Sphenopalatine (pterygopalatine) ganglion stimulation and cluster headache: new hope for ye who enter here

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Sphenopalatine ganglion block in primary headaches: An American Headache Society member survey

Background

The sphenopalatine ganglion (SPG), in the pterygopalatine fossa, is a known current and historical target for therapeutic intervention in headache disorders because of its role in cranial autonomics and vasodilation. There remains an overall lack of well-established SPG treatment protocols, particularly with the advent of newer commercial devices.

Methods

A 22 multiple-choice question survey was created to evaluate clinical practice patterns with SPG block and sent to members of the American Headache Society (AHS). Questions focused on determining indications, preferred applicators, medications applied, perceived efficacy, tolerability, and reimbursement.

Results

One hundred seventy-two of 1,346 (12.8%) AHS members participated. Ninety-three respondents (56.3%) had performed SPG blocks on 50 or fewer patients. The SphenoCath (42.4%) and the Tx360 (41.8%) were the most common methods of application. Ease of use was the top reason for provider preference in applicator type. SPG blocks were mostly used as an as-needed one-time procedure. When a scheduled protocol was used, twice weekly for 6 weeks was most common. Chronic migraine was the most commonly treated headache disorder and rated the most likely to respond to SPG block. Experienced clinicians found SPG more helpful as a stand-alone treatment and tended to report that acute relief was not predictive of enduring response.

Conclusions

The variety of responses strongly suggests that clinicians would benefit from formalized protocols for SPG blocks. More experienced clinicians may have developed individualized protocols that they feel are more effective. The lack of evidence-based protocols contribute to clinicians not performing SPG blocks more frequently.

Pilot Study of Injection of OnabotulinumtoxinA Toward the Sphenopalatine Ganglion for the Treatment of Classical Trigeminal Neuralgia

Background

The sphenopalatine ganglion (SPG) has previously been targeted in trigeminal neuralgia (TN), but its role in this condition has not been established.

Objective

To investigate the safety of injecting onabotulinumtoxinA (BTA) toward the SPG using the MultiGuide^® in 10 patients with refractory classical TN, and collect preliminary efficacy data.

Methods

Twenty‐five international units (IU) of BTA were injected toward the SPG in a prospective, open‐label study in 10 patients with refractory classical TN. All patients were recruited and treated on an out‐patient basis at St. Olav's University Hospital in Trondheim (Norway). Primary outcome: adverse events (AEs). Primary efficacy outcome: number of TN attacks at weeks 5‐8 after injection compared to baseline. A treatment responder was predefined as at least 50% reduction in the median number of attacks per day between baseline and weeks 5‐8. Other efficacy outcomes were intensity of attacks (numeric rating scale, 0 to 10) and functional level (1 to 4; 1 best and 4 worst) at weeks 5‐8 after injection compared to baseline. Percentage of the day with concomitant persistent pain was registered at baseline and at weeks 1‐4, 6, 8, and 12 after injection. Patient global impression of change (PGIC) was ascertained at month 3.

Results

For the primary endpoint, we analyzed data for all 10 patients. For efficacy outcomes we analyzed data for 9 patients (1 patient violated protocol). We registered 13 AEs, none of which were serious. The median number of TN attacks during the 4‐week baseline and weeks 5‐8 after injection was 5.5 (range: 1.0‐51.5) and 5 (range: 0‐225.0), respectively (P = .401). Four patients were treatment responders. The median intensity of attacks at baseline and weeks 5‐8 after injection was 6 (range: 3.0‐8.5) and 3 (range: 0.0‐9.0) respectively (P = .024). The median functional level at baseline was 2 (range: 1.0‐3.3) and at month 2, 1 (range 1.0‐4.0; P = .750). Median percentage of the day with concomitant persistent pain was 75% (minimum 37.5%, maximum 100%) at baseline and 18.75% (minimum 0%, maximum 100%) at week 8 (P = .023).

Conclusions

Injection of BTA toward the SPG using the MultiGuide^® in patients with TN appears to be safe and well tolerated. This study was negative for the main efficacy endpoint (reduction in the number of attacks from baseline to weeks 5‐8). Further studies examining the role of the SPG in TN are necessary.

Aberrant facial flushing following monobloc fronto-facial distraction

BACKGROUND

Patients with syndromic forms of craniosynostosis may experience functional problems such as raised intracranial pressure, proptosis, obstructive sleep apnoea and failure to thrive. The monobloc fronto-facial advancement with osteogenic distraction is increasingly used to correct these functional problems in one procedure as well as improve appearance. The authors report the phenomenon of post operative aberrant facial flushing - an unusual and previously unreported complication of the procedure.

METHODS

The case notes of 80 consecutive patients undergoing fronto-facial advancement by distraction using the rigid external distraction device (RED) were reviewed for features of aberrant facial flushing.

RESULTS

Four out of eighty individuals developed facial flushing after monobloc fronto-facial distraction using the rigid external distractor (RED) frame. All were female with Crouzon or Pfeiffer syndromes causing the severe functional problems for which they underwent the surgery. They were aged 6-8 years. Following removal of the frame, they developed intermittent but severe facial flushing. The flushing spontaneously settled in three patients after up to four years but persists in the other child seven years after her surgery.

CONCLUSION

Aberrant facial flushing is a rare but significant complication of monobloc fronto-facial surgery. It occurred in 4 of our 80 (5%) patients. The skull base osteotomies essential for the procedure are made anterior to the pterygopalatine ganglion and it is our contention that damage from these was responsible for a neuropraxia of its efferent nerve branches. A review of the autonomic control of the facial vascular system suggests that the phenomenon is due to an unequal process of recovery that leaves the cutaneous vasodilating parasympathetic or beta-adrenergic innervation relatively unopposed - a situation that persists until with time a normal balance of autonomic input is achieved.

Evaluation of interictal autonomic function during attack and remission periods in cluster headaches

Objective

To investigate which part of the autonomic system is mainly involved and assess the sensitivity of face sympathetic skin response in cluster headache.

Material and methods

The study sample consisted of 19 drug-free cluster headache patients (16 males, three females) and 19 healthy volunteers. Demographic features and pain characteristics were thoroughly identified. Dysautonomic symptoms were evaluated during attack and remission periods of cluster headache patients. Orthostatic hypotension, R-R interval variation and sympathetic skin responses obtained from the face and four extremities were evaluated and the sensitivity of face sympathetic skin responses was assessed in contrast to extremity sympathetic skin responses.

Results

All sympathetic skin responses of face and extremities could be obtained during attack and remission periods. On the symptomatic side, mean latency of face sympathetic skin responses was longer compared to the asymptomatic side and controls (p = 0.02, p = 0.004). There were no differences in latency or amplitude of extremity sympathetic skin responses between symptomatic and asymptomatic sides and controls. No significant relationship was determined between sympathetic skin responses, R-R interval variation, orthostatic hypotension and cluster headache clinical features.

Conclusion

Sympathetic hypoactivity of the face seems to predominate the pathophysiology of cluster headache. Face sympathetic skin responses might be more sensitive compared to extremity sympathetic skin response in demonstrating dysautonomic symptoms in cluster headache patients.

A randomized, double-blind, placebo-controlled study of breath powered nasal delivery of sumatriptan powder (AVP-825) in the treatment of acute migraine (The TARGET Study)

Objective

To evaluate the efficacy and safety of AVP-825, a drug–device combination of low-dose sumatriptan powder (22 mg loaded dose) delivered intranasally through a targeted Breath Powered device vs an identical device containing lactose powder (placebo device) in the treatment of migraine headache.

Background

Early treatment of migraine headaches is associated with improved outcome, but medication absorption after oral delivery may be delayed in migraineurs because of reduced gastric motility. Sumatriptan powder administered with an innovative, closed-palate, Bi-Directional, Breath Powered intranasal delivery mechanism is efficiently absorbed across the nasal mucosa and produces fast absorption into the circulation. Results from a previously conducted placebo-controlled study of AVP-825 showed a high degree of headache relief with an early onset of action (eg, 74% AVP-825 vs 38% placebo device at 1 hour, P < .01).

Methods

In this double-blind, placebo-controlled, parallel-group study in adults with a history of migraine with or without aura, participants were randomized via computer-generated lists to AVP-825 or placebo device to treat a single migraine headache of moderate or severe intensity. The primary endpoint was headache relief (defined as reduction of headache pain intensity from severe or moderate migraine headache to mild or none) at 2 hours post-dose.

Results

Two hundred and thirty patients (116 AVP-825 and 114 placebo device) were randomized, of whom 223 (112 and 111, respectively) experienced a qualifying migraine headache (their next migraine headache that reached moderate or severe intensity). A significantly greater proportion of AVP-825 patients reported headache relief at 2 hours post-dose compared with those using the placebo device (68% vs 45%, P = .002, odds ratio 2.53, 95% confidence interval [1.45, 4.42]). Between-group differences in headache relief were evident as early as 15 minutes, reached statistical significance at 30 minutes post-dose (42% vs 27%, P = .03), and were sustained at 24 hours (44% vs 24%, P = .002) and 48 hours (34% vs 20%, P = .01). Thirty-four percent of patients treated with AVP-825 were pain-free at 2 hours compared with 17% using the placebo device (P = .008). More AVP-825 patients reported meaningful pain relief (patient interpretation) of migraine within 2 hours of treatment vs placebo device (70% vs 45%, P < .001), and fewer required rescue medication (37% vs 52%, P = .02). Total migraine freedom (patients with no headache, nausea, phonophobia, photophobia, or vomiting) reached significance following treatment with AVP-825 at 1 hour (19% vs 9%; P = .04). There were no serious adverse events (AEs), and no systemic AEs occurred in more than one patient. Chest pain or pressure was not reported, and only one patient taking AVP-825 reported mild paresthesia. No other triptan sensations were reported.

Conclusions

Targeted delivery of a low-dose of sumatriptan powder via a novel, closed-palate, Breath Powered, intranasal device (AVP-825) provided fast relief of moderate or severe migraine headache in adults that reached statistical significance over placebo by 30 minutes. The treatment was well tolerated with a low incidence of systemic AEs.

Breath powered nasal delivery: a new route to rapid headache relief

The nose offers an attractive noninvasive alternative for drug delivery. Nasal anatomy, with a large mucosal surface area and high vascularity, allows for rapid systemic absorption and other potential benefits. However, the complex nasal geometry, including the narrow anterior valve, poses a serious challenge to efficient drug delivery. This barrier, plus the inherent limitations of traditional nasal delivery mechanisms, has precluded achievement of the full potential of nasal delivery. Breath Powered bi-directional delivery, a simple but novel nasal delivery mechanism, overcomes these barriers. This innovative mechanism has now been applied to the delivery of sumatriptan. Multiple studies of drug deposition, including comparisons of traditional nasal sprays to Breath Powered delivery, demonstrate significantly improved deposition to superior and posterior intranasal target sites beyond the nasal valve. Pharmacokinetic studies in both healthy subjects and migraineurs suggest that improved deposition of sumatriptan translates into improved absorption and pharmacokinetics. Importantly, the absorption profile is shifted toward a more pronounced early peak, representing nasal absorption, with a reduced late peak, representing predominantly gastrointestinal (GI) absorption. The flattening and “spreading out” of the GI peak appears more pronounced in migraine sufferers than healthy volunteers, likely reflecting impaired GI absorption described in migraineurs. In replicated clinical trials, Breath Powered delivery of low-dose sumatriptan was well accepted and well tolerated by patients, and onset of pain relief was faster than generally reported in previous trials with noninjectable triptans. Interestingly, Breath Powered delivery also allows for the potential of headache-targeted medications to be better delivered to the trigeminal nerve and the sphenopalatine ganglion, potentially improving treatment of various types of headache. In brief, Breath Powered bi-directional intranasal delivery offers a new and more efficient mechanism for nasal drug delivery, providing an attractive option for improved treatment of headaches by enabling or enhancing the benefits of current and future headache therapies.