Deep brain stimulation in trigeminal autonomic cephalalgias

Potential hypothalamic mechanisms in trigeminal neuropathic pain: a comparative analysis with migraine and cluster headache

Trigeminal neuropathic pain (TNP), migraine, and cluster headache (CH) profoundly impact the quality of life and present significant clinical challenges due to their complex neurobiological underpinnings. This review delves into the pivotal role of the hypothalamus in the pathophysiology of these facial pain syndromes, highlighting its distinctive functions and potential as a primary target for research, diagnosis, and therapy. While the involvement of the hypothalamus in migraine and CH has been increasingly supported by imaging and clinical studies, the precise mechanisms of its role remain under active investigation. The role of the hypothalamus in TNP, in contrast, is less explored and represents a critical gap in our understanding. The hypothalamus's involvement varies significantly across these conditions, orchestrating a unique interplay of neural circuits and neurotransmitter systems that underlie the distinct characteristics of each pain type. We have explored advanced neuromodulation techniques, such as deep brain stimulation (DBS) and optogenetics, which show promise in targeting hypothalamic dysfunction to alleviate pain symptoms. Furthermore, we discuss the neuroplastic changes within the hypothalamus that contribute to the chronicity of these pains and the implications of these findings for developing targeted therapies. By offering a comprehensive examination of the hypothalamus's roles, this paper aims to bridge existing knowledge gaps and propel forward the understanding and management of facial neuralgias, underscoring the hypothalamus's critical position in future neurological research.

Primaries non-migraine headaches treatment: a review

In the "headache world," great attention has always been paid to migraine patients, especially for the research and development of new therapies. For the other forms of primary headaches, especially those of Chapters 2 and 3 of the classification, there are however therapies that, even if not specific, can give significant results. Tension-type headache recognizes in NSAIDs the most effective drugs to treat acute attack, while prevention is based on the use of tricyclic antidepressants and muscle relaxants. For TACs, the discussion is more complex: first of all, there are two forms of primary headache that respond absolutely to indomethacin. For these, the main problem is how to manage the possible side effects arising from prolonged treatments and possibly what to use as an alternative. For cluster headaches and short-lasting unilateral neuralgiform headache attacks, we have drugs with good efficacy as regards medical therapy, such as verapamil or lamotrigine, but in recent years, neuromodulation techniques, both surgical and non-invasive, have also been affirming themselves, which represent a more possibility for forms of headache that are often very disabling and resistant to common analgesics.

Neuromodulation in headache and craniofacial neuralgia: guidelines from the Spanish Society of Neurology and the Spanish Society of Neurosurgery

INTRODUCTION

Numerous invasive and non-invasive neuromodulation devices have been developed and applied to patients with headache and neuralgia in recent years. However, no updated review addresses their safety and efficacy, and no healthcare institution has issued specific recommendations on their use for these 2 conditions.

METHODS

Neurologists from the Spanish Society of Neurology's (SEN) Headache Study Group and neurosurgeons specialising in functional neurosurgery, selected by the Spanish Society of Neurosurgery (SENEC), performed a comprehensive review of articles on the MEDLINE database addressing the use of the technique in patients with headache and neuralgia.

RESULTS

We present an updated review and establish the first set of consensus recommendations of the SEN and SENC on the use of neuromodulation to treat headache and neuralgia, analysing the current levels of evidence on its effectiveness for each specific condition.

CONCLUSIONS

Current evidence supports the indication of neuromodulation techniques for patients with refractory headache and neuralgia (especially migraine, cluster headache, and trigeminal neuralgia) selected by neurologists and headache specialists, after pharmacological treatment options are exhausted. Furthermore, we recommend that invasive neuromodulation be debated by multidisciplinary committees, and that the procedure be performed by teams of neurosurgeons specialising in functional neurosurgery, with acceptable rates of morbidity and mortality.

Therapeutic Approaches for the Management of Trigeminal Autonomic Cephalalgias

Trigeminal autonomic cephalalgia (TAC) encompasses 4 unique primary headache types: cluster headache, paroxysmal hemicrania, hemicrania continua, and short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing and short-lasting unilateral neuralgiform headache attacks with cranial autonomic symptoms. They are grouped on the basis of their shared clinical features of unilateral headache of varying durations and ipsilateral cranial autonomic symptoms. The shared clinical features reflect the underlying activation of the trigeminal-autonomic reflex. The treatment for TACs has been limited and not specific to the underlying pathogenesis. There is a proportion of patients who are refractory or intolerant to the current standard medical treatment. From instrumental bench work research and neuroimaging studies, there are new therapeutic targets identified in TACs. Treatment has become more targeted and aimed towards the pathogenesis of the conditions. The therapeutic targets range from the macroscopic and structural level down to the molecular and receptor level. The structural targets for surgical and noninvasive neuromodulation include central neuromodulation targets: posterior hypothalamus and, high cervical nerves, and peripheral neuromodulation targets: occipital nerves, sphenopalatine ganglion, and vagus nerve. In this review, we will also discuss the neuropeptide and molecular targets, in particular, calcitonin gene-related peptide, somatostatin, transient receptor potential vanilloid-1 receptor, nitric oxide, melatonin, orexin, pituitary adenylate cyclase-activating polypeptide, and glutamate.

Further evidence for a pain pathway involving the cingulate gyrus: a case of chronic cluster headache cured by glioblastoma

The authors report a case of a 49-year-old man with long-standing, chronic cluster headache (CH) refractory to medical therapy and occipital nerve stimulation that resolved a few weeks prior to the diagnosis of glioblastoma involving primarily the right cingulate gyrus. An attempt to explore the underlying role of the cingulate cortex in pain modulation by appraising the current literature is presented. This report suggests that the cingulate gyri could be a potential target for neuromodulation in patients with medically refractory chronic CH.

Peripheral neuromodulation: a review

Peripheral nerve stimulation (PNS) is likely the most diverse and rapidly expanding area of neuromodulation. Its expansion has become possible due to both technological and clinical advances in pain medicine. The first implantable systems were surgically placed. However, it is currently commonplace to use percutaneous leads, as this approach has become instrumental in its expansion. The first percutaneous peripheral nerve stimulators were reported in 1999. Cylindrical leads were implanted to stimulate the greater occipital nerve to manage intractable headache. It has been expanded into other individual nerves or nerve plexuses to treat neuropathic, visceral, cardiac, abdominal, low back and facial pain. The use of PNS in modulating organ function in treatment of syndromes such as epilepsy, incontinence and obesity with vagal, tibial and gastric stimulation is under extensive investigation. New technologies that allow easier and safer electrode placement are expected to further expand the uses of PNS. A noninvasive stimulation will open this treatment modality to more clinicians of varying backgrounds.

Supraspinal stimulation for treatment of refractory pain

Refractory pain syndromes often have far reaching effects and are quite a challenge for primary care providers and specialists alike to treat. With the help of site-specific neuromodulation and appropriate patient selection these difficult to treat pain syndromes may be managed. In this article, we focus on supraspinal stimulation (SSS) for treatment of intractable pain and discuss off-label uses of deep brain stimulation (DBS) and motor cortex stimulation (MCS) in context to emerging indications in neuromodulation. Consideration for neuromodulatory treatment begins with rigorous patient selection based on exhaustive conservative management, elimination of secondary gains, and a proper psychology evaluation. Trial stimulation prior to DBS is nearly always performed while trial stimulation prior to MCS surgery is symptom dependent. Overall, a review of the literature demonstrates that DBS should be considered for refractory conditions including nociceptive/neuropathic pain, phantom limb pain, and chronic cluster headache (CCH). MCS should be considered primarily for trigeminal neuropathic pain (TNP) and central pain. DBS outcome studies for post-stroke pain as well as MCS studies for complex regional pain syndrome (CRPS) show more modest results and are also discussed in detail.

Role of trigeminal microvascular decompression in the treatment of SUNCT and SUNA

Short-lasting unilateral neuralgiform headache with conjunctival injection and tearing (SUNCT) and short-lasting unilateral neuralgiform headache attacks with cranial autonomic symptoms (SUNA) are primary headache disorders. Evidence suggests that SUNCT/SUNA have similar pathophysiology to the trigeminal autonomic cephalalgias and involves the trigeminal autonomic reflex. This review provides an overview of microvascular decompression of the trigeminal nerve and other surgical therapeutic options for SUNCT/SUNA. We have undertaken a mini-meta-analysis of available case reports and case series with the aim of providing recommendations for the use of such therapies in SUNCT/SUNA. There is some evidence supporting microvascular decompression of the trigeminal nerve in selected patients who have medically refractory SUNCT/SUNA and a demonstrable ipsilateral aberrant vessel on magnetic resonance imaging (MRI). We also consider what further investigations could be undertaken to assess the role of surgical interventions in the treatment of these often debilitating conditions.

Occipital nerve stimulation for intractable chronic cluster headache or migraine: A critical analysis of direct treatment costs and complications

Background

Occipital nerve stimulation (ONS) has been shown to be effective for selected patients with intractable headache disorders. We performed a prospective critical evaluation of complications and direct treatment costs.

Methods

Twenty-seven patients with chronic cluster headache (CCH, n = 24) or chronic migraine (CM, n = 3) underwent a trial phase with bilateral ONS and subsequent implantation of a permanent generator (IPG), if responsive to treatment according to predefined criteria. Procedural and long-term complications as well as direct treatment costs of neuromodulation therapy of ONS were recorded over a mean follow-up period of 20 months (range 5–47 months).

Results

Twenty-five of 27 patients (93%) responded to treatment. Twenty-one complications in 14 patients were identified, necessitating reoperation in 13 cases. Overall treatment costs were €761,043, including hardware-related costs of €506,019, costs for primary hospital care of €210,496, and complications related to hospitalization costs of €44,528. This results in a per case-based cost of €9445 for hospitalization and €18,741 for hardware costs, totaling €28,186.

Conclusion

ONS for treatment of refractory CCH and CM is a cost-intensive treatment option with a significant complication rate. Nevertheless, patients with refractory primary headache disorders may experience substantial relief of pain attacks, and headache days, respectively.

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.

Drug-resistant chronic migraine: the Italian GON project

Chronic daily headache is a major problem due to severe disability and high socio-economic costs. In the last years, some trials have shown potential benefit from new therapeutic approach by occipital neurostimulation techniques, already applied with some success for the treatment of chronic cluster headache. Due to the extremely heterogeneous population suffering from refractory chronic daily headaches, we propose a national multicenter experimental study involving Italian ANIRCEF Headache Centres with the aim to evaluate the efficacy of occipital neurostimulation in a selected group representative for the drug-resistant chronic migraine. Patients with chronic migraine according to Manzoni's modified IHS criteria-2011, with or without medication overuse headache, will be selected. Duration of illness should be at least 2 years and pharmacological refractoriness defined strictly for experimental-surgical purposes as those patients who have properly tried without success almost all available classes of prophylactic medications. Those presenting with medication overuse should have tried at least two previous detoxification treatments. A full psychopathological assessment will be performed by a psychiatrist, to exclude mainly psychotic disorder, ongoing severe status of an affective disorder, severe post traumatic stress disorder. Headache characteristics and abortive treatments used will be reported daily on a predisposed diary during 3-month baseline and continuously through the post implant follow up, while disability and QoL scale (MIDAS, SF-12) will be completed baseline, 6 and 12 months after implant.

The impact of sexual activity on idiopathic headaches: an observational study

BACKGROUND

Headache associated with sexual activity is a well-known primary headache disorder. In contrast, some case reports in the literature suggest that sexual activity during a migraine or cluster headache attack might relieve the pain in at least some patients. We performed an observational study among patients of a tertiary headache clinic.

METHODS

A questionnaire was sent to 800 unselected migraine patients and 200 unselected cluster headache patients. We asked for experience with sexual activity during a headache attack and its impact on headache intensity. The survey was strictly and completely anonymous.

RESULTS

In total, 38% of the migraine patients and 48% of the patients with cluster headache responded. In migraine, 34% of the patients had experience with sexual activity during an attack; out of these patients, 60% reported an improvement of their migraine attack (70% of them reported moderate to complete relief) and 33% reported worsening. In cluster headache, 31% of the patients had experience with sexual activity during an attack; out of these patients, 37% reported an improvement of their cluster headache attack (91% of them reported moderate to complete relief) and 50% reported worsening. Some patients, in particular male migraine patients, even used sexual activity as a therapeutic tool.

CONCLUSIONS

The majority of patients with migraine or cluster headache do not have sexual activity during headache attacks. Our data suggest, however, that sexual activity can lead to partial or complete relief of headache in some migraine and a few cluster headache patients.

Drug-resistant cluster headache: long-term evaluation of pain control by posterior hypothalamic deep-brain stimulation

OBJECTIVE

On the basis of recent findings about the pathophysiology of cluster headache and through the experience reported in recent literature, we have reviewed the outcome of four patients affected by drug-resistant cluster headache treated in our department by posterior hypothalamic deep brain stimulation with a follow-up of more than 5 years.

METHODS

Between 2004 and 2006, we selected four patients affected by cluster headache. The diagnosis was based on the International Classification of Headache Disorders II criteria, and all patients were refractory to drug therapy. Under local anesthesia they underwent stereotactic positioning of a stimulation electrode within the posterior hypothalamus, ipsilateral to the site of pain. An intraoperative neurophysiological test stimulation was performed to assess possible side effects and symptoms related to hypothalamic neuronal activity. A second surgery was then performed with the patient under general anesthesia to implant the extension cable and the implantable pulse generator.

RESULTS

After 5 years of follow up, all patients had a valuable benefit with a reduction in episode frequency from 90% to 50% associated with a decrease in pain intensity perception.

CONCLUSION

The long-lasting pain reduction and the improvement in the patients' symptoms should be considered a real positive prospective, not only because there was uncertainty about the persistence of the beneficial effects at a long-term follow-up, but also for the improvement of the quality of life. The stimulation can restore important aspects concerning the psychic condition that very often constitutes an important limiting factor in normal daily life for this type of patient.

SUNCT syndrome successfully treated by gamma knife radiosurgery: case report

BACKGROUND

The SUNCT syndrome (short-unilateral neuralgiform headache with conjunctival injection and tearing) can be very disabling for affected patients and is often refractory to medical management. We report the first case of SUNCT with a successful response to stereotactic radiosurgery without any adverse effect.

CASE

After failing optimal medical treatment, a 82-year old male patient suffering from SUNCT syndrome was treated with Gamma knife radiosurgery. The trigeminal nerve and sphenopalatine ganglion were targeted with a maximum dose of 80 Gy each. The patient had complete pain cessation 2 weeks after the treatment, and remains pain-free with no medication at the latest follow-up 39 months after radiosurgery. He did not have any side effect from the procedure.

CONCLUSION

Gamma knife radiosurgery is an option for medically refractory SUNCT patients.

Addressing neurological disorders with neuromodulation

Neurological disorders are becoming increasingly common in developed countries as a result of the aging population. In spite of medications, these disorders can result in progressive loss of function as well as chronic physical, cognitive, and emotional disability that ultimately places enormous emotional and economic on the patient, caretakers, and the society in general. Neuromodulation is emerging as a therapeutic option in these patients. Neuromodulation is a field, which involves implantable devices that allow for the reversible adjustable application of electrical, chemical, or biological agents to the central or peripheral nervous system with the objective of altering its functioning with the objective of achieving a therapeutic or clinically beneficial effect. It is a rapidly evolving field that brings together many different specialties in the fields of medicine, materials science, computer science and technology, biomedical, and neural engineering as well as the surgical or interventional specialties. It has multiple current and emerging indications, and an enormous potential for growth. The main challenges before it are in the need for effective collaboration between engineers, basic scientists, and clinicians to develop innovations that address specific problems resulting in new devices and clinical applications.