Low frequency activation of the sphenopalatine ganglion does not induce migraine-like attacks in migraine patients.

INTRODUCTION: Cephalic autonomic symptoms occur in 27‒73% of migraine patients during attacks. The role of parasympathetic activation in migraine attack initiation remains elusive. Low frequency stimulation of the sphenopalatine ganglion increases parasympathetic outflow. In this study, we hypothesized that low frequency stimulation of the sphenopalatine ganglion would provoke migraine-like attacks in migraine patients. METHODS: In a double-blind randomized sham-controlled crossover study, 12 migraine patients with a sphenopalatine ganglion neurostimulator received low frequency or sham stimulation for 30 min on two separate days. We recorded headache characteristics, cephalic autonomic symptoms, ipsilateral mechanical perception and pain thresholds, mean blood flow velocity in the middle cerebral artery (VMCA) and diameter of the superficial temporal artery during and after stimulation. RESULTS: Five patients (42%) reported a migraine-like attack after low frequency stimulation compared to six patients (50%) after sham (p = 1.000). We found a significant increase in mechanical detection thresholds during low frequency stimulation compared to baseline (p = 0.007). Occurrence of cephalic autonomic symptoms and changes in mechanical perception thresholds, VMCA and diameter of the superficial temporal artery showed no difference between low frequency stimulation compared to sham (p = 0.533). CONCLUSION: Low frequency stimulation of the sphenopalatine ganglion did not induce migraine-like attacks or autonomic symptoms in migraine patients. These data suggest that increased parasympathetic outflow by the sphenopalatine ganglion neurostimulator does not initiate migraine-like attacks.Study protocol: ClinicalTrials.gov registration number NCT02510742.

Cluster headache: crosspoint between otologists and neurologists-treatment of the sphenopalatine ganglion and systematic review.

Among cephalgias, cluster headache (CH) is the rarest and the most disabling, explaining the appellation of "suicide headache." Up to 20% of chronic CH reveals to be resistant to pharmacological treatments, in which case interventional procedures should be considered. Many reports evaluated invasive approaches and a wide strand of research is dedicated to the sphenopalatine ganglion. Our paper will now be focused on providing an overview on modern applications on the sphenopalatine ganglion (SPG), their outcomes, and their feasibility in terms of risks and benefits. The group reviewed the international literature systematically for procedures targeting the sphenopalatine ganglion and its branches for episodic and chronic CH, including block, stimulation, radiofrequency, stereotactic radiosurgery, and vidian neurectomy. Seventeen articles fixed our inclusion criteria. Comparing the outcomes that have been analyzed, it is possible to notice how the most successful procedure for the treatment of refractory chronic and episodic CH is the SPG block, which reaches respectively 76.5% and 87% of efficacy. Radiofrequency has a wide range of outcomes, from 33 to 70.3% in CCH. Stimulation of SPG only achieved up to 55% of outcomes in significant reduction in attack frequency in CCH and 71% in ECH. Radiosurgery and vidian neurectomy on SPG have also been analyzed. Generally, ECH patients show better response to standard medical therapies; nevertheless, even this more manageable condition may sometimes benefit from interventional therapies mostly reserved for CCH. First results seem promising and considering the low frequency of side effects or complications, we should think of expanding the indications of the procedures also to those conditions. Outcomes certainly suggest that further studies are necessary in order to understand which method is the most effective and with less side effects. Placebo-controlled studies would be pivotal, and tight collaboration between neurologists and otorhinolaryngologists should also be central in order to give correct indications, which allow us to expect procedures on the SPG to be an effective and mostly safe method to control either refractory ECH or CCH.

Cranial parasympathetic activation induces autonomic symptoms but no cluster headache attacks.

Background Low frequency (LF) stimulation of the sphenopalatine ganglion (SPG) may increase parasympathetic outflow and provoke cluster headache (CH) attacks in CH patients implanted with an SPG neurostimulator. Methods In a double-blind randomized sham-controlled crossover study, 20 CH patients received LF or sham stimulation for 30 min on two separate days. We recorded headache characteristics, cephalic autonomic symptoms (CAS), plasma levels of parasympathetic markers such as pituitary adenylate cyclase-activating polypeptide-38 (PACAP38) and vasoactive intestinal peptide (VIP), and mechanical detection and pain thresholds as a marker of sensory modulation. Results In the immediate phase (0-60 min), 16 (80%) patients experienced CAS after LF stimulation, while nine patients (45%) reported CAS after sham ( p = 0.046). We found no difference in induction of cluster-like attacks between LF stimulation (n = 7) and sham stimulation (n = 5) ( p = 0.724). There was no difference in mechanical detection and pain thresholds, and in PACAP and VIP plasma concentrations between LF and sham stimulation ( p ≥ 0.162). Conclusion LF stimulation of the SPG induced autonomic symptoms, but no CH attacks. These data suggest that increased parasympathetic outflow is not sufficient to induce CH attacks in patients. Study protocol ClinicalTrials.gov registration number NCT02510729.

Upper airway stabilization by osteopathic manipulation of the sphenopalatine ganglion versus sham manipulation in OSAS patients: a proof-of-concept, randomized, crossover, double-blind, controlled study.

BACKGROUND: Osteopathic manipulative treatment (OMT) of the sphenopalatine ganglion (SPG) is used empirically for the treatment of rhinitis and snoring and is thought to increase pharyngeal stability. This trial was designed to study the effects of this treatment on pharyngeal stability evaluated by critical closing pressure in obstructive sleep apnoea syndrome. METHODS: This single-centre, randomized, crossover, double-blind study compared active manipulation and sham manipulation of the SPG. Randomization was computer-generated. Patients each received one active manipulation and one sham manipulation at an interval of 21 days and were evaluated 30 min and 48 h after each session administered by a qualified osteopath. Neither the patients, nor the investigator performing the evaluations were informed about the order of the two techniques (double-blind). The primary endpoint was the percentage of responding patients presenting increased pharyngeal stability defined by a variation of critical closing pressure (Pcrit) of at least -4 cmH2O at 30 min. Secondary endpoints were the variation of Pcrit in absolute values, sleepiness and snoring. Others endpoints were lacrimation (Schirmer's test), induced pain, sensations experienced during OMT. RESULTS: Ten patients were included and nine (57 [50; 58] years, comprising 7 men, with an apnoea-hypopnoea index of 31.0 [25.5; 33.2]/h; (values are median [quartiles])) were analysed. Seven patients were analysed for the primary endpoint and nine patients were analysed for secondary endpoints. Five patients responded after active manipulation versus no patients after sham manipulation (p = 0.0209). Active manipulation induced more intense pain (p = 0.0089), increased lacrimation (ns) and more tactile, nociceptive and gustatory sensations (13 versus 1) compared to sham manipulation. No significant difference was observed for the other endpoints. CONCLUSIONS: Osteopathic manipulative treatment of the SPG may improve pharyngeal stability in obstructive sleep apnoea syndrome. This trial validates the feasibility of the randomized, controlled, double-blind methodology for evaluation of this osteopathic treatment. Studies on a larger sample size must specify the efficacy on the apnoea-hypopnoea index. TRIAL REGISTRATION: The study was retrospectively registered in the clinicaltrial.gov registry under reference NCT01193738 on 1st September 2010 (first inclusion May 19, 2010).

Long-term effectiveness of sphenopalatine ganglion stimulation for cluster headache.

Objectives The sphenopalatine ganglion (SPG) plays a pivotal role in cluster headache (CH) pathophysiology as the major efferent parasympathetic relay. We evaluated the long-term effectiveness of SPG stimulation in medically refractory, chronic CH patients. Methods Thirty-three patients were enrolled in an open-label follow-up study of the original Pathway CH-1 study, and participated through 24 months post-insertion of a microstimulator. Response to therapy was defined as acute effectiveness in ≥ 50% of attacks or a ≥ 50% reduction in attack frequency versus baseline. Results In total, 5956 attacks (180.5 ± 344.8, range 2-1581 per patient) were evaluated. At 24 months, 45% ( n = 15) of patients were acute responders. Among acute responders, a total of 4340 attacks had been treated, and in 78% of these, effective therapy was achieved using only SPG stimulation (relief from moderate or greater pain or freedom from mild pain or greater). A frequency response was observed in 33% ( n = 11) of patients with a mean reduction of attack frequency of 83% versus baseline. In total, 61% (20/33) of all patients were either acute or frequency responders or both. The majority maintained their therapeutic response through the 24-month evaluation. Conclusions In the population of disabled, medically refractory chronic CH patients treated in this study, SPG stimulation is an effective acute therapy in 45% of patients, offering sustained effectiveness over 24 months of observation. In addition, a maintained, clinically relevant reduction of attack frequency was observed in a third of patients. These long-term data provide support for the use of SPG stimulation for disabled patients and should be considered after medical treatments fail, are not tolerated or are inconvenient for the patients.

Cluster headache attack remission with sphenopalatine ganglion stimulation: experiences in chronic cluster headache patients through 24 months.

BACKGROUND: Cluster headache (CH) is a debilitating headache disorder with severe consequences for patient quality of life. On-demand neuromodulation targeting the sphenopalatine ganglion (SPG) is effective in treating the acute pain and a subgroup of patients experience a decreased frequency of CH attacks. METHODS: We monitored self-reported attack frequency, headache disability, and medication intake in 33 patients with medically refractory, chronic CH (CCH) in an open label follow-up study of the original Pathway CH-1 study. Patients were followed for at least 24 months (average 750 ± 34 days, range 699-847) after insertion of an SPG microstimulator. Remission periods (attack-free periods exceeding one month, per the ICHD 3 (beta) definition) occurring during the 24-month study period were characterized. Attack frequency, acute effectiveness, medication usage, and questionnaire data were collected at regular clinic visits. The time point "after remission" was defined as the first visit after the end of the remission period. RESULTS: Thirty percent (10/33) of enrolled patients experienced at least one period of complete attack remission. All remission periods followed the start of SPG stimulation, with the first period beginning 134 ± 86 (range 21-272) days after initiation of stimulation. On average, each patient's longest remission period lasted 149 ± 97 (range 62-322) days. The ability to treat acute attacks before and after remission was similar (37 % ± 25 % before, 49 % ± 32 % after; p = 0.2188). Post-remission headache disability (HIT-6) was significantly improved versus baseline (67.7 ± 6.0 before, 55.2 ± 11.4 after; p = 0.0118). Six of the 10 remission patients experienced clinical improvements in their preventive medication use. At 24 months post insertion headache disability improvements remained and patient satisfaction measures were positive in 100 % (10/10). CONCLUSIONS: In this population of 33 refractory CCH patients, in addition to providing the ability to treat acute attacks, neuromodulation of the SPG induced periods of remission from cluster attacks in a subset of these. Some patients experiencing remission were also able to reduce or stop their preventive medication and remissions were accompanied by an improvement in headache disability.

Sphenopalatine Ganglion Stimulation in Neurovascular Headaches.

The interest for the sphenopalatine ganglion (SPG) in neurovascular headaches dates back to 1908 when Sluder presented his work on the role of the SPG in 'nasal headaches', which are now part of the trigeminal autonomic cephalalgias and cluster headache (ICHD-III-beta). Since then various interventions with blocking or lesional properties have targeted the SPG (transnasal injection of lidocaine and other agents, alcohol or steroid injections, radiofrequency lesions, or even ganglionectomy); success rates vary, but benefit is usually transient. Here we briefly review some anatomophysiological characteristics of the SPG and hypotheses about its pathophysiological role in neurovascular headaches before describing recent therapeutic results obtained with electrical stimulation of the SPG. Based on results of a prospective randomized controlled study, SPG stimulation appears to be an effective treatment option for patients with chronic cluster headaches; efficacy data indicate that acute electrical stimulation of the SPG provides significant attack pain relief and in many cases pain freedom compared to sham stimulation. Moreover, in some patients SPG stimulation has been associated with a significant and clinically meaningful reduction in cluster headache attack frequency; this preventive effect of SPG stimulation warrants further investigation. For migraine attacks, the outcome of a proof-of-concept study using a temporary electrode implanted in the pterygopalatine fossa was less encouraging; however, an ongoing multicenter trial is evaluating the efficacy of long-term SPG stimulation against sham stimulation for acute and preventive treatment in patients with frequent migraine.

Advanced technologies and novel neurostimulation targets in trigeminal autonomic cephalalgias.

The trigeminal autonomic cephalalgias (TACs) are a group of rare but disabling primary headache disorders. Their management is challenging, since only few effective treatments are available and high doses may be required to control the headache, compromising patients' adherence to treatments. A significant minority of patients, who fail to respond to or tolerate established treatments, are left with enormous level of disability and disruption to their quality of life. A growing body of evidence demonstrates the efficacy of central and peripheral neuromodulation approaches for management of patients with refractory TACs. In view of the potential risks related to deep brain stimulation of the posterior hypothalamic region, occipital nerve stimulation is currently considered the first treatment option for refractory chronic TACs. However, in view of the presence of paraesthesia induced by the stimulator, no robust controlled trials have been possible so far. Additionally, the equipment used for occipital nerve stimulation is not designed specifically for peripheral nerve stimulation, thus a significant proportion of patients experience device-related complications that often require surgical revisions. To overcome these issues, new neurostimulation technologies using less invasive or non-invasive approaches and modulating different neuroanatomical targets have been recently studied.

Value of intra- and post-operative cone beam computed tomography (CBCT) for positioning control of a sphenopalatine ganglion neurostimulator in patients with chronic cluster headache.

INTRODUCTION: The objective of this study was to determine whether postoperative control of the neurostimulator placement within the pterygopalatine fossa (PPF) by means of 3-dimensional (3D) cone beam computed tomography (CBCT) was of therapeutic relevance compared to intraoperative CBCT imaging alone. MATERIAL AND METHODS: Immediately after implantation of the sphenopalatine ganglion (SPG) neurostimulator, intraoperative CBCT datasets were generated in order to visualize the position of the probe within the PPF. Postoperatively, all patients received a CBCT for comparison with intraoperatively acquired radiographs. RESULTS: Twenty-four patients with cluster headache (CH) received an SPG neurostimulator. In 4 patients, postoperative CBCT images detected misplacement not found in intraoperative CBCT. In 3 cases, electrode tips were misplaced into the maxillary sinus and in 1 case into the apex of the PPF superior to the suspected location of the SPG. Immediate revision with successful repositioning within 3 days was done in 2 patients and a deferred reimplantation in 1 patient within 6 months. One patient declined revision. CONCLUSION: We were able to demonstrate the clinical value of postoperative dental CBCT imaging with a wide region of interest (ROI) due to a superior image quality compared with that achieved with intraoperative medical CBCT. Although intraoperative 3D CBCT imaging of electrode placement is helpful in the acute surgical setting, resolution is, at present, too low to safely exclude misplacement, especially in the maxillary sinus. High-resolution postoperative dental CBCT allows rapid detection and revision of electrode misplacement, thereby avoiding readmission and recurrent tissue trauma.

Stimulation of the sphenopalatine ganglion in intractable cluster headache: expert consensus on patient selection and standards of care.

CONTEXT AND OVERVIEW: Chronic cluster headache (CCH) is a debilitating headache disorder with a significant impairment of the patients' lives. Within the past decade, various invasive neuromodulatory approaches have been proposed for the treatment of CCH refractory to standard preventive drug, but only very few randomized controlled studies exist in the field of neuromodulation for the treatment of drug-refractory headaches. Based on the prominent role of the cranial parasympathetic system in acute cluster headache attacks, high-frequency sphenopalatine ganglion (SPG) stimulation has been shown to abort ongoing attacks in some patients in a first small study. As preventive effects of SPG-stimulation have been suggested and the rate of long-term side effects was moderate, SPG stimulation appears to be a promising new treatment strategy. AIMS AND CONCLUSION: As SPG stimulation is effective in some patients and the first commercially available CE-marked SPG neurostimulator system has been introduced for cluster headache, patient selection and care should be standardized to ensure maximal efficacy and safety. As only limited data have been published on SPG stimulation, standards of care based on expert consensus are proposed to ensure homogeneous patient selection and treatment across international headache centres. Given that SPG stimulation is still a novel approach, all expert-based consensus on patient selection and standards of care should be re-reviewed when more long-term data are available.

Bilateral atrial ganglionated plexus involvement in atrial responses to left-sided plexus stimulation in canines.

AIMS: Given the clinical interest concerning 'reflex vagal' responses to identify left atrial (LA) targets for ablative therapy of atrial fibrillation, we investigated whether vagal and bilateral atrial neural pathways may be involved in chronotropic and atrial repolarization responses to LA ganglionated plexus (GP) stimulation. METHODS AND RESULTS: Unipolar electrograms were recorded from 191 right atrial (RA) and LA sites in anaesthetized canines prior to and during electrical stimulation of the right vagus nerve (VgN), left VgN, or LAGP at baseline and following (i) bilateral VgN decentralization, and radiofrequency ablation of (ii) periaortic/superior vena cava (Ao/SVC) and (iii) RAGP in 14 animals (anterograde group), and in the reverse order in 7 (retrograde). Repolarization changes were also measured in similar preparations during Ao/SVC (n = 8) and RAGP stimulation (n = 23). Sinus cycle length (SCL) prolongation, and RA and LA repolarization changes (affected atrial surface area) were induced during LAGP stimulation. SCL prolongation and RA repolarization changes were unaffected by VgN decentralization but reduced following Ao/SVC and RAGP ablation in the anterograde group. In the retrograde group, chronotropic and RA repolarization changes were reduced following RAGP and abolished following Ao/SVC ablation. In contrast, LA repolarization responses to LAGP stimulation were reduced following VgN decentralization and each subsequent ablation step, with small residual responses after completing the anterograde protocol. Ao/SVC and RAGP stimulation exerted predominant influences in adjacent regions as well as demonstrating LA extensions. CONCLUSION: Vagal as well as bilateral atrial neural pathways are involved in mediating chronotropic and LA repolarization responses to LAGP stimulation.

Stimulation of the sphenopalatine ganglion (SPG) for cluster headache treatment. Pathway CH-1: a randomized, sham-controlled study.

BACKGROUND: The pain and autonomic symptoms of cluster headache (CH) result from activation of the trigeminal parasympathetic reflex, mediated through the sphenopalatine ganglion (SPG). We investigated the safety and efficacy of on-demand SPG stimulation for chronic CH (CCH). METHODS: A multicenter, multiple CH attack study of an implantable on-demand SPG neurostimulator was conducted in patients suffering from refractory CCH. Each CH attack was randomly treated with full, sub-perception, or sham stimulation. Pain relief at 15 minutes following SPG stimulation and device- or procedure-related serious adverse events (SAEs) were evaluated. FINDINGS: Thirty-two patients were enrolled and 28 completed the randomized experimental period. Pain relief was achieved in 67.1% of full stimulation-treated attacks compared to 7.4% of sham-treated and 7.3% of sub-perception-treated attacks ( P < 0.0001). Nineteen of 28 (68%) patients experienced a clinically significant improvement: seven (25%) achieved pain relief in ≥50% of treated attacks, 10 (36%), a ≥50% reduction in attack frequency, and two (7%), both. Five SAEs occurred and most patients (81%) experienced transient, mild/moderate loss of sensation within distinct maxillary nerve regions; 65% of events resolved within three months. INTERPRETATION: On-demand SPG stimulation using the ATI Neurostimulation System is an effective novel therapy for CCH sufferers, with dual beneficial effects, acute pain relief and observed attack prevention, and has an acceptable safety profile compared to similar surgical procedures.

Spectral characteristics of atrial electrograms in sinus rhythm correlates with sites of ganglionated plexuses in patients with paroxysmal atrial fibrillation.

AIMS: To verify whether spectral components of atrial electrograms (AE) during sinus rhythm (SR) correlate with cardiac ganglionated plexus (GP) sites. METHODS AND RESULTS: Thirteen patients undergoing atrial fibrillation (AF) ablation were prospectively enrolled. Prior to radio frequency application, endocardial AE were recorded with a sequential point-by-point approach. Electrical stimuli were delivered at 20 Hz, amplitude 100 V, and pulse width of 4 ms. A vagal response was defined as a high-frequency stimulation (HFS) evoked atrioventricular block or a prolongation of RR interval. Spectral analysis was performed on single AE during SR, sampling rate of 1000 Hz, Hanning window. Overall, 1488 SR electrograms were analysed from 186 different left atrium sites, 129 of them corresponding to negative vagal response sites, and 57 to positive response sites. The electrogram duration and the number of deflections were similar in positive and negative response sites. Spectral power density of sites with vagal response was lower between 26 and 83 Hz and higher between 107 and 200 Hz compared with negative response sites. The area between 120 and 170 Hz normalized to the total spectrum area was tested as a diagnostic parameter. Receiver operating characteristic curve analysis demonstrated that an area 120-170/area(total) value >0.14 identified vagal sites with 70.9% sensitivity and 72.1% specificity. CONCLUSION: Spectral analysis of AE during SR in sites that correspond to the anatomical location of the GP is feasible and may be a simpler method of mapping the cardiac autonomic nervous system, compared with the HFS technique.

Sphenopalatine ganglion stimulation for vasospasm after experimental subarachnoid hemorrhage.

OBJECT: Sphenopalatine ganglion stimulation activates perivascular vasodilatory nerves in the ipsilateral anterior circle of Willis. This experiment tested whether stimulation of the ganglion could reverse vasospasm and improve cerebral perfusion after subarachnoid hemorrhage (SAH) in monkeys. METHODS: Thirteen cynomolgus monkeys underwent baseline angiography followed by creation of SAH by placement of autologous blood against the right intradural internal carotid artery, the middle cerebral artery (MCA), and the anterior cerebral artery. Seven days later, angiography was repeated, and the right sphenopalatine ganglion was exposed microsurgically. Angiography was repeated 15 minutes after exposure of the ganglion. The ganglion was stimulated electrically 3 times, and angiography was repeated during and 15 and 30 minutes after stimulation. Cerebral blood flow (CBF) was monitored using laser Doppler flowmetry, and intracranial pressure (ICP) was measured throughout. The protocol was repeated again. Evans blue was injected and the animals were killed. The brains were removed for analysis of water and Evans blue content and histology. RESULTS: Subarachnoid hemorrhage was associated with significant vasospasm of the ipsilateral major cerebral arteries (23% ± 10% to 39% ± 4%; p < 0.05, paired t-tests). Exposure of the ganglion and sham stimulation had no significant effects on arterial diameters, ICP, or CBF (4 monkeys, ANOVA and paired t-tests). Sphenopalatine ganglion stimulation dilated the ipsilateral extracranial and intracranial internal carotid artery, MCA, and anterior cerebral artery compared with the contralateral arteries (9 monkeys, 7% ± 9% to 15% ± 19%; p < 0.05, ANOVA). There was a significant increase in ipsilateral CBF. Stimulation had no effect on ICP or brain histology. Brain water content did not increase but Evans blue content was significantly elevated in the MCA territory of the stimulated hemisphere. CONCLUSIONS: Sphenopalatine ganglion stimulation decreased vasospasm and increased CBF after SAH in monkeys. This was associated with opening of the blood-brain barrier.

Implant for augmentation of cerebral blood flow trial 1: a pilot study evaluating the safety and effectiveness of the Ischaemic Stroke System for treatment of acute ischaemic stroke.

INTRODUCTION: In rat stroke models, sphenopalatine ganglion stimulation up to 24 h after stroke onset augments cerebral blood flow, reduces infarct volume and improves neurological deficits. The ischaemic stroke system 500 has been designed to stimulate the sphenopalatine ganglion in humans. OBJECTIVES: (1) To determine the safety and tolerability of the ischaemic stroke system 500 in acute ischaemic stroke within 24 h of stroke onset. (2) To determine the effectiveness of ischaemic stroke system 500 in acute ischaemic stroke treatment. DESIGN/METHODS: Implant for augmentation of cerebral blood flow trial-1 is a multi-national open-label study in patients of acute ischaemic stroke in the anterior circulation with National Institutes of Health Stroke Scales 7-20. The treatment initiation will be within 24 h of stroke onset. The ischaemic stroke system is implanted adjacent to the sphenopalatine ganglion via the greater palatine canal using local anaesthesia and a minimally invasive approach. The treatment protocol is constituted as 3-4 h of daily stimulation over 5-7 days. CONCLUSIONS: The implant for augmentation of cerebral blood flow trial-1 will determine the safety and tolerability of the ischaemic stroke system 500 in acute ischaemic stroke as reflected by the incidence of adverse events.

[Study on needling depth and direction from different acupoints to sphenopalatine ganglion].

OBJECTIVE: To observe and survey the location of Xiaguan (ST 7), "Die'e" and Quanliao (SI 18) on the surface, and the needling depth and direction from the 3 points to sphenopalatine ganglion. METHODS: Fifteen corpses (30 sides) of adult male were fixed by 10% formalin. The lateral areas of face were dissected from the surface to the deep on the 3 acupoints: the electric drill with the kirschner wire punctured towards the sphenopalatine ganglion and extended to the contralateral areas according to different directions of puncturing sphenopalatine ganglion from the 3 acupoints. The corresponding puncturing points of the 3 acupoints were measured by the coordinate location method. RESULTS: (1) Surface location: the distance between Quanliao (SI 18) and "Die'e" was 21 mm and the distance between Xiaguan (ST 7) and "Die'e" was 17 mm; (2) Inserting depth of each point to sphenopalatine ganglion: the depths of Xiaguan (ST 7), "Die'e" and Quanliao (SI 18) were 49.9 mm, 46.9 mm and 46.6 mm, respectively; (3) The coordinate location of the corresponding puncturing points: the puncturing direction of Xiaguan (ST 7) was anterointernal upper corresponding to the area of connecting center between contralateral Taiyang (EX-HN 5) and Tongziliao (GB 1), the distance between the corresponding inserting point of Xiaguan (ST 7) and Sizhukong (TE 23) was 17.6 mm; the puncturing direction of "Die'e" point was posterointernal upper, and the horizontal distance from the corresponding puncture point to the zygomatic arch was 33 mm and the vertical distance from the corresponding puncture point to the eyes' outer canthus was 42 mm; the puncturing direction of Quanliao (SI 18) was posteriointernal upper and the distance between the corresponding inserting point and the area of contralateral parietal tuber, the distance between the corresponding inserting point of Quanliao (SI 18) and the connecting line of bilateral external acoustic pore was 28 mm, the distance between the corresponding inserting point of Quan-liao (SI 18) and the medial line of the head was 62 mm. CONCLUSION: Understanding the surface location, inserting depths and the general puncturing directions of the 3 points can provide basis for puncturing the sphenopalatine ganglion in clinical practice.

Activation of potassium conductance by ophiopogonin-D in acutely dissociated rat paratracheal neurones.

1. The effect of ophiopogonin-D (OP-D), a steroidal glycoside and an active component of Bakumondo-to, a Chinese herbal antitussive, on neurones acutely dissociated from paratracheal ganglia of 2-week-old Wistar rats was investigated using the nystatin-perforated patch recording configuration. 2. Under current-clamp conditions, OP-D (10 microM) hyperpolarized the paratracheal neurones from a resting membrane potential of -65.7 to -73.5 mV. 3. At the concentration of 1 microM and above, OP-D concentration-dependently activated an outward current accompanied by an increase in the membrane conductance under voltage-clamp conditions at a holding potential of -40 mV. 4. The reversal potential of the OP-D-induced current (I(OP-D)) was -79.4 mV, which is close to the K(+) equilibrium potential of -86.4 mV. The changes in the reversal potential for a 10 fold change in extracellular K(+) concentration was 53.1 mV, indicating that the current was carried by K(+). 5. The I(OP-D) was blocked by an extracellular application of 1 mM Ba2+ by 59.0%, but other K(+) channel blockers, including 4-aminopyridine (3 mM), apamin (1 microM), charybdotoxin (0.3 microM), glibenclamide (1 microM), tolbutamide (0.3 mM) and tetraethylammonium (10 mM), did not inhibit the I(OP-D). 6. OP-D also inhibited the ACh- and bradykinin-induced depolarizing responses which were accompanied with firing of action potentials. 7. The results suggest that OP-D may be of benefit in reducing the excitability of airway parasympathetic ganglion neurones and consequently cholinergic control of airway function and further, that the hyperpolarizing effect of OP-D on paratracheal neurones via an activation of K(+) channels might explain a part of mechanisms of the antitussive action of the agent.

[The pharmacological blockade of the cardiac and gastric enteric ganglia by a new parasympatholytic]. / Farmakolohichna blokada sertsevykh i enteral'nykh hanhliïv shlunka novym parasympatolitykom.

The blocking effects of a newly synthetized compound N-decyltropine bromide (IEM-1556), on pentagastrin-, carbachol- and histamine-induced gastric secretion in chronic dogs, on stress-induced changes in gastric mucosa in rats, on vagus-induced effect in heart and on arterial blood pressure in rats were studied. The effects were compared with those produced by hexamethonium, a conventional ganglionic blocking agent. IEM-1556 inhibited gastric secretion and acid output for a much longer time than hexamethonium did. It also effectively protected gastric mucosa against stress-induced erosions and hemorrhages. IEM-1556 much more effectively blocked the vagus-induced reduction of the heart rate than hexamethonium did, and, in contrast to latter, did not reduce the arterial blood pressure. The results suggest that IEM-1556 is a highly selective blocking agent for parasympathetic and enteric ganglia versus sympathetic ganglia.

[Control of blood flow in nasal mucosa by electro-stimulation of sphenopalatine ganglion].

The effects of control of blood flow on cat nasal mucosa by stimulating sphenopalatine ganglion (SPG) were studied using laser Doppler flowmetry in order to investigate the role of SPG. The study showed that the stimulation on one side of SPG could induce vasodilation, with increased blood flow, as well as protective reflexes on both sides. The reactivity depended on the stimulation intensity, frequency and duration. The stimulation on one side of postganglionic parasympathetic nerves, in which the stellate ganglion was resected, caused vasodilation only ipsilaterally. The results indicated that the vasodilation induced by stimulating SPG might be mediated via central reflex arc. The "reverse blood regulation" phenomenon was observed during stimulation of SPG as well. The mechanisms of "reverse blood regulation" induced by stimulating SPG need further investigation.