Short-Lasting Unilateral Neuralgiform Headache Attacks with Conjunctival Injection and Tearing

Complementary and Integrative Medicine for the Treatment of Trigeminal Neuralgia and Trigeminal Autonomic Cephalalgia

PURPOSE OF REVIEW

Trigeminal neuralgia (TN) and trigeminal autonomic cephalalgias (TACs) are both painful diseases which directly impact the branches of the trigeminal nerve, which supply the face. Patients who have experienced adverse effects, have not responded to mainstream treatments, or have a personal preference for nonmedication options, often turn to complementary and integrative medicine (CIM). The aim of this review is to discuss the efficacy and safety of CIM therapies available for the treatment of TN and TACs.

RECENT FINDINGS

Not only are there limited therapeutic options for TN and TAC patients, but also is there a proportion of patients who are intolerant to standard medical treatments. Recent findings have illustrated that 86% of patients with headache disorders utilize CIM modalities in combination with mainstream medical therapy. CIM modalities can be helpful for these diseases and have primarily been studied in combination with standard medical therapy. There is limited evidence for CIM and behavioral therapies in managing these conditions, and more research is needed to confirm which therapies are safe and effective.

SUNCT, SUNA and short-lasting unilateral neuralgiform headache attacks: Debates and an update

BACKGROUND

Short-lasting unilateral neuralgiform headache attacks (SUNHA) have the features of both short-lasting unilateral neuralgiform pain, such as trigeminal neuralgia or stabbing headache, and associated trigeminal autonomic symptoms, such as paroxysmal hemicrania or cluster headache. Recognizing and adequately treating SUNHA is essential but current treatment methods are ineffective in treating SUNHA.

METHODS

We reviewed the changes in the concept of short-lasting unilateral neuralgiform headache attacks and provide a narrative review of the current medical and surgical treatment options, from the first choice of treatment for patients to treatments for selective intractable cases.

RESULTS

Unlike the initial impression of an intractable primary headache disorder affecting older men, SUNHA affects both sexes throughout their lifespan. One striking feature of SUNHA is that the attacks are triggered by cutaneous or intraoral stimulation. The efficacy of conventional treatments is disappointing and challenging, and preventive therapy is the mainstay of treatment because of highly frequent attacks of a very brief duration. Amongst them, lamotrigine is effective in approximately two-third of the patients with SUNHA, and intravenous lidocaine is essential for the management of acute exacerbation of intractable pain. Topiramate, oxcarbazepine and gabapentin are considered good secondary options for SUNHA, and botulinum toxin can be used in selective cases. Neurovascular compression is commonly observed in SUNHA, and surgical approaches, such as neurovascular compression, have been reported to be effective for intractable cases.

CONCLUSIONS

Recent advances in the understanding of SUNHA have improved the recognition and treatment approaches for this unique condition.

Pathophysiology of cluster headache: From the trigeminovascular system to the cerebral networks

BACKGROUND

Despite advances in neuroimaging and electrophysiology, cluster headache's pathogenesis remains unclear. This review will examine clinical neurophysiology studies, including electrophysiological and functional neuroimaging, to determine if they might help us construct a neurophysiological model of cluster headache.

RESULTS

Clinical, biochemical, and electrophysiological research have implicated the trigeminal-parasympathetic system in cluster headache pain generation, although the order in which these two systems are activated, which may be somewhat independent, is unknown. Electrophysiology and neuroimaging have found one or more central factors that may cause seasonal and circadian attacks. The well-known posterior hypothalamus, with its primary circadian pacemaker suprachiasmatic nucleus, the brainstem monoaminergic systems, the midbrain, with an emphasis on the dopaminergic system, especially when cluster headache is chronic, and the descending pain control systems appear to be involved. Functional connection investigations have verified electrophysiological evidence of functional changes in distant brain regions connecting to wide cerebral networks other than pain.

CONCLUSION

We propose that under the impact of external time, an inherited misalignment between the primary circadian pacemaker suprachiasmatic nucleus and other secondary extra- suprachiasmatic nucleus clocks may promote disturbance of the body's internal physiological clock, lowering the threshold for bout recurrence.

Management of Trigeminal Autonomic Cephalalgias Including Chronic Cluster: A Review

Importance

Trigeminal autonomic cephalalgias (TACs) comprise a unique collection of primary headache disorders characterized by moderate or severe unilateral pain, localized in in the area of distribution of the first branch of the trigeminal nerve, accompanied by cranial autonomic symptoms and signs. Most TACs are rare diseases, which hampers the possibility of performing randomized clinical trials and large studies. Therefore, knowledge of treatment efficacy must be based only on observational studies, rare disease registries, and case reports, where real-world data and evidence play an important role in health care decisions.

Observations

Chronic cluster headache is the most common of these disorders, and the literature offers some evidence from randomized clinical trials to support the use of pharmacologic and neurostimulation treatments. Galcanezumab, a monoclonal antibody targeting the calcitonin gene-related peptide, was not effective at 3 months in a randomized clinical trial but showed efficacy at 12 months in a large case series. For the other TACs (ie, paroxysmal hemicrania, hemicrania continua, short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing, and short-lasting unilateral neuralgiform headache attacks with cranial autonomic symptoms), only case reports and case series are available to guide physicians in everyday management.

Conclusions and Relevance

The accumulation of epidemiologic, pathophysiologic, natural history knowledge, and data from case series and small controlled trials, especially over the past 20 years from investigators around the world, has added to the previously limited evidence and has helped advance and inform the treatment approach to rare TACs, which can be extremely challenging for clinicians.

Trigeminal Neuralgia

Trigeminal neuralgia (TN) is a rare neuropathic pain disorder characterized by recurrent, paroxysmal episodes of short-lasting severe electric shock-like pain along the sensory distribution of the trigeminal nerve. Recent classification systems group TN into 3 main categories depending on the underlying pathophysiology. This article will present a case history and review the epidemiology, diagnostic criteria, classification, clinical features, diagnostic investigations, pathophysiology, and management of TN.

Recent Advances and Updates in Trigeminal Autonomic Cephalalgias

Trigeminal autonomic cephalalgias (TACs) are discrete primary headache disorders, characterized by severe unilateral head pain, typically trigeminal distribution, with ipsilateral cranial autonomic symptoms. The conditions within this group are hemicrania continua, cluster headache, paroxysmal hemicrania, and short-lasting unilateral neuralgiform headache with conjunctival injection and tearing and short-lasting unilateral neuralgiform headache with autonomic symptoms. Several advances have been made in understanding the pathogenesis and evolving treatment options in TACs. This review will outline the advances and updates in each TAC.

Oxygen Therapy in Cluster Headache, Migraine, and Other Headache Disorders

Oxygen therapy (OT) can relieve head pain in certain primary headache disorders, including cluster headache (CH). The exact underlying mechanism is currently uncertain, but suggested mechanisms include inhibition of the trigeminoautonomic reflex, modulation of neurotransmitters, and cerebral vasoconstriction. OT is the standard for acute treatment of CH, but patients with CH often experience considerable difficulties accessing home OT due to problems with insurance coverage. Inhalation of 100% oxygen at 6–12 L/min for 15–30 min using a non-rebreather face mask is one of the most effective acute therapies for CH, but several trials have indicated the superiority of higher oxygen flow rates of up to 15 L/min and/or using a demand-valve oxygen mask that can produce very high flow rates. Two randomized controlled trials have demonstrated the efficacy of OT in migraine, but obtaining reliable evidence is considered difficult because of different inhalation protocols, varying outcome measures, and small samples. There are some reports on the efficacy of OT as an adjuvant therapy in hypnic headache, primary headache in the emergency department, and even postdural puncture headache. The goal of this review article is to expand the knowledge regarding the use of oxygen in the treatment of headache disorders.

Refractory Short-Lasting Unilateral Neuralgiform Headache Attacks With Conjunctival Injection and Tearing (SUNCT) Responding to Erenumab Adjuvant Therapy: A Case Report

Many patients with short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT) fail to respond to the first-line treatment of lamotrigine. Additionally, data for other treatments are limited in this rare headache disorder. SUNCT involves activation of the trigeminal nerve which uses the neuropeptide calcitonin gene-related peptide (CGRP); thus CGRP-targeted treatments may be beneficial in this disorder. We present a patient with SUNCT who failed to respond optimally to 10 medications and four surgical treatments. However, she had minimal attacks after erenumab 140 mg was added to carbamazepine 200 mg three times daily and pregabalin 75 mg twice daily. Decreasing any of these three medications worsened her attacks. Our case represents the second case report of a SUNCT patient responding to a CGRP monoclonal antibody, suggesting this treatment may be a consideration in refractory SUNCT.

Trigeminal microvascular decompression for short-lasting unilateral neuralgiform headache attacks

A significant proportion of patients with short-lasting unilateral neuralgiform headache attacks (SUNHA) are refractory to medical treatments. Neuroimaging studies have suggested a role for ipsilateral trigeminal neurovascular conflict with morphological changes in the pathophysiology of this disorder. We present the outcome of an uncontrolled open-label prospective single centre study conducted between 2012 and 2020, to evaluate the efficacy and safety of trigeminal microvascular decompression in refractory chronic SUNHA with magnetic resonance imaging evidence of trigeminal neurovascular conflict ipsilateral to the pain side. Primary endpoint was the proportion of patients who achieved an "excellent response", defined as 90-100% weekly reduction in attack frequency, or "good response", defined as a reduction in weekly headache attack frequency between 75% and 89% at final follow-up, compared to baseline. These patients were defined as responders. The study group consisted of 47 patients of whom 31 had SUNCT and 16 had SUNA (25 females, mean age ± SD 55.2 years ± 14.8). Participants failed to respond or tolerate a mean of 8.1 (±2.7) preventive treatments pre-surgery. Magnetic resonance imaging of the trigeminal nerves (n = 47 patients, n = 50 symptomatic trigeminal nerves) demonstrated ipsilateral neurovascular conflict with morphological changes in 39/50 (78.0%) symptomatic nerves and without morphological changes in 11/50 (22.0%) symptomatic nerves. Post-operatively, 37/47 (78.7%) patients obtained either an excellent or a good response. Ten patients (21.3%, SUNCT = 7 and SUNA = 3) reported no post-operative improvement. The mean post-surgery follow-up was 57.4 ± 24.3 months (range 11-96 months). At final follow-up, 31 patients (66.0%) were excellent/good responders. Six patients experienced a recurrence of headache symptoms. There was no statistically significant difference between SUNCT and SUNA in the response to surgery (p = 0.463). Responders at the last follow-up were however more likely not to have interictal pain (77.42% vs 22.58%, p = 0.021) and to show morphological changes on the magnetic resonance imaging (78.38% vs 21.62%, p = 0.001). The latter outcome was confirmed in the Kaplan Meyer analysis, where patients with no morphological changes were more likely to relapse overtime compared to those with morphological changes (p = 0.0001). All but one patient who obtained an excellent response without relapse, discontinued their preventive medications. Twenty-two post-surgery adverse events occurred in 18 patients (46.8%) but no mortality or severe neurological deficit was seen. Trigeminal microvascular decompression may be a safe and effective long-term treatment for short-lasting unilateral neuralgiform headache attacks patients with magnetic resonance evidence of neurovascular conflict with morphological changes.

Areas of cerebral blood flow changes on arterial spin labelling with the use of symmetric template during nitroglycerin triggered cluster headache attacks

•

Cluster headache is a severe unilateral primary headache disorder; however, the brain is asymmetric, therefore using a symmetric template before flipping in the x-axis allows for ipsilateral analysis of attacks without loss of coherence across the group.

•

Increases in cerebral blood flow beyond pain anticipation, processing and modulation areas, including hypothalamic regions and ipsilateral pons, have a crucial pathophysiological role in cluster headache attacks.

•

The pain experienced during cluster headache attacks is so severe that it “switches off” areas involved in the default brain network.

Background

Cluster headache is a rare, strictly unilateral, severe episodic primary headache disorder. Due to the unpredictable and episodic nature of the attacks, nitroglycerin has been used to trigger attacks for research purposes to further our understanding of cluster headache pathophysiology.

Objectives

We aimed to identify regions of significant cerebral blood flow (CBF) changes during nitroglycerin triggered cluster headache attacks, using MRI with arterial spin labelling (ASL).

Methods

Thirty-three subjects aged 18–60 years with episodic and chronic cluster headache were recruited and attended an open clinical screening visit without scanning to receive an intravenous nitroglycerin infusion (0.5 μg/kg/min over 20 min). Those for whom nitroglycerin successfully triggered a cluster headache attack, were invited to attend two subsequent scanning visits. They received either single-blinded intravenous nitroglycerin (0.5 μg/kg/min) or an equivalent volume of single-blinded intravenous 0.9% sodium chloride over a 20-minute infusion. Whole-brain CBF maps were acquired using a 3 Tesla MRI scanner pre-infusion and post-infusion. As cluster headache is a rare condition and purely unilateral disorder, an analysis strategy to ensure all the image data corresponded to symptomatology in the same hemisphere, without losing coherence across the group, was adopted. This consisted of spatially normalising all CBF maps to a standard symmetric reference template before flipping the images about the anterior-posterior axis for those CBF maps of subjects who experienced their headache in the right hemisphere. This procedure has been employed in previous studies and generated a group data set with expected features on the left hemisphere only.

Results

Twenty-two subjects successfully responded to the nitroglycerin infusion and experienced triggered cluster headache attacks. A total of 20 subjects completed the placebo scanning visit, 20 completed the nitroglycerin scanning visit, and 18 subjects had completed both the nitroglycerin and placebo scanning visits. In a whole-brain analysis, we identified regions of significantly elevated CBF in the medial frontal gyrus, superior frontal gyrus, inferior frontal gyrus and cingulate gyrus, ipsilateral to attack side, in CBF maps acquired during cluster headache attack; compared with data from the placebo session. We also identified significantly reduced CBF in the precuneus, cuneus, superior parietal lobe and occipital lobe contralateral to the attack side. Of particular interest to this field of investigation, both the hypothalamus and ipsilateral ventral pons showed higher CBF in a separate region of interest analysis.

Conclusion

Our data demonstrate that severe cluster headache leads to significant increases in regional cerebral perfusion, likely to reflect changes in neuronal activity in several regions of the brain, including the hypothalamus and the ventral pons. These data contribute to our understanding of cluster headache pathophysiology; and suggest that non-invasive ASL technology may be valuable in future mechanistic studies of this debilitating condition.

Drug Treatment of Cluster Headache

Cluster headache belongs to the group of trigeminal autonomic headaches. This review summarizes drug therapy of cluster attacks and prophylactic treatment. Neurostimulation methods are not addressed. The therapy for acute cluster attacks includes inhalation of 100% oxygen, subcutaneous administration of sumatriptan, and intranasal application of sumatriptan or zolmitriptan. Bridging therapy, which is used until oral prophylactic therapy is effective, is performed either with oral prednisolone or with a pharmacological block of the major occipital nerves. Best documented drugs for preventive treatment of cluster headache are verapamil and lithium, and possibly effective drugs are gabapentin, topiramate, divalproex sodium, and melatonin. The efficacy of monoclonal antibodies to the calcitonin gene-related peptide so far has been only demonstrated for episodic cluster headache. Several drug therapies are being investigated including ketamine, onabotulinumtoxinA, lysergic acid, and sodium oxybate.

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.

SUNCT and SUNA: An Update

Background

Short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT) and short-lasting unilateral neuralgiform headache with autonomic symptoms (SUNA) are rare and disabling primary headache disorders that are subtypes of Short-lasting unilateral neuralgiform headache attacks (SUNHA).

Aim

The aim of this narrative review was to provide a comprehensive update on headache phenotype, pathophysiology, and various treatment options available for SUNCT and SUNA.

Methods

References for this review were identified by searches of articles published in the English language in PubMed between 1978 and October 2020 using "short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT)", "short-lasting unilateral neuralgiform headache with autonomic symptoms (SUNA)", "short-lasting unilateral neuralgiform headache attacks (SUNHA)", "trigeminal autonomic cephalalgias" as keywords in various combinations.

Results

Of a potential 1103 articles, seven case series describing clinical characteristics of SUNCT/SUNA patients were identified for this review. For symptomatic/secondary SUNCT/SUNA, 53 individual case reports, and one case series were reviewed. One placebo-controlled trial and 11 open-label case series that evaluated various medical and surgical treatments in SUNCT/SUNA were also reviewed. Available literature suggests that SUNCT and SUNA are subtypes of the same disorder characterized by severe side locked short duration headache with ipsilateral prominent cranial autonomic symptoms and signs. Pathophysiology may involve both peripheral and central mechanisms. Lamotrigine is the most effective preventive therapy while intravenous lidocaine is the most efficacious drug as transitional therapy for severe disabling attacks. Surgical options including microvascular decompression in those having neurovascular conflict, occipital nerve stimulation, and hypothalamic deep brain stimulation can be alternative treatment options for medically refractory patients.

Medical treatment of SUNCT and SUNA: a prospective open-label study including single-arm meta-analysis

INTRODUCTION

The management of short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT) and short-lasting unilateral neuralgiform headache attacks with cranial autonomic symptoms (SUNA) remains challenging in view of the paucity of data and evidence-based treatment recommendations are missing.

METHODS

In this single-centre, non-randomised, prospective open-label study, we evaluated and compared the efficacy of oral and parenteral treatments for SUNCT and SUNA in a real-world setting. Additionally, single-arm meta-analyses of the available reports of SUNCT and SUNA treatments were conducted.

RESULTS

The study cohort comprised 161 patients. Most patients responded to lamotrigine (56%), followed by oxcarbazepine (46%), duloxetine (30%), carbamazepine (26%), topiramate (25%), pregabalin and gabapentin (10%). Mexiletine and lacosamide were effective in a meaningful proportion of patients but poorly tolerated. Intravenous lidocaine given for 7-10 days led to improvement in 90% of patients, whereas only 27% of patients responded to a greater occipital nerve block. No statistically significant differences in responders were observed between SUNCT and SUNA. In the meta-analysis of the pooled data, topiramate was found to be significantly more effective in SUNCT than SUNA patients. However, a higher proportion of SUNA than SUNCT was considered refractory to medications at the time of the topiramate trial, possibly explaining this isolated difference.

CONCLUSIONS

We propose a treatment algorithm for SUNCT and SUNA for clinical practice. The response to sodium channel blockers indicates a therapeutic overlap with trigeminal neuralgia, suggesting that sodium channels dysfunction may be a key pathophysiological hallmark in these disorders. Furthermore, the therapeutic similarities between SUNCT and SUNA further support the hypothesis that these conditions are variants of the same disorder.

Trigeminal neurovascular contact in SUNCT and SUNA: a cross-sectional magnetic resonance study

Emerging data-points towards a possible aetiological and therapeutic relevance of trigeminal neurovascular contact in short lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT) and perhaps in short lasting unilateral neuralgiform headache attacks with cranial autonomic symptoms (SUNA). We aimed to assess the prevalence and significance of trigeminal neurovascular contact in a large cohort of consecutive SUNCT and SUNA patients and evaluate the radiological differences between them. The standard imaging protocol included high spatial and nerve-cistern contrast resolution imaging acquisitions of the cisternal segments of the trigeminal nerves and vessels. MRI studies were evaluated blindly by two expert evaluators and graded according to the presence, location and degree of neurovascular contact. The degree of contact was graded as with or without morphological changes. Neurovascular contact with morphological changes was defined as contact with distortion and/or atrophy. A total of 159 patients (SUNCT = 80; SUNA = 79) were included. A total of 165 symptomatic and 153 asymptomatic trigeminal nerves were analysed. The proportion of neurovascular contact on the symptomatic trigeminal nerves was higher (80.0%) compared to the asymptomatic trigeminal nerves (56.9%). The odds on having neurovascular contact over the symptomatic nerves was significantly higher than on the asymptomatic nerves [odds ratio (OR): 3.03, 95% confidence interval (CI) 1.84–4.99; P < 0.0001]. Neurovascular contact with morphological changes were considerably more prevalent on the symptomatic side (61.4%), compared to the asymptomatic side (31.0%) (OR 4.16, 95% CI 2.46–7.05; P < 0.0001). On symptomatic nerves, neurovascular contact with morphological changes was caused by an artery in 95.0% (n = 77/81). Moreover, the site of contact and the point of contact around the trigeminal root were respectively proximal in 82.7% (67/81) and superior in 59.3% (48/81). No significant radiological differences emerged between SUNCT and SUNA. The multivariate analysis of radiological predictors associated with the symptomatic side, indicated that the presence of neurovascular contact with morphological changes was strongly associated with the side of the pain (OR: 2.80, 95% CI 1.44–5.44; P = 0.002) even when adjusted for diagnoses. Our findings suggest that neurovascular contact with morphological changes is involved in the aetiology of SUNCT and SUNA. Along with a similar clinical phenotype, SUNCT and SUNA also display a similar structural neuroimaging profile, providing further support for the concept that the separation between them should be abandoned. Furthermore, these findings suggest that vascular compression of the trigeminal sensory root, may be a common aetiological factor between SUNCT, SUNA and trigeminal neuralgia thereby further expanding the overlap between these disorders.

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.

Pulsed radiofrequency on the occipital nerve for treatment of short-lasting unilateral neuralgiform headache: A case report

Short-lasting unilateral neuralgiform headache (Short-lasting Unilateral Neuralgiform headache attacks with Conjunctival injection and Tearing (SUNCT)/Short-lasting Unilateral Neuralgiform headache attacks with Autonomic Symptoms) is a trigeminal autonomic cephalalgia with difficult treatment and its management is based on neuromodulator drugs and sometimes ablative procedures on the trigeminal nerve. A positive response to occipital anesthetic blocks and peripheral and deep neurostimulation has also been described. We present the case of a patient with criteria of left SUNCT and transient response to occipital anesthetic blocks, satisfactorily controlled with pulsed radiofrequency (PRF) of the occipital nerve. Upon examination, the patient had tenderness in the left greater occipital nerve (GON). Blockade was performed with anesthetic and corticosteroid, obtaining a highly positive but transient response. After several nerve blocks, the patient was referred to the Pain Unit where pulsed radiofrequency on the left GON was performed. After two sessions, more than 90% of reduction of pain was achieved, maintained for 12 months. There haven’t been found data in the literature on the use of GON PRF for the treatment of SUNCT, while there are descriptions for other types of cranial pain. The intention of our case is to make this procedure to be considered as an alternative for the treatment of this entity in patients who respond to anesthetic blocks.

Sphenopalatine Ganglion Pulsed Radiofrequency for the Treatment of Refractory Chronic SUNCT and SUNA: A Prospective Case Series

OBJECTIVES

We aimed to evaluate the safety and effectiveness of sphenopalatine ganglion pulsed radiofrequency (SPG-PRF) for the treatment of patients with refractory chronic short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT) and with cranial autonomic symptoms (SUNA).

BACKGROUND

SPG-PRF is a minimally invasive, non-neurodestructive procedure already tested in refractory chronic cluster headache with mixed outcomes. However, no data have been produced in SUNCT/SUNA.

METHODS

This was a prospective clinical audit of outcomes. Consecutive patients with chronic SUNCT/SUNA refractory to medical treatments and treated with SPG-PRF, were included in the analysis. The SPG-PRF was performed percutaneously via a lateral, infra-zygomatic approach. Responders were defined as patients with a reduction in number and/or severity of headache episodes by ≥30% for ≥3 months. Responders to the first procedure were offered to have the treatment repeated.

RESULTS

Nine patients (6 female) were analyzed. After a median follow-up of 30 months (range 2-30), 7 patients were considered responders to the treatment (77.8%) for a median of 6 months (range: 4-10), 1 patient obtained 40% improvement for 2 months, and 1 patient did experience any improvement. No procedure-related immediate or delayed side effects were reported. Three patients (33.3%) experienced a worsening of the head pain for 2-4 weeks immediately after the procedure. Four responders had SPG-PRF repeated; a reproducible response was obtained in two of them.

CONCLUSIONS

In our small series of patients with refractory chronic SUNCT/SUNA, SPG-PRF was a safe and effective treatment modality. The potential reproducible positive effect of subsequent treatments may prevent or delay the use of more invasive and costly interventions for at least a proportion of these patients.

A prospective comparative study and analysis of predictors of SUNA and SUNCT

OBJECTIVE

Despite the similar phenotypes, comparison between short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT) and short-lasting unilateral neuralgiform headache attacks with autonomic features (SUNA) has hitherto not been possible due to the dearth of studies validating the phenotype of SUNA. Therefore, these 2 syndromes have been kept separate in the International Classification of Headache Disorders. The aim of this study is to characterize and compare the clinical phenotypes of large clinic-based cohorts of patients with SUNA and SUNCT.

METHODS

The clinical phenotype of consecutive patients with SUNA identified from a single specialist headache center in the United Kingdom between 2007 and 2012 was studied and compared to that of patients with SUNCT.

RESULTS

Sixty-three patients with SUNA (18 male, 28.6%) and 70 patients with SUNCT (32 male, 35.7%) were included. The demographic and clinical characteristics of patients with SUNA were similar to those of patients with SUNCT. Ptosis and rhinorrhea were predictors of SUNCT. The corresponding odds ratios (ORs) (95% confidence interval) were 3.79 (1.64-8.77, p = 0.002) and 2.46 (1.09-5.59, p = 0.031), respectively. The presence of spontaneous only attacks was a predictor for SUNA (OR 2.58 [1.10-6.05], p = 0.029).

CONCLUSION

No major clinical differences have emerged between SUNCT and SUNA, bar the fact that SUNCT is characterized by more prominent cranial autonomic features and triggerability. We propose that the 2 disorders be placed together in a single diagnostic category for which new diagnostic criteria are proposed.

Differential diagnosis short-lasting unilateral neuralgiform headache attacks and trigeminal neuralgia

The article presents diagnostic criteria, comparative characteristics of short-lasting unilateral neuralgiform headache attacks, including short-term unilateral neuralgic headaches with conjunctival injection and lacrimation (SUNCT) and short-term unilateral neuralgic headaches with cranial autonomic symptoms (SUNA), differential diagnosis with trigeminal neuralgia.

Dramatic response of intravenous lidocaine in a patient with status like SUNA

Short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT) and short-lasting unilateral neuralgiform headache attacks with cranial autonomic symptoms (SUNA) are rare primary headaches that can sometimes present with a status like pattern which can be highly disabling. Intravenous (IV) lidocaine has been reported to be useful in status like SUNCT but its use in status like SUNA remains unexplored. We report a patient of episodic SUNA who despite on multiple conventional drugs had status like presentation. He had an excellent sustained response to IV lidocaine. Relevant literature on treatment of status like SUNCT/SUNA is briefly reviewed. IV lidocaine can be a very useful treatment for status like SUNA.

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.

Short-Lasting Unilateral Neuralgiform Headache Attacks

Short-lasting unilateral neuralgiform headache attacks (SUNHA) is characterized by strictly unilateral trigeminal distribution pain that occurs in association with ipsilateral cranial autonomic features. There are two subtypes: 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 disorders are rare but highly disabling. The management of SUNHA can be challenging. The abortive therapies are not generally useful as the attacks are relatively short-lasting. A myriad of pharmacological preventive treatments has been tried in single case reports or small series in an open-label fashion. Lamotrigine, as an oral preventive treatment, and lidocaine, as an intravenous transitional treatment, seems to be the most effective therapies. For medically intractable SUNHA, several surgical approaches have been tried. These include ablative procedures involving the trigeminal nerve or the Gasserian ganglion, microvascular decompression (MVD) of the trigeminal nerve, and neurostimulation techniques. MVD, occipital nerve stimulation, and ventral tegmental area deep brain stimulation have all been found to be effective in open-label series with relatively high-response rates. There is a considerable clinical, therapeutic, and radiological overlap between SUNCT, SUNA, and trigeminal neuralgia (TN). Despite being considered distinct conditions, the emerging evidence suggests a broader nosological concept of SUNCT, SUNA, and TN; these conditions may constitute a continuum of the same disorder, rather than separate clinical entities. Consideration needs to be given to classifying SUNHA with TN as a cranial neuralgia rather than as a trigeminal autonomic cephalalgia.

[A case of short-lasting unilateral neuralgiform headache with conjunctival injection and tearing triggered by mumps meningitis in a patient with recurrent primary stabbing headache]

A 32-year-old man with a 16-year history of recurrent primary stabbing headache was admitted to our hospital, owing to mumps meningitis. On day 2 of admission, he began experiencing episodes of unbearable intermittent stabbing pain, each lasting few seconds, with conjunctival injection and tearing, on the temporal side of the left orbit. We suspected trigeminal autonomic cephalgias, and administered non-steroidal anti-inflammatory drugs (NSAIDs), oxygen, and sumatriptan; however, the pain episodes persisted. Subsequently, after the start of intravenous lidocaine administration, the pain episodes stopped. We diagnosed a short-lasting unilateral neuralgiform headache with conjunctival injection and tearing (SUNCT), triggered by mumps meningitis. This is a valuable case report, involving a patient with a history of primary stabbing headache who was diagnosed with SUNCT triggered by mumps meningitis.

Termination of SUNCT with intravenous lignocaine followed by oral mexiletine

Background:

The trigeminal autonomic cephalalgias (TACs) are a group of debilitating, pathophysiologically similar headache syndromes characterized by facial pain and autonomic symptoms in areas supplied by the trigeminal nerve. Short-lasting unilateral neuralgiform headache with conjunctival injection and tearing (SUNCT) is among the rarest of the TAC syndromes and can be particularly recalcitrant to treatment.

Case:

We describe the case of a 50-year old woman with difficult-to-control SUNCT whose pain was completely aborted within hours of commencing intravenous lignocaine therapy and was maintained pain-free after transitioning to oral mexiletine.

Conclusion:

This is the first report of successful transition from intravenous lignocaine to oral mexiletine in SUNCT, and we suggest that this treatment should be tried early in difficult-to-control SUNCT. This therapy is safe, effective and with minimal side effects if administered in an appropriate manner.

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.

Long-term follow up of intractable chronic short lasting unilateral neuralgiform headache disorders treated with occipital nerve stimulation

Background Occipital nerve stimulation is a potential treatment option for medically intractable short-lasting unilateral neuralgiform headache attacks. We present long-term outcomes in 31 patients with short-lasting unilateral neuralgiform headache attacks treated with occipital nerve stimulation in an uncontrolled open-label prospective study. Methods Thirty-one patients with intractable short-lasting unilateral neuralgiform headache attacks were treated with bilateral occipital nerve stimulation from 2007 to 2015. Data on attack characteristics, quality of life, disability and adverse events were collected. Primary endpoint was change in mean daily attack frequency at final follow-up. Results At a mean follow-up of 44.9 months (range 13-89) there was a 69% improvement in attack frequency with a response rate (defined as at least a 50% improvement in daily attack frequency) of 77%. Attack severity reduced by 4.7 points on the verbal rating scale and attack duration by a mean of 64%. Improvements were seen in headache-related disability and depression. Adverse event rates were favorable, with no electrode migration or erosion reported. Conclusion Occipital nerve stimulation appears to offer a safe and efficacious treatment for refractory short-lasting unilateral neuralgiform headache attacks with significant improvements sustained in the long term. The procedure has a low adverse event rate when conducted in highly specialised units.

SUN: Short-Lasting Unilateral Neuralgiform Headache Attacks

PREMISE

Short-lasting unilateral neuralgiform headache attacks (SUN) are part of the group of primary headaches called trigeminal autonomic cephalalgias (TACs). They are characterized by unilateral attacks of pain with associated ipsilateral cranial autonomic symptoms.

PROBLEM

Recently the classification of these attacks has changed, to incorporate the different types of autonomic symptoms such as conjunctival injection and tearing (or lack thereof). Previously considered to be rare and rather refractory to treatment, there is an increasing awareness of this syndrome and the therapeutic possibilities.

DISCUSSION

This article discusses the clinical aspects of the syndrome, pathophysiology, current, and future treatments.

A boy with bilateral SUNA: A case report

Background Short-lasting unilateral neuralgiform headache attacks (SUNA) is a primary headache characterized by frequent attacks of severe headaches in association with ipsilateral cranial autonomic features. SUNA is defined as a strictly unilateral pain and bilateral cases are very unusual, so secondary causes should be searched for vigorously if there are bilateral symptoms. Despite a number of therapeutic trials, effective management for the majority of SUNA patients is not available at present. Management of SUNA is often difficult. Case We report the case of a young boy with bilateral SUNA attacks, with no detected underlying cause, who is responsive to indomethacin. Conclusion Rarely, primary SUNA can present with bilateral symptoms. According to our experience in this case, indomethacin should always be offered to patients with suspected SUNA.

Medullary infarction causing coexistent SUNCT and trigeminal neuralgia

Background

Short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT) or with autonomic symptoms (SUNA) are grouped together within the trigeminal autonomic cephalalgias (TACs). However, the SUNCT and SUNA phenotype and management overlap with those of trigeminal neuralgia (TN). Additionally, a broad variety of cerebral pathologies are reportedly able to trigger either TN- or SUNCT-like pain, and emerging structural neuroimaging findings suggest the possible role of neurovascular conflict with the trigeminal nerve in SUNCT, further supporting aetiological and pathophysiological overlaps among SUNCT, SUNA and TN.

Case report

We present the first case of coexisting chronic SUNCT- and TN-like phenotypes caused by haemorrhagic infarct of the dorsolateral medulla.

Discussion

In light of our case, a perturbation of the dorsolateral medullary circuits may constitute an important pathophysiological component, supporting a unifying nosological hypothesis that considers SUNCT, SUNA and TN clinical variants of the same disorder.

Case Report: Coexistence of SUNCT and Hypnic Headache in the Same Patient

BACKGROUND

Short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT) and hypnic headache (HH) are two exceedingly rare and distinctly classified primary headaches. The hypothalamus seems to be a crucial region involved in the pathophysiology of both conditions, but no cases of SUNCT and HH co-occurrence have been described so far.

CASE RESULTS

A 49-year-old woman who has been suffering from SUNCT for years, with alternation of symptomatic periods and remissions, developed a new headache with different clinical features, presenting exclusively during sleep and with a dramatic responsiveness to caffeine, that met the diagnostic criteria for HH.

CONCLUSIONS

The available literature suggests that SUNCT and HH are different conditions but the association in the same patient that we describe supports the concept that they are not mutually exclusive. Further studies are needed to establish if they share a common pathophysiological mechanism.

Botulinum Toxin A for the Treatment of a Child with SUNCT Syndrome

Background. Short-lasting unilateral neuralgiform headache with conjunctival injection and tearing (SUNCT) syndrome is an unusual cause of headache, mainly described in older adults, and is rare in children. Pain attacks may be severe, frequent, and prolonged. The therapeutic benefits of many drugs are disappointing. Patient and Methods. A 12-year-old boy suffered severe headache and toothache for 20 days. As treatment with nonsteroidal anti-inflammatory drugs, anticonvulsants, and steroids proved ineffective, he was treated with ipsilateral multisite subcutaneous injections of botulinum toxin A 70 U around the orbit, the temporal area, and the upper gum. Results. The pain had reduced in frequency and severity by the fourth day after treatment and had completely disappeared after 7 days. There were no side effects or recurrence during a subsequent 17-month follow-up period. Conclusion. Botulinum toxin A can be used to treat the first episode of SUNCT in children over the age of 12 years.

SUNCT/SUNA: A Review

Short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT) and short-lasting neuralgiform headache attacks with cranial autonomic features (SUNA) are rare headache disorders characterized by severe, short-lasting headaches. These headache disorders are often refractory to treatment and can be secondary phenomena. This article reviews the history, pathophysiology, and treatment of these disorders. Both pharmacotherapy and procedural interventions are discussed in context of historical and more recent reports.

Tic versus TAC: differentiating the neuralgias (trigeminal neuralgia) from the cephalalgias (SUNCT and SUNA)

Trigeminal neuralgia, short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT) and short-lasting unilateral neuralgiform headache attacks with autonomic symptoms (SUNA) are classified as distinct disorders in the International Classification of Headache Disorders 3 beta (ICHD-3 beta). SUNCT and SUNA are primary headache disorders included among the trigeminal autonomic cephalalgias. Trigeminal neuralgia is classified under painful cranial neuropathies and other facial pains. The classification criteria of these conditions overlap significantly which could lead to misdiagnosis. The reported overlap among these conditions has called into question whether they should be considered distinct entities or rather a continuum of the same disorder. This review explores the known overlap and how other features not included in the ICHD-3 beta criteria may better differentiate the "Tics" (trigeminal neuralgia) from the "TACs" (SUNCT and SUNA).

Trigeminal neuralgia (part I): Revisiting the clinical phenotype

Aims

We conducted a cross-sectional study to re-examine the clinical profile of patients with a clinical diagnosis of classical trigeminal neuralgia (CTN).

Methods

Inclusion criteria consisted of the International Headache Society’s published classification of CTN. For the specific purposes of the study, features such as autonomic signs, persistent background pain, attack durations of >2 minutes and reports of pain-related awakening were included. The demographic and clinical phenotype of each patient were carefully recorded for analysis.

Results

The study cohort consisted of 81 patients and based on reported attack duration these were divided into short (≤ 2 minutes, n = 61) and long (> 2 minutes, n = 20) groups for further analysis. The group with short attack duration neatly fit most of the criteria for CTN while the long attack group presents a more challenging diagnosis. There were no significant differences in pain severity, quality and location between the short and long attack groups. The frequency of persistent background pain was significantly higher in the long (70%) compared to the short attack group (29.5%, p = 0.001). There were significantly more reports of pain-related awakenings in the long (55%) than in the short attack groups (29.5%, p = 0.04). There were no significant differences in the frequency of autonomic signs between the short (21.3%) and long attack groups (40%, p = 0.1). In the short attack group, the presence of autonomic signs was significantly associated with longer disease duration, increased pain-related awakenings, and a reduced prognosis.

Conclusion

There are clear diagnostic criteria for CTN but often patients present with features, such as long pain attacks, that challenge such accepted criteria. In our cohort the clinical phenotype of trigeminal, neuralgiform pain with or without autonomic signs and background pain was observed across both short and long attack groups and the clinical implications of this are discussed.

Gabapentin in Headache Disorders: What Is the Evidence?

OBJECTIVE

Gabapentin (GBP), originally an antiepileptic drug, is more commonly used in the treatment of pain, including headache disorders. Off-label GBP is used in headache disorders with some success, some failure, and much debate. Due to this ambiguity, a clinical evidence literature review was performed investigating GBP's efficacy in headache disorders.

METHODS

Bibliographic reference searches for GBP use in headache disorders were performed in PUBMED and OVID Medline search engines from January 1, 1983 to August 31, 2014. Based on abstracts read by two reviewers, references were excluded if: GBP was not a study compound or headache symptoms were not studied. The resulting references were then read, reviewed, and analyzed.

RESULTS

Fifty-six articles pertinent to GBP use in headache disorders were retained. Eight headache clinical trials were quality of evidence Class 2 or higher based on American Academy of Neurology criteria. Seven of the eight clinical trials showed statistically significant clinical benefit from GBP in various headache syndromes (though modest affects at times). One study, Mathew et al., had concerns about intention-treat analysis breaches and primary outcomes.

CONCLUSION

Despite the conflicting evidence surrounding select studies, a significant amount of evidence shows that GBP has benefit for a majority of primary headache syndromes, including chronic daily headaches. GBP has some efficacy in migraine headache, but not sufficient evidence to suggest primary therapy. When primary headache treatments fail, a GBP trial may be considered in the individual patient.

Sunct syndrome. Report of a case and treatment update

Short-lasting unilateral neuralgiform headache attacks with conjuntival injection and tearing (SUNCT) is considered a rare trigeminal autonomic cephalgias, a group of primary headache disorders characterized by brief episodes of severe unilateral headache in the distribution territory of the trigeminal nerve, accompanied by prominent ipsilateral and cranial parasympathetic autonomic features. The present report describes a SUNCT syndrome in a 64-year-old male who had been diagnosed with trigeminal neuralgia several years ago. The patient reported stabbing pain in the orbital zone and in the left upper maxillary region, of great intensity, brief duration, and a frequency of 20-100 attacks a day. Pain episodes were accompanied by conjunctival injection and tearing. Based on the anamnesis, clinical examination and a magnetic resonance imaging scan, episodic SUNCT syndrome was diagnosed and pharmacological treatment with topiramate was started. This reduced the intensity and number of attacks to 3-6 a day.

Key words:Trigeminal autonomic cephalgias, SUNCT, Cluster headache, topiramate.

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.

SUNCT, SUNA and trigeminal neuralgia: different disorders or variants of the same disorder?

PURPOSE OF REVIEW

Short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT), short-lasting unilateral neuralgiform headache attacks with autonomic symptoms (SUNA) and trigeminal neuralgia are considered different disorders, thus grouped in separate sections of the International Classification of Headache Disorders 3 beta. However, the clinical, radiological and therapeutic overlap between SUNCT, SUNA, and trigeminal neuralgia has challenged this traditional view. This review summarizes the available clinical and pathophysiological evidence on whether SUNCT, SUNA and trigeminal neuralgia should be considered separate entities or variants of the same disorder.

RECENT FINDINGS

Data on the clinical phenotype and effective management strategies in SUNCT and SUNA syndromes have shown striking similarities with trigeminal neuralgia. Moreover, studies exploring radiological findings supported the hypothesis of common aetiological and pathophysiological basis between SUNCT/SUNA and trigeminal neuralgia. However, a limitation of most studies is that they have included small samples of patients and therefore any conclusions need to be drawn cautiously.

SUMMARY

Despite being considered distinct conditions, emerging clinical and radiological evidence supports a broader nosological concept of SUNCT, SUNA, and trigeminal neuralgia. These conditions may constitute a continuum of the same disorder, rather than separate clinical entities. Further evidence is required to shed light on this nosological issue, given its potential impact on clinical practice and further research studies in this area.

SUNCT and SUNA: medical and surgical treatments

Short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT) and short-lasting unilateral neuralgiform headache attacks with cranial autonomic symptoms (SUNA) are rare and often disabling primary headache disorders. Their management can be challenging. The abortive therapies are not generally useful as the attacks are relatively short lasting. A myriad of pharmacological preventive treatments have been tried in single case reports or small series in an open-label fashion. Lamotrigine, as an oral preventive treatment, and lidocaine, as an intravenous transitional treatment, seem to be the most effective therapies. For medically intractable chronic forms of SUNCT and SUNA, several surgical approaches have been tried. These include ablative procedures involving the trigeminal nerve or the Gasserian ganglion, microvascular decompression of the trigeminal nerve, and neurostimulation techniques. This review provides an overview of the current pharmacological and surgical options for SUNCT and SUNA syndromes.

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.