Treatment of tension-type headache with botulinum toxin type A: a double-blind, placebo-controlled study

OBJECTIVE: To determine whether injections of botulinum toxin could be of therapeutic value in the treatment of tension-type headache. BACKGROUND: Botulinum toxin A is very effective at reducing muscle tenderness and pain in many diseases. Increased muscle tension may contribute to tension-type headache. METHODS: We performed a double-blind, placebo-controlled study with 21 patients fulfilling the International Headache Society criteria for tension-type headache. Participants were randomly assigned to treatment (pericranial injection of 10 x 20 mouse units botulinum toxin A) or placebo (injection of isotonic saline in the same manner). RESULTS: After 4, 8, and 12 weeks, no significant differences between placebo and treatment could be observed (with respect to visual analog scale, frequency and duration of headache attacks, consumption of analgesics, pressure pain threshold, total tenderness score, and quality-of-life parameters). CONCLUSIONS: The findings of our study strongly support the hypothesis that peripheral mechanisms, such as increased muscle tenderness, only play a minor role in the pathogenesis of tension-type headache.     

Botulinum toxin type A (BOTOX) for the prophylactic treatment of chronic daily headache: a randomized, double-blind, placebo-controlled trial

OBJECTIVE: The objective of this study was to evaluate the safety and efficacy of botulinum toxin type A (BoNT-A; BOTOX, Allergan, Inc.) for the prophylactic treatment of chronic daily headache (CDH). BACKGROUND: Several open-label and small controlled trials suggest that BoNT-A may be effective in the prophylactic treatment of headache. DESIGN AND METHODS: This was an 11-month, randomized double-blind, placebo-controlled study of BoNT-A for the treatment of patients aged 18 to 65 years old with 16 or more headache days per 30 days conducted at 13 North American study centers. Following a 30-day screening period and a 30-day, single-blind, placebo-response period to identify placebo responders, eligible patients from both the placebo responder and placebo nonresponder groups were injected with BoNT-A or placebo every 90 days and assessed every 30 days for 9 months, a period encompassing three treatment cycles. The primary efficacy measure was the change from baseline in the frequency of headache-free days in a 30-day period for the placebo nonresponder group at day 180, the chosen efficacy time point. The secondary efficacy measure was the proportion of patients with a decrease from baseline of 50% or more in the frequency of headache days per 30-day period for the placebo nonresponder group at day 180. The change from baseline in the frequency of headaches (per 30-day period), the proportion of patients with a decrease from baseline of 50% or greater in the frequency of headaches per 30-day period, acute medication use, and adverse events were also assessed. RESULTS: Of 571 patients assessed over the baseline period, 355 (mean age, 43.5 years; 300/355 [84.5%] female) were enrolled and randomized. At the end of the placebo run-in period, 279 patients (79%) were classified as placebo nonresponders and 76 patients (21%) as placebo responders. Subsequently, patients were randomized within each group to receive either BoNT-A or placebo. In the placebo nonresponder stratum, the mean number of headache-free days at baseline was 5.8 (+/-4.7) for BoNT-A- versus 5.5 (+/-4.7) for placebo-treated patients. At day 180, placebo nonresponders treated with BoNT-A had an improved mean change from baseline of 6.7 headache-free days per 30-day period compared to a mean change from baseline of 5.2 headache-free days for placebo-treated patients. The between-group difference of 1.5 headache-free days favored BoNT-A treatment, although the difference between the groups was not statistically significant. However, a statistically significant difference was observed at day 180 endpoint for the secondary efficacy measure. A significantly higher percentage of BoNT-A patients had a decrease from baseline of 50% or greater in the frequency of headache days per 30-day period at day 180 (32.7% vs. 15.0%, P=.027). Also, the mean change from baseline in the frequency of headaches per 30-day period at day 180 was -6.1 for BoNT-A patients vs. -3.1 for the placebo patients (P=.013). Only 4 of 173 BoNT-A patients (2.3%) discontinued the study due to adverse events. The majority of treatment-related adverse events were transient and mild to moderate in severity. CONCLUSIONS: BoNT-A treatment resulted in patients having, on average, approximately seven more (1 week) headache-free days compared to baseline. Although at the primary time point (day 180) the BoNT-A treatment resulted in a 1.5 between-group difference compared to placebo, this difference was not statistically significant. The treatment met secondary efficacy outcome measures, including the percentage of patients experiencing a 50% or more decrease in the frequency of headache days, in addition to statistically significant reductions in headache frequency. BoNT-A was also well tolerated in patients with CDH.     

Long-term benefits of botulinum toxin type A (BOTOX) in chronic daily headache: a five-year long experience

Botulinum toxin type A (BoNT-A) has been recently suggested as prophylaxis therapy for the treatment of primary headache chronic forms. Several studies on its efficacy are available, but results are often contradictory and not univocal. The effects of BoNTA on chronic forms of both tension- type headache and migraine have been investigated. In this study we introduce our five-year long experience with BoNT-A (Botox, Allergan, Irvine, CA). The employed dosage was 100 U and the Fixed Sites-Fixed Doses (FSFD) protocol was used. The period of study was April 2001 to July 2006. A sum of 1347 patients suffering from chronic daily headache (CDH) were treated. We registered in these patients the number of headache days per month and observed their reduction in relation to the number of injections. The best results were found after 12 months of treatment, with patients being free of attacks 23 days per month. The BoNT-A treatment was safe and well tolerated, as only 1.6% of patients reported adverse events, and they were all mild and transient. In conclusion, BoNT-A therapy appears to be an efficacious new therapeutic choice in the prophylaxis of CDH, especially for patients not responding to previous prophylactic treatments.     

A one-year retrospective economic evaluation of botulinum toxin type A treatment of chronic tension headache

Abstract The objective was to measure the impact of botulinum toxin type A (BTX-A) treatment on symptoms and medication utilisation patterns in patients with chronic tension-type headache. A retrospective chart analysis was completed in the Day Hospital of the Regional Referral Headache Centre at SantAndrea Hospital in Rome. Clinical charts were randomly selected for 100 patients treated from February 2002 to January 2003. Patients were treated with 100 U of BTX-A every three months for one year by using the Fixed Doses Fixed Sites procedure. Treatment outcome ranged from complete resolution of headache symptoms to a worsening of symptoms resulting in discontinuation. Headache medication use before and after treatment was analysed. After BTX-A treatment, 85% of patients experienced at least some degree of pain relief and reduced their use of analgesics. The reduced percentages of patients using a variety of headache medications after BTX-A treatment results from a reduction in their headache symptoms.     

A one-year prospective costing study of botulinum toxin type A treatment of chronic tension headache

Abstract The objective was to measure the cost of botulinum toxin type A (BTX-A) treatment of chronic tension-type headache. A prospective pharmaceutical costing analysis was completed in the Day Hospital of the Regional Referral Headache Centre at SantAndrea Hospital in Rome, chronic tension-type headache patients were treated from February 2003 to January 2004. Patients were treated with 100 U of BTX-A every three months for one year by using the Fixed Doses Fixed Sites procedure. The cost of treatment was based on drug acquisition costs, supplies and professional time needed to administer treatment. The average cost of conventional headache medications was € 853.43 before BTX-A treatment, and € 450.47 after. The cost of BTX-A treatment was € 642.00. Adding the cost of adjunctive conventional medications brought the total cost of BTX-A treatment to € 1092.47. BTX-A treatment reduced use of conventional headache medications and expenditures although the net cost of treatment increased with BTX-A use.     

Prophylactic pharmacological treatment of chronic daily headache

Objective.—To review all the prophylactic pharmacological treatments for chronic daily headache from the past decade.
Background.—Chronic daily headache is among the most common diagnoses seen in specialized headache centers. Prior to 1988, there were no criteria for the diagnosis of chronic tension-type headache and chronic daily headache. An expanded chronic daily headache classification has been proposed.
Methods.—A MEDLINE search was performed using the following key words: chronic daily headache, intractable headache, transformed migraine, chronic tension headache, and chronic tension-type headache. We limited our review to those studies published in English in the last decade, including published abstracts and letters to the editor. Double-blind studies carried out prior to 1988 were also included.
Results.—Pharmacological treatments for chronic daily headache include antidepressants (tricyclics, tetracyclics, monoamine oxidase inhibitors, selective serotonin reuptake inhibitors), anticonvulsants, muscle relaxants, 5-HT₁ agonists, ergots, 5-HT₂ antagonists, antianxiety agents, and miscellaneous drugs. Many of these reports are anecdotal, and most are open rather than double-blind studies.
Conclusions.—There is a great variety of pharmacological treatments available for chronic daily headache. Only the antidepressants have been extensively studied. Other medications may be used if these fail. Recommendations based on our experience at the Headache Unit of the Montefiore Medical Center are outlined here.     

Effect of botulinum toxin A injections in the treatment of chronic tension-type headache: a double-blind, placebo-controlled trial

In addition to vascular and supraspinal influences, contraction of craniofacial muscles or central sensitization processes following continuous nociceptive input of craniofacial muscles may play an important role in the pathogenesis of tension-type headache. Chemodenervation induced by botulinum toxin injection is successfully used to decrease muscle tension. If muscle tension is important in this type of headache, then botulinum toxin could be helpful in its treatment. We conducted a randomized, placebo-controlled study to examine the effect of 20 U botulinum toxin injected into frontal and temporal muscles in patients with chronic tension-type headache. During a baseline of 4 weeks and a posttreatment period of 8 weeks, the effect was evaluated with daily records and the West Haven-Yale Multidimensional Pain Inventory. Some improvement in affective variables were demonstrated in the botulinum group, but important outcome variables, such as pain intensity, the number of pain-free days, and consumption of analgesics, were not statistically different between the groups. Reasons for these moderate effects may include the injection sites, dose of botulinum toxin, and duration of treatment.     

Botulinum toxin type A for the treatment of nummular headache: four case studies

OBJECTIVE: We assessed the efficacy and safety of botulinum toxin type A (BoNTA; BOTOX): Allergan, Inc., Irvine, CA, USA) in patients with nummular headache who did not respond to other treatments including nonsteroidal anti-inflammatory drugs (NSAIDs), local anesthetics, and/or gabapentin. BACKGROUND: Nummular headache is characterized by circumscribed round or elliptical areas of fluctuating mild-to-moderate head pain in a chronic or remitting pattern. It is a relatively rare primary headache disorder that responds poorly to adequate treatment trials with local anesthetic, migraine, or neuropathic pain agents or NSAIDs. METHODS: Four patients aged 35-58 years with intractable nummular headaches were given 25 units of BoNTA divided among 10 injection sites in and around the circumscribed affected areas of pain, paresthesia, and allodynia. All patients had 2 sets of injections approximately 14 weeks apart. RESULTS: All patients met the International Headache Society criteria for nummular headache (International Classification of Headache Disorders, A13.7.1). Patients were female; mean age of onset was 42 years. Average disease duration prior to BoNTA treatment was 3.75 years. One patient reported concurrent episodic migraine and another reported concurrent tension-type headache. Patients reported round-shaped (n = 2; 6 and 3 cm in diameter), oval (n = 1; 4 x 2 cm), and elliptical (n = 1; 6 cm in length) areas of pain. Painful symptoms were reported in the right parietal convexity (n = 2) and the posterior frontal, unilaterally (n = 2). All patients experienced spontaneous or stimuli-triggered exacerbations and variable combinations of sensory disturbances, including allodynia, tenderness, and paresthesia. The temporal pattern was continuous in 3 patients and intermittent in one. Both the size and shape of the pain remained unchanged in all patients since the onset of nummular headache symptoms. Six to 10 days following BoNTA treatment, all patients experienced a reduction in nummular headache symptoms, which lasted approximately 14 weeks on average. Repeat injections gave the same degree of improvement. No treatment-related adverse events were reported. CONCLUSIONS: BoNTA appears to be a well-tolerated effective treatment for intractable, persistent nummular headache in patients with an inadequate response to other treatments including NSAIDs, gabapentin, or local anesthetics.     

Duration of migraine is a predictor for response to botulinum toxin type A

OBJECTIVE: To identify the clinical characteristics and/or injection parameters that predict a favorable response to botulinum toxin type A in patients with episodic and chronic migraine. BACKGROUND: There is emerging scientific and clinical evidence to support the utility of botulinum toxin type A (BoNT-A) in the prophylaxis of episodic and chronic migraine headache. However, the patient characteristics and injection strategies that predict a favorable treatment response are unknown. METHODS: We conducted a prospective, open-label study on 74 patients from our clinic receiving BoNT-A for episodic or chronic migraine. For all patients, migraine-related disability (Migraine Disability Assesment [MIDAS]), headache frequency, and average headache intensity were obtained at baseline and at 3 months post-BoNT-A. Information regarding demographic characteristics and injection parameters was also collected. RESULTS: Sixty-one patients met the study criteria and were available for 3-month follow-up. At the 3-month follow-up visit, the mean MIDAS scores of the 61 qualified study patients had decreased from 102 at baseline to 49 (52% decrease, P<.001). The mean number of headache days was reduced from 60 to 39 (P<.001), and the mean headache intensity decreased from 7.6 at baseline to 5.9 (P<.001). Frequency of migraine attacks, presence of analgesic overuse, total BoNT-A dose, and presence of underlying muscle tenderness were not predictive of treatment response. Age and duration of migraine were the only clinical factors significantly predictive of treatment response. Age likely was a predictor only as a consequence of duration of illness as subjects with migraine duration greater than 30 years were significantly less likely to respond to treatment with BoNT-A. CONCLUSION: BoNT-A may be effective in decreasing headache frequency, headache intensity, and headache-related disability in episodic and chronic migraine patients. Duration of illness emerged as a predictor of treatment response. Randomized controlled studies should evaluate headache-related disability as a primary endpoint in patients with episodic and chronic headache.     

Treatment of chronic tension-type headache with botulinum toxin: a double-blind, placebo-controlled clinical trial

Botulinum toxin is increasingly advocated as effective treatment in chronic tension-type headache. We conducted a randomized, placebo-controlled clinical trial to prove efficacy of botulinum toxin in chronic tension-type headache. Patients were randomly assigned to receive botulinum toxin (maximum 100 units) or placebo (saline) in muscles with increased tenderness. After 12 weeks there was no significant difference between the two treatment groups in decrease of headache intensity on VAS (-3.5 mm, 95% confidence interval (CI) - 20 to +13), mean number of headache days (-7%; 95% CI - 20 to +4), headache hours per day (-1.4%; 95% CI - 3.9 to +1.1), days on which symptomatic treatment was taken (-1.9%; 95% CI - 11 to +7) and number of analgesics taken per day (-0.01; 95% CI -0.25-0.22). There was no significant difference in patient's assessment of improvement after week 4, 8 and 12. Botulinum toxin was not proven effective in treatment of chronic tension-type headache. Increased muscle tenderness might not be as important in pathophysiology of chronic tension-type headache as hitherto believed.     

Repetitive intravenous prochlorperazine treatment of patients with refractory chronic daily headache

OBJECTIVES: To investigate the efficacy and long-term outcome of intravenous prochlorperazine for the treatment of refractory chronic daily headache. BACKGROUND: Unlike dihydroergotamine, the treatment results of intravenous neuroleptics as first-line agents for refractory chronic daily headache have rarely been reported. METHODS: We retrospectively analyzed the data of inpatients with refractory chronic daily headache who received intravenous repetitive prochlorperazine treatment from November 1996 to March 1999. A semistructured telephone follow-up interview was done in September 1999. RESULTS: A total of 135 patients (44 men, 91 women) were recruited, including 95 (70%) with analgesic overuse. After intravenous prochlorperazine treatment, 121 (90%) achieved a 50% or greater reduction of headache intensity, including 85 (63%) who became headache-free. The mean hospital stay was 6.2 +/- 2.7 days, and mean total prochlorperazine used was 98 +/- 48 mg. Acute extrapyramidal symptoms occurred in 21 patients (16%). One hundred twenty-four patients (92%) were successfully followed up, with a mean duration of 14.3 +/- 7.5 months. Compared with pretreatment status, 93 patients (75%) considered their headache intensity decreased, and 86 patients (69%) considered their headache frequency decreased, although 40 (32%) still had a daily headache. Of the 87 patients with analgesic overuse who could be followed, 61 (70%) no longer overused analgesics. Poor response to prochlorperazine treatment (relative risk, 1.8) and presence of major depression (relative risk, 1.8) were predictors of persistent chronic daily headache at follow-up. CONCLUSIONS: Prochlorperazine was effective and safe in the treatment of patients with refractory chronic daily headache with or without analgesic overuse. Compared with dihydroergotamine, prochlorperazine seemed less effective at achieving "freedom from headache" during hospitalization, but had a similar outcome at follow-up.     

Evaluation of chronic daily headache—comparison to criteria for chronic tension-type headache

The purpose of this study was to evaluate the adequacy of the International Headache Society (IHS) criteria for chronic tension-type headache and, if appropriate, suggest modifications of the IHS classification. We evaluated 100 consecutive patients with chronic daily headache. Approximately two-thirds of our patients fulfilled the criteria for chronic tension-type headache. Most of the patients who failed to meet the criteria did so because they had more than one migrainous feature. Approximately 50% of patients took excessive amounts of analgesic medication. We conclude that the IHS criteria should be modified to include chronic daily headache evolving from migraine; subtypes with and without medication overuse should be distinguished.     

Comorbidity of depressive and anxiety disorders in chronic daily headache and its subtypes

OBJECTIVE: To investigate the frequency of depressive and anxiety disorders in patients with chronic daily headache. BACKGROUND: There is a lack of data in the literature on the extent of psychiatric comorbidity in patients with different subtypes of chronic daily headache. METHODS: We recruited consecutive patients with chronic daily headache seen in a headache clinic from November 1998 to December 1999. The subtypes of chronic daily headache were classified according to the criteria proposed by Silberstein et al. A psychiatrist evaluated the patients according to the structured Mini-International Neuropsychiatric Interview to assess the comorbidity of depressive and anxiety disorders. RESULTS: Two hundred sixty-one patients with chronic daily headache were recruited. The mean age was 46 years, and 80% were women. Transformed migraine was diagnosed in 152 patients (58%) and chronic tension-type headache in 92 patients (35%). Seventy-eight percent of patients with transformed migraine had psychiatric comorbidity, including major depression (57%), dysthymia (11%), panic disorder (30%), and generalized anxiety disorder (8%). Sixty-four percent of patients with chronic tension-type headache had psychiatric diagnoses, including major depression (51%), dysthymia (8%), panic disorder (22%), and generalized anxiety disorder (1%). The frequency of anxiety disorders was significantly higher in patients with transformed migraine after controlling for age and sex (P =.02). Both depressive and anxiety disorders were significantly more frequent in women. CONCLUSION: Psychiatric comorbidity, especially major depression and panic disorders, was highly prevalent in patients with chronic daily headache seen in a headache clinic. These results demonstrate that women and patients with transformed migraine are at higher risk of psychiatric comorbidity.     

A pilot study of botulinum toxin A for headache in cervical dystonia

OBJECTIVE: To evaluate the prevalence of associated headache (HA) pain with craniocervical dystonia and the therapeutic effect of BoNT-A injections on the HA component when injected for cervical dystonia. BACKGROUND: HA associated with craniocervical dystonia is a recent formally codified entity, but has not been systematically studied. METHODS: We identified 44 subjects from three movement disorder clinics who presented with craniocervical dystonia and concurrent HA pain. The subjects were injected with botulinum toxin type A (BoNT-A) and prospectively evaluated with the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS), headache diaries, Headache Impact Test (HIT-6), and Migraine Disability Assessment Scale (MIDAS), along with HA pain anatomy and adverse events, at baseline, and at 4, 8, and 12 weeks post-injection. RESULTS: As expected, all aspects of the TWSTRS robustly improved. Headache diaries and the HIT-6 also improved at 4, 8, and 12 weeks post-injection. Sections of the MIDAS improved, and adverse events were minimal. CONCLUSION: BoNT-A safely improves headache associated with craniocervical dystonia when administered for the primary condition of craniocervical dystonia.     

The prophylactic treatment of chronic daily headache

Chronic daily headache (CDH), a heterogeneous group of headache disorders occurring on at least 15 days per month, affects up to 4% to 5% of the general population. CDH disorders include transformed (or chronic) migraine, chronic tension-type headache, new daily persistent headache, and hemicrania continua. Patients with CDH have greater disability and lower quality of life than episodic migraine patients and often overuse headache pain medications. To date, only topiramate, gabapentin, tizanidine, fluoxetine, amitriptyline, and botulinum toxin type A (BoNTA) have been evaluated as prophylactic treatment of CDH in randomized, double-blind, placebo-controlled, or active comparator-controlled trials. The evidence supporting the use of BoNTA as prophylaxis of CDH is composed of larger and longer trials, as over 1000 patients were evaluated for up to 11 months duration. Compared with placebo BoNTA has significantly reduced the frequency of headache episodes, a recommended efficacy measure for headache trials and has been demonstrated to be safe and very well tolerated with few discontinuations due to adverse events. Side effects are generally transient, mild to moderate, and nonsystemic. The results of clinical trials using traditional oral pharmacotherapy, while supportive of their use as prophylactic treatment of CDH, are limited by several factors, including small numbers of patients, the choice of efficacy measures, and short treatment periods. The use of oral agents was associated with systemic side effects, which may limit their effectiveness as prophylactic treatment of CDH.     

Chronic daily headache in children and adolescents presenting to tertiary headache clinics

BACKGROUND: Adults with chronic daily headache often describe a transformation from episodic migraine and partial retention of migrainous features. Although chronic daily headache has not been investigated as carefully in the pediatric population, one study showed a predominance of coexisting daily headache and episodic migraine, without a clear history of transformation. OBJECTIVE: To identify the clinical features of chronic daily headache in children and adolescents, to evaluate the efficacy of current headache classification criteria, and to compare the features of coexistent daily and episodic headaches so as to determine whether they represent separate syndromes or different stages in the "transformation" process. DESIGN: We surveyed 189 consecutive patients, 18 years of age or younger, who presented for initial evaluation of daily or near daily headache at one of 9 tertiary headache clinics. Data were collected in semistructured interviews employing a standard questionnaire and analyzed using Statistical Analysis Systems and Stata statistical software computer programs. RESULTS: Of the patients enrolled, 70% were female and 87% were white. Mean age was 13.0 +/- 3.1 years. Male gender was associated with a higher degree of reported disability. A family history of headache (typically migraine) was described in 79%. Use of nonsteroidal anti-inflammatory drugs 5 days per week or more was reported by 44% of patients. The International Headache Society (IHS) criteria failed to classify 64% of patients and criteria proposed by Silberstein et al failed to classify 31% of patients. Participating physicians misclassified patients according to criteria of the IHS and Silberstein et al in one third of cases. Nearly one quarter of patients reported two separate headache types with distinguishing characteristics. "Baseline" headache was present 27.3 +/- 4.1 days per month with a mean pain intensity of 5.9 +/- 2.1 on a 10-point scale. Superimposed episodic headache occurred 4.7 +/- 3.8 days per month with a mean pain intensity of 8.4 +/- 1.4, and was more often accompanied by other migrainous symptoms. After logistic regression to control for pain intensity, the only statistically significant difference between the two headache types was a lower prevalence of tension-type head pain with the superimposed headache. CONCLUSIONS: Our data suggest that rather than having two coexistent headache types, children and adolescents with chronic daily headache have a single syndrome that, in many cases, will paroxysmally worsen and gather migrainous features.     

Botulinum toxin type a for the prophylaxis of chronic daily headache: subgroup analysis of patients not receiving other prophylactic medications: a randomized double-blind, placebo-controlled study

OBJECTIVE: To assess the efficacy and safety of botulinum toxin type A (BoNT-A; BOTOX, Allergan, Inc., Irvine, CA) for the prophylaxis of headaches in patients with chronic daily headache (CDH) without the confounding factor of concurrent prophylactic medications. BACKGROUND: Several open-label studies and an 11-month, randomized, double-blind, placebo-controlled study suggest that BoNT-A may be an effective therapy for the prophylaxis of headaches in patients with CDH. DESIGN AND METHODS: This was a subgroup analysis of an 11-month, randomized double-blind, placebo-controlled study of BoNT-A for the treatment of adult patients with 16 or more headache days per 30-day periods conducted at 13 North American study centers. All patients had a history of migraine or probable migraine. This analysis involved data for patients who were not receiving concomitant prophylactic headache medication and who constituted 64% of the full study population. Following a 30-day screening period and a 30-day single-blind, placebo injection, eligible patients were injected with BoNT-A or placebo and assessed every 30 days for 9 months The following efficacy measures were analyzed per 30-day periods: change from baseline in number of headache-free days; change from baseline in headache frequency; proportion of patients with at least 30% or at least 50% decrease from baseline in headache frequency; and change from baseline in mean headache severity. Acute medication use was assessed, and adverse events were recorded at each study visit. RESULTS: Of the 355 patients randomized in the study, 228 (64%) were not taking prophylactic medication and were included in this analysis (117 received BoNT-A, 111 received placebo injections). Mean age was 42.4+/-10.90 years; the mean frequency of headaches per 30 days at baseline was 14.1 for the BoNT-A group and 12.9 for the placebo group (P=.205). After two injection sessions, the maximum change in the mean frequency of headaches per 30 days was -7.8 in the BoNT-A group compared with only -4.5 in the placebo group (P=.032), a statistically significant between-group difference of 3.3 headaches. The between-group difference favoring BoNT-A treatment continued to improve to 4.2 headaches after a third injection session (P=.023). In addition, BoNT-A treatment at least halved the frequency of baseline headaches in over 50% of patients after three injection sessions compared to baseline. Statistically significant differences between BoNT-A and placebo were evident for the change from baseline in headache frequency and headache severity for most time points from day 180 through day 270. Only 5 patients (4 patients receiving BoNT-A treatment; 1 patient receiving placebo) discontinued the study due to adverse events and most treatment-related events were transient and mild to moderate in severity. CONCLUSIONS: BoNT-A is an effective and well-tolerated prophylactic treatment in migraine patients with CDH who are not using other prophylactic medications.