Sphenopalatine ganglion stimulation in cluster headache and other types of headache.

Objectives The cluster headache is the most excruciatingly painful primary headache. In some patients, neither preventive treatment nor acute treatment is effective or treatment is poorly tolerated. The sphenopalatine ganglion (SPG) has an important role in the pathophysiology of cluster headache and, for this reason, SPG stimulation has been used to treat cluster headache. Methods We have reviewed the published literature on the role of the SPG in cluster headache and the use of different treatments targeting the SPG. Results Multiple procedures have been used over the SPG to treat pain and trigemino-autonomic symptoms in patients with refractory cluster headache. After obtaining good results in a small number of patients, a miniaturized stimulator was developed. Stimulation of the SPG with this device proved to be efficacious in acute and preventive treatment in a clinical trial involving patients with chronic refractory cluster headache. Implantation of the device is minimally invasive and the most frequent side-effects are mild, such as paraesthesia and pain over the maxillary area. In patients who have used the SPG device for longer than one year, the therapeutic effect remains effective and the side-effects decrease. Conclusions The reported studies have demonstrated that SPG stimulation is a safe and effective treatment for chronic cluster headache. Long-term studies have shown that the effect remains over time and this treatment could be a good choice in patients with chronic refractory headache. We need more data about its potential use in other forms of headache, such as other trigemino-autonomic headaches or migraine.

Role of sphenopalatine ganglion stimulation in cluster headache.

Cluster headache attacks are characterized by extreme unilateral pain mostly in the first trigeminal branch and an ipsilateral activation of the cranial parasympathetic system, pointing to a relevant role of the cranial parasympathetic system in the pathophysiology, and therapy of cluster headache. Based on animal experiments and several interventions of the sphenopalatine ganglion (such as an aesthetic or alcoholic blocks and radiofrequency ablation) in cluster headache patients, stimulation of the sphenopalatine ganglion (SPGS) as the major efferent peripheral parasympathetic structure was established with an encouraging abortive effect on acute attacks and a frequency reduction over time. In this review, the clinical data and potentially underlying pathophysiological concepts of SPGS are discussed in detail, which in brief point to a relevant role of the parasympathetic system both in the induction and termination of attacks.

Neurostimulation at pterygopalatine fossa for cluster headaches and cerebrovascular disorders.

There are numerous neural structures (parasympathetic, sympathetic, and trigeminal sensory) that are compacted in a small well defined area of the pterygopalatine fossa (PPF). These targets can be readily accessed via minimally invasive neuromodulation techniques making the methods more desirable than neurosurgical deep brain or hypothalamic intervention. Recent research has shed light over the important role of the sphenopalatine ganglion (SPG), which is located within the PPF, in cerebrovascular autonomic physiology as well as in the pathophysiology of different headache disorders (cluster headache, migraine, and trigeminal autonomic cephalalgias). Accordingly, neuromodulation of the autonomic fibers (parasympathetic and sympathetic) may play a key role in the management of headaches, stroke, or cerebral vasospasm. Another important structure within the PPF is the maxillary nerve (V2), which passes through the roof of the fossa. Here the trigeminal system is accessible for a reliable neuromodulation by targeting its second branch -the maxillary nerve- and this could be utilized in various painful conditions of the head and face.

Sphenopalatine ganglion neuromodulation in migraine: what is the rationale?

OBJECTIVE: The objective of this article is to review the prospect of treating migraine with sphenopalatine ganglion (SPG) neurostimulation. BACKGROUND: Fuelled by preliminary studies showing a beneficial effect in cluster headache patients, the potential of treating migraine with neurostimulation has gained increasing interest within recent years, as current treatment strategies often fail to provide adequate relief from this debilitating headache. Common migraine symptoms include lacrimation, nasal congestion, and conjunctival injection, all parasympathetic manifestations. In addition, studies have suggested that parasympathetic activity may also contribute to the pain of migraineurs. The SPG is the largest extracranial parasympathetic ganglion of the head, innervating the meninges, lacrimal gland, nasal mucosa, and conjunctiva, all structures involved in migraine with cephalic autonomic symptoms. CONCLUSION: We propose two possible mechanisms of action: 1) interrupting the post-ganglionic parasympathetic outflow to inhibit the pain and cephalic autonomic symptoms, and 2) modulating the sensory processing in the trigeminal nucleus caudalis. To further explore SPG stimulation in migraineurs as regards therapeutic potential and mode of action, randomized clinical trials are warranted.

Experimental activation of the sphenopalatine ganglion provokes cluster-like attacks in humans.

BACKGROUND: High frequency (HF) stimulation of the sphenopalatine ganglion (SPG) is an emerging abortive treatment for cluster headache (CH) attacks. HF SPG stimulation is thought to exert its effect by physiologically blocking parasympathetic outflow. We hypothesized that low frequency (LF) SPG stimulation may activate the SPG, causing increased parasympathetic outflow and thereby provoking cluster attacks in CH patients. METHODS: In a double-blind randomized cross-over study, seven CH patients implanted with an SPG neurostimulator were randomly allocated to receive HF or LF stimulation for 3 min on 2 separate days. We recorded headache characteristics and autonomic symptoms during and after stimulation. RESULTS: Six patients completed the study. Three out of six patients (50%) reported ipsilateral cluster-like attacks during or within 30 min of LF SPG stimulation. These cluster-like attacks were all successfully treated with the therapeutic HF SPG stimulation. One out of six reported a cluster-like attack with 3 min HF SPG stimulation, which was also successfully treated with continued HF therapeutic SPG stimulation. DISCUSSION: LF SPG stimulation may induce cluster-like attacks with autonomic features, which can subsequently be treated by HF SPG stimulation. Efferent parasympathetic outflow from the SPG may initiate autonomic symptoms and activate trigeminovascular sensory afferents, which may initiate the onset of pain associated with CH.

Schwanoma de la fosa pterigopalatina. Abordaje endoscópico / Pterygopalatine fossa schwannoma. Endoscopic approach

Exponemos las características anatómicas de la fosapterigopalatina (FPP) y la patología que se puede originar en ella. A continuación se muestra la experiencia quirúrgica en un caso de schwanoma de FPP de cinco centímetros de diámetro que pudo ser extirpada por cirugía endoscópica transnasal, evitando así un abordaje externo. Los schwanomas constituyen del 8 al 10% de los tumores intracraneales. Su asiento principal es la rama vestibular del VIII nervio craneal, siendo los trigeminales a nivel de FPP de escasa frecuencia (AU)

We expose the anatomical characteristics of the pterygopalatine fossa (FPP) and the pathology that cancause it. Below is the surgical experience in a case of schwannoma of FPP five centimeters in diameter that could be removed by transnasal endoscopic surgery,being unnecessary an external surgery. Schwannomas constitute the 8-10% of intracranial tumors, normally localized in the vestibular branch of the VIII cranial nerve. A schwannoma of a branche of the trigeminallnerve in the pterigopalatine fossa is exceptional (AU)