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.

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.

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.

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.

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.

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.

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.

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.

Trigeminal autonomic cephalalgias: beyond the conventional treatments

The trigeminal autonomic cephalalgias include cluster headache, paroxysmal hemicrania, short-lasting unilateral neuralgiform headache attacks, and hemicrania continua. While the majority responds to conventional pharmacological treatments, a small but significant proportion of patients are intractable to these treatments. In these cases, alternative choices for these patients include oral and injectable drugs, lesional or resectional surgery, and neurostimulation. The evidence base for conventional treatments is limited, and the evidence for those used beyond convention is more so. At present, the most evidence exists for nerve blocks, deep brain stimulation, occipital nerve stimulation, sphenopalatine ganglion stimulation in chronic cluster headache, and microvascular decompression of the trigeminal nerve in short-lasting unilateral neuralgiform headache attacks.

SUNCT/SUNA and neurovascular compression: new cases and critical literature review

BACKGROUND

Short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT) and short-lasting unilateral neuralgiform headache with cranial autonomic symptoms (SUNA) are primary headache syndromes. A growing body of literature has focused on brain magnetic resonance imaging (MRI) evidence of neurovascular compression in these syndromes.

OBJECTIVE

The objective of this article is to assess whether SUNCT is a subset of SUNA or whether the two are separate syndromes and clarify the role of neurovascular compression.

METHOD

We describe three new SUNCT cases with MRI findings of neurovascular compression and critically review published SUNCT/SUNA cases.

RESULTS

We identified 222 published SUNCT/SUNA cases. Our three patients with neurovascular compression added to the 34 cases previously described (16.9%). SUNCT and SUNA share the same clinical features and therapeutic options. At present, there is no available abortive treatment for attacks. Lamotrigine was effective in 64% of patients; topiramate and gabapentin in about one-third of cases. Of the 34 cases with neurovascular compression, seven responded to drug therapies, 16 patients underwent microvascular decompression of the trigeminal nerve (MVD) with effectiveness in 75%.

CONCLUSIONS

We suggest that SUNCT and SUNA should be considered clinical phenotypes of the same syndrome. Brain MRI should always be performed with a dedicated view to exclude neurovascular compression. The high percentage of remission after MVD supports the pathogenetic role of neurovascular compression.

SUNCT, SUNA and pituitary tumors: Clinical characteristics and treatment

Background

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 types of trigeminal autonomic cephalalgias (TACs).

Objective

To describe a series of patients with SUNCT and SUNA including relationship to pituitary tumors.

Method

All patients diagnosed with SUNCT or SUNA in the Calgary Headache Assessment and Management Program were reviewed.

Results

Six patients (five SUNCTs and one SUNA) were identified. The pain was severe, sharp, showed fixed-laterality, involved mainly the orbito-fronto-temporal region and was associated with autonomic symptoms. Attack duration ranged from 3 to 300 seconds and frequency was 1–200 paroxysms/day. MRI showed ipsilateral pituitary adenomas to the pain in five out of five of the SUNCT patients. Patients with adenomas underwent surgery. Pathology included three prolactinomas, and one mixed adenoma and gangliocytoma. One patient has remained headache free for 4 years after surgery. One was pain free for a year, and then headaches returned with tumor recurrence. Another had major improvement, and two have not improved. Patients were generally refractory to medications.

Conclusion

All five of our patients with typical SUNCT had pituitary tumors, with headache ipsilateral to the pituitary tumors in all cases. Tumor removal provided major improvement in three out of five patients. Medical treatment was only partially effective.

[Japanese SUNCT patient responsive to gabapentin]

We report a Japanese patient with short lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUCNT) responsive to gabapentin. A 29-year-old man presented with sudden-onset intermittent left-sided orbital headache, which was not accompanied by lacrimation and conjunctival injection. We diagnosed trigeminal neuralgia at first and administered carbamazepine and loxoprofen. However, these medications were entirely ineffective at all and 6 days later, autonomic symptoms including conjunctival injection and tearing appeared. Diagnosis of SUNCT was made and gabapentin was started at up to 800 mg per day. Soon after, the headache and autonomic symptoms disappeared. Gabapantin at 800 mg per day was continued for 3 months and then reduced to 400 mg per day. Soon he had only a slight headache without tearing and conjunctival injection. He has continued to take gabapenin at 400 mg per day until now. This case indicated that headache and autonomic symptoms in SUNCT did not always emerge simultaneously, but they sometimes appear with time lag. Furthermore, the long-term clinical course and therapeutic outcome in SUNCT remain unknown. A therapeutic strategy and optimal dosage of medications including gabapentin should be established for the treatment of SUNCT.

The Role of Lamotrigine in the Treatment of Short-Lasting Unilateral Neuralgiform Headache Attacks with Conjunctival Injection and Tearing Syndrome

Objective

To evaluate the efficacy of lamotrigine for treatment of short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT) syndrome.

Data Sources:

Literature was accessed through MEDLINE (1950-June 2010) using the terms lamotrigine, triazines, SUNCT, and trigeminal autonomic cephalgia.

Study Selection And Data Extraction:

All articles in English and studies conducted in humans were identified and evaluated.

Data Synthesis:

SUNCT syndrome can be an extremely challenging headache type to manage and has been considered refractory to pharmacotherapy. Many anticonvulsants have been evaluated as promising SUNCT treatments, with lamotrigine specifically reported as an effective first-line treatment option. There is a lack of randomized placebo-controlled clinical trials evaluating lamotrigine in SUNCT syndrome therapy; however, 2 observational studies, 3 case series, and 5 case reports were reviewed. Lamotrigine appears to decrease the frequency and severity of SUNCT attacks, leading to complete resolution in some patients. A decrease in symptoms was achieved with doses ranging from 25 to 600 mg/day. In some cases, there was initial response to low doses, but dosage titrations were often necessary when symptoms returned several days after being managed at the same dose. Lamotrigine should be initiated at 25 mg/day and gradually titrated, guided by response and adverse effects. The risk of Stevens-Johnson syndrome, a dose-related adverse effect, can be minimized with gradual titration.

Conclusions:

According to case reports and observational studies, lamotrigine therapy has resulted in decreased frequency or resolution of SUNCT syndrome attacks. Randomized, controlled trials are necessary to confirm the efficacy of lamotrigine for this indication.

A case of SUNCT syndrome responsive to zonisamide

Short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT) is a rare headache syndrome that represents a subtype of trigeminal autonomic cephalalgia thought to be highly refractory to treatment. More recently, numerous anticonvulsant agents including lamotrigine, topiramate, gabapentin, and carbamazepine have been reported to be partially or completely effective for treating SUNCT. We report the case of a patient with SUNCT in whom symptoms were completely relieved with carbamazepine at 600 mg/day. However, carbamazepine had to be discontinued due to severe rash. Zonisamide was selected for continued treatment, as a Na-channel blocker like carbamazepine but with lower risk of producing skin rashes as caused by carbamazepine. Attacks ceased completely with 300 mg/day of zonisamide achieving a blood serum level of 19μg/ml. This is the first case report to describe zonisamide alone completely eliminating SUNCT symptoms. Zonisamide should be considered a viable candidate drug for the treatment of SUNCT.

Meningioma causing gabapentin-responsive secondary SUNCT syndrome

Short-lasting unilateral neuralgiform headache with conjunctival injection and tearing (SUNCT) is one of the rarest and most serious headache disorders. Cases of symptomatic SUNCT syndromes are reported, which demonstrate that brain imaging is very important for diagnosis. In this study, we describe the first case of secondary SUNCT syndrome caused by a meningioma. So far, a clearly effective therapy for SUNCT syndrome has not been known. In this case, however, SUNCT was completely responsive to gabapentin. This underlines that this drug is worthy of being considered as a potential therapeutic option in the treatment of SUNCT syndrome.