Management of trigeminal autonomic cephalgias and hemicrania continua

Pharmacogenomic study-A pilot study of the effect of pharmacogenomic phenotypes on the adequate dosing of verapamil for migraine prevention

OBJECTIVE

To investigate factors affecting the efficacy and tolerability of verapamil for migraine prevention using individual pharmacogenomic phenotypes.

BACKGROUND

Verapamil has a wide range of dosing in headache disorders without reliable tools to predict the optimal doses for an individual.

METHODS

This is a retrospective chart review examining adults with existing pharmacogenomic reports at Mayo Clinic who had used verapamil for migraine. Effects of six cytochrome P450 phenotypes on the doses of verapamil for migraine prevention were assessed.

RESULTS

Our final analysis included 33 migraine patients (82% with aura). The mean minimum effective and maximum tolerable doses of verapamil were 178.2(20-320) mg and 227.9(20-480) mg. A variety of CYP2C9, CYP2D6, and CYP3A5 phenotypes were found, without significant association with the verapamil doses after adjusting for age, sex, body mass index, and smoking status.

CONCLUSIONS

We demonstrated a wide range of effective and tolerable verapamil doses used for migraine in a cohort with various pharmacogenomic phenotypes.

Trigeminal Autonomic Cephalalgias and Neuralgias in Children and Adolescents: a Narrative Review

PURPOSE OF REVIEW

To summarize the available literature as well as the authors' experience on trigeminal autonomic cephalalgias (TACs) and cranial neuralgias in children and adolescents.

RECENT FINDINGS

While TACs and cranial neuralgias are rare in children, several recent case series have been published. TACs in children share most of the clinical features of TACs in adults. However, there are many reported cases with clinical features which overlap more than one diagnosis, suggesting that TACs may be less differentiated in youth. Indomethacin-responsive cases of cluster headache and SUNCT/SUNA have been reported in children, whereas in adults indomethacin is usually reserved for paroxysmal hemicrania and hemicrania continua. Neuralgias appear to be rare in children. Clinical features are often similar to adult cases, though clinicians should maintain a high index of suspicion for underlying causes.

Treatment of SUNCT/SUNA, Paroxysmal Hemicrania, and Hemicrania Continua: An Update Including Single-Arm Meta-analyses

Purpose of Review

This review presents a critical appraisal of the treatment strategies for short-lasting unilateral neuralgiform headache attacks (SUNHA), paroxysmal hemicrania (PH), and hemicrania continua (HC). We assess the available, though sparse, evidence on both medical and surgical treatments. In addition, we present estimated pooled analyses of the most common treatments and emphasize recent promising findings.

Recent Findings

The majority of literature available on the treatment of these rare trigeminal autonomic cephalalgias are small open-label observational studies and case reports. Pooled analyses reveal that lamotrigine for SUNHA and indomethacin for PH and HC are the preventative treatments of choice. Second-line choices include topiramate, gabapentin, and carbamazepine for SUNHA; verapamil for PH; and cyclooxygenase-2 inhibitors and gabapentin for HC. Parenteral lidocaine is highly effective as a transitional treatment for SUNHA. Novel therapeutic strategies such as non-invasive neurostimulation, targeted nerve and ganglion blockades, and invasive neurostimulation, including implanted occipital nerve stimulators and deep brain stimulation, appears to be promising options.

Summary

At present, lamotrigine as a prophylactic and parenteral lidocaine as transitional treatment remain the therapies of choice for SUNHA. While, by definition, both PH and CH respond exquisitely to indomethacin, evidence for other prophylactics is less convincing. Evidence for the novel emerging therapies is limited, though promising.

Facial paroxysmal hemicrania associated with the menstrual cycle

Paroxysmal hemicrania (PH) is a rare trigeminal autonomic cephalalgia (TAC) which is usually not associated with the menstrual cycle and usually affects the first trigeminal branch. We present a 47-year-old female patient with a facial variant of PH. For over 11 years, the patient had suffered from 8 to 12 typical PH attacks per day localized in the left maxilla in bouts of 4–9 days solely during her menstruation and ovulation. Single dosages of indomethacin 25 mg showed good efficacy in the prevention of the attacks for several hours. However, the intake of indomethacin had to be ceased due to severe psychiatric side effects. Ibuprofen 400 mg also reliably reduces the attack frequency with the same effectiveness as indomethacin. Attacks of PH can occur solely in the facial region and can be associated with the menstrual cycle which can prove to be a diagnostic challenge. Also, the intake of indomethacin can be limited by psychiatric side effects but can be adequately substituted by ibuprofen.

Primary Headaches

The primary headaches are composed of multiple entities that cause episodic and chronic head pain in the absence of an underlying pathologic process, disease, or traumatic injury. The most common of these are migraine, tension-type headache, and the trigeminal autonomic cephalalgias. This article reviews the clinical presentation, pathophysiology, and treatment of each to help in differential diagnosis. These headache types share many common signs and symptoms, thus a clear understanding of each helps prevent a delay in diagnosis and inappropriate or ineffective treatment. Many of these patients seek dental care because orofacial pain is a common presenting symptom.

Therapeutical approaches to paroxysmal hemicrania, hemicrania continua and short lasting unilateral neuralgiform headache attacks: a critical appraisal

Background

Hemicrania continua (HC), paroxysmal hemicrania (PH) and short lasting neuralgiform headache attacks (SUNCT and SUNA) are rare syndromes with a difficult therapeutic approach. The aim of this review is to summarize all articles dealing with treatments for HC, PH, SUNCT and SUNA, comparing them in terms of effectiveness and safety.

Methods

A survey was performed using the pubmed database for documents published from the 1st January 1989 onwards. All types of articles were considered, those ones dealing with symptomatic cases and non-English written ones were excluded.

Results

Indomethacin is the best treatment both for HC and PH. For the acute treatment of HC, piroxicam and celecoxib have shown good results, whilst for the prolonged treatment celecoxib, topiramate and gabapentin are good options besides indomethacin. For PH the best drug besides indomethacin is piroxicam, both for acute and prolonged treatment. For SUNCT and SUNA the most effective treatments are intravenous or subcutaneous lidocaine for the acute treatment of active phases and lamotrigine for the their prevention. Other effective therapeutic options are intravenous steroids for acute treatment and topiramate for prolonged treatment. Non-pharmacological techniques have shown good results in SUNCT and SUNA but, since they have been tried on a small number of patients, the reliability of their efficacy is poor and their safety profile mostly unknown.

Conclusions

Besides a great number of treatments tried, HC, PH, SUNCT and SUNA management remains difficult, according with their unknown pathogenesis and their rarity, which strongly limits the studies upon these conditions. Further studies are needed to better define the treatment of choice for these conditions.

Electronic supplementary material

The online version of this article (doi:10.1186/s10194-017-0777-3) contains supplementary material, which is available to authorized users.

Invasive pericranial nerve interventions

Background

In many patients suffering from primary headaches, the available pharmacological and behavioural treatments are not satisfactory. This is a review of (minimally) invasive interventions targeting pericranial nerves that could be effective in refractory patients.

Methods

The interventions we will cover have in common pericranial nerves as targets, but are distinct according to their rationale, modality and invasiveness. They range from nerve blocks/infiltrations to the percutaneous implantation of neurostimulators and surgical decompression procedures. We have critically analysed the published data (PubMed) on their effectiveness and tolerability.

Results and conclusions

There is clear evidence for a preventative effect of suboccipital injections of local anaesthetics and/or steroids in cluster headache, while evidence for such an effect is weak in migraine. Percutaneous occipital nerve stimulation (ONS) provides significant long-term relief in more than half of drug-resistant chronic cluster headache patients, but no sham-controlled trial has tested this. The evidence that ONS has lasting beneficial effects in chronic migraine is at best equivocal. Suboccipital infiltrations are quasi-devoid of side effects, while ONS is endowed with numerous, though reversible, adverse events. Claims that surgical decompression of multiple pericranial nerves is effective in migraine are not substantiated by large, rigorous, randomized and sham-controlled trials.

Pain Part 9: Trigeminal Autonomic Cephalalgias

The trigeminal autonomic cephalalgias are a group of rare, highly disabling, primary headache syndromes distinctly characterized by the unilaterality of their attacks and presence of cranial autonomic symptoms. Although pain is often localized to the peri-orbital and temporal regions, it is not uncommon for pain to radiate to tooth-bearing areas and mimic toothache or jaw pain. Hence, dental practitioners should be aware of these syndromes to enable appropriate referral and avoid unnecessary, and often irreversible, dental treatments. Many dentists will not have heard of these conditions but must remain vigilant, and ensure that they are not confused with trigeminal neuralgia, so that their patients are appropriately advised and referred. Clinical relevance: The dental practitioners may be the first line of healthcare providers consulted by these patients in the hope of obtaining pain relief. Lack of familiarity with an uncommon condition may lead to poor patient management.

High-Dose Verapamil in Episodic and Chronic Cluster Headaches and Cardiac Adverse Events: Is It as Safe as We Think?

Cluster headache (CH) is a primary headache disorder with relatively effective treatments. Although few sufficiently controlled trials are available, verapamil is recommended as the first-line prophylactic drug for CH by the French Headache Society (with a low level of evidence, level B) and by the EFNS (European Federation of Neurological Societies, level A). Daily doses of more than 480 mg (and up to 1200 mg daily) are frequently used off-label, while 360 mg daily is the only dosage to have demonstrated its effectiveness in a double-blind trial against placebo, and the usual label posology used by cardiologists is 240 mg daily in hypertension. We report the case of a 19-year-old man who was self-reported to our cardiology consultation for dyspnea and asthenia for 18 months. His medical history consisted of CH crisis for 4 years treated by verapamil 720 mg/day for 18 months with relatively good efficiency. His electrocardiogram (ECG) showed a sinus bradycardia at 40 bpm with a first-degree atrio-ventricular block. Evolution was favorable after progressive verapamil discontinuation. Analysis performed on the French Pharmacovigilance Database between July 1, 2000 and December 1, 2014 found four other cases of cardiac adverse events related to high-dose verapamil used in CH prevention (two cases of syncope with complete atrio-ventricular block with verapamil 1200 and 240 mg daily, respectively, one syncope related to sick sinus syndrome with verapamil 360 mg daily, and one case of sinus bradycardia with verapamil 720 mg daily). Although available studies seem to demonstrate an apparent good tolerance, this off-label practice should not be considered as standard of care and requires strict cardiac monitoring, as suggested by the Agence Nationale de Sécurité du Médicament (ANSM) in a recent re-evaluation of the benefit/risk ratio of high-dose verapamil used in CH prevention.

Exacerbation of SUNCT and SUNA syndromes during intravenous dihydroergotamine treatment: A case series

BACKGROUND

The management of short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT) and with short-lasting unilateral neuralgiform headache attacks with autonomic symptoms (SUNA) remains challenging in view of the limited understanding of their pathophysiological mechanisms.

METHODS

An initial observation that patients with both chronic migraine (CM) or cluster headache (CH) and SUNCT/SUNA receiving intravenous dihydroergotamine (IV DHE) had complained of dramatic worsening of the latter led to review of the case notes of patients with CM or CH and co-existent SUNCT/SUNA seen between 2008 and 2013 and who had a trial of IV DHE.

RESULTS

Twenty-four patients were identified. IV DHE was ineffective for SUNCT/SUNA in 16 patients, while one patient reported a marginal improvement. Five patients reported dramatic worsening of the SUNCT/SUNA. Moreover, two patients developed new-onset SUNA during their first IV DHE infusion. Out of these seven patients, those requiring repeated courses of IV DHE consistently experienced exacerbations of SUNCT/SUNA which were suppressed with IV lidocaine.

CONCLUSIONS

DHE is an ineffective treatment option for SUNCT and SUNA. Physicians who intend to offer IV DHE to CH or CM patients should warn them that IV DHE could exacerbate and possibly even lead to a de novo onset of SUNCT/SUNA. In view of the reported worsening or new onset of SUNCT/SUNA in patients using dopamine agonists for the treatment of pituitary prolactinomas, we speculate that DHE might worsen or induce SUNCT and SUNA, at least in a sub-group of patients, through a perturbation in the dopaminergic system.

Paroxysmal hemicrania: an update

Paroxysmal hemicrania (PH) is an underreported and underdiagnosed primary headache disorder. It usually begins in the third or fourth decade of life. The recent observations indicate that it is equally prevalent in both males and females. PH is characterized by severe, strictly unilateral head pain attacks that occur in association with ipsilateral autonomic features. The attacks in PH are shorter and more frequent compared with cluster headache (CH) but otherwise PH and CH have similar clinical features. The hallmark of PH is the absolute cessation of the headache with indomethacin. However, a range of drugs may show partial to complete relief in certain groups of patients. Neuromodulatory procedures, such as greater occipital nerve blockade, blockade of sphenopalatine ganglion and neurostimulation of the posterior hypothalamus, are reserved for refractory PH.

Occipital nerve stimulation in medically intractable, chronic cluster headache. The ICON study: Rationale and protocol of a randomised trial

Background

About 10% of cluster headache patients have the chronic form. At least 10% of this chronic group is intractable to or cannot tolerate medical treatment. Open pilot studies suggest that occipital nerve stimulation (ONS) might offer effective prevention in these patients. Controlled neuromodulation studies in treatments inducing paraesthesias have a general problem in blinding. We have introduced a new design in pain neuromodulation by which we think we can overcome this problem.

Methods/design

We propose a prospective, randomised, double-blind, parallel-group international clinical study in medically intractable, chronic cluster headache patients of high- versus low-amplitude ONS. Primary outcome measure is the mean number of attacks over the last four weeks. After a study period of six months there is an open extension phase of six months. Alongside the randomised trial an economic evaluation study is performed.

Discussion

The ICON study will show if ONS is an effective preventive therapy for patients suffering medically intractable chronic cluster headache and if there is a difference between high- and low-amplitude stimulation. The innovative design of the study will, for the first time, assess efficacy of ONS in a blinded way.

Neurostimulation in cluster headache: A review of current progress

Purpose of review

Neurostimulation has emerged as a viable treatment for intractable chronic cluster headache. Several therapeutic strategies are being investigated including stimulation of the hypothalamus, occipital nerves and sphenopalatine ganglion. The aim of this review is to provide an overview of the rationale, methods and progress for each of these.

Latest findings

Results from a randomized, controlled trial investigating sphenopalatine ganglion stimulation have just been published. Reportedly the surgery is relatively simple and it is apparently the only therapy that provides relief acutely.

Summary

The rationale behind these therapies is based on growing evidence from clinical, hormonal and neuroimaging studies. The overall results are encouraging, but unfortunately not all patients have benefited. All the mentioned therapies require weeks to months of stimulation for a prophylactic effect to occur, suggesting brain plasticity as a possible mechanism, and only stimulation of the sphenopalatine ganglion has demonstrated an acute, abortive effect. Predictors of effect for all modes of neurostimulation still need to be identified and in the future, the least invasive and most effective strategy must be preferred as first-line therapy for intractable chronic cluster headache.

Neuromodulation for cephalgias

Headaches (cephalgias) are a common reason for patients to seek medical care. There are groups of patients with recurrent headache and craniofacial pain presenting with malignant course of their disease that becomes refractory to pharmacotherapy and other medical management options. Neuromodulation can be a viable treatment modality for at least some of these patients. We review the available evidence related to the use of neuromodulation modalities for the treatment of medically refractory craniofacial pain of different nosology based on the International Classification of Headache Disorders, 2(nd) edition (ICHD-II) classification. This article also reviews the scientific rationale of neuromodulation application in management of cephalgias.

Trigeminal autonomic cephalalgias: A review of recent diagnostic, therapeutic and pathophysiological developments

The trigeminal autonomic cephalalgias (TACs) are a group of primary headache disorders that are characterized by strictly unilateral trigeminal distribution pain occurring in association with ipsilateral cranial autonomic symptoms. This group includes cluster headache, paroxysmal hemicrania and short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing. These disorders are very painful, often considered to be some of the most painful conditions known to mankind, and consequently are highly disabling. They are distinguished by the frequency of attacks of pain, the length of the attacks and very characteristic responses to medical therapy, such that the diagnosis can usually be made clinically, which is important because it dictates therapy. The management of TACs can be very rewarding for physicians and highly beneficial to patients.

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.

Management of cluster headache

The prevalence of cluster headache is 0.1% and cluster headache is often not diagnosed or misdiagnosed as migraine or sinusitis. In cluster headache there is often a considerable diagnostic delay - an average of 7 years in a population-based survey. Cluster headache is characterized by very severe or severe orbital or periorbital pain with a duration of 15-180 minutes. The cluster headache attacks are accompanied by characteristic associated unilateral symptoms such as tearing, nasal congestion and/or rhinorrhoea, eyelid oedema, miosis and/or ptosis. In addition, there is a sense of restlessness and agitation. Patients may have up to eight attacks per day. Episodic cluster headache (ECH) occurs in clusters of weeks to months duration, whereas chronic cluster headache (CCH) attacks occur for more than 1 year without remissions. Management of cluster headache is divided into acute attack treatment and prophylactic treatment. In ECH and CCH the attacks can be treated with oxygen (12 L/min) or subcutaneous sumatriptan 6 mg. For both oxygen and sumatriptan there are two randomized, placebo-controlled trials demonstrating efficacy. In both ECH and CCH, verapamil is the prophylactic drug of choice. Verapamil 360 mg/day was found to be superior to placebo in one clinical trial. In clinical practice, daily doses of 480-720 mg are mostly used. Thus, the dose of verapamil used in cluster headache treatment may be double the dose used in cardiology, and with the higher doses the PR interval should be checked with an ECG. At the start of a cluster, transitional preventive treatment such as corticosteroids or greater occipital nerve blockade can be given. In CCH and in long-standing clusters of ECH, lithium, methysergide, topiramate, valproic acid and ergotamine tartrate can be used as add-on prophylactic treatment. In drug-resistant CCH, neuromodulation with either occipital nerve stimulation or deep brain stimulation of the hypothalamus is an alternative treatment strategy. For most cluster headache patients there are fairly good treatment options both for acute attacks and for prophylaxis. The big problem is the diagnosis of cluster headache as demonstrated by the diagnostic delay of 7 years. However, the relatively short-lasting attack of pain in one eye with typical associated symptoms should lead the family doctor to suspect cluster headache resulting in a referral to a neurologist or a headache centre with experience in the treatment of cluster headache.

Oral triptans in the preventive management of cluster headache

Cluster headache is a rare primary neurovascular headache and a severe pain condition with unilateral headache over 15-180 minutes and concomitant unilateral autonomic symptoms. The detailed pathophysiology of the condition is still unclear. Only a few evidence-based therapeutic options for acute therapy and the preventive management of the disease are available. Triptans, in particular sumatriptan 6 mg subcutaneously, are highly effective for acute treatment. This review focuses on the potential use of oral triptans in the prophylaxis of cluster headache.

Ocular and orbital pain for the headache specialist

Ocular pain is most commonly associated with redness and inflammation; however, eye pain can also occur in the absence of grossly visible pathology. Pain in the quiet eye can be the first sign of a number of threatening conditions. Many of these conditions such as intermittent angle closure glaucoma, carotid artery dissection, idiopathic intracranial hypertension, and giant cell arteritis can lead to permanent vision loss or blindness. In this review, ocular history and examination techniques are summarized. The article also reviews pertinent ocular, orbital, referred, and other causes of eye pain in the quiet eye. The neurologist and headache specialist should recognize when consultation with an ophthalmologist is necessary.

Treatment of miscellaneous idiopathic headache disorders (Group 4 of the IHS classification)--report of an EFNS task force

BACKGROUND AND PURPOSE

Certain miscellaneous idiopathic headache disorders, which are regarded as entities, are grouped in Chapter 4 of the International Classification of Headache Disorders. Recent epidemiological research suggests that these headache disorders are underdiagnosed.

OBJECTIVES

To give expert recommendations for the different drug and non-drug treatment procedures of these different headache disorders based on a literature search and on consensus of an expert panel.

METHODS

All available medical reference systems were screened for all kinds of clinical studies on these headache disorders. The findings in these studies were evaluated according to the recommendations of the EFNS resulting in level A, B or C recommendations and good practice points.

RECOMMENDATIONS

For all headache disorders, acute and prophylactic drug treatment is recommended based on case series and on expert consensus. Furthermore, recommendations for the differential diagnoses are given because these headache disorders can also present with a symptomatic form. The most effective drug for the majority of these headache disorders is indomethacin, mostly applied as long-term or short-term prophylaxis.

A possible case of symptomatic hemicrania continua from an osteoid osteoma of the ethmoid sinus

We report a case of osteoid osteoma involving the ethmoid sinus, which presented as a unilateral fixed headache with some features suggestive of hemicrania continua.

N-methyl-D-aspartate receptor-mediated modulations of the anti-allodynic effects of 5-HT1B/1D receptor stimulation in a rat model of trigeminal neuropathic pain

Previous studies showed that triptans and other 5-HT(1B/1D)-receptor agonists attenuate hyper-responsiveness to mechanical stimulation of the face in a rat model of trigeminal neuropathic pain, probably by activating 5-HT(1B/1D)-receptors on primary afferent nociceptive fibers. We now tested whether blockade of post-synaptic receptors for the excitatory amino acid glutamate released by these fibers would increase this action. We thus evaluated whether (±)1-hydroxy-3-aminopyrrolidine-2-one (HA-966), an antagonist at the glycine/D-serine site of N-methyl-D-aspartate (NMDA)-receptors, would potentiate the anti-allodynic action of dihydroergotamine and zolmitriptan in rats with chronic constriction injury to the infraorbital nerve (CCI-ION). Complementary studies were performed with other NMDA-receptor ligands and in rats with chronic constriction injury to the sciatic nerve (CCI-SN) for comparison. Injury was produced by loose ligatures of the nerves. Responsiveness to mechanical stimulation (vibrissae or hindpaw territories) with von Frey filaments was used to evaluate allodynia 2 weeks after nerve ligature. Rats received NMDA-receptor ligands or saline 20 min before dihydroergotamine (25-100 μg/kg, i.v.) or zolmitriptan (25-100 μg/kg, s.c.). HA-966 (2.5mg/kg, s.c.), inactive on its own, enhanced the anti-allodynic effects of dihydroergotamine (eightfold increase) and zolmitriptan (threefold increase) in CCI-ION rats, but these drugs exerted no effects in allodynic CCI-SN rats. NMDA-receptor blockade by memantine (5mg/kg, i.p.) also enhanced, whereas activation at glycine/NMDA site by D-cycloserine (3mg/kg, i.p.) reduced the anti-allodynic properties of zolmitriptan in CCI-ION rats. Combined administration of NMDA-receptor antagonist and 5-HT(1B/1D)-receptor agonist may be a promising approach for alleviating trigeminal neuropathic pain.

Familial hemicrania continua

There are now three known causative genes for familial hemiplegic migraine and increasing evidence to support a genetic predisposition to the more common types of migraine with and without aura, and for cluster headache. We present the first reported case of familial hemicrania continua. A mother and daughter developed hemicrania continua at the same time of life. Both showed an absolute response to indometacin and at similar doses. Both also suffered from migraine with aura. We discuss the increasing support for a genetic predisposition to dysfunction of the pain system within the brain manifesting as primary headache.

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.

Focus on therapy: hemicrania continua and new daily persistent headache

Hemicrania continua (HC) and new daily-persistent headache (NDPH) represent the only two forms of chronic daily headache in Chap. IV "Other Primary Headaches" of the second edition of the International Classification of Headache Disorders. HC and NDPH are rare and poorly defined from a pathophysiological point of view; as a consequence, their management is largely empirical. Indeed, there is a lack of prospective, controlled trials in this field, and treatment effectiveness is basically inferred from the results of sparse open-label trials, retrospective case series, clinical experience and expert opinions. In this narrative review we have summarised the information collected from an extensive analysis of the literature on the treatment of HC and NDPH in order to provide the best available and up-to-date evidence for the management of these two rare forms of primary headache. Indomethacin is the mainstay of HC management. The reported effective dose of indomethacin ranges from 50 to 300 mg/day. Gabapentin 600-3,600 mg tid, topiramate 100 mg bid, and celecoxib 200-400 mg represent the most interesting alternative choices in the patients who do not tolerate indomethacin or who have contraindications to its use. NDPH is very difficult to treat and it responds poorly only to first-line options used for migraine or tension-type headache.

Acute and preventive treatment of cluster headache and other trigeminal autonomic cephalgias

Patients with cluster headache or any of the trigeminal autonomic cephalalgias (TACs) are often good candidates for preventive treatment as their headaches are frequent and severe. While acute and symptomatic therapies must be used often, they do not alter the course of the cluster period or the duration of the TACs, and they do not usually decrease the frequency of attacks. In this chapter we discuss the aim and the choice of prevention. Verapamil is considered the first choice for prevention of cluster headache, but as with all of the medications to be mentioned, it has various adverse effects to be aware of. Other frequently used preventives for cluster include lithium carbonate, methysergide where available, methylergonovine, clonidine, melatonin, valproate, gabapentin, topiramate, and others. Several other medications can be used as bridge therapy, to decrease the frequency of cluster temporarily, giving time for the preventives to begin to work. The most commonly used bridge therapies are 7-21 days of prednisone at high and then tapering doses and ergots such as ergotamine tartrate and dihydroergotamine. Patients with chronic cluster headache who are unresponsive to all medical therapies can be considered for occipital nerve stimulation and various surgical procedures such as ganglyogliolysis of all three branches of the ipsilateral trigeminal nerve at the root entry zone. A somewhat controversial but highly successful procedure, at least as done by the neurosurgeons in Professor Bussone's group at the Institute of Neurology in Milan, has been deep-brain stimulation of the posterior hypothalamus. Other TACs, such as short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT), can be hard to treat effectively with medications, but the paroxysmal hemicranias and cluster tic respond somewhat better to traditional therapies.

Neurostimulation therapy in intractable headaches

A proportion of chronic headache patients become refractory to medical treatment and severely disabled. In such patients various neurostimulation methods have been proposed, ranging from invasive procedures such as deep-brain stimulation to minimally invasive ones like occipital nerve stimulation. They have been applied in single cases or small series of patients affected with varying headache disorders: cervicogenic headache, hemicrania continua, posttraumatic headache, chronic migraine, and cluster headache. Although favorable results were reported overall, it is premature to consider neurostimulation as a treatment with established utility in refractory headaches. At present, the most detailed clinical studies have been performed in intractable chronic cluster headache (iCCH) patients, who represent about 1% of all chronic cluster headache (CCH) patients. Various lesional interventions have been attempted in these patients, none with lasting benefits. In recent years, non-destructive neurostimulation methods have raised new hope. Hypothalamic deep-brain stimulation (hDBS) acts rapidly and has lasting efficacy, but is not without risk. Occipital nerve stimulation (ONS) was studied in two trials on a total of 17 iCCH patients. Clinical efficacy was found to be very satisfactory by most patients and by the investigators. Although slightly less efficacious than hDBS, ONS has the advantage of being rather harmless and reversible. At this stage, it should be preferred as first-line invasive therapy for iCCH. Recent case reports mention the efficacy of supraorbital (SNS) and vagal (VNS) nerve stimulation. Whether these neurostimulation methods have a place in the management of iCCH patients remains to be determined.

Pathophysiology of trigeminal autonomic cephalalgias

Cluster headache, paroxysmal hemicrania, and short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT) are primary headaches recently classified together as trigeminal autonomic cephalalgias (TACs). The causes of these headaches have long been debated, with "peripheral" hypotheses in opposition to "central" hypotheses. The available information indicates that the pain originates from within the brain in cluster headache. The hypothalamic activation observed during TAC attacks by use of functional neuroimaging, and the success of hypothalamic stimulation as a treatment, confirm that the posterior hypothalamus is crucial in the pathophysiology of these headaches. The posterior hypothalamus is now known to modulate craniofacial pain, and hypothalamic activation occurs in other pain disorders, suggesting that this brain area is likely to have a more complex role in the pathophysiology of TACs than that of a mere trigger. Hypothalamic activation might play a part in terminating rather than triggering attacks, and might also give rise to a central permissive state, allowing attacks to take place.

Chronic migraine and medication overuse headache: clarifying the current International Headache Society classification criteria

Despite the recent advances in the understanding and classification of the chronic daily headaches, considerable controversy still exists regarding the classification of individual headaches, including chronic migraine (CM) and medication overuse headache (MOH). The original criteria, published in 2004, were difficult to apply to most patients with these disorders and were subsequently revised, resulting in broader clinical applicability. Nonetheless, they remain a topic of debate, and the revisions to the criteria have further added to the confusion. Even some prominent headache specialists are unsure which criteria to use. We aimed to explain the nature of the controversies surrounding the entities of CM and MOH. A clinical case will be used to illustrate some of the problems faced by clinicians in diagnosing patients with chronic daily headache.

Diagnostic delay and suboptimal management in a referral population with hemicrania continua

AIM OF THE STUDY

To investigate a clinical population of patients with hemicrania continua (HC), looking at the diagnostic problems they have encountered and their use of healthcare resources and at issues relating to the effectiveness of treatments.

MATERIALS AND METHODS

We directly interviewed 25 patients fulfilling the International Classification of Headache Disorders, 2nd edition diagnostic criteria for HC selected among 1612 subjects attending the INI Grottaferrata Headache Clinic over a 3-year period.

RESULTS

No patient had received a correct diagnosis before being seen at our headache clinic. In total, 85% of the patients consulted a physician within 5 months of the onset of the symptoms but mean time to diagnosis was 5 years (SD 4.9). The average number of physicians seen before the condition was properly diagnosed was 4.6 (SD 2.2). General practitioners (100%), neurologists (80%), ear, nose, and throat surgeons (44%), ophthalmologists (40%), and dentists (32%) were the physicians most commonly consulted. All the patients had previously received an incorrect diagnosis. Migraine (52%), CH (28%), sinus headache (20%), and dental pain (20%) were the most common wrong diagnoses reported. Some 36.0% of patients had undergone ineffective invasive treatments. The patients had tried, on average, 3.6 (SD 2.1) classes of drugs. Nonsteroidal anti-inflammatory drugs (NSAIDs) (92%), triptans (32%), antidepressants (32%), and antiepileptics (24%) were the most commonly used. Patients rated 73.7% of medications as ineffective, 22.5% (all NSAIDs) as partially effective, and 3.7% (rofecoxib and nimesulide) as effective.

CONCLUSIONS

Hemicrania continua may be misdiagnosed and mistreated even by neurologists. There is a need for greater awareness and understanding of this condition.