The use of baclofen in cluster headache

Cluster headache: state of the art in treatment

Cluster headache (CH) is the most common and devastating autonomic headache with multiple and recent advances in treatment. However, it usually goes unrecognized and is found to have a delayed and inappropriate treatment. This paper aims to review the current therapeutic options for patients with CH. We conducted a narrative literature review on the treatments available for this condition using the American Academy of Neurology (AAN) classification of therapeutic evidence. We found effective and safe pharmacological and non-pharmacological therapies with heterogeneity of clinical trial designs for patients with CH, and they are divided into three phases, namely, transitional, acute, and preventive interventions. Prednisone (A) is the most studied treatment in the transitional phase; acute attacks are treated using triptans (A), oxygen (A), and non-invasive transcutaneous vagal nerve stimulation (A). Verapamil (A) and monoclonal antibodies (possible A) are considered the first options in preventive treatments, followed by multiple pharmacological and non-pharmacological options in prophylactic treatments. In conclusion, numerous effective and safe treatments are available in treating patients with episodic, chronic, and pharmacoresistant CH according to the clinical profile of each patient.

Recent advances in the diagnosis and management of cluster headache

Cluster headache, a primary headache disorder, consists of short (15-180 minutes), frequent (up to eight a day), unilateral attacks of facial pain with associated ipsilateral autonomic features and restlessness. The attacks are suspected to be one of the most painful human experiences, and the disorder is associated with a high rate of suicidal ideation. Proper diagnosis is key, as some of the most effective treatments, such as high flow oxygen gas, are rarely used in other headache disorders. Yet diagnostic delay is typically years for this disorder, as it is often confused with migraine and trigeminal neuralgia, and secondary causes may be overlooked. This review covers the clinical, pathophysiologic, and therapeutic features of cluster headache. Recent updates in diagnosis include the redefinition of chronic cluster headache (remission periods lasting less than three months instead of the previous one month), and recent advances in management include new treatments for episodic cluster headache (galcanezumab and non-invasive vagus nerve stimulation).

Randomized placebo-controlled study of baclofen in the treatment of muscle cramps in patients with liver cirrhosis

BACKGROUND AND AIMS

Muscle cramps adversely influence the quality of life of patients with liver cirrhosis. Indeed, to date, a well-established therapy for this complication is still lacking. This is the first randomized placebo-controlled trial of baclofen in the treatment of muscle cramps in patients with liver cirrhosis.

PATIENTS AND METHODS

A total of 100 patients with liver cirrhosis and muscle cramps signed an informed consent to participate in this study. They were recruited from the Department of Tropical Medicine-Tanta University Hospital. They were randomized to receive either baclofen or placebo for 3 months. Patients were followed monthly and 1 month after withdrawal. At each visit, the clinicoepidemiological data were recorded, the muscle cramp questionnaire was filled, and any drug-related side effects were reported.

RESULTS

In the baclofen group, the frequency of muscle cramps decreased significantly after 1 and 3 months of treatment (P<0.005), with a significant relapse after withdrawal (P<0.001). Patients receiving baclofen showed a significant decrease in the severity and duration of muscle cramps (P<0.001). After 3 months of baclofen therapy at a dose of 30 mg/day, muscle cramps disappeared completely in 72%, reduced in 20%, and led to no change in 8% of patients. No significant changes in the frequency, severity, and duration of muscle cramps were noted in the placebo group. There were few but nonsignificant side effects in the baclofen group compared with the placebo group.

CONCLUSION

Baclofen was well tolerated, safe, and effective in the treatment of muscle cramps in patients with liver cirrhosis.

Evidence-based treatments for cluster headache

Cluster headache (CH), one of the most painful syndromes known to man, is managed with acute and preventive medications. The brief duration and severity of the attacks command the use of rapid-acting pain relievers. Inhalation of oxygen and subcutaneous sumatriptan are the two most effective acute therapeutic options for sufferers of CH. Several preventive medications are available, the most effective of which is verapamil. However, most of these agents are not backed by strong clinical evidence. In some patients, these options can be ineffective, especially in those who develop chronic CH. Surgical procedures for the chronic refractory form of the disorder should then be contemplated, the most promising of which is hypothalamic deep brain stimulation. We hereby review the pathogenesis of CH and the evidence behind the treatment options for this debilitating condition.

Pharmacotherapy options for cluster headache

INTRODUCTION

Cluster headache (CH) is a primary headache disorder and the most common trigeminal autonomic cephalalgia. Patients suffer from very severe unilateral headache attacks accompanied by ipsilateral trigeminal autonomic symptoms. Previous studies described a high burden of disease due to its impact on social life as well as an increased suicide ideation rate. The mean time to diagnosis in western industrialized countries is estimated at 4 years.

AREAS COVERED

Many treatment options for CH exist, but due to the rarity of the disease, controlled randomized clinical studies remain difficult to perform. This review summarizes the current knowledge about the treatment of CH including internationally accepted treatment guidelines, and an additional MEDLINE search (1 February 2015).

EXPERT OPINION

International treatment recommendations and official guidelines give reassurance about specific pharmacotherapy options for CH, but only few of these are backed by sufficient scientific evidence. The limited therapeutic efficacy in some patients leads to the use of alternative, complementary, but also illicit drugs to better cope with the disease. Many single cases, case series and uncontrolled studies were performed with different substances in an attempt to find a better way to treat or prevent the excruciatingly painful attacks associated with CH. Large-scale, randomized controlled clinical trials are desperately needed in order to further increase the quality of patient care for this outstanding but terrifying disease.

Trigeminal autonomic cephalalgias: beyond the conventional treatments

The trigeminal autonomic cephalalgias include cluster headache, paroxysmal hemicrania, short-lasting unilateral neuralgiform headache attacks, and hemicrania continua. While the majority responds to conventional pharmacological treatments, a small but significant proportion of patients are intractable to these treatments. In these cases, alternative choices for these patients include oral and injectable drugs, lesional or resectional surgery, and neurostimulation. The evidence base for conventional treatments is limited, and the evidence for those used beyond convention is more so. At present, the most evidence exists for nerve blocks, deep brain stimulation, occipital nerve stimulation, sphenopalatine ganglion stimulation in chronic cluster headache, and microvascular decompression of the trigeminal nerve in short-lasting unilateral neuralgiform headache attacks.

Deletion of GABA-B receptor in Schwann cells regulates remak bundles and small nociceptive C-fibers

The mechanisms regulating the differentiation into non-myelinating Schwann cells is not completely understood. Recent evidence indicates that GABA-B receptors may regulate myelination and nociception in the peripheral nervous system. GABA-B receptor total knock-out mice exhibit morphological and molecular changes in peripheral myelin. The number of small myelinated fibers is higher and associated with altered pain sensitivity. Herein, we analyzed whether these changes may be produced by a specific deletion of GABA-B receptors in Schwann cells. The conditional mice (P0-GABA-B1(fl/fl)) show a morphological phenotype characterized by a peculiar increase in the number of small unmyelinated fibers and Remak bundles, including nociceptive C-fibers. The P0-GABA-B1(fl/fl) mice are hyperalgesic and allodynic. In these mice, the morphological and behavioral changes are associated with a downregulation of neuregulin 1 expression in nerves. Our findings suggest that the altered pain sensitivity derives from a Schwann cell-specific loss of GABA-B receptor functions, pointing to a role for GABA-B receptors in the regulation of Schwann cell maturation towards the non-myelinating phenotype.

Efficacy and tolerability of baclofen in substance use disorders: a systematic review

BACKGROUND

It has been reported that baclofen, a drug used in the treatment of spasticity, reduces the severity of withdrawal symptoms and substance use disorders (SUDs) for some psychoactive drugs.

AIMS AND METHODS

To evaluate the effectiveness and safety of baclofen in the treatment of withdrawal syndrome and/or SUDs, providing (1) an outline of its pharmacological features; (2) a summary of studies that have suggested its possible effectiveness in the treatment of SUDs, and (3) a review of randomized, controlled trials (RCTs) on baclofen and SUDs.

RESULTS

Baclofen tolerability is generally considered to be good. Eleven RCTs investigated its effectiveness in the treatment of SUDs. Of these, 5 RCTs found that baclofen is effective, 5 RCTs found that it is ineffective and the results of 1 RCT were not appreciable because it did not achieve the preplanned level of participation.

CONCLUSIONS

The number of RCTs on baclofen and SUDs is still low, and their results are divergent. Further RCTs should be undertaken, particularly with higher doses of baclofen. Its administration may be suggested in patients who fail to respond to other approved drugs or who are affected by liver disease that prevents their administration, or in patients affected by SUDs for which no approved drugs are available. Treatment should be conducted under strict medical supervision.

Cluster headache

Cluster headache (CH) is a primary headache disease characterized by recurrent short-lasting attacks (15 to 180 minutes) of excruciating unilateral periorbital pain accompanied by ipsilateral autonomic signs (lacrimation, nasal congestion, ptosis, miosis, lid edema, redness of the eye). It affects young adults, predominantly males. Prevalence is estimated at 0.5–1.0/1,000. CH has a circannual and circadian periodicity, attacks being clustered (hence the name) in bouts that can occur during specific months of the year. Alcohol is the only dietary trigger of CH, strong odors (mainly solvents and cigarette smoke) and napping may also trigger CH attacks. During bouts, attacks may happen at precise hours, especially during the night. During the attacks, patients tend to be restless. CH may be episodic or chronic, depending on the presence of remission periods. CH is associated with trigeminovascular activation and neuroendocrine and vegetative disturbances, however, the precise cautive mechanisms remain unknown. Involvement of the hypothalamus (a structure regulating endocrine function and sleep-wake rhythms) has been confirmed, explaining, at least in part, the cyclic aspects of CH. The disease is familial in about 10% of cases. Genetic factors play a role in CH susceptibility, and a causative role has been suggested for the hypocretin receptor gene. Diagnosis is clinical. Differential diagnoses include other primary headache diseases such as migraine, paroxysmal hemicrania and SUNCT syndrome. At present, there is no curative treatment. There are efficient treatments to shorten the painful attacks (acute treatments) and to reduce the number of daily attacks (prophylactic treatments). Acute treatment is based on subcutaneous administration of sumatriptan and high-flow oxygen. Verapamil, lithium, methysergide, prednisone, greater occipital nerve blocks and topiramate may be used for prophylaxis. In refractory cases, deep-brain stimulation of the hypothalamus and greater occipital nerve stimulators have been tried in experimental settings. The disease course over a lifetime is unpredictable. Some patients have only one period of attacks, while in others the disease evolves from episodic to chronic form.

EFNS guidelines on the treatment of cluster headache and other trigeminal-autonomic cephalalgias

Cluster headache and the other trigeminal-autonomic cephalalgias [paroxysmal hemicrania, short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT) syndrome] are rare but very disabling conditions with a major impact on the patient's quality of life. The objective of this study was to give evidence-based recommendations for the treatment of these headache disorders based on a literature search and consensus amongst a panel of experts. All available medical reference systems were screened for any kind of studies on cluster headache, paroxysmal hemicrania and SUNCT syndrome. The findings in these studies were evaluated according to the recommendations of the European Federation of Neurological Societies resulting in level A, B or C recommendations and good practice points. For the acute treatment of cluster headache attacks, oxygen (100%) with a flow of at least 7 l/min over 15 min and 6 mg subcutaneous sumatriptan are drugs of first choice. Prophylaxis of cluster headache should be performed with verapamil at a daily dose of at least 240 mg (maximum dose depends on efficacy or tolerability). Although no class I or II trials are available, steroids are clearly effective in cluster headache. Therefore, the use of at least 100 mg methylprednisone (or equivalent corticosteroid) given orally or at up to 500 mg i.v. per day over 5 days (then tapering down) is recommended. Methysergide, lithium and topiramate are recommended as alternative treatments. Surgical procedures, although in part promising, require further scientific evaluation. For paroxysmal hemicranias, indomethacin at a daily dose of up to 225 mg is the drug of choice. For treatment of SUNCT syndrome, large series suggest that lamotrigine is the most effective preventive agent, with topiramate and gabapentin also being useful. Intravenous lidocaine may also be helpful as an acute therapy when patients are extremely distressed and disabled by frequent attacks.

Cluster headache pharmacotherapy

Cluster headache is a well-known primary headache syndrome with a prevalence of about 5/10,000 of the adult population, making it much less common than migraine. Diagnostic terms such as histaminic cephalalgia, Horton's headache and ciliary neuralgia have been used for what is now known as cluster headache. This disorder can be differentiated from migraine by clinical and pathophysiologic features. Cluster headache also exhibits a differing therapeutic response to medications when compared with migraine. The pharmacologic treatment of cluster is reviewed in this article. In contrast to migraine, men are 3-4 times more likely to be diagnosed with cluster headache than women, and the cluster headache population is older. Cluster attacks are known for their brief intense unilateral excruciating pain during susceptible periods known as cluster periods, which typically last weeks. Attack-free months generally follow. Pain is experienced in the distribution of the trigeminal nerve, with unilateral autonomic features. Most patients are successfully managed with medical therapy. Medication management can be divided into abortive treatments for an ongoing attack and prophylactic treatment. Prophylaxis aims to induce and maintain a remission. There are a variety of different medications for abortive and prophylactic therapy, accompanied by a variable amount of evidence-based medicine. For patients refractory to medical management, interventional procedures are available as a last resort. Most procedures are directed against the sensory trigeminal nerve and associated ganglia, eg, anesthetizing the sphenopalatine ganglion.

Cluster headache: pathogenesis, diagnosis, and management

Cluster headache is a stereotyped primary pain syndrome characterised by strictly unilateral severe pain, localised in or around the eye and accompanied by ipsilateral autonomic features. The syndrome is characterised by the circadian rhythmicity of the short-lived attacks, and the regular recurrence of headache bouts, which are interspersed by periods of complete remission in most individuals. Headaches often start about 1-2 h after falling asleep or in the early morning, and show seasonal variation, suggesting that the hypothalamus has a role in the illness. Consequently, the vascular theory has been superseded by recognition that neurovascular factors are more important. The increased familial risk suggests that cluster headache has a genetic component in some families. Neuroimaging has broadened our pathophysiological view and has led to successful treatment by deep brain stimulation of the hypothalamus. Although most patients can be treated effectively, some do not respond to therapy. Fortunately, time to diagnosis of cluster headache has improved. This is probably the result of a better understanding of the pathophysiology in combination with efficient treatment strategies, leading to a broader acceptance of the syndrome by doctors.

Cluster Headache and Cluster Variants

Patients must be cognizant of the time course of the cluster headache periods to optimally tailor their therapy. Steroids provide the fastest onset of prophylactic effect. Once steroids are initiated, it remains difficult to wean patients off of them, and that is why it is always recommended to associate another prophylactic agent from the onset with the steroids. All triptans can be considered; however, only injectable sumatriptan and zolmitriptan have been the subject of controlled studies, and the former remains the gold standard because of its speed of action. Lithium, although not a first-line therapy, remains mainly efficacious for the chronic form of cluster headache. There does not seem a significant tendency for analgesic rebound-withdrawal headache with cluster headache compared with migraine. Scientific studies of the treatment of cluster headache are inherently difficult because of the rarity of the syndrome, the short duration of attacks, and the relatively short duration of the cluster period, along with the presence of spontaneous remissions. Moreover, still a significant proportion of the available evidence on this subject is uncontrolled. Active, rather than placebo, control individuals are recommended. As far as surgical procedures are concerned, although only recently introduced and less documented, gamma-knife radiosurgery should be preferred to the procedures associated with craniotomy, which are inherently associated with a higher complication potential risk.

Topiramate in the treatment of cluster headache

Cluster headache is a well-characterized, strictly unilateral headache with cranial autonomic features and can be classified as episodic or chronic. Cluster attacks reliably are short-lived, often have a clockwise regularity, and can occur daily for weeks or months during an active cluster period. Pharmacologic treatment for this disorder can be divided into abortive and prophylactic agents. Prophylactic agents aim to quickly induce and maintain a remission. Short-term prophylaxis may be attained with the use of steroids, ergotamine, or methysergide, but these agents are not as suitable for continuous use. Verapamil and lithium commonly are used for longer periods and other agents, such as melatonin and baclofen, also are considered useful. There has been increased interest in the use of anticonvulsants for pain syndromes such as primary headache disorders. This includes topiramate use for cluster prophylaxis; a number of open-label studies have had encouraging results. This article provides an overview of topiramate and the open-label studies of this agent in the prevention of cluster headache.