SUNCT syndrome responsive to gabapentin (Neurontin)

Craniofacial Neural Disorders: A Guide for Diagnosis and Management

The purpose of this article is to provide a succinct diagnosis and management regimen for neural disorders of the craniofacial region. This guide is an attempt to organize available data in a format for use by the craniofacial pain practitioner. The management regimens are brief because the management of many of these disorders may be outside the scope of dentistry. Also, the purpose of this guide is to be user-friendly and complete. Terminology is based on a literature review so individual disorders may be researched more completely.

Miscellaneous primary headache

There are many types of miscellaneous primary headache, but two groups have been selected for discussion: trigeminal autonomic cephalalgias (TAC) and cephalalgias without autonomic dysfunction(CWAD). TAC are strictly unilateral and CWAD are usually bilateral. Sudden onset and relatively short duration characterize most,but some are frightening to patient and doctor alike. One, thunderclap headache, is symptomatic until proven otherwise. Although the others are rarely symptomatic, therapy can be difficult until it is recognized that diagnosis often predicts treatment.

SUNCT syndrome in association with persistent Horner syndrome in a Chinese patient

This is the first case report of a chinese patient with SUNCT (shortlasting, unilateral, neuralgiform headache attacks with conjunctival injection and tearing) presenting with persistent Horner's syndrome. She had episodic, brief, right periorbital pain in association with ipsilateral eye injection, lacrimation and rhinorrhea as well as persistent ipsilateral miosis and ptosis. She had partial response to a combination of indomethacin and carbamazepine therapy.

Indomethacin-responsive headache syndromes

Indomethacin-responsive headache syndromes represent a unique group of primary headache disorders characterized by a prompt and often complete response to indomethacin to the exclusion of other nonsteroidal anti-inflammatory drugs and medications usually effective in treating other primary headache disorders. Because these headache disorders can easily be overlooked in clinical practice, they likely are more common than previously recognized. Indomethacin-responsive headache syndromes can be divided into several distinct categories: a select group of trigeminal-autonomic cephalgias, valsalva-induced headaches, and primary stabbing headache (ice-pick headache or jabs and jolts syndrome). Each category can be differentiated clinically and by the extent to which the individual headache disorders respond to indomethacin. The paroxysmal and continuous hemicranias invariably respond in an absolute manner to indomethacin, whereas valsalva-induced and ice-pick headaches may respond in an equally dramatic, but somewhat less consistent fashion. Hypnic headache recently has been described as another primary headache disorder that may respond to indomethacin.

Management of trigeminal autonomic cephalgias and hemicrania continua

The trigeminal autonomic cephalgias (TACs) are a group of primary headache disorders characterised by unilateral trigeminal distribution pain that occurs in association with ipsilateral cranial autonomic features. This group of headache disorders includes cluster headache, paroxysmal hemicrania and short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT syndrome). Although hemicrania continua has previously been classified amongst the TACs, its nosological status remains unclear. Despite their similarities, these disorders differ in their clinical manifestations and response to therapy, thus underpinning the importance of recognising them. We have outlined the clinical manifestations, differential diagnoses, diagnostic workup and the treatment options for each of these syndromes.

Influence of lamotrigine over the sunct syndrome: one patient follow-up for two years

The SUNCT syndrome is characterized by a short-lasting headache in the first division of the trigeminal nerve, associated with ipsilateral autonomic symptoms. It is highly refractory to prophylactic medication. We describe a case where lamotrigine reduced the intensity, duration, and frequency of attacks and increased the remission period of this disorder. Over a two-year period, the attacks came back immediately whenever the patient reduced the dose or neglected treatment. We concluded that lamotrigine is effective in treating SUNCT syndrome when used in high doses for a prolonged period of time.

Short-lasting unilateral neuralgiform headache with conjunctival injection and tearing syndrome: a review

The clinical features of short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT) syndrome have been reviewed in 50 patients reported in the English language literature. SUNCT syndrome is a rare condition that predominates slightly in men. The mean age at onset is 50 years. It is characterized by strictly unilateral attacks centered on the orbital or periorbital regions, forehead, and temple. Generally, the pain is severe and neuralgic in character. The usual duration ranges from 5 to 250 seconds, although the reported range of duration is 2 seconds to 20 minutes. Ipsilateral conjunctival injection and lacrimation are present in most, but not all patients. Most patients are thought to have no refractory periods and this has probably been unreported in the past. Episodic and chronic forms of SUNCT exist. The attack frequency varies from less than one attack daily to more than 60 attacks per hour. The attacks are predominantly diurnal, although frequent nocturnal attacks can occur in some patients. A functional magnetic resonance imaging study in SUNCT syndrome has demonstrated ipsilateral hypothalamic activation. SUNCT was thought to be highly refractory to treatment. However, recent open-label trials of lamotrigine, gabapentin, topiramate, and intravenous lidocaine have produced beneficial therapeutic responses. These results offer the promise of better treatments for this syndrome, but require validation in controlled trials.

SUNCT syndrome: priming of symptomatic periods and worsening of symptoms by treatment with calcium channel blockers

We report a SUNCT patient who showed both a precipitation and worsening of symptomatic periods after treatment with L-type calcium channel blockers. This pharmacological response may provide us with important clues for understanding the pathophysiology of SUNCT, and hopefully to find a remedy for the victims of this syndrome. This observation could also support a verapamil trial in SUNCT patients as a precipitating of attacks.

SUNCT Syndrome: diagnosis and treatment

Short-lasting Unilateral Neuralgiform headache attacks with Conjunctival injection and Tearing (SUNCT) is a syndrome predominant in males, with a mean age of onset around 50 years. The attacks are strictly unilateral, generally with the pain persistently confined to the ocular/periocular area. Most attacks are moderate to severe in intensity and burning, stabbing or electrical in character. The mean duration of paroxysms is 1 minute, with a usual range of 10 to 120 seconds (total range 5 to 250 seconds). Prominent, ipsilateral conjunctival injection and lacrimation regularly accompany the attacks. Nasal stuffiness/rhinorrhoea are frequently noted. In addition, there is subclinical forehead sweating. During attacks, there is increased intraocular pressure on the symptomatic side and swelling of the eyelids. No changes in pupil diameter have been observed. Attacks can be triggered mostly from trigeminally innervated areas, but also from the extratrigeminal territory. There are also spontaneous attacks. An irregular temporal pattern is the rule, with symptomatic periods alternating with remissions in an unpredictable fashion. During active periods, the frequency of attacks may vary from <1 attack/day to >30 attacks/hour. The attacks predominate during the daytime, nocturnal attacks being seldom reported. A SUNCT-like picture has been described in some patients with either intra-axial or extra-axial posterior fossa lesions, mostly vascular disturbances/ malformations. In the vast majority of patients, however, aetiology and pathogenesis are unknown. In SUNCT syndrome, there is a lack of persistent, convincingly beneficial effect of drugs or anaesthetic blockades that are generally effective in cluster headache, chronic paroxysmal hemicrania, trigeminal neuralgia, idiopathic stabbing headache ('jabs and jolts syndrome'), and other headaches more faintly resembling SUNCT syndrome. Single reports have claimed that carbamazepine, lamotrigine, gabapentin, corticosteroids or surgical procedures may be of help. However, caution is recommended when assessing any therapy in a disorder such as SUNCT syndrome, in which the rather chaotic and unpredictable temporal pattern makes the assessment of any drug/therapeutic effect per se a particularly difficult matter.

Gabapentin: pharmacology and its use in pain management

Although its exact mode of action is not known, gabapentin appears to have a unique effect on voltage-dependent calcium ion channels at the postsynaptic dorsal horns and may, therefore, interrupt the series of events that possibly leads to the experience of a neuropathic pain sensation. Gabapentin is especially effective at relieving allodynia and hyperalgesia in animal models. It has been shown to be efficacious in numerous small clinical studies and case reports in a wide variety of pain syndromes. Gabapentin has been clearly demonstrated to be effective for the treatment of neuropathic pain in diabetic neuropathy and postherpetic neuralgia. This evidence, combined with its favourable side-effect profile in various patient groups (including the elderly) and lack of drug interactions, makes it an attractive agent. Therefore, gabapentin should be considered an important drug in the management of neuropathic pain syndromes.

Two cases of medically and surgically intractable SUNCT: a reason for caution and an argument for a central mechanism

We report two cases of SUNCT that demonstrate the medically and surgically refractory nature of this disorder and support the hypothesis that the causative 'lesion' lies within the central nervous system. After both patients had failed medical therapies, the first underwent a glycerol rhizotomy, gammaknife radiosurgery and microvascular decompression of the trigeminal nerve. The second patient underwent gammaknife radiosurgery of the trigeminal root exit zone and two microvascular decompression surgeries. Neither patient benefited from these procedures. Currently, the first patient suffers from anaesthesia dolorosa and the second patient from unilateral deafness, chronic vertigo and dysequilibrium as a result of surgical trauma. These cases of SUNCT highlight the uncertainty regarding the role of surgery given the potential for significant morbidity. These cases also suggest that SUNCT originates and may be maintained from within the CNS and this central locus explains why SUNCT is not typically amenable to interventions aimed at the peripheral portion of the trigeminal nerve.