially lamotrigine) appear to be increasingly useful in SUNCT. We highlight the need for appropriate studies investigating treatments for these rare, but lifelong and disabling conditions.

Orofacial pain syndromes: evaluation and management

Patients will often visit their primary medical practitioner with orofacial pain complaints. Hence, it is important to recognize and have an understanding of these conditions to properly evaluate and potentially manage these disorders. If the practitioner is uncertain or uncomfortable with these conditions, then patient referral to a knowledgeable health care practitioner should be considered for further evaluation and management. In this article, the evaluation and management of various neuropathic, neurovascular, and vascular pains are discussed.

Migraine with cranial autonomic features following surgically induced post-ganglionic sympathetic lesion

BACKGROUND

Although not typically considered as part of the clinical phenotype of migraine, cranial autonomic symptoms, such as lacrimation or conjunctival injection, can certainly occur. Their appearance can lead to the common misdiagnosis of sinus headache in clinical practice.

CASE

The patient presented developed post-ganglionic sympathetic denervation at the level of the superior cervical ganglion/carotid plexus. Her subsequent partial Horner's syndrome symptoms intensified during subsequent migraine attacks indicating increasing sympathetic autonomic dysfunction. At the time of the pain, recruitment and activation of the trigeminal autonomic reflex were demonstrated by lacrimation.

CONCLUSION

The clinical picture suggests peripheral unmasking of the underlying central trigeminal autonomic reflex that is active in migraine. Recognition of cranial autonomic symptoms in migraine is a key to confident differential diagnosis from trigeminal autonomic cephalalgias and from sinus-related headache disorders.

Concomitant occurrence of different trigeminal autonomic cephalalgias: A case series and review of the literature

Introduction

The trigeminal autonomic cephalalgias (TACs) subsume four primary headache disorders. Hemicrania continua is increasingly regarded as an additional TAC. In rare cases patients may present with two different TACs or a TAC and hemicrania continua.

Cases

We report four patients with two different TACs or one TAC and hemicrania continua. Two patients presented with cluster headache and paroxysmal hemicrania, one patient with cluster headache and hemicrania continua, and one patient suffered from cluster headache and SUNCT.

Discussion

While the International Classification of Headache Disorders (ICHD-II) proposes specific diagnostic criteria, the variability of clinical presentation may make clear diagnosis difficult. All patients fulfilled the ICHD-II criteria. The manifestation of two different TACs or hemicrania continua in one patient is uncommon but possible and should be taken into account especially when chronic headache patients present with changing headache symptoms.

Short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing syndrome secondary to an epidermoid tumor in the cerebellopontine angle

Short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT) syndrome is classified under trigeminal autonomic cephalalgias. This rare headache syndrome is infrequently associated with secondary pathologies. In this paper the authors report on a patient with paroxysmal left retroorbital pain with associated autonomic symptoms of ipsilateral conjunctival injection and lacrimation, suggestive of SUNCT syndrome. After failed medical treatment an MRI sequence was obtained in this patient, demonstrating an epidermoid tumor in the left cerebellopontine angle. The patient's symptoms completely resolved after a gross-total resection of the tumor. This case demonstrates the effectiveness of resection as definitive treatment for SUNCT syndrome associated with tumoral compression of the trigeminal nerve. Early MRI studies should be considered in all patients with SUNCT, especially those with atypical signs and symptoms.

Primary headache disorders

Primary headache disorders include migraine, tension-type headaches, and the trigeminal autonomic cephalgias (TACs). "Primary" refers to a lack of clear underlying causative pathology, trauma, or systemic disease. The TACs include cluster headache, paroxysmal hemicrania, and short-lasting neuralgiform headache attacks with conjunctival injection and tearing; hemicrania continua, although classified separately by the International Headache Society, shares many features of both migraine and the TACs. This article describes the features and treatment of these disorders.

Posterior hypothalamic modulation of light-evoked trigeminal neural activity and lacrimation

Enhanced light sensitivity is a common feature of many neuro-ophthalmic conditions and some chronic headaches. Previously we reported that the bright light-evoked increases in trigeminal brainstem neural activity and lacrimation depended on a neurovascular link within the eye (Okamoto et al., 2012). However, the supraspinal pathways necessary for these light-evoked responses are not well defined. To assess the contribution of the posterior hypothalamic area (PH), a brain region closely associated with control of autonomic outflow, we injected bicuculline methiodide (BMI), a GABAa receptor antagonist, into the PH and determined its effect on the encoding properties of ocular neurons at the ventrolateral trigeminal interpolaris/caudalis transition (Vi/Vc) and caudalis/upper cervical cord junction (Vc/C1) regions and on reflex lacrimation in male rats under isoflurane anesthesia. BMI markedly reduced light-evoked (>80%) responses of Vi/Vc and Vc/C1 neurons at 10 min with partial recovery by 50 min after injection. BMI also reduced (>35%) the convergent cutaneous receptive field area of Vi/Vc and Vc/C1 ocular neurons indicating that both intra-ocular and periorbital cutaneous inputs were affected by changes in PH outflow. Light-evoked lacrimation was reduced by >35% at 10 min after BMI, while resting mean arterial pressure increased promptly and remained elevated (>20 mmHg) throughout the 50-min post-injection period. These results suggested that PH stimulation, acting in part through increased sympathetic activity, significantly inhibited light- and facial skin-evoked activity of ocular neurons at the Vi/Vc and Vc/C1 region. These data provide further support for the hypothesis that autonomic outflow plays a critical role in mediating light-evoked trigeminal brainstem neural activity and reflex lacrimation.

Headache and facial pain: differential diagnosis and treatment

Headaches affect 90% of the population sometime during their life. Most are benign and fleeting, some are serious and life-threatening, and others require ongoing medical consultation and treatment. A careful history and physical is necessary to establish a differential diagnosis and to guide the choice of testing to make an accurate diagnosis. The most common types of headaches are discussed in this review. They are divided into primary and secondary headache disorders as classified by the International Headache Society. Primary headache disorders include migraine without and with aura, cluster and tension-type headaches. Secondary headaches are those that occur as a result of some other disorder and include brain tumors, rhinosinusitis, diseases of intracranial and extracranial vasculature, and temporomandibular joint disease.

Italian guidelines for primary headaches: 2012 revised version

The first edition of the Italian diagnostic and therapeutic guidelines for primary headaches in adults was published in J Headache Pain 2(Suppl. 1):105–190 (2001). Ten years later, the guideline committee of the Italian Society for the Study of Headaches (SISC) decided it was time to update therapeutic guidelines. A literature search was carried out on Medline database, and all articles on primary headache treatments in English, German, French and Italian published from February 2001 to December 2011 were taken into account. Only randomized controlled trials (RCT) and meta-analyses were analysed for each drug. If RCT were lacking, open studies and case series were also examined. According to the previous edition, four levels of recommendation were defined on the basis of levels of evidence, scientific strength of evidence and clinical effectiveness. Recommendations for symptomatic and prophylactic treatment of migraine and cluster headache were therefore revised with respect to previous 2001 guidelines and a section was dedicated to non-pharmacological treatment. This article reports a summary of the revised version published in extenso in an Italian version.

Trigeminal autonomic cephalalgias

PURPOSE OF REVIEW

This article covers the clinical manifestations and differential diagnosis of the trigeminal autonomic cephalalgias (TACs).

RECENT FINDINGS

TACs comprise a subgroup of primary headache disorders presenting with lateralized, often severe, pain accompanied by cranial autonomic features. The key syndromes are cluster headache, paroxysmal hemicrania, short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT)/short-lasting unilateral neuralgiform headache attacks with cranial autonomic features (SUNA), and hemicrania continua. Lateralization of symptoms and signs is the key feature differentiating the TACs and migraine. When diagnosing a TAC, it is appropriate to consider underlying pituitary or pituitary region pathology. Cluster headache responds to oxygen and parenteral triptans, with verapamil having the most success for prevention. Paroxysmal hemicrania responds to indomethacin. SUNCT/SUNA responds to lamotrigine and topiramate. Hemicrania continua responds to indomethacin.

SUMMARY

TACs are a unique group of primary headache syndromes with individual features and specific responses to treatment that make their identification crucial for optimum management.

Trigeminal interpolaris/caudalis transition neurons mediate reflex lacrimation evoked by bright light in the rat

Abnormal sensitivity to bright light can cause discomfort or pain and evoke protective reflexes such as lacrimation. Although the trigeminal nerve is probably involved, the mechanism linking luminance to somatic sensory nerve activity remains uncertain. This study determined the effect of bright light on second-order ocular neurons at the ventral trigeminal interpolaris/caudalis transition (Vi/Vc) region, a major termination zone for trigeminal sensory fibers that innervate the eye. Most Vi/Vc neurons (80.9%) identified by responses to mechanical stimulation of the ocular surface also encoded bright light intensity. Light-evoked neural activity displayed a long latency to activation (> 10 s) and required transmission through the trigeminal root ganglion. Light-evoked neural activity was inhibited by intravitreal injection of phenylephrine or l-N(G) -nitro-arginine methyl ester (L-NAME), suggesting a mechanism coupled to vascular events within the eye. Laser Doppler flowmetry revealed rapid light-evoked increases in ocular blood flow that occurred prior to the increase in Vi/Vc neural activity. Synaptic blockade of the Vi/Vc region by cobalt chloride prevented light-evoked increases in tear volume, whereas blockade at the more caudal spinomedullary junction (Vc/C1) had no effect. In summary, Vi/Vc neurons encoded bright light intensity and were inhibited by drugs that alter blood flow to the eye. These results support the hypothesis that light-responsive neurons at the Vi/Vc transition region are critical for ocular-specific functions such as reflex lacrimation, whereas neurons at the caudal Vc/C1 junction region probably serve other aspects of ocular nociception.

Trigeminal autonomic cephalgias

1. Trigeminal autonomic cephalgias (TACs) are headaches/facial pains classified together based on:a suspected common pathophysiology involving the trigeminovascular system, the trigeminoparasympathetic reflex and centres controlling circadian rhythms;a similar clinical presentation of trigeminal pain, and autonomic activation. 2. There is much overlap in the diagnostic features of individual TACs. 3. In contrast, treatment response is relatively specific and aids in establishing a definitive diagnosis. 4. TACs are often presentations of underlying pathology; all patients should be imaged. 5. The aim of the article is to provide the reader with a broad introduction to, and an overview of, TACs. The reading list is extensive for the interested reader.

A probable cluster headache case from a textbook of 1726: Francisco Suárez de Rivera’s description

Background: Few descriptions of cluster and cluster-like headache made before the 19th century have been reported.

Case description: We present a previously unreported early description of a probable cluster headache case made by Francisco Suárez de Rivera (1686− c.1751), one of the main physicians of the Spanish Age of Enlightenment, writer of almost 40 textbooks about medicine, surgery, pharmacology, and therapeutics.

Discussion: The depiction here reported of a woman with probable cluster headache is possibly one of the earliest known and, to our knowledge, the first in Hispanic literature. We also review other descriptions of cluster and cluster-like headache from the same time period.

Deep brain stimulation of the posterior hypothalamic area in intractable short-lasting unilateral neuralgiform headache with conjunctival injection and tearing (SUNCT)

Background: SUNCT (short-lasting unilateral neuralgiform headache with conjunctival injection and tearing) is a rare syndrome characterized by the sudden onset of excruciating unilateral periorbital pain that is accompanied by conjunctival injection and lacrimation or further autonomic signs. Similar to patients with chronic cluster headache, Leone and Lyons showed a beneficial effect of deep brain stimulation of the posterior hypothalamic region in two patients with a chronic SUNCT.

Case: Here, we present the case of a man with a chronic SUNCT responding to deep brain stimulation of the posterior hypothalamic area.

Conclusion: This case supports the idea of a central origin of SUNCT and shows that deep brain stimulation of the hypothalamic region can be effective in the treatment of the chronic form of this rare disorder.

Guidance for the management of headache in sport on behalf of The Royal College of General Practitioners and The British Association for the Study of Headache

Headache is prevalent within the community and can have an impact on sport in both the amateur and elite player, either coincidentally or as a direct result of participation. Against a background of a limited evidence base, this paper suggests how headache can be classified within this context and offers guidance for treating both the amateur and elite athlete. The impact of headache in sport may be unrecognised and undertreated, and further research is needed in this area.

Different forms of trigeminal autonomic cephalalgias in the same patient: description of a case

The trigeminal autonomic cephalalgias (TACs), including cluster headache, paroxysmal hemicrania and SUNCT, are characterized by the cardinal combination of short-lasting unilateral pain and autonomic phenomena affecting the head. Hemicrania continua (HC) shares many clinical characteristics with TACs, including unilateral pain and ipsilateral autonomic features. Nevertheless, HC is separately classified in the revised International Classification of Headache Disorders (ICHD-II). Here, we describe the case of a 45-year-old man presenting an unusual concurrence of different forms of primary headaches associated with autonomic signs, including subsequently ipsilateral cluster headache, SUNCT and HC. This report supports the theory that common mechanisms could be involved in pathophysiology of different primary headache syndromes.

SUNCT syndrome or first division trigeminal neuralgia associated with cerebellar hypoplasia

Short-lasting unilateral neuralgiform headache (SUNCT) and first division trigeminal neuralgia (TN) are rare and very similar periorbital unilateral pain syndromes. Few cases of SUNCT are associated with posterior skull lesions. We describe a 54-year-old man with symptoms compatible with both the previous painful syndromes, associated with a small posterior skull and a cerebellar hypoplasia. The short height and the reported bone fractures could be compatible with a mild form of osteogenesis imperfecta, previously described in one case associated with SUNCT. However, a hypoplastic posterior cranial fossa characterizes also Chiari I malformation. The difficult differential diagnosis between SUNCT and TN and their relation with posterior skull malformations is debated.

Sleep and headache

There is a strong interaction between sleep and headache. Sleep and headache disorders overlap epidemiologically, and share elements of anatomy and physiology. Perhaps as a result, their treatment is often mutually interdependent. Despite this, headache and sleep disorders tend to be treated separately, by different subspecialties of neurology. The headache disorders and their relationship to sleep, the commonalities of headache and sleep pathophysiology, and headache disorders that are particularly susceptible to sleep modulation (and vice versa) are reviewed. Practical management advice for sleep-modulated headaches is provided.

Neurostimulation approaches to primary headache disorders

PURPOSE OF REVIEW

Conventional management options in medically intractable chronic-headache syndromes, such as chronic migraine, chronic cluster headache and hemicrania continua, are often limited. This review summarizes the current concepts, approaches and outcome data of invasive device-based neurostimulation approaches using occipital-nerve stimulation and deep-brain stimulation.

RECENT FINDINGS

Recently, there has been considerable progress in neurostimulation approaches to medically intractable chronic-headache syndromes. Previous studies have analysed the safety and efficacy of suboccipital neurostimulation in drug-resistant chronic-headache syndromes such as in chronic migraine, chronic cluster headache and hemicrania continua. The studies suggest suboccipital neurostimulation can have an effect even decades after onset of headaches, thus representing a possible therapeutic option inpatients that do not respond to any medication. Similarly, to date over 50 patients with cluster headaches underwent hypothalamic deep-brain stimulation. From these, an average of 50-70% did show a significant positive response.

SUMMARY

These findings will help to further elucidate the clinical potential of neurostimulation in chronic headache.

Response to Intravenous Lidocaine in a Patient with SUNCT Syndrome

Short-lasting unilateral neuralgiform headache with conjunctival injection and tearing (SUNCT) syndrome represents a serious therapeutic and diagnostic challenge, since it is usually refractory to most drugs and lacks biological markers. Response to intravenous lidocaine administration has been reported in some patients while it has failed in others. We report a patient with SUNCT syndrome who showed a clear-cut and consistent response to intravenous lidocaine therapy, which proved superior to placebo in a single-blinded fashion. Intravenous lidocaine should be considered in all patients with SUNCT syndrome. Response to this therapy could represent a diagnostic tool.

Hemicrania continua unresponsive or partially responsive to indomethacin: does it exist? A diagnostic and therapeutic dilemma

Hemicrania continua (HC) is a primary headache disorder characterized by a continuous, unilateral headache that varies in intensity, waxing and waning without disappearing completely. Ipsilateral cranial autonomic features and response to indomethacin are essential features for the diagnosis of HC. We hereby, describe three patients with the clinical phenotypes of HC in whom response to indomethacin was either incomplete or not sustained. We also review the literature especially for the presence of indomethacin response and ipsilateral cranial autonomic features.