Microlesion Effect Induced by Electrode Implantation in the Posteroventral Globus Pallidus Interna for Severe Dystonic Tics

Background

Tourette syndrome (TS) is a neurologic condition characterized by motor and phonic tics. Dystonic tics, including blepharospasm, are considered atypical or unusual in severe TS.

Case Report

We report a severe case of TS with facial dystonic tics resembling blepharospasm in which the microlesion effect and a sustained therapeutic effect was observed with bilateral globus pallidus interna (GPi) deep brain stimulation (DBS).

Discussion

Bilateral GPi DBS can be beneficial for blepharospasm-like tics and severe symptoms of TS. The improvements seen can be explained by the microlesion effect induced by DBS lead placement in the GPi.

Activating the levator to elevate the eyelid

PURPOSE

To demonstrate in an animal model the feasibility of elevating the eyelid in a functionally useful manner by chronically stimulating the levator palpebrae superioris (LPS) muscle with an implanted electrode.

METHODS

Five rabbits were implanted with electrodes designed to stimulate the nerve innervating the LPS near its entry to the muscle. Bipolar platinum electrodes in a silicone rubber envelope with silicone-sleeved, PTFE-coated platinum lead wires were used to provide long-term stimulation with bipolar square-wave pulse trains of 0.18-0.80 mA and 200 Hz at a duty cycle of 8 seconds on and 2 seconds off. Explanted electrodes were examined for damage, and stimulated tissues were evaluated for abnormalities by light microscopy.

RESULTS

We achieved mean lid elevation of 1.6 mm, approaching the diameter of the light-adapted pupil, with 0.5 mA stimulus. Stimulus currents below 1.0 mA produced no signs of discomfort. Three animals with which we attempted daily stimulation, averaged 16.1 hours per week. Experiments lasted 22 weeks on average. Lid lifting with a well-implanted platinum electrodes was stable, with no apparent tissue or electrode damage after as long as 29.1 weeks.

CONCLUSIONS

Stable, functionally useful eyelid lifting was achieved with stimulation currents that caused no apparent discomfort or damage to muscles or nerves. A simple, discrete bipolar electrode was effective and survivable.

Intractable Blepharospasm Treated with Bilateral Pallidal Deep Brain Stimulation

BACKGROUND

Blepharospasm can be present as an isolated dystonia or in conjunction with other forms of cranial dystonia, causing significant disability.

CASE REPORT

We report a case of a 69-year-old male with craniocervical dystonia, manifesting primarily as incapacitating blepharospasm refractory to medical treatments. He underwent bilateral globus pallidus (GP) deep brain stimulation (DBS) with complete resolution of his blepharospasm and sustained benefit at 12 months postoperatively.

DISCUSSION

This case illustrates successful treatment of blepharospasm with pallidal stimulation. GP-DBS should be considered a reasonable therapeutic option for intractable blepharospasm.

[Efficacy observation of acupuncture method of tonifying-qi and dredging-meridian for blepharospasm]

OBJECTIVE

To compare differences of therapeutic effect between acupuncture method of tonifying-qi and dredging-meridian and conventional acupuncture method.

METHODS

Seventy cases of blepharospasm were randomly divided into an observation group and a control group, 35 cases in each one. Cuanzhu (BL 2), Yuwei (Extra) through Yuyao (EX-HN 4), Xinming 1 (Extra), Sibai (ST 2) and Yintang (GV 29) were selected as main acupoints. The acupuncture method of tonifying-qi and dredging-meridian was applied in the observation group, which was an acupuncture manipulation that could achieve strong needling sensation of qi arrival combined with electric-impulse stimulation. The conventional acupuncture method was applied in the control group. The treatment was given once every other day, 10 times as a session for continuous three sessions in both groups. The severity of blepharospasm was compared before and after treatment in two groups and clinical therapeutic effect was assessed. Follow-up visit was performed after half a year to observe the recurrence rate.

RESULTS

The cured and markedly effective rate was 77.1% (27/35) in the observation group, which was superior to 51.4% (18/35) in the control group (P < 0.05). Among cured and markedly effective patients in both groups, the recurrence rate was 20.0% (4/20) in the observation group, which was inferior to 54.5% (6/11) in the control group (P < 0.05) in the follow-up visit.

CONCLUSION

The acupuncture method of tonifying-qi and dredging-meridian could effectively improve severity of blepharospasm, which has superior short-term and long-term effects to conventional acupuncture method.

Update on blepharospasm: report from the BEBRF International Workshop

This review updates understanding and research on blepharospasm, a subtype of focal dystonia. Topics covered include clinical aspects, pathology, pathophysiology, animal models, dry eye, photophobia, epidemiology, genetics, and treatment. Blepharospasm should be differentiated from apraxia of eyelid opening. New insights into pathology and pathophysiology are derived from different types of imaging, including magnetic resonance studies. Physiologic studies indicate increased plasticity and trigeminal sensitization. While botulinum neurotoxin injections are the mainstay of therapy, other therapies are on the horizon.

Electroconvulsive therapy and ocular dystonia

Electroconvulsive therapy (ECT) has been reported to be beneficial in various movement disorders, especially tardive dystonic reactions. In this article, we report an interesting case of drug-induced blepharospasm with ocular dystonia which improved with ECT. To our knowledge, a case of ocular dystonia improving with ECT has not been previously reported in the literature.

[What to do in cases of inadequate effectiveness of botulinum toxin for the treatment of eyelid cramping?]

In 5-15% of individuals suffering essential blepharospasm, treatment with botulinum toxin is insufficient. In these cases the following measures can be applied: increase the dose, increase or vary the injection sites, change the botulinum toxin medication, use additional oral medication, or perform surgery. Certain measures can also be carried out by the patient. In cases of hemifacial spasm, inadequate results of botulinum toxin injections are even more unusual. But for these cases, additional oral medication or the neurosurgical Janetta operation can be used.

Modified Lundie loops improve apraxia of eyelid opening

BACKGROUND

Current treatments are unsatisfactory for improving apraxia of eyelid opening, defined as a delay or inability to open closed eyelids voluntarily in the presence of intact motor pathways.

METHODS

Improvement in functional health was assessed using the Blepharospasm Disability Scale (BDS) in five consecutive patients with apraxia of eyelid opening treated with wire loops affixed behind ordinary spectacles (Lundie loops) and modified to provide pressure on the brow as a stimulus to keep the eyelids elevated.

RESULTS

All five patients showed improvement in BDS scores. The mean percentage of normal activity of the study population improved from 25% to 37.6%. Outdoor activities were not significantly altered with the use of the device.

CONCLUSIONS

Modified Lundie loops appear to be helpful in improving the functional health of patients with eyelid apraxia. These results will need to be verified in larger trials.

Is there a place for placebo in management of psychogenic movement disorders?

INTRODUCTION

The management of psychogenic movement disorders is fraught with difficulties. Empathy and a non-judgmental manner are essential in dealing with patients, and a neurobiological explanation of the symptoms may help to foster trust, acceptance, understanding and recovery.

CLINICAL PICTURE

We report a 17-year-old Chinese girl with psychogenic blepharospasm. Her parents refused psychotherapy and pharmacotherapy.

TREATMENT AND OUTCOME

Placebo therapy (with parental consent) was prescribed with favourable results.

CONCLUSION

We examine the ethical considerations for and against placebo therapy, and explore the role of placebo therapy in the management of psychogenic movement disorders.

Apraxia of eyelid opening: clinical features and therapy

PURPOSE

Botulinum toxin injection is the treatment of choice in cases of benign essential blepharospasm. However, about 10% of the patients do not get sufficient effect from this treatment, and many of them have concomitant apraxia of lid opening.

METHODS

Over a 3-year period we treated 12 patients. Three had pure apraxia of lid opening and in the other nine it was associated with blepharospasm. All patients were initially treated with botulinum toxin injections with poor results. They underwent surgical treatment like blepharoplasty, limited myectomy, aponeurosis repair, and/or frontalis suspension. Some of them needed post operative botulinum toxin injections in the pretarsal part of orbicularis oculi muscles.

RESULTS

This combined therapy gave good functional and aesthetic results.

CONCLUSIONS

The specific causes of blepharospasm and apraxia of lid opening are unknown, but these two conditions coexist in some patients and can be difficult to treat. It is important to make a correct diagnosis, and a combined surgical and botulinum toxin treatment can be very effective.

[Upper lid frontalis suspension as a treatment for essential blepharospasm]

BACKGROUND

Essential blepharospasm is a progressive disease of unknown etiology causing a significant decline in the quality of life of patients suffering from the disease. Currently used treatment for this condition is repeated injections of Botulinum toxin. Some of the patients' therapeutic response to Botox injections is insufficient, and some develop ocular complications.

GOALS AND METHODS

This report presents our experience with sling frontalis suspension for essential blepharospasm in 4 patients with follow-up periods of six months to 2 years. A literature review is presented and discussed.

RESULTS

A treatment trial with Botox injections was attempted in all four patients. Three of the patients showed insufficient treatment response. Three of the patients developed side effects of recurrent episodes of upper lid ptosis following injections. In all four patients that underwent operations significant reduction of blepharospasm was observed. In two of the patients Botulinum toxin could be discontinued, in one patient treatment intensity could be reduced, and in three--treatment complications were prevented. All four patients reported a high degree of satisfaction from treatment results.

CONCLUSIONS

Our results indicate that sling frontalis suspension for essential blepharospasm is a safe and efficient treatment for essential blephrospasm with a high degree of patient satisfaction. Further large-scale studies are needed to substantiate our results.

Remission of tardive dystonia (blepharospasm) after electroconvulsive therapy in a patient with treatment-refractory schizophrenia

Tardive dystonia is a movement disorder dominated by involuntary muscle contractions that may be tonic, spasmodic, patterned or repetitive, associated with the use of dopamine-receptor blocking agents. Most of the patients with tardive dystonia present initially with blepharospasm. Treatment of dystonia is generally disappointing. A patient with chronic paranoid schizophrenia who developed blepharospasm is described here. Blepharospasm remitted after a course of electroconvulsive therapy. Remission was sustained until 3 months after stopping maintenance electroconvulsive therapy.

Assessment of Blepharospasm Surgery Using an Improved Disability Scale: Study of 138 Patients

PURPOSE

To assess a new scale for grading functional disability in a series of patients operated on for blepharospasm resistant to treatment by botulinum toxin (BT) injections.

METHODS

The bicentric study included 138 patients: 80 (58%) with essential blepharospasm; 46 (33%) with apraxia of eyelid opening; and 12 (9%) with intermediate forms. They had undergone orbicularis myectomy (92 cases, 67%), frontalis suspension (31 cases, 22%), or both (15 cases, 11%). Functional disability was assessed by using an original scale covering 6 daily life activities, each graded using 5 levels from 0 (no disability) to 4 (activity impossible). The score obtained was related to the total of activities actually performed to produce a functional disability score (FDS) from 0 to 100. Each patient's FDS was prospectively determined, before surgery and 3 months after surgery (M3). In patients who, after surgery, required a further course of BT injections, the FDS was assessed immediately before the third injection.

RESULTS

The mean FDS fell significantly, from 78 +/- 15 (standard deviation) before surgery to 45 +/- 21 at M3 (p < 0.01%), whatever the clinical form of essential blepharospasm or surgical procedure. The mean postoperative FDS was significantly lower in the 62 patients (45%) weaned off BT than in the unweaned group, respectively (31 +/- 17 versus 56 +/- 18; p < 0.01). In the latter group, the mean FDS after BT reinjection (34 +/- 19) fell to a level comparable with that of the weaned patients.

CONCLUSIONS

This accurate, easy-to-use scale makes it possible to quantify in patients with blepharospasm functional improvement as the result of surgery and, where applicable, of BT reinjection.

Dysphagia as a side effect of botulinum toxin injection

Dysphagia is a known adverse effect of botulinum toxin injection into the cervical region for dystonia. We present an unusual case of dysphagia arising from injection into the orbicularis oculi muscle, which has hitherto not been described. We postulate that her dysphagia was caused by distant side effects of botulinum toxin due to repeated injections. We recommend that clinicians should restrict the frequency of injections to as few life-time doses of the toxin as possible for adequate management of spasm. The practice of re-injecting patients routinely every three months, or at the first return of mild spasms should be discouraged.

Is acupuncture an useful tool for pain-treatment in ophthalmology?

Pain that does not respond to conventional treatment procedures makes it necessary to look for alternative methods. Acupuncture is an ancient procedure with empirical effects on pain. Previous studies established the increased output of messengers at neuronal junctions in spinal cord and hypothalamic locations, especially of endorphins which inhibit the perception of pain. We treated several painful symptoms with acupuncture and evaluated the outcome of the treatment. Patients with various kinds of therapy-refractory pain and patients in whom conventional treatment methods could not be applied were included in the study. The diagnoses included glaucoma. Tolosa-Hunt-Syndrome, ophthalmic migraine, blepharospasm, and dry eyes. In one case acupuncture was used for analgesia during surgery. Acupuncture was performed with sterile disposable needles, at points known to have an empirical analgesic effect. The stimulation was adapted to the patient's individual needs. VAS assessments before and after acupuncture were compared. The t-test was used for statistical evaluation. Acupuncture had no side effects, but reduced pain to a variable extent. Especially in cases of severe pain and in surgery, very effective pain reduction was achieved. In general, pain was significantly reduced in all patients by the use of acupuncture. A statistically significant effect was noted (p < 0.05). Further studies should be conducted to demonstrate the specific effect in larger patient populations. Monitoring neurotransmitter activity will possibly help to illustrate the effect.

Blepharospasm: recent advances

Benign essential blepharospasm is a common focal dystonia characterized by involuntary eyelid closure. Its etiology, supported by animal models, appears to be multifactorial, representing the influence of a genetic background and an environmental trigger. The genetic background could be responsible for the reduced brain inhibition, identified with physiologic studies that would set up a permissive condition for increased brain plasticity. Reduced D2 receptors identified with PET might be an indicator of this reduced inhibition. The trigger could be repetitive use or local ocular disease. Although symptomatic therapy is available, better approaches are needed and will likely become available as the genetics and pathophysiology become well understood.

[Treatment of local hyperkinesis]

Insufficient effectiveness of medicamentous therapy of local hyperkineses necessitated quest for other treatment options. In view of pathogenetic features of this pathological process we have chosen reflexotherapy to be instituted in our patients: auriculopuncture, electro-corporal- and acupuncture which have been shown to be expedient and effective in treating 65 patients with local hyperkinesis (blepharospasm, facial paraspasm, writer's spasm, spasmodic torticollis). Positive findings from clinical and paraclinical methods of investigation corroborate the results of the treatments administered.

Blepharospasm and Meige syndrome: a review of diagnostic, aetiological and treatment approaches

No known pathophysiological mechanism can explain the majority of cases of blepharospasm, i.e. spasm of the orbicularis oculi muscle; it may also affect the lower face, neck and jaw--Meige syndrome. Only symptomatic treatment is possible, and surgery should be a last resort for severe cases. Much more clinical research will be required before promising behavioural interventions, including biofeedback, can be considered treatments of choice.

[Focal dystonia: clinical, etiologic and therapeutic aspects]

Blepharospasm, spasmodic torticoli, and writer's cramp are the most frequently observed forms of focal dystonia. Primary dystonia is often a hereditary condition with a dominant autosomal mode of transmission and variable penetrance. Secondary conditions are generally the expression of a lesion to the basal ganglia due to an iatrogenic cause or exceptionally the inaugural sign of a metabolic disease. The basal ganglia play an important role in the pathophysiology of this reciprocal innervation disorder but progress in genetics may help better understand the different molecular mechanisms involved. Treatment relies on botulin toxin associated with physical therapy depending on the localization. Drug therapy is often disappointing due to minimal efficacy and poor tolerance.

[Torticollis spasmodicus, blepharospasm and hemifacial spasm. Subjective evaluation of therapy by patients]

Injections with botulinum toxin type A (BTX) are considered the first-line treatment for spasmodic torticollis (ST), blepharospasm (BL) and hemifacial spasm (HFS). Because BTX brings only temporary and partial relief, patients frequently try other additional therapies to minimize their symptoms. The subjective rating of all therapies ever tried by patients with ST, BL and HFS was evaluated by using a simple questionnaire. Two hundred questionnaires were considered (112 TS, 54 BL, 34 HFS). BTX was rated subjectively the best therapy in all three diagnostic groups (median: 2 = good effect). Despite Citalopram and physiotherapy (median: 3 = average effect), all other therapies were rated with a median of > or = 4 (= minimal effect). Patients with ST tried 7.7, patients with BL 2.4 and patients with HFS 2.6 different types of therapy. In conclusion, BTX is the most effective treatment for patients with ST, BL and HFS, as rated subjectively. Further evaluation of therapies additional to BTX injections is recommended.

[Blepharospasm and hemifacial spasm treated with botulinum A toxin injection]

OBJECTIVE

To study the efficacy of botulinum A toxin (BTA) injections for the treatment of blepharospasm and hemifacial spasm (HFS).

METHODS

Twelve patients with blepharospasm and thirty eight patients with HFS were treated with BTA local injections (2.5 U to 5 U for each injection).

RESULTS

Of the fifty patients, ten (86.7%) in blepharospasm and thirty two (84.2%) in HFS were completely relieved, two (13.3%) and five (13.2%) were remarkably relieved respectively, zero and one (2.6%) were partial relieved respectively. All patients experienced relief from spasm. The duration of the effect in blepharospasm were 10 to 24 weeks (mean, 18 weeks) and in HFS 14 to 32 weeks (mean, 22 weeks). The local side effects were transient and mild, including minor facial paralysis in eight patients, ptosis in four patients and tearing in four patients. No systemic adverse and allergic reactions were noted.

CONCLUSION

Botulinum A toxin local injection is a safe, effective and simple means for the treatment of blepharospasm and HFS.

Blepharospasm: past, present, and future

To investigate causes, associations, and results of treatment with blepharospasm, 1,653 patients were evaluated by extensive questionnaires to study blepharospasm and long-term results of treatment with the full myectomy operation, botulinum-A toxin, drug therapy, and help from the Benign Essential Blepharospasm Research Foundation (BEBRF). The percent of patients improved by the BEBRF was 90%, full myectomy 88%, botulinum-A toxin 86%, and drug therapy 43%. The patient acceptance rate for the BEBRF was 96%, full myectomy 82%, botulinum-A toxin 95%, and drug therapy 57%. Blepharospasm is multifactorial in origin and manifestation. A vicious cycle and defective circuit theory to explain in origin and direct treatment rather than a defective specific locus is presented. All four forms of therapy evaluated are useful and must be tailored to the patient's needs. Mattie Lou Koster and the BEBRF have helped blepharospasm sufferers more than any other modality, and all patients should be informed of this support group. The full myectomy is reserved for botulinum-A toxin failures, and the limited myectomy is an excellent adjunct to botulinum-A toxin.

Necrotising fasciitis as a complication of botulinum toxin injection

PURPOSE

To highlight the need for early diagnosis and treatment of the rare condition of necrotising fasciitis as a complication of botulinum toxin injection, and to illustrate that injections in immunocompromised patients carry a rare but serious risk.

RESULTS AND METHODS

A case report is presented of an 80-year-old woman suffering from blepharospasm and chronic myeloid leukaemia, who developed necrotising fasciitis 3 days after a botulinum toxin injection.

CONCLUSIONS

Chronic debilitating processes such as diabetes, alcoholism and polymyositis have been suggested as predisposing factors in the development of necrotising fasciitis. We believe this is the first reported case of necrotising fasciitis occurring secondary to a botulinum toxin injection. The fact that this infection extended through the fascial planes and led to the death of muscle was, probably, because an inoculum was introduced directly into the muscle at the time of botulinum toxin treatment. This may have led to its deep spread and difficulty in debriding the area. Chronic myeloid leukaemia does not in itself cause significant immunosuppression, but our patient was on anti-proliferative treatment and had a low leucocyte count, which may have been a predisposing factor in this case.

Botulinum toxin increases tearing in patients with Sjögren's syndrome: a preliminary report

Three patients with Sjögren's syndrome (SS) who had severe xerophthalmia and blepharospasm received botulinum toxin injections for the treatment of their blepharospasm. They had a remarkable increase in tearing, measured by Schirmer's test, and a decrease in signs and symptoms of dry eyes after botulinum toxin injection periorbitally for blepharospasm. The mechanism for this increased tearing is unclear, but suggests a potential treatment for patients with severe xerophthalmia with SS.

[Motor dysfunction in the aged--approach to involuntary movements]

The clinical, pathophysiological and therapeutic approaches to the representative involuntary movements encountered in the aged are described. The prevalence rates of Parkinson disease and essential tremor are very high, and their diagnoses and treatments are quite important. Recent advances in treating Parkinson disease with anti-parkinsonian medications and essential tremor with beta-adrenergic blockers were presented. Blepharospasms, though uncommon, but occasionally seen in the aged persons, are disabled conditions. The botulinus toxin injections to the orbicularis oculi muscles proved to show dramatic therapeutic effects, greatly contributing to these patients' ADL. The importance of neuroscience in the coming 21st century is also stressed.

Preventing ptosis after botulinum treatment

In a series of 33 blepharospasm patients who had the side effect of ptosis following therapeutic botulinum toxin type A (Botox: Allergan, Inc., Irvine, CA, U.S.A.) injection, we administered 41 injections of human botulinum immune globulin (IG) following injections of the toxin to test the dosage and timing of IG injection and its effectiveness in limiting or avoiding ptosis. An IG dose of 3.2 x 10(-3) international units (IU) per unit of Botox was effective in blocking toxin effect when injected into the same tissue site within 4 hours. An IG dose of 1.6 x 10(-2) to 3.2 x 10(-2) into the levator of the eye having more frequent ptosis in 19 patients reduced the incidence of ptosis to 11%. The fellow (control) eye had a ptosis incidence of 37%. No orbital hemorrhage or other adverse effect occurred from the IG or its injection.

[Treatment of focal dystonia with botulinic toxin]

Dystonia is a neurologic disease characterized by involuntary repetitive muscular contractions which frequently causes torsion, spasmodic movements or abnormal postures. Pharmacologic and surgical treatment had been unsatisfactory in the majority of the cases. Intramuscular botulinic toxin application in focal dystonia disorders, achieve relief in approximately 90% of the cases by quimiodenervation. We included 35 patients with focal dystonia treated between November 1994 through June 1996: 14 facial hemispasm, nine blepharospasm, five cervical dystonia, two writer's cramps, one oromandibular dystonia and four patients with mixed focal dystonia. Improvement between 50-90% was observed in 32/34 (94%) of the patients; one case (2.8%) with therapeutic failure and one case (2.8%) never returned to quantify the response. Actually, botulinic toxin is the first choice treatment of focal dystonia and other diseases related to involuntary muscle spasm.

Personal defense sprays: effects and management of exposure

BACKGROUND

Most personal defense sprays contain o-chlorobenzylidene malononitrile (CS), w-chloroacetophenone (CN), oleoresin capsicum (OC), or a combination of these ingredients as the active agent. They are designed to incapacitate by causing acute ocular irritation, lacrimation, conjunctivitis, blepharospasm, and mild to moderate respiratory distress.

METHODS

To assess the ocular effects of sprays containing OC as the active agent. Snellen visual acuities and anterior segment appearances of 22 police officers were determined before and after spray exposure. To assess the effects of OC spray contamination on soft contact lenses, four brands of lenses were sprayed and cleaned twice with an alcohol-based cleaner. Gas chromatography was used to search for residual OC in the lenses.

RESULTS

All officers experienced intense blepharospasm, lacrimation, conjunctivitis, and incapacitation as the result of spray exposure. Acute effects lasted about 5 to 10 min, with relatively complete recovery occurring in about 30 to 60 min. All had significant conjunctivitis, and some had water-drop-shaped corneal defects that stained with fluorescein. These defects resolved within 24 hours without treatment. OC residue was found to be present in the soft lenses that had been sprayed and cleaned twice.

CONCLUSIONS

Optometrists can manage uncomplicated spray exposure patients by directing at-home irrigation with water, and following up with an in-office examination. Soft lenses contaminated by OC spray should be discarded.

Long-term treatment of blepharospasm with botulinum toxin type A

The treatment of essential blepharospasm with botulinum toxin has been known for a decade and is becoming increasingly more popular. To our knowledge, only a few longterm studies in major patient populations have been published. Of a total of more than 1,600 patients, results of treatment were evaluated in 115 patients (31 men and 84 women) treated continuously for a minimum of 3 years and a maximum of 8 years (mean, 5.7 years). Patients were divided into two groups. Group I represents the "good responders" and contains all patients who received only 4-10 injections over that time (n = 55). Group II represents the "poor responders, " who received at least 20 injections over that period (n = 60). Group I received a mean of 7.1 injections, whereas group II had a mean of 24.4 injections (total, 1,855). In group I the beneficial effect lasted for an average of 14.6 weeks (range, 2-52 weeks), whereas group II had a mean beneficial effect for only 6.8 weeks (range, 0-18 weeks). The time of efficacy remained statistically stable even in the case of frequent treatment (up to 36 injections in group II). Systemic or severe long-lasting local side effects were never observed; the most frequent side effects were: group I-ptosis, 5.4%; tearing, 5.1%; double vision, 1.8%; and lid lag, 1.5%; group II-ptosis, 4.3%; tearing, 3.3% lid lag, 1.9%, and double vision, 1.6%. The treatment of essential blepharospasm with botulinum toxin is a very effective therapy with minimal and transient complications. It may be used for long-term treatment without showing a decrease in efficacy.

Blepharospasm and related facial movement disorders

The variable clinical features and the relatively good response of blepharospasm to botulinum-toxin type A are now well established. The etiology and pathophysiology of blepharospasm and related facial movement disorders are still poorly understood. Genetic and histopathologic studies over the last year have contributed to our understanding of this disease. The most significant progress has been made in the electromyographic studies of the the levator palpebrae and orbicularis oculi muscles. Subclassification based on the electromyographic abnormalities of these two muscles have begun to improve our understanding of the variable responses to botulinum-toxin type A. Further electromyographic studies may help identify the best sites of injection for optimal response and differentiate patients requiring limited or complete myectomy. The development of the limited myectomy has provided excellent functional and cosmetic results with quick recovery times in selected patients.

[Botulinum toxin in blepharospasm, in hemifacial spasm, and in cervical dystonia: results in 33 patients]

The effects of botulinum toxin type A were studied in 33 patients with dystonia (12 blepharospasms, 10 hemifacial spasms and 11 spasmodic torticollis). A rate scale was used to evaluate the severity of the dystonic movements, before and two weeks after each injection. Among blepharospasm patients, eight were female and four were male; the mean age was 57.7 years; the mean time of the disease duration was four years. Three had familial history for similar disease; nine were essential and three had used neuroleptic drugs (tardive dystonia). The mean dose used was 51.3 U, with a mean time of beneficial effects of 2.8 months. For 22 injections and reinjections, 14 (63.7%) showed an excellent result, five (22.7%) good and three (13.6%) null. In the hemifacial spasm group, eight were female and two male; the mean age was 52.6 years; the mean time of the disease duration was 7.4 years; eight were essential and two post-paralytic. The mean dose used was 32 U. From the total of 15 injections and reinjections, all of them (100%) had an excellent result, with a mean time of beneficial effect of 3.4 months. Among the cervical dystonic patients, eight were male and three female; the mean age was 44.2 years; the mean time of the disease duration was 12.2 years; six had essential dystonia, three had used neuroleptic drugs and two had familial history for similar disease. The mean dose used was 238.6 U, with the mean duration of effect of 3.5 months. From the total of 20 injections and reinjections, 18 (90%) had good result, one (5%) mild and one (5%) null.(ABSTRACT TRUNCATED AT 250 WORDS)