Therapeutic uses of botulinum toxin

Comparison of two injection techniques using botulinum toxin in spastic hemiplegia

This study sought to test the hypothesis that injections of botulinum toxin type A (BTX-A) at the mid belly of the gastrocnemius muscle in spastic hemiplegic adults produce superior clinical results to proximal injections directed toward the muscular origin. We designed a randomized, double-blind, placebo-controlled intervention study at a university tertiary care setting. Seventeen subjects with chronic spastic hemiplegic gait were enrolled from a volunteer community sample; time range from acute neurologic insult was 0.75 to 31 yr; age range was 19 to 71 yr; gender consisted of 11 men and 4 women; diagnoses were 12 patients with stroke, 2 with traumatic brain injuries, and 1 with a brain tumor. Two subjects were withdrawn from the study because of (1) acute vascular occlusion before intervention and (2) noncompliance with follow-up visits. After baseline measurements, subjects were injected with 50 units of BTX-A (volume, 0.5 cc) into the medial or lateral gastrocnemius: (1) proximally at one site near the muscular origin; (2) distally at three sites along the mid belly. We measured outcome using the Fugl-Meyer score, Ashworth scale, ankle range of motion, and a timed 50-ft fastest walk. No outcome measures showed a significant effect attributable to site of injections. Confounding variables included physical therapy and varying duration of illness in the study cohort. We conclude that the results failed to support the hypothesis that BTX-A injections at the mid belly of the gastrocnemius produced superior functional improvements to injections located near the muscular origin using localization techniques described. Additional research comparing more precise localization methods for BTX-A injections might further establish the importance of electromyographic guidance using BTX-A in management of spasticity.

Initial North American experience with botulinum toxin type A for treatment of anismus

PURPOSE

Botulinum toxin type A (BTX-A), produced by Clostridium botulinum, is a potent neurotoxin. The purpose of this study was to evaluate the efficacy of BTX-A for treatment of anismus.

MATERIALS AND METHODS

All patients treated with BTX-A for anismus were evaluated. Eligibility criteria included a history of chronic assisted evacuation (laxatives, enemas, or suppositories), demonstration of anismus by cinedefecogram and electromyography, and failure of a minimum of three sessions of supervised biofeedback therapy (BF). Contingent on body mass, 6 to 15 units of BTX-A was injected bilaterally under electromyography guidance into the external sphincter or the puborectalis muscle. Treatment was repeated as necessary for a maximum of three sessions during a three-month period. Success was considered as discontinuation of evacuatory assistance and was evaluated between one and three months and again at up to one year.

RESULTS

Between July 1994 and May 1995, four patients ranging from 29 to 82 years in age (2 females, 2 males) had anismus that failed to respond to between 3 and 15 biofeedback sessions. All patients improved between one and three months after BTX-A injection, and two had sustained improvement for a range of three months to one year. There was no morbidity or mortality associated with BTX-A injection.

CONCLUSIONS

BTX-A is extremely successful for temporary treatment of anismus that is refractory to BF management. However, because the mechanism of action is short, longer term results are only 50 percent successful. Hopefully, modifications in the strain of BTX-A and dose administered will allow longer periods of success or a repeat trial of BF. Nonetheless, this preliminary report is very encouraging in offering a method of managing this recalcitrant condition.

Aetiology and treatment of anal fissure

Anal fissure is a common problem that causes significant morbidity in a young and otherwise healthy population. Treatment has remained largely unchanged for over 150 years and the pathogenesis of this condition is not yet fully explained. Acute fissure should be treated conservatively with dietary modification. Chronic fissures do not respond to conservative treatment. The current recommended surgical treatment for chronic fissure is lateral internal sphincterotomy. However, there is a disturbance of continence in a sizeable proportion of those undergoing this procedure. As yet there is no proven non-surgical treatment for chronic fissure. Although local injection of botulinum toxin and the topical application of nitrates show early promise, further controlled trials are needed.

Hypnosis and spasmodic torticollis--report of four cases: a brief communication

Dystonia and particularly spasmodic torticollis are neuromuscular disorders that are extremely resistant to most therapies (physical, medical, or surgical). Torticollis is a unilateral spasm of the neck muscles, particularly of the sternocleidomastoid, that produces violent, tonic turning of the head to one side. The etiology remains uncertain, although the role of psychogenic factors has been emphasized. This article reviews the literature and reports four cases of spasmodic torticollis treated successfully with hypnosis. In all four cases, psychogenic causes were involved. Postural hypnosis (i.e., hypnosis in the standing position) was employed to counteract and minimize muscle spasms due to postural reflexes. A hypnobehavioral approach was adopted along with hypnotic strategies that included hierarchical desensitization, sensory-imaging conditioning, ego-boosting suggestions, and hypnosis-facilitated differential muscle retraining. In two cases, a combined hypnosis and electromyographic-biofeedback approach was used to equilibrate and retrain affected neck muscles. Although the hypnotherapeutic process took several months to induce and stabilize significant changes, outcome results were good to excellent in all cases, with marked reduction of the torticollis and the hypertrophy of the neck muscles as well as a reduced interference of symptoms in daily living.

Therapeutic botulinum type A toxin: factors affecting potency

The type A neurotoxin produced by Clostridium botulinum is a potent neuromuscular blocking agent which causes paralysis by preventing the release of neurotransmitter from motor neurons. This property has resulted in the use of the toxin in the treatment of a number of neuromuscular diseases involving muscle spasms. At present, the only recognised assay to estimate accurately the potency of botulinum toxin in clinical preparations is bioassay, in which lethality is used as the endpoint. Such bioassay is inherently variable and large interlaboratory variability has been reported, highlighting problems for standardisation of activity in the absence of any commonly used reference preparation. In the present study, we have confirmed that many different assay conditions can affect potency estimates of clinical formulations of type A botulinum toxin. Further, our studies indicate that different preparations, because of their unique formulation and stability, are differentially affected by some of these assay conditions and that these differences might well contribute to the differences observed in their clinical use.

Use of high-resolution endoscopic ultrasonography to assess esophageal wall damage after pneumatic dilation and botulinum toxin injection to treat achalasia

OBJECTIVE

The purpose of this study was to utilize high-resolution endoscopic ultrasonography to assess esophageal wall damage in patients with achalasia treated by either pneumatic dilation or botulinum toxin injection and to compare their symptomatic response.

METHODS

Twenty-nine patients were treated with pneumatic dilation (11) or botulinum toxin injection (18) in a nonrandomized, controlled manner. An achalasia balloon dilator inflated at the gastroesophageal junction was used for dilation. Botulinum toxin was injected during endoscopy into the gastroesophageal junction. Endoscopic ultrasonography was performed at the level of the diaphragm before, immediately after, and 24 hours after treatment. Symptoms were assessed before and 7, 30, 60, and 90 days after therapy.

RESULTS

The mucosal-submucosal thickness increased significantly immediately after pneumatic dilation, but normalized by 24 hours. No significant change in mucosal-submucosal thickness occurred after botulinum toxin injection. No significant alteration in muscularis propria thickness was observed after either procedure. Dysphagia and regurgitation improved significantly at 7, 30, 60, and 90 days after both procedures.

CONCLUSIONS

Pneumatic dilation produced transient thickening of the mucosa-submucosa, but no thickening or breaks in the muscularis propria. This transient wall damage suggestive of edema was not seen after botulinum toxin injection. Over a 3-month period, botulinum toxin was equivalent to pneumatic dilation in relieving dysphagia and regurgitation in patients with achalasia.

Treatment of nonoccupational limb and trunk dystonia with botulinum toxin

We report the results of treatment of 16 patients (14 women, two men; 18-81 years old) with nonoccupational limb and trunk dystonia with botulinum toxin A (BTX; Dysport). A total of 18 clinical problems were identified. Outcomes were assessed in terms of pain relief and improvement in posture and function by the combined observations of the patient and physician. Patients' satisfaction with treatment was high--the benefit in 15 of 18 problems was rated as good to excellent. Reduction in pain was achieved in nine of 10 painful problems, with total relief in four cases. Some normalisation of posture was obtained in 17 of 18; it was complete in three cases. Functional improvement was less common (10 of 18). Excessive weakness was the most common side effect, affecting five patients, but it was disabling in only two. We conclude that BTX can provide substantial benefit with minimal side effects in the majority of patients with these conditions, particularly with pain relief and postural improvements.

Repeatedly successful closure of the larynx for the treatment of chronic aspiration with the use of botulinum toxin A

Botulinum toxin A was used preoperatively to temporarily paralyze the intrinsic laryngeal muscles to hinder movements during the healing period after operation. In addition, toxin was injected into the cricopharyngeal muscle to allow a better passive drainage of the saliva into the esophagus. We treated six patients. Three suffered from chronic aspiration problems after multiple lower cranial nerve lesions, and three patients were apallic (after stroke and major brain injury). Two weeks before scheduled operation, we injected the toxin into the posterior cricoarytenoid muscles, the aryepiglottic muscles, and the vocalis muscle on both sides, as well as the cricopharyngeal muscle. The amount of injected toxin varied between 1.0 and 1.4 mL, equal to 200 to 280 units of botulinum toxin A (Dysport). After a complete palsy of these muscles (controlled by direct electromyography), a closure of the larynx was performed. After laminotomy and exposure of the intralaryngeal structures, the false vocal cords were mobilized and adapted with sutures. Because involuntary movements of the intralaryngeal musculature were absent, primary healing without complications occurred in all cases. Aspiration and related complications disappeared in all patients. In addition, the intensity of patient care could be considerably reduced. Preoperative use of botulinum toxin A allows sufficient laryngeal closure. This procedure is especially useful in the treatment of children and young adults, preserving the ability of later speech rehabilitation because of the return of voluntary movements of the intrinsic laryngeal muscles 6 months after the injection. Furthermore, this technique, as minimal surgical intervention, can be performed in high-risk patients.

Molecular mechanisms of action of bacterial exotoxins

Toxins are one of the inventive strategies that bacteria have developed in order to survive. As virulence factors, they play a major role in the pathogenesis of infectious diseases. Recent discoveries have once more highlighted the effectiveness of these precisely adjusted bacterial weapons. Furthermore, toxins have become an invaluable tool in the investigation of fundamental cell processes, including regulation of cellular functions by various G proteins, cytoskeletal dynamics and neural transmission. In this review, the bacterial toxins are presented in a rational classification based on the molecular mechanisms of action.

Botulinum toxin A in the treatment of spasticity: functional implications and patient selection

OBJECTIVE

To explore the range of functional indications and benefit of botulinum toxin A (BTA) in spastic patients.

DESIGN

Case report of a series of patients selected for BTA treatment. Clinical information was collected in a prospective fashion on each patient.

SETTING

Freestanding acute rehabilitation hospital.

PATIENTS

39 consecutive patients with 40 limbs with acquired spasticity.

INTERVENTION

All 39 patients received BTA injections into muscles targeted for treatment based on functional indications.

MAIN OUTCOME MEASURES

Objective evaluation of outcome was measured by Ashworth Scale, goniometry, ambulation score, and brace wear scale. Subjective measures included patient self report of improvement and pain relief.

RESULTS

Mean BTA dose per limb was 180 units, mean number of muscles injected per limb was 2. Twenty-nine patients had subjective and/or objective improvement with treatment. Mean Ashworth Scale improvement was one point. Mean gain in active range of motion (AROM) was 17.0 degrees, and in passive range of motion (PROM) 18.4 degrees. Brace tolerance improved in 14 of 22 patients and pain relief occurred in 10 of 13 patients. There were no adverse effects, and there was no difference in duration of effect compared to dystonia patients.

CONCLUSION

BTA is a useful intervention in the treatment of spasticity, with the majority of patients demonstrating improvement on objective measures of tone and function, and reporting improvement on subjective measures. Careful patient selection will maximize functional benefit.

Botulinum toxin injection into vocal cord in the treatment of malignant coprolalia associated with Tourette's syndrome

We describe a 13-year-old boy with Tourette's syndrome (TS) manifested chiefly by severe coprolalia, obsessive compulsive disorder, and attention deficit hyperactivity disorder. He was treated with unilateral injections of botulinum toxin to the vocal cord and experienced marked improvement in coprolalia as well as marked reduction in the premonitory urges associated with the vocal tics and coprolalia. As a result of the improvement, the patient was able to attend school and church and was able to socialize. Botulinum toxin may interfere with a sensory reflex arc required to perpetuate tics and coprolalia in TS, possibly by reducing local build-up of tension or muscle contraction in affected areas.

Pretarsal injections of botulinum toxin improve blepharospasm in previously unresponsive patients

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Botulinum toxin for spasticity and athetosis in children with cerebral palsy

Botulinum toxin A has been used therapeutically in humans for a variety of conditions since 1980. Over the past few years, it has been used more frequently for spasticity management. We describe the use of botulinum toxin for spasticity or athetosis management in three children with cerebral palsy. Two of these children had severe spasticity or athetosis that was unresponsive to other forms of treatment. The injection of botulinum toxin decreased pain and improved ease of care in these two children. Another child with left hemiparetic cerebral palsy underwent injection of botulinum toxin into upper and lower limb muscles to improve function. In this patient, the injections were combined with other forms of treatment. In this patient spasticity was decreased and function was increased temporarily. The use of botulinum toxin in general is discussed and related to these three cases.

A randomized, double-blind, placebo-controlled study to evaluate botulinum toxin type A in essential hand tremor

Twenty-five patients with hand tremor of 2+ (moderate) to 4+ (severe) on the tremor severity rating scale were randomized to receive either 50 U of botulinum toxin (BTX) type A (Allergan, Irvine, CA) or placebo injections into the wrist flexors and extensors of the dominant limb. If patients failed to respond to the initial injection, they were eligible to receive another injection of 100 U 4 weeks later. Rest, postural, and kinetic tremors were evaluated at 2- to 4-week intervals over a 16-week study period using tremor severity rating scales, accelerometry, and assessments of improvement and disability. A significant improvement (p < 0.05) was observed on the tremor severity rating scale 4 weeks after injection in patients treated with BTX as compared with placebo, and this effect was maintained for the duration of the study. Four weeks after injection, 75% of BTX-treated patients vs. 27% of placebo-treated patients (p < 0.05) reported mild to moderate improvement (peak effect rating > or = 2). There were no significant improvements in functional rating scales, although trends were observed for some items. Postural accelerometry measurements showed a > or = 30% reduction in amplitude in nine of 12 BTX-treated subjects and in one of nine placebo-treated subjects (p < 0.05). Although all patients treated with BTX reported some degree of finger weakness, no severe, irreversible, or unexpected adverse events occurred. Chemodenervation with BTX may significantly ameliorate essential hand tremor in patients who fail to improve with conventional pharmacologic therapy.

Refinement and validation of an alternative bioassay for potency testing of therapeutic botulinum type A toxin

The type A neurotoxin produced by Clostridium botulinum is a potent neuromuscular blocking agent which causes paralysis by preventing the release of neurotransmitter from motor neurones. This property has led to the use of the toxin in the treatment of a number of neuromuscular diseases involving muscle spasms. At present, the only recognised assay with the specificity and sensitivity to estimate accurately the potency of botulinum toxin in clinical preparations is bioassay, in which lethality is used as the end point. Refinement of this assay, with respect to the end point, was explored on the basis of the development of flaccid paralysis of muscles following subcutaneous injection of the toxin at the inguinocrural region. Potency estimates, relative to in house reference preparations, for different therapeutic preparations obtained using flaccid paralysis as a scored response gave excellent agreement with estimates obtained in independent assay using the currently required control method. This study demonstrates that an alternative, more humane bioassay for potency testing of clostridia neurotoxins gives valid estimates equivalent to those currently in use.

Nerve terminal sprouting in botulinum type-A treated mouse levator auris longus muscle

The marked outgrowth of the motor nerve terminal arborization triggered by an in vivo local injection of Clostridium botulinum type-A toxin in the mouse levator auris longus muscle was studied with morphological and immunochemical approaches. The increase in total nerve terminal length depended on the time elapsed after toxin administration and was due to both increased number of terminal branches and branch length as revealed by a quantitative morphological analysis of whole mounts using the combined cholinesterase-silver stain. Nerve terminal sprouts increased in number, length and complexity even after the functional recovery of neuromuscular transmission had occurred as revealed by electrophysiological examination. Although we cannot exclude that transmitter release sites from the original nerve terminal arborization may still be functional after botulinum type-A toxin (BoTx-A) treatment, it is likely that newly formed functional release sites on the sprouts play a major role in the functional recovery of neuromuscular transmission. The presence of an immunoreactivity to synaptophysin and synaptotagmin-II, integral proteins of synaptic vesicles, gives support to our previous findings suggesting that nerve terminal sprouts have the molecular machinery for acetylcholine release.

Subcutaneous botulinum toxin type A inhibits regional sweating: an individual observation

Botulinum toxin inhibits neuromuscular transmission by blocking the exocytosis of acetylcholine. It was tested for a similar effect on cholinergic postganglionic sympathetic neurones at the sudomotor junction. Subcutaneous injections of 0.1 and 1.0 units of type A botulinum toxin into the forearm of a healthy subject abolished local thermoregulatory sweating in cutaneous regions spanning 1.0 and 1.5 cm for nearly 1 year without producing weakness. Botulinum toxin, therefore appears to have potent anhidrotic activity.

Distonias: aspectos terapêuticos

Diversas abordagens terapêuticas são utilizadas em pacientes com distonias. Sempre que possível, causas específicas devem ser identificadas e tratadas. As modalidades de tratamento sintomático podem ser agrupadas em três categorias: tratamento farmacológico, cirúrgico e injeções locais de toxina botulínica. Cada uma dessas modalidades apresenta algumas vantagens e limitações. Formas generalizadas, particularmente as de ocorrência na infância, podem se beneficiar com drogas anticolinérgicas ou, em alguns casos, com a levodopa ou outros agentes tais como antagonistas da dopamina, baclofeno e benzodiazepínicos. As formas focais não respondem adequadamente ao tratamento farmacológico sistêmico mas beneficiam-se significativamente com injeções de toxina botulínica nos grupos musculares acometidos. Cerca de 90% dos pacientes com blefarospasmo e 70% daqueles com distonia cervical apresentam resposta satisfatória a esse tipo de terapia. O tratamento cirúrgico tem sido utilizado em algumas formas de distonias generalizadas (lesões estereotáxicas), axiais (rizotomias) ou focais (miectomias e neurectomias) com resultados variáveis.

[Dystonias: clinical and therapeutic aspects in 64 patients]

The experience with 64 patients with dystonia seen at the Extrapyramidal Diseases Sector of the Neurology Department of the Hospital Universitário Clementino Fraga Filho of the UFRJ is presented as well as the pertinent review of the literature. The five-and-a-half-year of follow-up showed that 33 were male and 31 female; 48 were white, 10 mulatto and 6 negro; the mean time of disease was 9 years and 8 months. According to the distribution of the movement disorder, 30 (46.9%) were focal, 17 (26.6%) segmental, 13 (20.3%) generalized, 3 (4.7%) hemidystonia and 1 (1.5%) multifocal. In 11 (17.2%) the age of onset was before 12 years old, in 6 (9.4%) between 13 and 20 years old, and in 47 (73.4%) after 20 years old. According to the etiology, 39 (60.9%) were idiopathic sporadic, 6 (9.4%) were idiopathic familial and 19 (29.7%) were symptomatic. The therapeutical approach used in these patients were anticholinergic drugs, dopaminergic agonists or antagonists and baclofen, alone or associated with anticholinergic drugs for generalized dystonia. The authors conclude that botulinum toxin type A is the most valuable therapeutic agent in the treatment of focal dystonia.

Diagnosis in neuromuscular diseases

The diagnosis of neuromuscular diseases can be challenging and successful in the majority of patients, due to advancements in electrophysiology, muscle and nerve biopsy immunohistochemistry, and cytogenetics. This article reviews diverse topics, highlighting these recent achievements, with an emphasis on how they affect the clinical and laboratory diagnosis of specific neuromuscular disorders.

Botulinum toxin in the therapy of gustatory sweating

Three patients suffering from gustatory sweating following trauma to the preauricular region from a bullet wound or parotid gland surgery were treated by intracutaneous injection of botulinum toxin A. Within 2 weeks, gustatory sweating in the area injected completely ceased in all patients with no side-effects. The efficacy of treatment was confirmed by repeated Minor's iodine starch tests. So far, sweating has not recurred during a follow-up period of up to 8 months. Botulinum toxin appears to be a promising new drug for the treatment of this autonomic disorder.

Unilateral injection of botulinum toxin in blepharospasm: single fiber electromyography and blink reflex study

We studied six patients affected with blepharospasm (BSP). We injected botulinum toxin (BTX) around only one eye and saline solution around the other. Clinical rating of BSP was performed. Single fiber electromyography (SFEMG), compound motor action potential (cMAP) at the orbicularis oculi muscle by stimulation of the facial nerve, blink reflex, and blink reflex recovery curve were recorded. All clinical and electrophysiological investigations were carried out before, and 1, 2, and 4 weeks after treatment. Evidence of bilateral clinical benefit was provided. Following therapy, facial cMAP decreased bilaterally and SFEMG revealed statistically significant changes on both sides while the excitability curve of blink reflex remained unmodified. The results confirm that BTX affects merely the neuromuscular junctions. The clinical and neurophysiological effects are present on both sides also for unilateral injection probably because of toxin spreading.

Electrophysiological studies in patients with blepharospasm before and after botulinum toxin A therapy

Botulinum toxin (BTX) is the treatment of choice for blepharospasm. To investigate if the locally injected BTX influences the central nervous system and in particular the brain stem, amplitude and latency of compound muscle action potential (CMAP) of orbicularis oculi, blink reflex and brain stem auditory evoked potential were studied in 12 blepharospasm patients before BTX therapy, 9 patients after BTX therapy and 9 age and sex matched healthy controls. The mean amplitude of orbicularis oculi in patients was significantly lower before BTX therapy (p < 0.05) and after BTX therapy (p < 0.02). The amplitudes of R1, R2 and contralateral R2 (CR) was higher in patients than controls but did not reach statistical significance. Following BTX therapy there was a reduction in amplitude of R1, R2 and CR (p < 0.001) and prolongation of latency of R2 and CR (p < 0.05). The ratio of blink reflex amplitude/CMAP amplitude of orbicularis oculi showed a significant decline after BTX therapy (p < 0.01). This small study suggests the involvement of brain stem pathways following BTX therapy in patients with blepharospasm.

Botulinum toxin F in the treatment of torticollis clinically resistant to botulinum toxin A

Two reports have shown a Japanese preparation of botulinum toxin type F (BTX-F) to be an effective alternative for patients with torticollis who develop clinical resistance to botulinum toxin type A (BTX-A). A group of patients with torticollis, comprising five secondary non-responders and one primary non-responder, were treated with a preparation of BTX-F produced in the UK (Speywood Pharmaceuticals). A low dose of BTX-F (220 mouse units (MU) in total) was given into clinically affected neck muscles, followed six weeks later by an injection of a total of 520 MU. Antibodies to BTX-A (mouse protection assay) were present in all secondary non-responders but not in the primary non-responder. No patients developed atrophy after injection of Dysport BTX-A (40 MU) into the left extensor digitorum brevis muscle whereas pronounced atrophy occurred in all patients after injection of 40 MU of BTX-F into the right extensor digitorum brevis muscle. Three patients improved subjectively after treatment with 220 MU BTX-F and five (all secondary non-responders) after the subsequent dose of 520 MU (two considerably), with reduced Tsui scores, but group scores were only significantly changed after the higher dose. The primary non-responder remained unchanged after both doses of BTX-F. One patient reported mild dysphagia with 520 MU BTX-F. Mean duration of improvement with 520 MU BTX-F was five (range 4-6)weeks. Thus BTX-F provides benefit for BTX-A non-responders with few side effects but for a shorter period than BTX-A, possibly due to relative underdosing. As with BTX-A, biological sensitivity to BTX-F does not necessarily predict a clinical response.

Toxina botulínica no blefaroespasmo, no espasmo hemifacial e na distonia cervical: resultados em 33 pacientes

Avaliamos os resultados terapêuticos obtidos com o emprego de toxina botulínica do tipo A em 33 pacientes com distonia (12 com blefaroespamo; 10 com espasmo hemifacial e 11 com torcicolo espasmódico). Utilizamos uma escala de pontuação de gravidade antes de cada aplicação, sendo reavaliados duas semanas após, seguindo a mesma escala. Entre os com blefaroespasmo, oito eram mulheres e quatro homens; a média de idade foi 57,7 anos; a média do tempo de doença de quatro anos; três tinham história similar na família; nove eram essenciais e três fizeram uso de neurolépticos (distonia tardia). A dose média empregada ficou em 51,3 U, com a duração média do efeito benéfico de 2,8 meses. Do total de 22 aplicações (injeções e reinjeções), 14 (63,7%) tiveram resultado ótimo, 5 (22,7%) bom e três (13,6%) nulo. Naqueles com espasmo hemifacial, oito eram mulheres e dois homens; a média de idade foi 52,6 anos; a média do tempo de doença 7,4 anos; oito eram essenciais e dois pós-páralíticos. A dose média empregada ficou em 32 U. Do total de 15 aplicações, todos (100%) tiveram resultado ótimo, com a duração média do efeito benéfico de 3,4 meses. Nos pacientes com distonia cervical, oito eram homens e três mulheres; a média de idade foi 44,2 anos; a média do tempo de doença 12,2 anos; seis eram essenciais, três fizeram uso de neuroléptico e dois tinham história familiar. A dose média empregada ficou em 238,6 U, com a duração média do efeito benéfico de 4,7 meses. Do total de 20 aplicações, 18 (90%) tiveram resultado bom, 1 (5%) regular e 1 (5%) nulo. Ptose palpebral, paresia facial e disfagia foram os efeitos colaterais mais encontrados. Concluímos que a toxina botulínica revelou-se eficaz no tratamento destas condições.

Botulinum toxin in cervical dystonia: low dosage with electromyographic guidance

Sixty patients with idiopathic cervical dystonia were treated a total of 240 times with botulinum toxin type A (BTA). Selected muscles were injected with BTA under electromyographic (EMG) guidance. The clinical effect was measured on the Tsui scale and a 10-point anchored visual analogue scale. A dosage of 150-300 mouse units was used in 77% of the treatments (mean 204 mouse units). Based on the Tsui scale, 45% of 240 treatments were still effective at the moment of reinjection (median improvement 2 points). Based on the 10-point anchored visual analogue scale, 73% of treatments were successful (median improvement 3 points). Forty-eight patients (80%) responded favourably to the treatment. Side-effects were mild and transient. Dysphagia occurred in 9% of treatments. Antibody production was investigated in 41 patients and was negative in all. A striking difference from previous reports is the lower dosage used in this study. The clinical response, however, was similar to that of other studies. We conclude that a dosage of 200-400 mouse units BTA (Dysport) may also be effective in the treatment of cervical dystonia, but with fewer side effects. EMG guidance and application of BTA into deep cervical muscles may further improve the clinical effect.

The blepharospasm disability scale: an instrument for the assessment of functional health in blepharospasm

Assessment of the functional status in patients with blepharospasm is of major importance for clinical practice and outcome studies. The Blepharospasm Disability Scale (BDS) is specifically directed to measure the disability in these patients. The metric properties of this instrument were evaluated. Reliability, validity, and responsiveness to within-patient health changes over time of the BDS were assessed in 40 patients with essential blepharospasm treated with botulinum toxin injections. The reliability of the scale was sufficient for use on group level (Cronbach's alpha coefficient, 0.69). Evidence of discriminant validity was provided by the difference in median score on the BDS between 21 newly admitted patients and 19 patients already under treatment (p < 0.001). Convergent validity was supported by correlations between BDS and neurological impairment scores (range, Spearman correlation coefficients, 0.65-0.79). Responsiveness to health changes was demonstrated by a significant difference between median BDS scores before treatment and 2 weeks after treatment with botulinum toxin (p < 0.01). The BDS is a useful disease-specific instrument to assess disability. Completion of the questionnaire is easy and takes only a few minutes. The instrument is suitable for use in patient care, descriptive outcome studies, and should be considered in controlled clinical trials.

Rhinorrhea is decreased in dogs after nasal application of botulinum toxin

At this time no effective long-term therapy exists for the excessive secretion of vasomotor rhinitis. Because rhinorrhea is under parasympathetic control, it was theorized that botulinum toxin--a powerful and long-acting cholinergic blocker that has been successful in the treatment of dystonia--might be useful in blocking the cholinergic control of rhinorrhea. Four male mongrel dogs were studied. Fifty units of type A botulinum toxin was soaked into sterile gauze, which was then packed into the left nasal cavity of each dog for 1 hour. Saline-soaked gauze was similarly introduced into the right nasal cavity to serve as control. Six days later, rhinorrhea was produced by inserting a bipolar needle electrode into the sphenopalatine ganglion and electrically stimulating for 10 minutes (6 mA, 50 Hz). Nasal secretions were collected with a suction catheter placed in the nasal vestibule. Three of four dogs exposed to the toxin showed a 41% average decrease in rhinorrhea (specifically 53%, 41%, and 30%). One dog showed a 10% increase in secretion after exposure to the toxin. We conclude that topically applied botulinum toxin reduced neurally evoked rhinorrhea by an average of 41%. Because some secretion is mediated by noncholinergic neurotransmitters such as vasoactive intestinal peptide, topical application of an anticholinergic substance has limitations. However, because all the nasal parasympathetic nerves appear to originate from cholinergic synapses in the sphenopalatine ganglion, direct injections of toxin into this ganglion may possibly allow complete blockade of all cholinergically mediated rhinorrhea.

Intrasphincteric botulinum toxin for the treatment of achalasia

BACKGROUND

Achalasia is a disorder of swallowing in which the lower esophageal sphincter fails to relax. We report the use of botulinum toxin, a paralytic agent, for the treatment of this condition.

METHODS

In a double-blind trial, 21 patients with achalasia received either 80 units of botulinum toxin or placebo, injected endoscopically into the lower esophageal sphincter. One week later, the response to treatment was assessed on the basis of changes in the symptom scores (measured on a scale from 0 to 9), pharyngoesophagograms, and results of esophageal manometric and scintigraphic studies. Patients who received placebo initially were subsequently treated with botulinum toxin. After six months, esophageal scintigraphy was repeated.

RESULTS

One week after treatment, the mean decrease in the symptom score was 5.4 points for the patients treated with botulinum toxin and 0.5 point for the placebo group (P = 0.001). The mean decrease in the pressure of the lower esophageal sphincter was 33 percent in the treatment group, as compared with a mean increase of 12 percent in the placebo group (P = 0.02), and the mean increase in the width of the opening of the lower esophageal sphincter was 204 percent in the treatment group, as compared with a mean decrease of 14 percent in the placebo group (P = 0.02). Nineteen of the 21 patients treated with botulinum toxin had symptomatic improvement initially; after six months 14 patients were still in remission. This improvement was accompanied by a decrease in esophageal retention that was sustained at six months (46 percent, as compared with a pretreatment value of 77 percent; P = 0.04). There were no serious adverse effects.

CONCLUSIONS

Injection of botulinum toxin into the lower esophageal sphincter is an effective, safe, and simple method of treatment for achalasia, with results that are sustained for several months.

Effects of local injections of botulinum toxin on electrophysiological parameters in patients with hemifacial spasm: role of synaptic activity and size of motor units

Ten patients with typical hemifacial spasm were examined before and after treatment with local injections of botulinum toxin type A. After a mean follow-up period of 38 days there was a reduction of the compound muscle action potential (CMAP) of the injected orbicularis oculi muscle of 40%. Ephaptic transmission studied by selective stimulation of facial nerve branches revealed a preserved delayed response of the affected mentalis muscle. However, no delayed response could be recorded in the injected orbicularis oculi muscle in nine patients. The discrepancy between complete loss of the delayed (ephaptic) response and only moderate reduction of the CMAP amplitude of the direct response may be explained by preferential uptake of botulinum toxin type A by hyperactive synapses involved in ephaptic transmission.

Outcome after stereotactic thalamotomy for dystonia and hemiballismus

The outcome after single or staged stereotactic thalamotomies in 17 patients with dystonia and 2 patients with hemiballismus is reviewed. All patients were severely disabled by their movement disorders despite optimal pharmacological therapies. Eight of the patients with dystonia (47%) showed moderate improvement immediately after the procedures. Six of these eight patients maintained their improvement, and two other patients with dystonia improved significantly, during the follow-up period (mean, 37.6 mo). The long-term outcome was better in patients with secondary dystonia (50% moderately or markedly improved at a mean of 41.0 mo) than in patients with primary dystonia (43% moderately or markedly improved at a mean of 32.9 mo). Excellent control was achieved in both of the patients who underwent thalamotomies for hemiballismus.

[Treatment of Parkinson disease]

Parkinson's disease (PD) accounts for 58% of patients with Parkinsonism. The second most common cause is drug-induced Parkinsonism, diagnosed in 20% of patients. Levodopa remains as the mainstay of PD treatment. Although there is controversy regarding the timing for beginning levodopa, it should be used when the patient develops significant disability. Other drugs that may be used are anticholinergic agents, useful for tremor; amantadine, for rigidity and bradykinesia; dopamine agonists, for the management of levodopa complications; and selegiline which may be a neuroprotector agent. Problems in the management of PD include primary failure, secondary failure and levodopa complications. Antidopaminergic drugs, severe rest tremor and diagnosis error may lead to primary failure. Progression of PD is the most common explanation for secondary failure. The most important levodopa therapy complications are dyskinesias and fluctuations. Other common problems are dysautonomia, depression, psychosis and dementia. The author discusses the phenomenology and management of these complications. Future perspectives include brain repair surgeries.

The median paralysis unit: a more pharmacologically relevant unit of biologic activity for botulinum toxin

Although the LD50 has been used to quantify the biologically active toxin in clinical preparations of botulinum A toxin (Botox and Dysport), a discrepancy exists between the clinical potency of equivalent international units of different formulations of botulinum A toxin for multiple clinical indications. Our laboratory previously reported that a regional chemodenervation assay in the mouse could be utilized to detect the difference in the potencies of the clinical preparations of toxin [Pearce et al. (1994) Toxic. appl. Pharmac. 128, 69-77]. The purpose of this study was to quantify the regional paralysis produced by botulinum toxin and define a new pharmacologic/biologic unit of activity that more accurately reflects the mechanism of action of botulinum toxin in the clinical setting. Quantal analysis of regional paralysis revealed that the ED50, defined as the median paralysis unit (MPU) for Botox and Dysport, was 0.41 +/- 0.01 and 1.00 +/- 0.02 LD50 units, respectively. Differences in the potencies found in retrospective clinical studies comparing Botox and Dysport were accurately reflected, for the first time, by the dose of toxin expressed in terms of the MPU (median paralysis unit). The data suggested that the MPU may be a more appropriate measure of the biologic activity in therapeutic formulations of botulinum toxin.

Botulinum toxin for chronic anal fissure

Botulinum toxin can chemically denervate striated muscle. Botulinum toxin A (15 U) was used to treat ten patients with chronic anal fissure by injection in the internal sphincter. In seven patients, the lesion healed at 2 months after treatment; one relapsed at 3 months. In one patient the lesion healed at 1 month, but partly relapsed a month later. Mild faecal incontinence lasting for 1 day was observed in one patient. We propose that botulinum toxin injections in the internal anal sphincter be considered an alternative approach to surgical therapy of anal fissure.

Botulinum toxin in the treatment of myofascial pain syndrome

Six patients with chronic myofascial pain syndrome involving cervical paraspinal and shoulder girdle muscles received trigger point injections of botulinum toxin type A (Botox) or saline in a randomized, double-blind, placebo-controlled study. Four patients experienced reduction in pain of at least 30% following Botox, but not saline, injections, as measured by visual analog scales, verbal descriptors for pain intensity and unpleasantness, palpable muscle firmness, and pressure pain thresholds. Results were statistically significant. Botox, which inhibits muscle contraction by blocking the release of acetylcholine from peripheral nerves, appears to be an effective treatment for focal myofascial pain disorders.