Therapeutic uses of botulinum toxin

Health related quality of life is improved by botulinum neurotoxin type A in long term treated patients with focal dystonia

OBJECTIVES

The advent of botulinum neurotoxin type A (BoNT/A) gave rise to substantial progress in the treatment of focal dystonias. In the light of the high costs of the toxin and the necessity to establish valid outcome indices for this treatment apart from sheer reduction of dystonic muscle tone and posture, the impact of focal dystonia and its treatment with BoNT/A on patients' health related quality of life (HRQL) was determined.

METHODS

Fifty patients with cranial and cervical dystonia treated long term with BoNT/A were enrolled in a prospective, open labelled cohort study. The HRQL was assessed using the EuroQol (EQ-5D) and the short form 36 health survey questionnaire (SF-36) at baseline before BoNT/A injections and at two follow up visits after 6 and 12 weeks covering one BoNT/A treatment period with maximum effect size at the first follow up.

RESULTS

Compared with a general population sample, a considerable negative impact of focal dystonia on HRQL was found in patients under investigation. In both disease types, BoNT/A treatment led to a significant improvement in several HRQL dimensions, in particular providing moderate to marked effect sizes in the fields of mental health and pain. The impairment of HRQL due to pain as well as the BoNT/A induced improvement within this SF-36 subscore were significantly higher in patients with cervical dystonia. Under BoNT/A therapy, no correlation was found between changes of clinical outcome scores and HRQL measures.

CONCLUSIONS

The data confirm that BoNT/A is able to induce a significant, but temporary amelioration of several aspects of HRQL in both types of focal dystonia. This may substantially contribute to the patients' subjective benefit from the therapy. Moreover, the data provide further arguments to accept high costs of the BoNT/A treatment in these severely handicapped patients, as a consequence of its considerable benefit on quality of life.

Clostridium botulinum and the ophthalmologist: a review of botulism, including biological warfare ramifications of botulinum toxin

The anaerobic bacterium Clostridium botulinum causes disease by elaborating an extremely potent neurotoxin that inhibits release of acetylcholine at presynaptic nerve endings, thereby resulting in a descending flaccid paralysis and autonomic nervous system dysfunction. Possible ophthalmological effects of this neurotoxin are many and typically constitute the earliest manifestations of botulism. This review summarizes the medical literature on botulism with regard to historical perspective, epidemiology, clinical manifestations, and treatment. Ophthalmological findings of botulism are tabulated and their frequencies are provided. Finally, the bioterrorism/biologic warfare ramifications of botulinum toxin are briefly discussed.

The pharmacology of the internal anal sphincter and new treatments of ano-rectal disorders

Surgical options for faecal incontinence in the presence of intact sphincters are limited. Furthermore, in patients with fissures, lateral sphincterotomy reduces anal sphincter hypertonia but there has been concern about complications. A greater understanding of the basic pharmacology of the internal anal sphincter has led to the development of novel treatments for both these disorders. A Medline review was undertaken for internal anal sphincter pharmacology, anal fissures and faecal incontinence. This review is based on these articles and those found by further cross-referencing. Nitric oxide released from non-adrenergic non-cholinergic nerves is the main inhibitory agent in the internal anal sphincter. Relaxations are also mediated through beta-adrenoceptors and muscarinic receptors. Stimulation of alpha-receptors results in contraction. Calcium and its entry through L-type calcium channels is important for the maintenance of tone. Nitric oxide donors produce reductions in resting anal tone and heal fissures but are associated with side-effects. Muscarinic agents and calcium channel antagonists show promise as low side-effect alternatives. Botulinum toxin appears more efficacious than other agents in healing fissures. To date, alpha-receptor agonists have been disappointing at improving incontinence. Further understanding of the pharmacology of the internal anal sphincter may permit the development of new agents to selectively target the tissue with greater efficacy and fewer side-effects.

Complications and adverse reactions with the use of botulinum toxin

Botulinum toxins are the causative agents of the severe food-borne illness botulism. With lethal doses approximating 10(-9) g/kg body weight, these neurotoxins represent some of the most toxic naturally occurring substances. Regardless, botulinum toxin is considered a safe therapy for inappropriate muscle spasms with adverse effects being typically self-limited. This article deals with some of the complications that have occurred with these treatments. The greatest concern with the use of BOTOX is probably the formation of blocking antibodies leading to nonresponse of subsequent treatment. Prevalence of resistance is less than 5%. Most complications associated with its aesthetic use are few and anecdotal. Nevertheless, the common problems and pitfalls associated with aesthetic treatment of the various areas of the face and neck with botulinum toxin are discussed. Also included are recommendations as to how to avoid these very undesirable, yet common, problems.

Anterior rectocele due to obstructed defecation relieved by botulinum toxin

Background. Surgical repair of rectocele does not always alleviate symptoms related to difficulty in defecation, and some patients have impaired fecal continence after surgical treatment. To avoid complications of surgical repair, we investigated the efficacy of botulinum toxin in treating patients with symptomatic rectocele. Methods. Fourteen female patients with anterior rectocele were included in the study. The patients were studied by using anorectal manometry and defecography, and then treated with a total of 30 units of type A botulinum toxin, injected into 3 sites, 2 on either side of the puborectalis muscle and the third anteriorly in the external anal sphincter, under ultrasonographic guidance. Results. After 2 months, symptomatic improvement was noted in 9 patients (P =.0003). At the same time, rectocele depth (mean +/- SD) was reduced from 4.3 +/- 0.6 cm to 1.8 +/- 0.5 cm (P =.0000001) and rectocele area from 9.2 +/- 1.3 cm(2) to 2.8 +/- 1.6 cm(2) (P =.0000001). Anorectal manometry demonstrated decreased tone during straining from 70 +/- 28 mm Hg at baseline to 41 +/- 19 mm Hg at 1 month (P =.003) and to 41 +/- 22 mm Hg at 2 months (P =.005). No permanent complications were observed in any patient for a mean follow-up period of 18 +/- 4 months. At 1 year evaluation, incomplete or digitally assisted rectal voiding was not reported by any patient, and a rectocele was not found at physical examination. Four recurrent, asymptomatic rectoceles were noted at defecography. Conclusions. Botulinum toxin injections should be considered as a simple therapeutic approach in patients with anterior rectocele. The treatment is safe and less expensive than surgical repair. A more precise method of toxin injections under transrectal ultrasonography accounts for the high success rate. Repeated injections may be necessary to maintain the clinical improvement.

Indications and efficacy of botulinum toxin in disorders of the gastrointestinal tract

In recent years, botulinum toxin type A (BT) has been found to be effective in the treatment of various spastic disorders of smooth muscle in the upper and lower gastrointestinal tract. The short-term efficacy of intrasphincteric injection of BT in achalasia is now well established, however, because of the chronic nature of the disease, patients will require repeated injections at regular intervals. In contrast, after a single injection into the anal sphincter, BT has impressively high healing rate with minimal side effects. BT remains a novel therapeutic approach in a range of other gastrointestinal motility disorders including diffuse oesophageal spasm, sphincter of Oddi dysfunction and anismus, and the list of its indications is increasing. BT seems to be safe but as its long-term effects remain unestablished, it should be used with caution in younger patients. In this review we discuss the mechanism of action, indications, efficacy and side-effects of BT with its use in various areas of gastrointestinal tract.

A prospective study of the effect of botulinum toxin A on masseteric muscle hypertrophy with ultrasonographic and electromyographic measurement

We evaluated the effect of botulinum toxin A on masseteric muscle hypertrophy by using ultrasound and electromyography. Five patients (four with bilateral and one with unilateral masseteric muscle hypertrophy) were studied prospectively. In each patient, ultrasound-guided percutaneous intramuscular injection of botulinum toxin A was carried out. The change in muscle bulk was evaluated using serial ultrasonography and the electrical activity was assessed with electromyography. All five patients (nine hypertrophic muscles) showed a good response, with the maximal effect of a 31% reduction in muscle bulk seen 3 months after treatment. The effect remained stable one year after injection for six of the hypertrophic muscles, whereas three muscles needed a second injection to maintain the atrophy. This preliminary prospective study suggests that botulinum toxin A is a safe alternative method of treating masseteric muscle hypertrophy. However, the effect may be temporary and further intramuscular injection may be required to maintain atrophy.

Remote F-wave changes after local botulinum toxin application

OBJECTIVE

Although the therapeutic effects of botulinum toxin A can be explained by its action at the neuromuscular junction, central or more proximal effects have also been discussed.

METHODS

Eleven patients with torticollis spasmodicus and 3 patients with writer's cramp were studied before and 1 and 5 weeks after the first treatment with botulinum toxin. We measured compound muscle action potentials (CMAPs), motor conduction velocities (MCVs), the shortest (SFL) and the mean F-wave latencies (MFL) and F-wave persistence (30 trials) of untreated muscles for each side (ulnar nerve-abductor digiti minimi muscle, peroneal nerve-tibialis anterior muscle).

RESULTS

CMAPs and MCVs showed no significant changes. For both nerves, however, SFL and MFL were prolonged slightly 1 week after treatment and returned to about baseline after 5 weeks (t test). The F-wave persistence was reduced 1 week after treatment for the right ulnar and both peroneal nerves (t test).

CONCLUSIONS

These results are not likely due to an impairment of neuromuscular transmission. Instead, we propose a decreased excitability of alpha-motoneurons supplying non-treated muscles. A reduction of muscle spindle activity or changes of the recurrent inhibition are discussed as possible causes.

Anal Fissure

Anal fissure is a common condition, and although most are short-lived and heal spontaneously, those that persist and require intervention cause considerable morbidity in an otherwise healthy young population. Traditionally, lateral internal sphincterotomy was the gold standard treatment for chronic fissures, but this procedure is associated with a risk of incontinence to some degree in 30% of patients. The discovery of pharmacologic agents that effectively cause a chemical sphincterotomy and heal most fissures has led to approximately two thirds of patients avoiding surgery. Topical 0.2% GTN ointment probably is the most widely used first-line treatment. Other drugs currently under investigation may offer effective treatment with fewer side effects. Another advantage of these novel treatments is that by acting through different pathways, they may be effective in the 30% of cases in which GTN fails, the risks associated with surgery may be avoided. Studies of botulinum toxin injection into the anal sphincter have reported excellent healing rates, although the procedure is more invasive, and patients may find it uncomfortable and less tolerable. Chemical sphincterotomy is particularly suitable in patients with associated inflammatory bowel disease, in whom sphincterotomy for anal fissure generally is contraindicated. When pharmacologic therapy fails or fissures recur frequently and patients have raised resting anal pressure, lateral internal sphincterotomy is the surgical treatment of choice. The results are satisfactory when patients are selected carefully and the incision is limited to the length of the fissure. When chemical sphincterotomy fails and resting anal pressures are not elevated, as is commonly the case with patients developing fissures postpartum, an advancement flap should be considered.

Treatment of tremor and dystonia

Treatment of movement disorders has expanded beyond traditional therapies with oral medications to include injection of drugs like botulinum toxin and the use of surgical interventions in cases that do not respond to medical therapy. This article provides an overview to the diagnosis and treatment of tremor and dystonia. The distinguishing features of rest, postural, and kinectic tremor are detailed with medical and surgical modalities for treatment. A discussion of idiopathic and secondary dystonia with focus on diagnosis and medical and surgical treatments encompasses the second part of the article.

A comparison of common bile duct pressures after botulinum toxin injection into the sphincter of Oddi versus biliary stenting in a canine model

BACKGROUND

Botulinum toxin A (Botox) functionally paralyzes the sphincter of Oddi in both animals and humans, resulting in reduced pressures. No study, however, has specifically addressed common bile duct (CBD) pressures after Botox injection into the sphincter of Oddi with regard to treating biliary leaks and fistulae. The goals of this present study are to compare, versus biliary stenting, the change in CBD pressures after Botox injection into the sphincter of Oddi, as well as to evaluate the timing of onset and duration of these effects on sphincteric relaxation.

METHODS

After midline laparotomy in 20 mongrel dogs, a pediatric umbilical catheter was inserted into the CBD via a small cholecystotomy and attached to a water-perfused pressure transducer. After baseline CBD pressure readings, a lateral duodenotomy was performed. A total of 100 units of Botox was injected with an endoscopic sclerotherapy needle into all four quadrants of the ampulla. The dogs were randomly divided into four groups to undergo repeat laparotomy at either postoperative day 1 (group I), postoperative day 3 (group II), postoperative day 7 (group III), or postoperative day 14 (group IV). At the time of second laparotomy, a pressure-sensing catheter was reinserted into the CBD and pressures recorded. Each dog then underwent transpapillary biliary stenting with a 7 Fr. x 5 cm Cotton-Leung biliary stent and CBD pressures were again recorded.

RESULTS

CBD pressures were significantly lower as compared with baseline for all groups after Botox injection and after biliary stenting (P <0.001) In addition, no significant differences in the degree of CBD pressure reduction were identified between groups I through IV after Botox injection. The measured decrease in CBD pressure from baseline after Botox injection as compared with biliary stenting was significantly different for groups I and II (P <0.05) but not for groups III and IV.

CONCLUSION

Botox injection into the sphincter of Oddi results in significant CBD pressure reduction within 24 hours and continues for 14 days. Also, after postoperative day 3, there is no significant difference in the reduction of CBD pressure from baseline between Botox injection and biliary stenting. Based on these findings, Botox injection into the sphincter of Oddi may be a beneficial alternative to biliary stenting for the treatment of biliary leaks and fistulae.

Dose thresholds and duration of the local anhidrotic effect of botulinum toxin injections: measured by sudometry

BACKGROUND

Local injections of botulinum toxin type A (BTX-A) have been used successfully to treat focal hyperhidrosis, but because experimental data were lacking, doses have been chosen arbitrarily or empirically.

OBJECTIVES

To analyse dose dependency and duration of BTX-A-derived suppression of sweat gland activity.

METHODS

Employing a standardized scheme (four injections, square 2 x 2 cm), different doses of BTX-A [Dysport(R); 2.5-120 mouse units (MU)] were injected subcutaneously at the lateral aspects of both of the lower legs in 15 healthy volunteers. Sweat tests were performed before, and 3 weeks and 6 months after, BTX-A injections. Sweating was visualized by staining with iodine starch, and quantified by capacitance hygrometry after carbachol iontophoresis, the quantitative sudomotor axon reflex test (QSART).

RESULTS

Iodine starch staining indicated a threshold dose of 10 MU (2.5 MU cm-2) leading to visible anhidrotic skin spots after 3 weeks in all subjects. This was maintained for 6 months with doses of 50 MU (12.5 MU cm-2) or higher, but the size of the anhidrotic skin area decreased over time (P < 0.001) indicating partial recovery at the edges. After 3 weeks QSART was significantly reduced (P < 0.02) and completely suppressed by doses of 80 MU (20 MU cm-2) or more, although after 6 months QSART increased again to pre-BTX-A levels (P < 0.001). Both methods indicated that the suppression of sweating is dose dependent (QSART: r = -0.70, P < 0.001; iodine starch staining: r = 0.74, P < 0.001).

CONCLUSIONS

Our findings suggest that BTX-A effectiveness can be quantified by testing sudomotor function. For the first time threshold doses for the suppression of sweating have been defined.

Efficacy and complications of dose increments of botulinum toxin-A in the treatment of horizontal comitant strabismus

PURPOSE

To investigate the efficacy and complications associated with dose increments of botulinum toxin-A (BTA) for comitant horizontal strabismus patients.

METHODS

Twenty-five esotropic (ET) and 45 exotropic (XT) patients received 2.5-20 U of BTA injection. Parameters for achieving less than 10 prism dioptres (pd) of horizontal deviation and percentage correction of the pretreatment deviation were assessed for injections of less than 10 U and more than 10 U of BTA. Induced ptosis and vertical deviation were examined within and after 6 months of follow-up.

RESULTS

The mean pretreatment deviations were 38.6 +/- 2.5 pd and 37.6 +/- 1.9 pd for the ET and XT groups, respectively. After receiving 1.6 and 1.5 injections on average, improvement to less than 10 pd at the primary position occurred in 32% of ET and 22% of XT patients; the difference was not statistically significant. The percentage corrections of the ET patients were 41.4 +/- 9.3% and 36.9 +/- 5.6% in those treated with less than 10 U and more than 10 U of BTA respectively; the difference between the two groups was insignificant. For the XT patients the values were 42.1 +/- 7.4% and 28.9 +/- 3.5% respectively, which also were not statistically significantly different. Frequency of induced ptosis was more common in ET than XT patients (p = 0.01) and this difference was more pronounced with increased doses of BTA (7.7% in ET and 5.3% in XT patients with less than 10 U of BTA, and 24.0% in ET and 4.3% in XT patients with more than 10 U of BTA). Ptosis resolved completely within 6 weeks in all cases. Induced vertical deviation with less than 10 U of BTA was encountered in one case of ET (11.1%, 9 pd) and in another case of XT (8.3%, 4 pd), increasing to 60.0% (2-20 pd) and 38.8% (4-16 pd) respectively with more than 10 U of BTA injection. In about a year, induced vertical deviation resolved in approximately 40%, and decreased in 30% of the cases.

CONCLUSION

Increasing the dose of BTA is clinically effective in larger deviations, although statistically indifferent, especially in ET compared with XT. However, an increased dose is accompanied by increased incidence of induced ptosis and vertical deviation. Ptosis is temporary, but vertical deviation may persist for a long time and may present a cosmetic problem for some patients when more than 10 U of BTA is used.

Randomised double blind placebo controlled trial of the effect of botulinum toxin on walking in cerebral palsy

BACKGROUND

Cerebral palsy is the commonest cause of severe physical disability in childhood. For many years treatment has centred on the use of physiotherapy and orthotics to overcome the problems of leg spasticity, which interferes with walking and can lead to limb deformity. Intramuscular botulinum toxin (BT-A) offers a targeted form of therapy to reduce spasticity in specific muscle groups.

AIMS

To determine whether intramuscular BT-A can improve walking in children with cerebral palsy.

DESIGN

Randomised, double blind, placebo controlled trial.

METHODS

Forty patients with spastic diplegia or hemiplegia were enrolled. Twenty two received botulinum toxin and 18 received placebo. The primary outcome measure was video gait analysis and secondary outcome measures were gross motor function measure (GMFM), physiological cost index (PCI), and passive ankle dorsiflexion.

RESULTS

Video gait analysis showed clinically and statistically significant improvement in initial foot contact following BT-A at six weeks and 12 weeks compared to placebo. Forty eight per cent of BT-A treated children showed clinical improvement in VGA compared to 17% of placebo treated children. The GMFM (walking dimension) showed a statistically significant improvement in favour of the botulinum toxin treated group. Changes in PCI and passive ankle dorsiflexion were not statistically significant.

CONCLUSION

The study gives further support to the use of intramuscular botulinum toxin type A as an adjunct to conventional physiotherapy and orthoses to reduce spasticity and improve functional mobility in children with spastic diplegic or hemiplegic cerebral palsy.

A prospective study of botulinum toxin for internal anal sphincter hypertonicity in children with Hirschsprung's disease

BACKGROUND

Internal anal sphincter hypertonicity with nonrelaxation can cause persistent constipation and obstructive symptoms in children after surgery for Hirschsprung's disease. Intractable symptoms traditionally have been treated with anal myectomy, which may be ineffective or complicated by long-term incontinence. The authors evaluated prospectively the use of intrasphincteric botulinum toxin for these patients.

METHODS

Eighteen children were studied (age 1 to 13; median, 4 years). Botulinum toxin was injected (total dose 15 to 60 U) into 4 quadrants of the sphincter. Resting sphincter pressure was measured in 14 patients before and after injection. Ten have had 1 to 5 additional injections (total dose, 30 to 60 U per injection).

RESULTS

Four patients had no improvement in bowel function, 2 had improvement for less than 1 month, 7 had improvement for 1 to 6 months, and 5 had improvement more than 6 months. Nine of those with symptomatic improvement longer than 1 month had pressures measured, with a documented decrease in 8. Five with no significant clinical improvement had pressure measurements, with a decrease in 3. There were no adverse effects associated with botulinum toxin injection. Four children had new encopresis postinjection, which was mild and resolved in each case.

CONCLUSIONS

Intrasphincteric botulinum toxin is a safe and less-invasive alternative to myectomy for symptomatic internal sphincter hypertonicity. Persistent symptoms, despite a fall in sphincter pressure, suggest a nonsphincteric etiology. Repeat injections often are necessary for recurrent symptoms.

Utility of an EMG mapping study in treating cervical dystonia

Intramuscular injections of botulinum toxin are the cornerstone of treatment for cervical dystonia. Controversy exists regarding the necessity for EMG-guided injections. We compared the clinical examination of four movement disorder specialists to an electromyographic (EMG) mapping study. Clinical predictions of individual muscle involvement were only 59% sensitive and 75% specific. Muscle hypertrophy, shoulder elevation, and dominant head vector did not bolster clinical accuracy. An EMG mapping study facilitates identification of dystonic muscles in cervical dystonia, which may enhance botulinum toxin therapy.

Botulinum toxin for achalasia in children

BACKGROUND

Injection of botulinum toxin (BTx) into the lower esophageal sphincter (LES) of adult patients with achalasia results in the effective relief of symptoms. The aim of the present study was to examine the effectiveness of BTx in pediatric patients suffering from achalasia.

METHODS

Seven patients suffering from achalasia with or without prior treatment were treated with intrasphincteric injection of BTx. The median duration of follow up was 15 months.

RESULTS

All seven patients improved. The median interval before recurrence of symptoms was 4 months (range 1-14 months). There was an inverse relationship between the pretreatment LES pressure and the duration of response (r=-0.6). The mean pretreatment LES pressure in the subgroup with a response greater than 6 months was 38+/-10 mmHg compared with 61+/-12 mmHg in the other four patients (P= 0.05). All seven patients required retreatment.

CONCLUSION

Botulinum toxin is effective in relieving symptoms in pediatric patients suffering from achalasia, producing a sustained response beyond 6 months in 43% of patients.

An evaluation of botulinum-A toxin injections to improve upper extremity function in children with hemiplegic cerebral palsy

OBJECTIVE

In a randomized, controlled, single-blind trial, to test the hypothesis that botulinum-A toxin (BTA) injections into the upper extremity of children with spastic hemiplegia improve upper extremity function.

STUDY DESIGN

Thirty children with hemiplegia, aged 2.5 to 10 years, were randomly assigned to receive: (1) a BTA injection into 1 or more of 3 muscle groups (biceps, volar forearm muscles, adductor pollicis) plus occupational therapy or (2) occupational therapy alone. Blinded outcomes obtained at baseline and at 1, 3, and 6 months included the Quality of Upper Extremity Skills Test (QUEST), goniometry measurements, grip strength, and Ashworth scores. The caregiver completed the self-care domain of the Pediatric Evaluation of Disability Inventory.

RESULTS

Twenty-nine subjects completed the study. The QUEST demonstrated a significant improvement favoring the treatment group on a 2-way analysis of variance (F = 4.69, df = 1,83; P =.039). BTA treatment was also associated with an improvement in score on the self-care domain of the Pediatric Evaluation of Disability Inventory (F = 4.68, df = 1,82; P =.04).

CONCLUSIONS

This study supports the effectiveness of BTA injections to improve upper extremity function of children with hemiplegia who have at least moderate spasticity.

Pharmacotherapy with botulinum toxin: harnessing nature's most potent neurotoxin

Botulinum toxin (BTX), a potent biologic neurotoxin, commonly is associated with lethal outbreaks of food poisoning; however, it also plays a role as a therapeutic agent. Since the 1970s physicians have investigated BTX therapy in patients with neurologic disorders. The number of applications greatly expanded over the years to include certain focal dystonias (blepharospasm, torticollis, laryngeal dystonias, writer's cramp), strabismus, and a wide variety of other indications (gastrointestinal disorders, cosmetic wrinkle correction, spasticity, hyperhidrosis). BTX's safety and efficacy are reviewed.

Identification of the characteristics that underlie botulinum toxin potency: implications for designing novel drugs

Botulinum toxin is a uniquely potent substance whose natural site of action is the peripheral cholinergic nerve ending. A substantial amount of information on the cellular, subcellular and molecular aspects of toxin action has been accumulated, and as a result a sound understanding of the basis for toxin potency has been developed. The principal characteristics of the toxin molecule that account for its potency are its ability: a) to be absorbed from the gut with minimal degradation; b) to bind to receptors that maximize the prospects of a pathophysiologic outcome; c) to act by a multiplicative (viz., enzymatic) mechanism; and d) to modify a substrate that is essential for neuronal function. Interestingly, the same properties that account for potency can also be exploited to utilize the toxin as a research tool and as a therapeutic agent. Several specific examples of ways to use the toxin advantageously are presented, including: a) development of oral medications and vaccines; b) analysis of subcellular mechanisms that govern transcytosis; c) identification of cell surface markers characteristic of cholinergic nerve endings; and d) analysis of specific aspects of exocytosis, such as spontaneous quantal release and synchronous quantal release. In all likelihood, further studies on the mechanism of botulinum toxin action will reveal yet further opportunities for utilizing it as a research tool or therapeutic agent.

Mexiletine in the treatment of torticollis and generalized dystonia

Mexiletine is an antiarrhythmic drug that has been reported to exert antidystonic properties. We performed an open-label study to collect further evidence of the antidystonic effect of mexiletine in spasmodic torticollis (ST) and to evaluate its possible use in generalized dystonia. We administered mexiletine to six patients with dystonia (three with generalized dystonia and three with ST) who had failed to respond to previous pharmacotherapy. The drug was started at a dose of 200 mg/d by mouth and increased up to a maximum dose of 800 mg/d. Patients were evaluated at regular intervals over a 6-week period with use of the Fahn & Marsden Dystonia Scale and the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) and videotaped. At the end of the trial, the videotapes were reviewed and scored by a blind observer. Patients were then followed for at least 1 year and evaluated every 3 months at the dose reached during the study period. No adverse effects were reported in five patients; in one patient, dizziness developed at the dosage of 800 mg/d, requiring a reduction of the dose. At the end of a 6-week period, a significant improvement in the rating scale for dystonia and in videotape ratings was observed after mexiletine treatment (p < 0.01). Our data indicate that mexiletine is a useful drug in dystonia treatment.

Intrasphincteric botulinum toxin type A for the diagnosis of sphincter of Oddi dysfunction: a case report

Biliary-type pain from sphincter of Oddi dysfunction is not uncommon after cholecystectomy. An increased basal pressure of sphincter of Oddi manometry establishes the diagnosis and treatment is usually by endoscopic sphincterotomy. Both procedures carry a significant complication rate. A few patients with elevated sphincter pressure do not respond to therapy; the source of their pain may be elsewhere. This case report describes the use of intrasphincteric botulinum toxin injection for the diagnosis of sphincter of Oddi dysfunction in a patient after repeated attempts at manometry had failed. This may provide a safe and easy method of determining whether sphincter of Oddi dysfunction may be the cause of biliary pain in post/ cholecystectomy patients and help select patients who would benefit from subsequent sphincter ablation, without the risks of sphincter of Oddi manometry. Prospective studies are first needed.

Long-term follow-up of achalasic patients treated with botulinum toxin

Botulinum toxin A (BoTx), a potent inhibitor of acetylcholine release from nerve endings both within the myenteric plexus and at the nerve-muscle junction, has been shown to decrease the lower esophageal sphincter (LES) pressure in patients with achalasia. Because of this property, the esophageal injection of BoTx has been suggested as an alternative treatment in achalasia. The objective of this study was to determine the long-term efficacy and safety of intrasphincteric injection of BoTx in a group of achalasic patients. Nineteen patients (mean age 56.1 +/- 19.2 years) were enrolled in the study. All of them were injected endoscopically with 100 U of BoTx by sclerotherapy needle at different sites of the LES. Symptom score (dysphagia, regurgitation and chest pain, each on a 0-3 scale), esophageal manometer and esophageal radionuclide emptying were assessed before the treatment and at 4 weeks, 3 months and 1 year after BoTx injection. In case of failure or relapse (symptom score > 2), the treatment was repeated. All but five patients (74%) were in clinical remission at 1 month. Mean symptom score after 1 month of BoTx decreased from 7.1 +/- 0.9 to 2.2 +/- 2.5 (p < 0.05). LES pressure decreased from 38.4 +/- 13.7 to 27.4 +/- 13.5 mmHg (p < 0.05) and 10-min radionuclide retention decreased from 70.9 +/- 20.7% to 33.8 +/- 27.0% (p < 0.05). Side-effects (transient chest pain) were mild and infrequent. At 12 months, the clinical score was 0.9 +/- 0.5 (p < 0.05 vs. basal); mean LES pressure was 22.0 +/- 7.1 (p < 0.05 vs. basal) and 10-min radionuclide retention was 15.8 +/- 6.0% (p < 0.05 vs. basal). The efficacy of the first injection of BoTx lasted for a mean period of 9 months (range 2-14 months). At the time of writing (follow-up period mean 17.6 months, range 2-31), 14 patients (10 with one injection) were still in remission (74%). Our results showed that one or two intrasphincteric injections of BoTx resulted in clinical and objective improvement in about 74% of achalasic patients and are not associated with serious adverse effects; the efficacy of BoTx treatment was long lasting; this procedure could be considered an attractive treatment, especially in elderly patients who are poor candidates for more invasive procedures.

Botulinum toxin injected in the gastric wall reduces body weight and food intake in rats

BACKGROUND

Botulinum toxin is a powerful, long-acting inhibitor of muscular contractions in both voluntary and smooth muscle. It acts by blocking the release of the neurotransmitter acetylcholine. In the stomach, propulsive contractions of the antrum are necessary for the gastric contents to pass into the duodenum.

AIMS

To investigate whether intramuscular injections of botulinum toxin type A into the gastric antrum of rats would cause a reduction in food intake and hence body weight, by inhibition of gastric emptying.

MATERIALS AND METHODS

This was a prospective, randomized, 3-way parallel group study in rats. The first group was anaesthetized, laparotomized and given 20 U of botulinum toxin type A by intramuscular injection into the gastric antrum (botulinum toxin type A group, n=14). The second group was anaesthetized, laparotomized and injected with saline (sham group, n=14) and the third group did not have any intervention (control group, n=5). Food intake was measured daily for 7 weeks and body weight was measured daily for 10 weeks.

RESULTS

There was a significant difference in loss of body weight between the two treated groups (14.0 +/- 8.2% botulinum toxin type A group, 4.4 +/- 2.7% sham group; P < 0.001). Further, the time to reach the weight nadir was significantly longer in the botulinum toxin type A group (8.7 +/- 3.9 days) compared with the sham group (5.3 +/- 3.8 days; P < 0.04). There were no significant differences between the sham and control groups for any of the body weight parameters. The minimum dietary intake was significantly lower in the botulinum toxin type A group than in the sham group (37.8 +/- 21.8% of the basal value in the botulinum toxin type A group, vs. 65.5 +/- 32.0 in the sham group, P < 0.05). In addition, the time to reach the nadir was significantly prolonged (8.2 +/- 3.5 days, botulinum toxin type A group vs. 4.9 +/- 1.7 days, sham group, P < 0.001).

CONCLUSIONS

The parallel reduction of body weight and food intake in botulinum toxin type A treated animals is consistent with a long lasting inhibition of the antral pump. This is probably due to slowed gastric emptying leading to early satiety. Patients with morbid obesity might benefit from endoscopic injections of botulinum toxin type A into the stomach wall.

Botulinum toxin injection of the cricopharyngeus muscle for the treatment of dysphagia

OBJECTIVE

This study was conducted to evaluate, subjectively and objectively, the diagnostic and therapeutic effects of botulinum toxin (Botox) in patients with dysphagia caused by cricopharyngeus (CP) muscle spasm and/or hypertonicity.

METHODS

A retrospective chart review was done of 5 patients with normally functioning larynges treated with CP Botox injection for dysphagia caused by perceived spasm. Subjective measures of swallowing function after injection were obtained with a patient questionnaire. Objective data were obtained both before and after surgery by one or more of the following tests: modified barium swallow study, manometry, videostroboscopy, and fiberoptic endoscopic evaluation of swallowing. Quality-of-life measures were obtained with a swallowing rating scale.

RESULTS

Overall, all patients had initial improvement in swallowing after Botox injection. The duration of benefit was from 2 to 14 months. There were no complications. Four of 5 patients had long-term benefits, as evidenced by decreased or eliminated aspiration symptoms, removal of tracheotomy, ability to eat solid foods, and weight gain. One patient continues to have poor swallowing function.

CONCLUSION

Botox injection of the CP muscle to treat dysphagia is effective in patients with underlying muscle spasm or hypertonicity. A positive response to Botox can also help confirm the diagnosis of CP muscle spasm.

Dystonia

Therapy for most people with dystonia is symptomatic, directed at lessening the intensity of the dystonic contractions. For a small minority of patients (eg, those with dopa-responsive dystonia, Wilson's disease, or psychogenic dystonia), specific therapy directed at one of the many causes of dystonia is available. Before initiating treatment, clinicians need to decide if a patient has a form of dystonia amenable to such therapy. The most sensitive and least costly method to diagnose DRD is a therapeutic trial of levodopa. It is, therefore, recommended to treat all those with dystonia beginning in childhood or adolescence with low-dose levodopa. For patients with generalized or segmental signs who do not respond to levodopa, other oral medications, including anticholinergics, baclofen, and benzodiazepines, may provide mild to moderate relief; these medications are often given in combinations. For those with focal dystonia, most having adult-onset disease, botulinum toxin A injections often effectively control contractions. The injections produce transient weakness and need to be repeated, generally every 3 to 5 months. There is growing renewed interest in surgical treatment. Peripheral denervating procedures may be helpful for patients with torticollis who do not obtain adequate benefit with botulinum toxin A. The central procedures of pallidotomy and pallidal stimulation are under study; their place in the treatment of the many dystonia subtypes (eg, limb vs axial, generalized vs focal, primary vs secondary) still needs to be established. There are very few studies evaluating physical and psychological therapies or the impact of diet or lifestyle in dystonia. Most clinicians consider physical therapy, including massage, a potential adjunct to medical therapy, and psychological support and stress reduction may help individuals cope with this chronic and frequently disabling condition.

Evaluation of the use of botulinum toxin in children with achalasia

BACKGROUND

Achalasia is rare in children. Recently, injection of botulinum toxin into the lower esophageal sphincter has been studied as an alternative to esophageal pneumatic dilatation or surgical myotomy as treatment for achalasia. In the current study, the effects of botulinum toxin were investigated in the largest known series of children with achalasia.

METHODS

Treatment for achalasia was assessed in 23 pediatric patients who received botulinum toxin from June 1995 through November 1998. Those who continued to receive botulinum toxin and did not subsequently undergo pneumatic dilatation or surgery were considered repeat responders. Results were compared with those of published studies evaluating the use of botulinum toxin in adults with achalasia.

RESULTS

Nineteen patients initially responded to botulinum toxin. Mean duration of effect was 4.2 months +/- 4.0 (SD). At the end of the study period, three were repeat responders, three experienced dysphagia but did not receive pneumatic dilatation or surgery, three underwent pneumatic dilatation, eight underwent surgery, three underwent pneumatic dilatation with subsequent surgery, and three awaited surgery. Meta-analysis shows that, in the current study group, the data point expressing time of follow-up evaluation versus percentage of patients needing one injection session without additional procedures (botulinum toxin injection, pneumatic dilatation, or surgery) falls within the curve for those in studies on adult patients receiving botulinum toxin for achalasia.

CONCLUSIONS

Botulinum toxin effectively initiates the resolution of symptoms associated with achalasia in children. However, one half of patients are expected to need an additional procedure approximately 7 months after one injection session. The authors recommend that botulinum toxin be used only for children with achalasia who are poor candidates for either pneumatic dilatation or surgery.

Tremor-predominant Parkinson's disease. Approaches to treatment

Parkinson's disease is a neurodegenerative disorder that manifests clinically with variable degrees of tremor, muscle rigidity, bradykinesia and postural instability. Tremor-predominant Parkinson's disease is characterised by prominent tremor of one or more limbs with a relative lack of significant rigidity and bradykinesia. Despite the lack of other disabling motor symptoms, the tremor of tremor-predominant Parkinson's disease can be very disabling, especially if a postural and kinetic component exists. A wide variety of treatments for Parkinson's disease tremor are currently available and include use of oral medications, injections with botulinum toxin and neurosurgical procedures. Some of the first line medications (levodopa, dopamine agonists, anticholinergics) are very effective in controlling tremor. However, some patients with Parkinson's disease tremors are unresponsive to first line drugs and treatment with second line medications (clozapine, amantadine, clonazepam, propranolol, neurontin) should be attempted. In the small number of patients with disabling tremor that is refractory to all medications, neurosurgical intervention should be considered. Both thermocoagulation and deep brain stimulation at several different neuroanatomical sites (thalamus, globus pallidus, subthalamic nucleus) offer good to excellent tremor control with relatively low risk to the patient.

The role of drug treatment in children with strabismus and amblyopia

Strabismus, or misalignment of the eyes, is a common ophthalmic problem in childhood, affecting 2 to 5% of the preschool population. Amblyopia is an important cause of visual morbidity frequently associated with strabismus, and both conditions should be treated simultaneously. Pharmacological means for treating strabismus and amblyopia can be divided into 3 categories: paralytic agents (botulinum toxin) used directly on the extraocular muscles to affect eye movements; autonomic agents (atropine, miotics) used topically to manipulate the refractive status of the eye and thereby affect alignment, focus and amblyopia; and centrally acting agents, including levodopa and citicoline, which affect the central visual system abnormalities in amblyopia. Botulinum toxin, the paralytic agent that causes the clinical symptoms of botulism poisoning, can be injected in minute quantities to achieve controlled paralysis of the extraocular muscles. Although the role of botulinum toxin is established in adults with paralytic strabismus, its usefulness in the treatment of comitant childhood strabismus (primary esotropia and exotropia) is not universally accepted. Botulinum injections tend to be more effective with smaller degrees of strabismus, in patients with good binocular fusion, and in managing overcorrections or undercorrections after traditional muscle surgery. Inadvertent ptosis and paralysis of adjacent muscles, unpredictable responses and technical constraints of the injections limit its use in children. Miotic therapy, by altering the refractive state of the treated eye, offers an alternative to optical correction with bifocals in treating esotropia due to excessive accommodative convergence. It is also effective in treating residual esotropia following surgery. The ease of use of glasses restricts the wide application of miotics in these common strabismus syndromes. Atropine, an anticholinergic agent, paralyses the ability of the eye to focus or accommodate. In amblyopia therapy, atropine is used to blur vision in the non-amblyopic eye and offers a useful alternative to traditional occlusion therapy with patching, especially in older children who are not compliant with patching. The neurotransmitter precursor levodopa and the related compound citicoline have been demonstrated to improve vision in amblyopic eyes. The therapeutic role of these centrally acting agents in the clinical management of amblyopia remains unproven.

The effects of tetanus toxin on the orbicularis oculi muscle

PURPOSE

Tetanus toxin can cause localized neuromuscular weakness, but it also can produce systemic tetany. The action of tetanus toxin on the orbicularis muscle has not been studied in animals immunized to prevent systemic tetany. Our objective was to determine whether tetanus toxin could be used to treat orbicularis oculi muscle spasms.

METHODS

We analyzed the clinical, electrophysiologic, and histopathologic effects of tetanus toxin injected into the orbicularis oculi muscle of rabbits with passive immunity to tetanus toxin. In six rabbits, the orbicularis oculi function in both eyes was assessed clinically, and the baseline orbicularis oculi muscle action potential was measured physiologically with electromyography (EMG). The rabbits then were immunized against tetanus toxin with tetanus immunoglobulin for immediate and definitive immunity. Tetanus toxin was injected into the left orbicularis oculi muscles, leaving the right eyes as controls. Ten days later, the rabbits were again assessed by clinical examination and with EMGs on both the injected side and the noninjected side. The animals were killed at 14 days, and the orbicularis muscle was removed from both sides. The injected and control tissues were examined microscopically for signs of neuromuscular denervation.

RESULTS

All six rabbits showed weakness in eye closure on the side injected with tetanus toxin. In addition, four rabbits developed complete ear ptosis on the tetanus toxin injected side because of spread of the toxin to adjacent ear muscles. EMGs showed both a denervation of the orbicularis oculi muscle and a poor blink potential on the side injected with tetanus toxin. Histopathologic studies of the orbicularis oculi muscle injected with tetanus toxin showed angulation of both slow and fast types of muscle fibers compatible with neuromuscular denervation.

CONCLUSIONS

Tetanus toxin can cause localized orbicularis oculi weakness, as documented clinically, physiologically, and microscopically, without producing systemic tetany in immunized rabbits. Tetanus toxin may have a potential application in the treatment of blepharospasm and hemifacial spasm.

Botulinum toxin in the treatment of outlet obstruction constipation caused by puborectalis syndrome

PURPOSE

Puborectalis syndrome has been difficult to treat. We investigated the efficacy of botulinum toxin in treating patients with puborectalis syndrome who had previously failed to respond to electromyographic biofeedback sessions and who refused to use anal dilators.

METHODS

Of a group of 50 patients with chronic outlet obstruction constipation, four patients with puborectalis syndrome were included in the study. The patients were studied using anorectal manometry, defecography, and electromyography and then treated with 30 units of Type A botulinum toxin, injected into two sites on either side of the puborectalis muscle, under ultrasonographic guidance.

RESULTS

One patient was lost to follow-up. After treatment in other patients, the frequency of natural bowel movements increased from zero to six per week and laxatives were needed by only one patient. Anorectal manometry demonstrated decreased tone during straining from (mean +/- standard deviation) 96.2 +/- 12 mmHg to 42.5 +/- 13 mmHg at four weeks (P = 0.003) and 63.2 +/- 22 mmHg at eight weeks (P = 0.009). Defecography performed eight weeks after treatment showed improvement in the anorectal angle, which increased from 94 +/- 11 degrees to 114 +/- 13 degrees (P = 0.01), and evacuation of barium paste. Electromyography demonstrated mild paradoxical contraction. However, 16 weeks after treatment one of these three patients suffered symptomatic recurrence. This patient was re-treated with 50 units of toxin; eight months later he required a further 60 units. Seven months after the last injection he reported normal daily bowel movements without the use of laxatives.

CONCLUSIONS

Botulinum toxin injection should be considered as a simple therapeutic approach in patients with puborectalis syndrome. The use of higher dosage and a more precise method of toxin injections under transrectal ultrasonography account for the long-term higher success rate. However, because the effects of the toxin wear off within three months of administration, repeated injections could be necessary to maintain the clinical improvement.

Effects of botulinum toxin on pathophysiology in spasmodic dysphonia

To determine the mechanism of symptom relief with treatment by botulinum toxin injection in persons with adductor spasmodic dysphonia (ADSD), we evaluated the effects of unilateral thyroarytenoid muscle injections on both injected and noninjected muscles in 10 subjects with ADSD, using electromyography on both sides of the larynx before and after treatment. The subjects' speech symptoms were reduced (p = .005) 2 weeks following injection, when the electromyographic study occurred. Muscle activation levels and the numbers of spasmodic muscle bursts decreased significantly (p < or = .03) postinjection in both the injected and noninjected muscles. The reductions in laryngeal muscle bursts correlated with symptom reduction (r > or = .7) in all muscles. Reductions in laryngeal muscle bursts did not relate to either absolute or normalized levels of muscle activity before or after botulinum toxin injection. The results suggest that changes in the central pathophysiology are responsible for changes in speech symptoms following treatment.

Treating severe bruxism with botulinum toxin

BACKGROUND

Locally administered botulinum toxin, or BTX, is an effective treatment for various movement disorders. Its usefulness in treating bruxism, however, has not been systematically evaluated.

SUBJECTS AND METHODS

The authors studied 18 subjects with severe bruxism and whose mean duration of symptoms was 14.8 +/- 10.0 years (range three-40 years). These subjects audibly ground their teeth and experienced tooth wear and difficulty speaking, swallowing or chewing. Medical or dental procedures had failed to alleviate their symptoms. The authors administered a total of 241 injections of BTX type A, or BTX A, in the subjects' masseter muscles during 123 treatment visits. The mean dose of the BTX A was 61.7 +/- 11.1 mouse units, or MU (range 25-100 MU), per side for the masseter muscles.

RESULTS

The mean total duration of response was 19.1 +/- 17.0 weeks (range six-78 weeks), and the mean peak effect on a scale of 0 to 4, in which 4 is equal to total abolishment of grinding, was 3.4 +/- 0.9. Only one subject (5.6 percent) reported having experienced dysphagia with BTX A.

CONCLUSION

The results of this study suggest that BTX administered by skilled practitioners is a safe and effective treatment for people with severe bruxism, particularly those with associated movement disorders. It should be considered only for those patients refractory to conventional therapy. Future placebo-controlled studies may be useful in further evaluating the potential of BTX in the treatment of bruxism.

Post-traumatic cervical dystonia: a distinct entity?

BACKGROUND/OBJECTIVE

The incidence of head/neck trauma preceding cervical dystonia (CD) has been reported to be 5-21%. There are few reports comparing the clinical characteristics of patients with and without a history of injury. Our aim was to compare the clinical characteristics of idiopathic CD (CD-I) to those with onset precipitated by trauma (CD-T).

METHODS

We evaluated 114 consecutive patients with CD over a 9-month period. All patients were interviewed using a detailed questionnaire and had a neurological examination. Their clinical charts were also reviewed.

RESULTS

Fourteen patients (12%) had mild head/neck injury within a year preceding the onset of CD. Between the two groups (CD-I and CD-T), the gender distribution (F:M of 3:2), family history of movement disorders (32% vs. 29%), the prevalence of gestes antagonistes (65% vs. 64%), and response to botulinum toxin were similar. There were non-specific trends, including an earlier age of onset (mean ages 43.3 vs. 37.6), higher prevalence of neck pain (86% vs. 100%), head tremor (67% vs. 79%), and dystonia in other body parts (23% vs. 36%) in CD-T.

CONCLUSIONS

CD-I and CD-T are clinically similar. Trauma may be a triggering factor in CD but this was only supported by non-significant trends in its earlier age of onset.

Effects of botulinum toxin A on upper limb spasticity in children with cerebral palsy

OBJECTIVE

Botulinum toxin A inhibits presynaptic release of acetylcholine at the neuromuscular junction and has reportedly been successful in the treatment of spastic disorders. This prospective study attempted to determine whether botulinum toxin A injection resulted in clinically measurable gains for 4 mo.

DESIGN

Measurements were obtained from 32 children (range, 1-18 yr; average age, 6.9 yr) with hemiplegic or quadriplegic cerebral palsy before and at 1, 3, and 4 mo after botulinum toxin A injections. Spasticity was measured using the Modified Ashworth Scale for 12 different joints.

RESULTS

Results showed that spasticity as measured by Ashworth scores for elbow and wrist extension clearly declined (P < 0.02) by 1 mo after botulinum toxin A injection, and diminished spasticity continued for 3-4 mo. Caregivers reported improvement in subjectively rated management, appearance, and function. However, patient response to botulinum toxin A injection was not predictable. Age had no significant relationship to gains.

CONCLUSIONS

Further research is needed on the use of botulinum toxin A to diminish spasticity and improve function.

Patients' perception of stopping or continuing treatment of cervical dystonia with botulinum toxin type A

Despite widespread commercial acceptance of botulinum toxin (BTX) for idiopathic cervical dystonia (ICD), no follow up has been performed to determine when and why some patients stop therapy. It has been suggested that some patients who stop BTX treatment may do so because of permanent improvement. We surveyed 155 patients with ICD who were treated over 6 years with BTX to determine when and why patients stopped treatment with BTX, and what adverse events and changes in dose and/or frequency of treatments occurred in those who continued treatment. Of the 133 (86.6%) individuals returning the surveys, 104 continued on BTX treatment and 29 had stopped therapy. Of the 29 subjects no longer receiving BTX, 11 individuals had only received one or two injections. Prior surgical treatment for ICD did not influence their decision to stop therapy. Of those 104 of 133 continuing on BTX treatments, two thirds of the subjects reported the injections always help, whereas one quarter estimated one set of injections did not help. One third of those continuing treatment reported the first injection was most helpful, whereas another one third felt all injections were similarly effective. After an initial adjustment, BTX dosages and frequency of treatment remained stable in this group.

Influence of botulinum toxin site of injections on healing rate in patients with chronic anal fissure

BACKGROUND

Botulinum toxin induces healing in patients with idiopathic anal fissure.

METHODS

Fifty patients affected by posterior anal fissure were treated with 20 units of botulinum toxin, injection in the internal anal sphincter on each side of the posterior midline (group I) or on each side of the anterior midline (group II).

RESULTS

At 2 months evaluation, a healing scar was observed in 15 patients of group I and in 22 patients of group II(P = 0.025). Resting anal pressure was significantly different from the baseline values at 1-month as well as at 2-month check-ups in both groups, but the values were significantly lower in patients of group II.

CONCLUSIONS

The intersite comparison revealed that anterior injection of the internal anal sphincter resulted in improved lowering of resting anal pressure and produced an earlier healing scar.

Clostridial toxins as therapeutic agents: benefits of nature's most toxic proteins

Toxins are increasingly being used as valuable tools for analysis of cellular physiology, and some are used medicinally for treatment of human diseases. In particular, botulinum toxin, the most poisonous biological substance known, is used for treatment of a myriad of human neuromuscular disorders characterized by involuntary muscle contractions. Since approval of type-A botulinum toxin by the US Food and Drug Administration in December 1989 for three disorders (strabismus, blepharospasm, and hemifacial spasm), the number of indications being treated has increased greatly to include numerous focal dystonias, spasticity, tremors, cosmetic applications, migraine and tension headaches, and other maladies. Many of these diseases were previously refractory to pharmacological and surgical treatments. The remarkable therapeutic utility of botulinum toxin lies in its ability to specifically and potently inhibit involuntary muscle activity for an extended duration. The clostridia produce more protein toxins than any other bacterial genus and are a rich reservoir of toxins for research and medicinal uses. Research is underway to use clostridial toxins or toxin domains for drug delivery, prevention of food poisoning, and the treatment of cancer and other diseases. The remarkable success of botulinum toxin as a therapeutic agent has created a new field of investigation in microbiology.

Early experience with intrasphincteric botulinum toxin in the treatment of achalasia

BACKGROUND

Recent reports have suggested that intrasphincteric injection of botulinum toxin is effective and long-lasting in the treatment of achalasia.

AIM

To report our experience of botulinum toxin injection in a prospective series of consecutive patients with achalasia.

METHODS

Eleven consecutive patients with achalasia (eight male, mean age 55 years, range 20-87) were treated with 60 units of botulinum toxin (Dysport; Speywood Pharmaceuticals Ltd, UK) into each of four quadrants at the lower oesophageal sphincter. Patients were assessed pre-treatment and 1 month after treatment using a symptom score and oesophageal manometry. Median follow-up was 12 months (range 6-28).

RESULTS

The injection procedure was simple to perform and free of adverse effects. Although treatment had a beneficial effect on dysphagia (median pre-treatment score 3 [interquartile range 3-3]; post-treatment score 2 [0-3]: P=0.03) 1 month following therapy, there was no significant improvement in chest pain or regurgitation scores. Similarly, no significant reduction in median lower oesophageal sphincter pressure was observed (29.5 mmHg [21-42] pre-treatment, 28.5 [17.5-55.5] post-treatment P=0.67). Four patients (36%) required further therapy within 3 months and the overall relapse rate was 73% (eight of 11) within 2 years.

CONCLUSION

Although botulinum toxin injection was well tolerated, these results using Dysport at a dose of 240 mouse units question its efficacy as a treatment for achalasia.

Therapeutic effects of different doses of botulinum toxin in chronic anal fissure

PURPOSE

The aim of this study was to evaluate the clinical and manometric results of three different doses of botulinum toxin and two methods of injection for the treatment of chronic idiopathic anal fissure.

METHODS

Sixty-nine patients with chronic anal fissure were included in a non-randomized, prospective trial of intrasphincteric injection of botulinum toxin. All patients reported postdefecatory anal pain lasting more than two months. Scoring systems were developed for anal pain, bleeding, and defecatory difficulty. Maximum resting and squeeze anal pressures were determined before and one month after treatment. Twenty-three patients undergoing a 5-U injection of diluted botulinum toxin A (BOTOX) on each side of the anal sphincter (total dose, 10 U) constituted the first group. In a second group 27 patients were injected as previously described, with an additional 5-U injection below the fissure (total dose, 15 U). The 19 patients constituting the third group received a 7-U injection on each side of the anus and below the fissure (total dose, 21 U). All patients were followed up for at least six months.

RESULTS

Pain relief one month after treatment was more evident in the second and the third group (48 percent of patients in the first group, 74 percent in the second group, and 100 percent in the third group). A significant reduction of the mean resting pressure was demonstrated only in Groups II and III (P < 0.05), whereas the mean squeeze pressure significantly decreased in the three groups (P < 0.01 in Group I and P < 0.001 in Groups II and III). Fifty-two percent of the patients in the first group, 30 percent in the second group, and 37 percent in the third group were reinjected during the follow-up period, because of persistence of symptomatology or early relapse. The need for surgery was similar in the first and the second group (17 and 19 percent, respectively) and clearly lower in the last group (5 percent). No serious complications or incontinence attributable to this therapeutic modality developed in any patient.

CONCLUSIONS

Intrasphincteric injection of botulinum toxin is a reliable new option in the treatment of uncomplicated chronic anal fissure. The healing rate is related to the dose and probably to the number of puncture sites. No permanent damage to the continence mechanism was detected in these patients.

A comparison of injections of botulinum toxin and topical nitroglycerin ointment for the treatment of chronic anal fissure

BACKGROUND AND METHODS

Lateral internal sphincterotomy, the most common treatment for chronic anal fissure, may cause permanent injury to the anal sphincter, which can lead to fecal incontinence. We compared two nonsurgical treatments that avert the risk of fecal incontinence. We randomly assigned 50 adults with symptomatic chronic posterior anal fissures to receive treatment with either a total of 20 U of botulinum toxin injected into the internal anal sphincter on each side of the anterior midline or 0.2 percent nitroglycerin ointment applied twice daily for six weeks.

RESULTS

After two months, the fissures were healed in 24 of the 25 patients (96 percent) in the botulinum-toxin group and in 15 of the 25 (60 percent) in the nitroglycerin group (P=0.005). No patient in either group had fecal incontinence. At some time during treatment, five patients in the nitroglycerin group had transient, moderate-to-severe headaches that were related to treatment. None of the patients in the botulinum-toxin group reported adverse effects. Ten patients who did not have a response to the assigned treatment - 1 in the botulinum-toxin group and 9 in the nitroglycerin group - crossed over to the other treatment; the fissures subsequently healed in all 10 patients. There were no relapses during an average of about 15 months of follow-up.

CONCLUSIONS

Although treatment with either topical nitroglycerin or botulinum toxin is effective as an alternative to surgery for patients with chronic anal fissure, botulinum toxin is the more effective nonsurgical treatment.

Botulinum toxin injection in the treatment of vocal fold paralysis associated with multiple sclerosis: a case report

Botulinum toxin has been demonstrated clinically to be an effective treatment for a variety of laryngeal problems, most notably spasmodic dysphonia. As in other movement disorders, the theory behind the injection of this substance in the larynx has been a weakening of the vocal fold musculature to relieve uncoordinated and spasmodic movement of the vocal folds, presumably rebalancing the forces within the intralaryngeal musculature. Recently, this concept was applied to help reposition the arytenoid cartilage in acute and longstanding anteromedial cricoarytenoid dislocations. This same concept may apply to the paralyzed vocal fold. In support of this idea, a number of investigators have shown that immobile, clinically paralyzed vocal folds may still have partial voluntary motor unit activity. This voluntary activation may not produce clinically evident movement but may be sufficient to produce tone within the fold. If the voluntary motor units in the abductor musculature of the paralyzed fold are weakened with botulinum toxin, the continued pull of the functioning adductor musculature may be sufficient to medialize the paralyzed fold. This idea has been supported by animal experiments, which have shown that botulinum toxin may affect the ability of the fold to rebalance itself. With this evidence in mind, a patient with fold immobility secondary to multiple sclerosis was treated in an attempt at laryngeal rebalancing, using botulinum toxin to medialize the fold. However, instead of simply having the fold return fixed to the midline, the patient regained normal laryngeal mobility and voice. While it is unclear whether the botulinum toxin alone was responsible, the coincidence of this occurrence certainly requires reporting. This paper is a report of the first successful treatment of vocal fold paralysis using botulinum toxin to treat vocal fold fixation in a patient with multiple sclerosis.