Pretarsal blepharospasm: Clinical and electromyographic characteristics

ObjectiveTo describe the clinical and electromyographic characteristics of blepharospasm caused by selective involvement of the pars pretarsalis of the orbicularis oculi muscle.MethodsClinical assessment and simultaneous electromyographic recordings from levator palpebrae superioris and pars orbitaria and pretarsalis of orbicularis oculi muscles were performed in patients with blepharospasm and primary failure to botulinum toxin injections. Patients with selective abnormal electromyographic activity of the pars pretarsalis of the orbicularis oculi muscle were identified and treated with selective pretarsal injections of botulinum toxin.ResultsWe found 24 patients with pretarsal blepharospasm confirmed by the electromyographic assessment. All of them were functionally blind. Three clinical-electromyographic patterns were identified: (a) Impairment of eyelid opening; (b) Increased blinking; (c) Spasms of eye closure combined with varying degrees of excessive blinking and impairment of eye-opening. Pretarsal injections of botulinum toxin induced a significant improvement in all patients and 50 % regained normal or near-normal vision. The clinical improvement was sustained after repeated pretarsal injections.ConclusionsPretarsal blepharospasm can be suspected on clinical grounds and it can be confirmed by electromyographic recordings.SignificanceRecognition of this type of blepharospasm is important because of its excellent response to botulinum toxin injections applied into the pretarsal part of the orbicularis oculi muscle.     

A comparative crossover study on the treatment of hemifacial spasm and blepharospasm: preseptal and pretarsal botulinum toxin injection techniques

Hemifacial spasm (HFS) and benign essential blepharospasm (BEB) are chronic and disabling abnormal craniofacial movements that produce involuntary eyelid twitching and closure. The efficacy and safety of botulinum toxin type A (BoNT-A) injections have been accepted and widely used for the treatment of HFS and BEB. However, different injection sites may influence the effectiveness, doses, and side effects. The aim of this study is to compare the efficacy, patient satisfaction, and complications of low-dose BoNT-A injections between injection at the preseptal (PS) and the pretarsal (PT) portion of the orbicularis oculi muscle. A total of 40 patients, 31 patients with HFS and 9 patients with BEB, participated in this study. Each patient received both PS and PT BoNT-A injections in a crossover design study. Latency to response, duration of improvement, the Jankovic Rating Scale (JRS), self-response scale, patient satisfaction scale, and complications were compared. Low-dose injections of BoNT-A at the PT portion produced a significantly higher response rate in terms of latency to response, duration of improvement, JRS, self-response scale, and patient satisfaction scale than the PS injections. Major side effects including ptosis and droopy eyelid were observed only after the PS injections. These findings confirmed that low-dose injections of BoNT-A at the PT portion provide more efficacy, patient satisfaction, and fewer complications than the PS injections for the treatment of involuntary eyelid twitching and closure in patients with HFS and BEB.     

Pretarsal application of botulinum toxin for treatment of blepharospasm.

The response to botulinum toxin type A was compared after two injection techniques in 45 patients with blepharospasm. Initially, patients were treated according to a triple injection technique; two injections into the upper eyelid and one injection into the lower eyelid. Subsequently, without altering the dose, the same patient group received two further injections into the pretarsal portion of the orbicularis oculi muscle of the upper lid. Triple injections were given in 227 treatments, of which 81% were successful. Mean duration of benefit was 8.5 weeks. Additional pretarsal injections were given in 183 treatment sessions. The number of successful treatments significantly increased, to 95% (P < 0.001), and the mean duration of benefit increased to 12.5 weeks (P < 0.001). Ptosis occurred significantly less often after pretarsal injections (P < 0.01). Patients with combined blepharospasm and involuntary levator palpebrae inhibition responded better to the pretarsal injection technique.     

Botulinum toxin in the management of blepharospasm

Seventy-seven patients with blepharospasm unresponsive to other forms of therapy were treated with botulinum A toxin. The drug was injected into the orbicularis oculi muscle of both upper and lower eyelids and, in some patients, into the brows and upper part of the face as well. A total of 192 treatment sessions were given, with follow-up ranging from four weeks to 18 months. Orbicularis muscle spasms decreased markedly over the first five days following injection, both in patients with essential blepharospasm and in those with hemifacial spasm. Beneficial effect was temporary, however, and repeated injections were required for sustained relief. Fifty-two patients received multiple treatments, ranging from two to eight injections each, with a mean duration of benefit of 11.8 weeks. Results of subsequent injections were similar to the first in rapidity of onset, degree of benefit, and duration of effect. Complications were local, mild, and transient, and no systemic side effects were encountered.     

偏侧面肌痉挛和良性特发性眼睑痉挛的临床与治疗特点

目的 探讨偏侧面肌痉挛(HFS)和良性特发性眼睑痉挛(BEB)的临床特点、治疗现状以及对A型肉毒毒素(BTX-A)治疗的反应.方法 对2013年4~10月在武汉大学人民医院神经内科门诊就诊的HFS患者和BEB患者进行调查,其中HFS患者110例,BEB患者90例.所有的患者均接受了BTX-A局部注射治疗.注射后2周左右复诊,在每周二下午的专病门诊随访,并记录BTX-A的疗效持续时间.结果(1)入组200例患者中,BTX-A治疗起效时间0~30 d(中位数4 d),疗效持续时间2~128周(中位数16周),总有效率96.9%.HFS患者症状明显好转(完全和明显缓解)占99.3%,BEB患者占90.2%.总的来说,BEB患者的疗效持续时间[(13.6±5.5)周]与HFS患者[(20.3±10.2)周]相比较短.HFS患者所用BTX-A剂量[(53.2±15.8)U]较BEB患者[(74.8±20.2)U]少.(2)BTX-A注射(70.9%)、针灸(68.2%)和口服药(65.5%)是HFS患者曾经选择的最多的非手术治疗方法.针灸和口服药大部分效果不好而自行停用.BTX-A注射(88.9%)、口服药(86.7%)和眼轮匝肌切割术(31.1%)是BEB患者曾经选择的最多的治疗方法,但患者均反映手术无效.结论 HFS和BEB是运动障碍门诊最常见的两种疾病,BTX-A治疗HFS和BEB安全、有效,对HFS效果更好,BEB患者需要更频繁的注射,其面部肌张力障碍的治疗更具挑战性.     

No clinical or neurophysiological evidence of botulinum toxin diffusion to non-injected muscles in patients with hemifacial spasm

Botulinum toxin injected into a muscle may diffuse to nearby muscles thus producing unwanted effects. In patients with hemifacial spasm, we evaluated clinically and neurophysiologically, whether botulinum toxin type A (BoNT-A) diffuses from the injection site (orbicularis oculi) to untreated muscles (orbicularis oris from the affected side and orbicularis oculi and oris from the unaffected side). We studied 38 patients with idiopathic hemifacial spasm. Botulinum toxin was injected into the affected orbicularis oculi muscle alone (at 3 standardized sites) at a clinically effective dose. Patients were studied before (T0) and 3-4 weeks after treatment (T1). We evaluated the clinical effects of botulinum toxin and muscle strength in the affected and unaffected muscles. We also assessed the peak-to-peak amplitude compound muscle action potential (CMAP) recorded from the orbicularis oculi and orbicularis oris muscles on both sides after supramaximal electrical stimulation of the facial nerve at the stylomastoid foramen. In all patients, botulinum toxin treatment reduced muscle spasms in the injected orbicularis oculi muscle and induced no muscle weakness in the other facial muscles. The CMAP amplitude significantly decreased in the injected orbicularis oculi muscle, but remained unchanged in the other facial muscles (orbicularis oris muscle on the affected side and contra-lateral unaffected muscles). In conclusion, in patients with hemifacial spasm, botulinum toxin, at a clinically effective dose, induces no clinical signs of diffusion and does not reduce the CMAP size in the nearby untreated orbicularis oris or contralateral facial muscles.     

Botulinum toxin injection into Riolan's muscle: somatosensory 'trick'

We studied the effect of injecting botulinum toxin A (BTX-A) into the pars ciliaris--also known as Riolan's muscle--of patients with eyelid apraxia (ELA). Six patients with ELA were treated with injections of BTX-A into the region of Riolan's muscle at the medial and lateral portions of the upper and lower pretarsal orbicularis oculi. Clinical benefit was seen in all 6 patients, 2 of whom had previously been treated with conventional pretarsal injections of BTX-A and had not improved. BTX-A injections into Riolan's muscle are effective as treatment for ELA. The proposed mechanism is not that of muscle relaxation but rather modulation of the somatosensory cortex, similar to that of a 'sensory trick' in patients with dystonia.     

Injection of doxorubicin into rabbit eyelid does not result in loss of facial motor neurons

In both laboratory and clinical studies, injection of doxorubicin directly into the eyelid results in permanent muscle loss of the majority of fibers within treated eyelids. A first clinical trial of this technique in blepharospasm and hemifacial spasm patients has been performed. All patients who completed a full course of doxorubicin treatment showed a permanent decrease in eyelid strength, with over 50% of these patients requiring no further treatment. Doxorubicin is known to be carried by retrograde axonal transport to the brain and is a known neurotoxin. This raises the question of the effect of these treatments on the facial neurons which innervate the orbicularis oculi muscle in the eyelids. The effect on the number of facial nuerons present after injection of doxorubicin into the eyelid of rabbits was determined using both HRP and diI retrograde labeling techniques. Despite the extensive and permanent muscle loss caused by the doxorubicin treatments, there was no measurable loss of facial neurons on the doxorubicin treated sides. DiI was shown to be myotoxic at high concentrations and amplified the myotoxic effect of doxorubicin. Lack of neuronal loss may offer assurance of clinical safety to the facial motor neurons of muscles spasm patients who receive doxorubicin injections into their eyelids.     

Bell's palsy-induced blepharospasm

We report two patients with blepharospasm that appeared during the recovery phase of Bell's palsy. It is well known that hemifacial spasm occasionally appears after Bell's palsy; however, blepharospasm associated with Bell's palsy has been rarely reported so far. Blepharospasm appeared within a month after the onset of Bell's palsy, suggesting that a certain causal relationship may be present between Bell's palsy and blepharospasm. We speculate that corneal irritation caused by lagophthalmos contributes to the induction of blepharospasm. Another speculation is that abnormal afferent input from the paralyzed side contributes to the abnormal sensitization of the blink reflex, thereby facilitating the induction of abnormal facial motor outputs such as blepharospasm. Received: 17 May 2001, Accepted: 27 August 2001     

Botulinum toxin in the treatment of blepharospasm and hemifacial spasm

Summary Blepharospasm and hemifacial spasm are the two most common craniofacial movement disorders. Blepharospasm is a syndrome characterized by excessive or continuous eye closure related to overactivity of the orbicularis oculi and adjacent muscles bilaterally. Hemifacial spasm is a peripherally-induced movement disorder typically caused by vascular compression of cranial nerve VII (CN VII) leading to involuntary unilateral contractions of muscles used in facial expression. Treatment options for both conditions include medications, botulinum toxin, and various surgical interventions. This article summarizes the existing medical literature which indicates that botulinum toxin is the treatment of choice for blepharospasm and hemifacial spasm. Correspondence: Christopher Kenney, Parkinson’s Disease Center and Movement Disorders Clinic, Department of Neurology, Baylor College of Medicine, 6550 Fannin, Suite 1801, Houston, Texas 77030, USA     

Botulinum toxin treatment of hemifacial spasm.

Six patients with hemifacial spasm were treated with injections of botulinum toxin A into the orbicularis oculi; the abnormal movements around the eye were relieved for an average of 15 weeks. There were no systemic or significant local side effects, and in view of the risks involved in neurosurgical treatment, a trial of botulinum toxin injections is recommended in the first instance in this condition.     

Serial SFEMG studies of orbicularis oculi muscle after the first administration of botulinum toxin

Serial single fiber electromyography (SFEMG) examinations of orbicularis oculi muscle in patients with blepharospasm or hemifacial spasm treated with botulinum toxin injections were performed. The aim of the study was to evaluate the impairment of neuromuscular transmission, to follow reinnervation after botulinum toxin administration and to find out whether there was a relationship between SFEMG parameters and clinical symptoms. Examinations were performed before injection, during early and late remission of symptoms, and after recurrence of the involuntary movement. Severe impairment of neuromuscular transmission, as revealed by increased jitter and increased presence of abnormal potential pairs and pairs with blocking, was found in early remission, but fiber density remained unchanged when compared with pretreatment values. In late remission, increased fiber density was registered for the first time. The recurrence of involuntary movements was related to the further increase of fiber density and tendency to normalization of jitter parameters. The study therefore suggests that formation of new neuromuscular junctions and their functional maturation is responsible for muscle recovery after botulinum toxin administration.     

Regional differences in the orbicularis oculi muscle: conservation between species.

The orbicularis oculi muscle is a complex facial muscle involved in eyelid closure. The central parts of pretarsal and preseptal regions of the palpebral part of the orbicularis oculi muscle in rabbit and cynomolgus monkey lower eyelids were examined histologically and were analyzed for muscle fiber number, muscle fiber cross-sectional area and fiber type composition. Distinct regional differences were seen in the muscle fiber composition in these two regions of the muscle. The pretarsal portion of the muscle, that closest to the eyelid margin, was quite homogeneous and almost completely composed of type 2 fibers. These fibers were the smallest in cross-sectional area. Type 2 fibers also predominated in the preseptal portion of the muscle, but this region contained between 10 and 20% type 1 fibers. They appeared to be a gradient in muscle fiber size, whereby the fiber size increased as a function of the distance from the eyelid margin. The same pattern of regional differences were found in both rabbit and monkey orbicularis oculi. Thus, there is a clear conservation of these regional differences in these two species. While the developmental significance is unknown, the identification of this pattern may facilitate the evaluation of chemomyectomy agents for treatment of eyelid spasms in humans and allow a more accurate analysis of biopsy material from this muscle.     

Severe but temporary injury to rabbit orbicularis oculi muscle using dihematoporphyrin ether and laser photochemomyectomy.

The use of local dihematoporphyrin ether (DHE) injections, followed by laser light activation, was investigated as a potential permanent myectomy treatment for muscle spasms, in particular blepharospasm and hemifacial spasm. DHE was injected into the eyelids of rabbits, followed by laser activation, as used in photochemotherapy. Four days after treatment, histological examination indicated that doses of greater than or equal to 0.5 mg of DHE and laser treatment with an energy density of at least 100 J/cm2 resulted in an almost total destruction of the orbicularis oculi muscle in the treated eyelid. The amount of muscle injury was dependent on both dose of DHE and energy density levels. Histologically, the tarsal glands and conjunctiva were damaged. Glandular tissue was markedly reduced, and the conjunctival epithelium showed hyperplasia and a loss of mucous cells. Six months after DHE and laser treatment, the majority of the muscle tissue had regenerated, although there was evidence of previous injury. While DHE injections combined with laser light activation were lethal to muscle at the site of treatment, this treatment was not permanent. The orbicularis oculi muscle retained its ability to regenerate. However, photochemomyectomy may be studied further as an adjuvant treatment to temporarily injure and debulk large muscles when botulinum toxin is contraindicated due to the large doses involved or as a permanent treatment when used together with an antimitotic agent such as doxorubicin.     

Botulinum toxin treatment of hemifacial spasm and blepharospasm: objective response evaluation.

Twenty seven patients with hemifacial spasm (HFS) and sixteen patients with blepharospasm (BS) having mean Jankovic disability rating scale score of 2.56+0.58 SD and 2.81+0.54 SD, respectively, were treated with botulinum toxin A (BTX-A) injections. The total number of injection sessions were ninety one with relief response in 98.91%. The mean improvement in function scale score was 3.78+0.64 SD and 3.29+1.07 SD respectively, in HFS and BS groups. The clinical benefit induced by botulinum toxin lasted for a mean of 4.46+3.11 SD (range 2 to 13) months in HFS group and 2.66+1.37 SD (range 1 to 6) months, in BS groups. Transient ptosis was seen in 4.39% of total ninety one injection sessions. These findings show that local botulinum toxin treatment provides effective, safe and long lasting relief of spasms.     

Chronic vascular irritation of the facial nerve causes facial spasm in rats

Abstract

The abnormal muscle response, elicited by electrical stimulation of one branch of the facial nerve and recorded from muscles innervated by another branch, has been used previously as an objective sign of hemifacial spasm in the development of animal models of this disorder. In the present study we recorded spontaneous electromyographic activity from the orbicularis oculi muscle from both sides in rats in which a demyelination of the peripheral portion of the facial nerve and vascular contact had been made previously. The root mean square value of the electromyographic activity on the affected side was significantly larger than that on the unaffected side in all rats in which the vascular irritation had caused the abnormal muscle response to appear. The results support our earlier finding that vascular contact together with demyelination of the peripheral facial nerve can cause the development of signs of hemifacial spasm, including involuntary muscle contractions. [Neurol Res 1994; 16: 284-288]     

The management of blepharospasm and hemifacial spasm

Summary The aetiology of blepharospasm and hemifacial spasm is different, but both produce involuntary eye closure and facial movements which do not respond to systemic drug treatment. The introduction of therapeutic focal muscle weakening with botulinum toxin injections in the early 1980s appeared to offer great promise in the management of these conditions. In this paper the results of botulinum toxin treatment of 234 patients with blepharospasm and 73 patients with hemifacial spasm over a 7-year period have been analysed. Most patients receive sustained benefit from repeated injections whilst side-effects become less frequent. A clinically recognisable subgroup of patients with blepharospasm respond poorly and may be better treated surgically.     

A型肉毒杆菌毒素治疗眼睑痉挛及面肌痉挛临床研究

应用Ａ型肉毒杆菌毒素局部注射治疗眼睑痉挛９例及面肌痉挛３３，例完全缓解者分别为６例及３１例，明显缓解者分别为３例及２例，所有病例均有效，总有效期分别为４～２０周（平均１４周）及１６～３４周（平均２２周）。局部副反应轻微、短暂，无全身反应及过敏反应，且操作简单。认为Ａ型肉毒杆菌毒素是一种安全有效的生物制剂，该方法可作为治疗眼睑痉挛及面肌痉挛的新方法．     

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.     

肌电图监测在面肌痉挛微血管减压术中的应用

目的 探讨面肌肌电图监测在面肌痉挛微血管减压术（MVD）中的应用价值。方法 回顾性分析MVD治疗的72例面肌痉挛患者的临床资料,术中仔细辨别并处理责任血管,通过实时记录面肌的肌电反应了解减压效果。结果 60例有明确责任血管压迫,6例单纯性蛛网膜粘连或增厚,6例存在隐匿性责任血管。术后异常肌电图波形完全消失54例,基本消失16例,无明显变化2例。术后临床症状完全消失57例,部分消失14例,无改善1例;总有效率为98.6%（71/72）。结论 面肌肌电图监测可实时了解术中减压效果,对面肌痉挛的MVD,尤其是隐匿性责任血管所致面肌痉挛具有重要的指导作用。