The treatment of hemifacial spasm using botulinum toxin]

Hemifacial spasm is a disagreeable disturbance with involuntary unilateral twitching of the facial muscles. Its most common form is supposedly due to an irritation of the facial nerve at its proximal intracranial segment by vascular structures. Various forms of treatment including surgical procedures are employed, very often without satisfactory results but frequently involving the risk for severe complications. For a few years a new method has been using injection of botulinum toxin into the affected muscles, which in the majority of patients relieves the abnormal movements for about half a year; therefore, this very effective and secure procedure is recommended as first-line treatment of hemifacial spasm.     

Treatment of hemifacial spasm with botulinum toxin

We injected botulinum toxin to treat hemifacial spasm, and investigated the effects and the patient's impression of this treatment. Average duration of improvement lasted about 3.5 months in both the initial treatment group and the recurrent group. However the patients in the recurrent group received fewer units of botulinum toxin than those in the initial treatment group. Except for local paralysis that disappeared within a month, there were very few complications. Most patient were satisfied with this treatment. We conclude that the treatment of hemifacial spasm with botulinum toxin is both simple and useful.     

Long term results of botulinum toxin type A (Dysport) in the treatment of hemifacial spasm: a report of 175 cases

Synthesis of artificial enzymes for catalyzing phosphoester hydrolysis has been attracting interest for a long time. The remarkable discovery that lanthanide ions catalyze the hydrolysis of DNA and RNA spurred the trend. Currently, progress is being made, mainly in the preparation of homogeneous catalysts, the promotion of catalytic activity by using acid/base cooperation within catalysts, the detailed understanding of the reaction mechanisms involved, and the design of artificial enzymes expressing high specificity and catalytic turn-over.     

Pediatric hemifacial spasm: the efficacy of microvascular decompression

Hemifacial spasm (HFS), generally a disease of the elderly, is caused by vascular compression of the seventh nerve. Vascular compression is thought to result from atherosclerotic changes within the vessels of the posterior fossa, and therefore rarely presents in childhood. Here we describe our experience with 12 patients with onset of HFS during childhood (age 18 or less) and who had surgical exploration of the cerebellopontine angle. These patients represent less than 1.2% of the patient population with HFS operated upon at this institution during the study period. Nine patients had follow-up data extending over 83 months. All 12 patients were found to have microvascular compression of the seventh nerve at the time of surgery. The most common operative finding was compression of the seventh nerve by a vein, alone or in combination with a branch of the anterior inferior cerebellar artery. At the time of discharge and after a mean follow-up period of 125 months, microvascular decompression resulted in complete relief of spasm in 67% of the patients.     

Blink reflex recovery cycle in patients with blepharospasm unilaterally treated with botulinum toxin

To study the role of arterial blood dynamics in the thrombogenesis of thrombin-induced experimental retinal vein obstruction, the retinal blood flow velocity was evaluated using scanning laser ophthalmoscopic fluorescein videoangiography in an experimental rabbit retinal vein obstruction model. Retinal vein obstruction was made by transadventitial direct instillation of thrombin to the retinal vessels from the vitreous side. The blood flow velocity in the retinal artery and vein was estimated by measuring the passing velocity of the flow head of the dye bolus and venous filling time, respectively. 23 animals were treated with thrombin and compared with 18 controls not treated. In the control group retinal artery blood flow velocity and retinal venous fluorescein filling time was 5.3 +/- 1.1 mm/sec (mean +/- standard deviation) and 6.2 +/- 1.2 sec, respectively. In the treated group the values were 5.7 +/- 1.3 mm/sec and 5.8 +/- 1.0 sec before the thrombin administration, and 3.0 +/- 0.9 mm/sec at 24 hours after its administration, and 5.7 +/- 2.0 sec and 4.0 +/- 1.5 mm/sec and 4.5 +/- 1.4 sec at 48 hours after the administration. These results indicate that a decrease in retinal artery blood flow velocity is strongly involved in the thrombogenesis in thrombin-induced experimental retinal vein obstruction.     

Dilution and storage of botulinum toxin

BACKGROUND: There has been an ongoing controversy as to the best dilution for botulinum toxin for use in cosmetic applications. Recommended dilutions have ranged from 1 ml per vial to 10 ml per vial. There has also been much discussion on the diluent, i.e., preserved versus unpreserved saline, to be used and on storage time of the material after dilution. OBJECTIVES: The objective of this paper is to examine the literature and experience of practitioners in the field to try to resolve some of the questions concerning dilution and storage of botulinum toxin. CONCLUSIONS: Although there is great variation in the dilutions adopted by various physicians, much of this is a matter of personal preference. It does seem to appear that most clinicians use a dilution near 2.5 to 3.0 ml per vial and three-quarters of them limit the storage of the diluted product to 1 week or less.     

Effect of repetitive stimulation on lateral spreads and F-waves in hemifacial spasm

The lateral spread (LS) response, which can be elicited in muscles innervated by other branches of the facial nerve, is electromyographycally specific for patients with hemifacial spasm (HFS), occurring about 10 ms after stimulus. The F-wave in facial muscles, which is a late response that antidromicaly propagates to the facial motonucleus and returns orthodromicaly down the same axon, revealed a trend toward enhancement in patients with HFS. The LSs were facilitated by repetitive stimulation during the microvascular decompression (MVD) operation, which has proved to be a successful treatment, and the F-waves were also facilitated by repetitive stimulation on the spasm side more than on the normal side. Greater facilitation of these responses was in direct proportion to higher stimulation rates and greater numbers of stimulations. The repetitive stimulation of the facial nerve may result in activation of the motoneuron pool and in the lowering of the threshold of somatic membranes. These results support the hypothesis that hemifacial spasm is caused by hyperexcitability of the facial motonucleus, which is increased by antidromic repetitive stimulation.     

Nonsurgical treatment of platysmal bands with injection of botulinum toxin A

Botulinum toxin A has been used therapeutically in humans for over 20 years for a variety of medical indications. For the past 7 years, the author has injected it for cosmetic purposes in a variety of muscles of the head and neck. Fifty patient-injections of the platysma muscle were performed in an attempt to correct platysmal banding. An improvement was seen in all patients who presented to the office for follow-up in a timely manner (44 injections). Results were limited by redundant skin. No incidence of dysphagia or airway obstruction was encountered. The only complication noted was bruising. Although at least a small improvement in platysmal banding was seen in all patients, in no patient was there evidence of lifting of the lower face. All results were temporary.     

Mechanism of action, clinical indication and results of treatment of botulinum toxin

Botulinum toxin, the most potent of the neurotoxins, produces paralysis by blocking presynaptic release of the neurotransmitter (acetylcholine) at the neuromuscular junction, with reversible chemical denervation of the muscle fibre, thereby inducing partial paralysis and atrophy. Because chemical denervation is reversible, botulinum toxin has temporary effects, the muscle being progressively reinnervated by nerve sproutings. Type A botulinum toxin (Bix-A) is available under two dosage forms: Botox and Dysport. Although the initial clinical indication was strabismus, subsequent studies have demonstrated the efficacy of Btx-A, mainly in dystonia, hemifacial spasm and spasticity. However, botulinum toxin has been successfully used in various other clinical indications. In regard to spasticity associated with cerebral palsy, Btx-A is a promising treatment requiring a multidisciplinary approach. Btx-A injections lead to effective reduction of muscle hyperactivity with minor side-effects. They are painless, even though electromyographic guidance may be required for the injection of deep muscles. However, the production of antibodies to Btx-A may compromise the effect of long-term treatment.     

Intrasphincteric injection of botulinum toxin is effective in long-term treatment of esophageal achalasia

We investigated the long-term efficacy and safety of intrasphincteric injections of botulinum toxin (100 U) in 57 patients with esophageal achalasia. One month after treatment, 50 patients had improved (88%); both symptom score and LES pressure were significantly reduced (P < 0.001). After a mean follow-up of 24+/-15 months (range 6-48), 43 patients (75%) are still in remission, although repeat injections of toxin were needed to achieve a stable effect on symptoms.     

Use of botulinum toxin type F injections to treat torticollis in patients with immunity to botulinum toxin type A

Fifteen patients with torticollis who had been treated with repeated injections of botulinum toxin type A (botox A) developed antibodies to the toxin. This resulted in loss of benefit in the 13 patients who had improved with botox A injections and failure to develop muscle atrophy after injection in all 15 patients. Patients were then injected with botulinum toxin type F (botox F) in the same muscles that had been injected with botox A. Ten of the 15 improved after botox F injections, including 9 of the 12 patients who had improved with type A toxin. Six of 9 patients with pain had improvement in pain after botox F injections. Patients reported similar improvement with type F and type A toxins, but duration of benefit was approximately 3 months with type A and approximately 1 month with type F. Botox F is an effective treatment for torticollis in patients who are immune to botox A. The usefulness of type F toxin, however, is limited by short duration of benefit.     

Therapeutic use of botulinum A toxin in neurology

The highly potent neurotoxins produced by Clostridium botulinum lead to botulism when ingested in appreciable amounts. However, botulinum toxin injections delivered intramuscularly in very small quantities can produce a therapeutically intended focal paresis while producing only negligible local or systemic side effects. Over the past several years, various neurological disorders, especially those involving increased muscle tone and/or abnormal movements, have been successfully treated with local botulinum A toxin injections. The success of this method has led to a general change in the management of blepharospasm, torticollis spasmodicus, hemifacial spasm, and other disorders. Treatment is usually effective for 4 to 12 weeks; if symptoms recur, the injections can be repeated over a period of several years, usually with the same success. Side effects depend on the site of the injections, and are rare at the optimal dosage and always reversible. For optimum therapeutic results, this treatment must be restricted to specialized centers.     

Interventional neuropediatrics: treatment of dystonic and spastic muscular hyperactivity with botulinum toxin A

Therapeutic effect of botulinum toxin A was studied in a group of pediatric patients (n = 28) aged between 6 months and 18 years. The patients were diagnosed with cervical dystonia (n = 6), adductor spasm of the hip (n = 8), spastic drop foot (n = 7) and various other focal motor problems associated with spastic muscular hyperactivity (n = 7). The mean dose of botulinum toxin A (Dysport) used to inject into the affected muscle was 22 U/kg body weight. Reduced muscular hyperactivity with a significant increase in joint mobility was achieved for dystonic (p < 0.0001) as well as for spastic conditions in patients with adductor spasm (p < 0.0002). For these patients the improved joint mobility represented a significant benefit for both daily activities and nursing care. Local paresis and local hematoma were observed in 1/28 and 1/28 patients, respectively; 1/28 patients developed a secondary non-response. However, apart from these side effects, no other adverse reactions to botulinum toxin A treatment were recorded during the treatment and observation period (12-64 months). Our results suggest that botulinum toxin A represents an effective and safe therapeutic substance for the treatment of pediatric patients suffering of focal motor problems due to dystonic or spastic muscular hyperactivity.     

Refinement in the rehabilitation of the paralyzed face using botulinum toxin

OBJECTIVE: The purpose of this study was to determine the distribution of referred pain from the lumbar zygapophyseal joints (L1/2 to L5/S1) and the medial branches of the lumbar dorsal rami (Th12 to L5) in a large number of patients with chronic low back pain. SETTING: This study was conducted at the pain clinics of Kanto Teishin Hospital and Hannan Central Hospital from March 1994 to May 1996. PATIENTS AND DESIGN: Chronic low back pain patients who underwent zygapophyseal joint injection or radiofrequency facet denervation were studied. Under fluoroscopic control, the joints from L1/2 to L5/S1 were stimulated by injection of contrast medium, and the lumbar medial branches of the dorsal rami from Th12 to L5 underwent electrical stimulation during radiofrequency facet denervation. OUTCOME MEASURES: If the injection or electrical stimulation reproduced the patient's usual pain, the distribution of induced pain was determined, and the sites of induced pain were divided into six areas. RESULTS AND CONCLUSIONS: A total of 71 joints and 91 medial branches were studied in 48 patients. The distribution of referred pain from the L1/2 to L5/S1 zygapophyseal joints, and the medial branches of the dorsal rami from L1 to L5 were similar for each level stimulated, and the overlap of referred pain between each level was considerable.     

Botulinum toxin type A purified neurotoxin complex for the treatment of blepharospasm: a dose-response study measuring eyelid force

The clinical efficacy of botulinum toxin type A was studied in patients with blepharospasm. Clinical symptoms were evaluated using the Jankovic rating scale. To measure dose response, we used a recently developed device to measure eyelid muscle force. The results showed significant improvement (P = 0.0000) in the Jankovic rating scale scores in all dose groups. The number of patients with marked improvement (6-point decrease or more in the total Jankovic rating scale score) increased with higher dose injections. After injections of 0.50, 1.25, or 2.50 U/site, 6 sites/eye, the eyelid muscle force decreased by 33.2 +/- 28.1%, 41.7 +/- 25.1%, or 69.6 +/- 5.0%, respectively. The decrease of eyelid muscle force showed a significant dose response (P = 0.0254). The mean duration of effect was 12.9 weeks in patients after dose injections of 1.25 U/site, which was significantly longer (P = 0.0205) than the 9.6 weeks in patients after dose injections of 0.50 U/site. No severe adverse effects were observed. We concluded that injections of botulinum toxin type A at an initial dose of 1.25 U/site are a safe and effective treatment for blepharospasm.