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

Lacrimal Neuralgia: A Case Report and Comprehensive Review of the Literature

PURPOSE OF REVIEW

Lacrimal neuralgia is a rare periorbital neuralgia. To date, only nine cases have been reported in the literature. Herein, we report a case and a comprehensive overview of the entity with a focus on the differential diagnosis of lacrimal neuralgia. Additionally, we propose putative diagnostic criteria for this rare neuralgia based on cases that have been reported.

RECENT FINDINGS

Among the ten cases of lacrimal neuralgia reported (including the one in this review), seven out of ten were idiopathic, and the other three were considered secondary. Most patients reported stabbing and shooting pain that was either paroxysmal or continuous. The most effective therapy was nerve block for seven patients and pregabalin for three patients. The most important clues to differentiate lacrimal neuralgia from other causes of periorbital pain include pain topography and pain with features suggestive of neuralgia. The core feature of lacrimal neuralgia is neuralgic pain located in the area supplied by the lacrimal nerve, and the etiology could be primary or secondary. Responsiveness to anesthetic blockade might better serve as a confirmational, rather than mandatory, criterion for diagnosis.

Cluster Headache, SUNCT, and SUNA

OBJECTIVE

This article reviews the epidemiology, clinical features, differential diagnosis, pathophysiology, and management of three types of trigeminal autonomic cephalalgias: cluster headache (the most common), short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT), and short-lasting unilateral neuralgiform headache attacks with cranial autonomic symptoms (SUNA).

LATEST DEVELOPMENTS

The first-line treatments for trigeminal autonomic cephalalgias have not changed in recent years: cluster headache is managed with oxygen, triptans, and verapamil, and SUNCT and SUNA are managed with lamotrigine. However, new successful clinical trials of high-dose prednisone, high-dose galcanezumab, and occipital nerve stimulation provide additional options for patients with cluster headache. Furthermore, new genetic and imaging tests in patients with cluster headache hold promise for a better understanding of its pathophysiology.

ESSENTIAL POINTS

The trigeminal autonomic cephalalgias are a group of diseases that appear similar to each other and other headache disorders but have important differences. Proper diagnosis is crucial for proper treatment.

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.

A Retrospective Comparative Study in Patients with SUNA and SUNCT

Introduction

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 headache disorders.

Aim

The aim of the study is to describe and compare the clinical characteristics of patients with SUNA and SUNCT.

Methods

Patients with SUNCT or SUNA observed in a neurology clinic of a tertiary hospital in India between January 2017 and December 2022 were evaluated.

Results

Thirteen patients with SUNA (seven female, 54%) and 16 patients with SUNCT (nine female, 56%) were identified for the evaluation. The mean ages at the onset of SUNA and SUNCT were 36.8.5 ± 8.1 years and 37.2 ± 8.4 years, respectively. The age of onset in our patients was somewhat younger than that of other large series. The demographic and clinical features of SUNA patients were comparable to those of SUNCT patients. Orbital/retro-orbital area was the most common site of pain in both types of headaches. The pattern of pain was noted as single stab (in all patients), repetitive stabs (SUNA vs. SUNCT: 77% vs. 75%), and sawtooth patterns (SUNA vs. SUNCT: 23% vs. 25%). The majority of attacks in both groups lasted less than two minutes. Conjunctival injection and tearing were present in all SUNCT patients (as a part of the diagnostic criteria). The prevalence of conjunctival injection and tearing in SUNA was 46% and 31%, respectively. All patients reported spontaneous attacks. Triggers were reported in seven (54%) patients with SUNA and nine (56%) with SUNCT. Only one patient in each group had a refractory period following a trigger-induced episode. Two patients in the SUNCT group had compression of the trigeminal nerve by a vascular loop.

Conclusion

This is the largest case series from India. There were no significant differences between patients with SUNA and SUNCT.

Approaching headaches and facial pains in eye care practice

Headaches and facial pains are among the most frequent ailments seen in outpatient or emergency settings. Given the fact that some of the primary headaches and facial pains mimic the characteristic patterns seen in ocular diseases and related conditions, it is fairly common for these situations to be sent to an ophthalmology or optometry clinic and misdiagnosed as ocular headaches. This may result in a delay in starting an appropriate therapy, therefore extending the patient's illness. This review article aims to help the practitioners in understanding common causes of headaches and facial pains, approaching such cases in eye OPD and differentiating them for similar ocular conditions to impart an appropriate treatment or referral.

Short-lasting unilateral neuralgiform headache attacks (SUNCT/SUNA): a narrative review of interventional therapies

Short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT) and short-lasting unilateral neuralgiform headache with autonomic symptoms (SUNA) are disabling primary headache disorders. The advent of advanced imaging technologies and surgical techniques has translated to a growing arsenal of interventional therapies capable of treating headache disorders. This literature review sheds light on the current evidence available for interventional therapies in medically intractable SUNCT/SUNA. PubMed and EMBASE were searched for publications between 1978 and 2022. Inclusion criteria were SUNCT/SUNA studies reporting outcomes following occipital nerve stimulation (ONS), pulsed radiofrequency (PRF) of sphenopalatine ganglion (SPG), stereotactic radiosurgery (SRS), deep brain stimulation (DBS) or microvascular decompression (MVD) of the trigeminal nerve. A greater than 50% reduction in severity or a greater than 50% reduction in the number of attacks was defined as a successful response. The rate of successful responses for the various treatment modalities were as follows: ONS 33/41 (80.5%), PRF of SPG 5/9 (55.6%), DBS of the ventral tegmental area 14/16 (86.7%), SRS to the SPG and/or trigeminal nerve 7/9 (77.8%) and MVD 56/73 (76.7%). Mean follow-up time in months was 42.5 (ONS), 24.8 (PRF), 25.3 (DBS), 20.8 (SRS) and 42.4 (MVD). A significant proportion of SUNCT/SUNA patients remain refractory to medical therapy (45%-55%). This review discusses existing literature on interventional approaches, including neuromodulation, radiofrequency ablation, gamma knife radiosurgery and MVD. The outcomes are promising, yet limited data exist, underscoring the need for further research to develop a robust surgical management algorithm.

Similarities and differences between SUNCT and SUNA: a cross-sectional, multicentre study of 76 patients in China

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) have not been evaluated sufficiently due to limited data, particularly in China.

Methods

Patients with SUNCT or SUNA treated in a tertiary headache centre or seven other headache clinics of China between April 2009 and July 2022 were studied; we compared their demographics and clinical phenotypes.

Results

The 45 patients with SUNCT and 31 patients with SUNA had mean ages at onset of 37.22 ± 14.54 years and 42.45 ± 14.72 years, respectively. The mean ages at diagnosis of SUNCT and SUNA were 41.62 ± 12.70 years and 48.68 ± 13.80 years, respectively (p = 0.024). The correct diagnosis of SUNCT or SUNA was made after an average of 2.5 (0–20.5) years or 3.0 (0–20.7) years, respectively. Both diseases had a female predominance (SUNCT: 1.14:1; SUNA: 2.10:1). The two diseases differed in the most common attack site (temporal area in SUNCT, p = 0.017; parietal area in SUNA, p = 0.002). Qualitative descriptions of the attacks included stabbing pain (44.7%), electric-shock-like pain (36.8%), shooting pain (25.0%), and slashing pain (18.4%). Lacrimation was the most common autonomic symptom in both SUNCT and SUNA patients, while eyelid oedema, ptosis, and miosis were less frequent. Triggers such as cold air and face washing were shared by the two diseases, and they were consistently ipsilateral to the attack site.

Conclusions

In contrast to Western countries, SUNCT and SUNA in China have a greater female predominance and an earlier onset. The shared core phenotype of SUNCT and SUNA, despite their partial differences, suggests that they are the same clinical entity.

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.

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.

[Trigeminal autonomic cephalgias: features of diagnosis and treatment]

Trigeminal autonomic cephalgias is a group of primary headaches, including cluster headache, paroxysmal hemicrania and hemicrania continua, as well as two forms of short- lasting unilateral neuralgiform headache attacks, the complexity of diagnosis of which is determined by the low prevalence and some similarity of clinical manifestations both among themselves and with other diseases in particular with migraine and trigeminal neuralgia. Despite the rather short duration of headache attacks, the intensity of the pain syndrome reaches a severe and very severe degree, and the high frequency of paroxysms per day significantly complicates abortion treatment and leads to a pronounced professional and social maladjustment. At the same time, the possibility of using effective specific prophylactic therapy determines the importance of accurate diagnosis and, therefore, the knowledge of neurologists on this issue.

Trigeminal neuralgia: a practical guide

Trigeminal neuralgia (TN) is a highly disabling disorder characterised by very severe, brief and electric shock like recurrent episodes of facial pain. New diagnostic criteria, which subclassify TN on the basis of presence of trigeminal neurovascular conflict or an underlying neurological disorder, should be used as they allow better characterisation of patients and help in decision-making regarding medical and surgical treatments. MR imaging, including high-resolution trigeminal sequences, should be performed as part of the diagnostic work-up. Carbamazepine and oxcarbazepine are drugs of first choice. Lamotrigine, gabapentin, pregabalin, botulinum toxin type A and baclofen can be used either alone or as add-on therapy. Surgery should be considered if the pain is poorly controlled or the medical treatments are poorly tolerated. Trigeminal microvascular decompression is the first-line surgery in patients with trigeminal neurovascular conflict while neuroablative surgical treatments can be offered if MR imaging does not show any neurovascular contact or where patients are considered too frail for microvascular decompression or do not wish to take the risk.

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.

Position Paper on Post-Traumatic Headache: The Relationship Between Head Trauma, Stress Disorder, and Migraine

Traumatic brain injury (mTBI) is a major public health concern, with mild TBI (mTBI) constituting the vast majority of the injuries. Post-traumatic headache (PTH) is one of the most frequent symptoms that follow a mTBI, occurring in isolation with a tension-type or migraine phenotype, or more often as part of a complex neurobehavioural array of symptoms. The existence of PTH as a separate entity from the primary headaches is still a matter of debate. Classification issues and a lack of methodologically robust epidemiological and clinical studies have made it difficult to elucidate the mechanisms underlying acute and even more persistent PTH (PPTH). Furthermore, psychiatric comorbidities such as post-traumatic stress disorder (PTSD), previous history of migraine, and legal issues often reported by PPTH patients have complicated the understanding of this condition, hence treatment approaches for PTH remain problematic. Recent findings from structural and functional neuroimaging studies have attempted to describe the brain architecture of PPTH, suggesting the involvement of different networks compared to migraine. It also seems that calcitonin gene-related peptide (CGRP) levels are not particularly raised in PPTH, although CGRP monoclonal antibodies have obtained positive initial open-label evidence of efficacy in PPTH, and more trials assessing the efficacy of this class of treatments are underway. The broad overlap between PTH, migraine, and PTSD suggests that research in this field should start with a re-appraisal of the diagnostic criteria, followed by methodologically sound epidemiological and clinical studies. Preclinical research should strive to create more reliable PTH models to support human neuroimaging, neurochemical, and neurogenetic studies, aiming to underpin new pathophysiological hypotheses that may expand treatment targets and improve the management of PTH 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.

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.