Secondary nonresponsiveness to botulinum toxin type A in patients with oromandibular dystonia.

Intramuscular injection of botulinum toxin type A is the treatment of choice for most cases of oromandibular dystonia. We report on five patients with oromandibular dystonia that developed secondary nonresponsiveness to botulinum toxin type A following multiple injections over a 6-year period.     

A型肉毒毒素治疗口下颌肌张力障碍

目的观察A型肉毒毒素治疗口下颌肌张力障碍(OMD)患者的临床效果。方法对19例口下颌肌张力障碍患者进行临床分析,依据患者临床特点,将A型肉毒毒素注射到患者一侧或双侧咀嚼肌、颞肌及翼外肌,并根据肌肉收缩力量大小、肌肉体积及患者体重调整剂量。结果 68.4%的患者功能改善评分≥3分,疗效平均维持8～12周(有效范围2～28周)。4例患者注射后有轻度咀嚼无力,2～3周恢复。1例混合型患者注射后出现轻度鼻音,持续13天后症状消失。所有患者未出现其它严重副作用。结论 A型肉毒毒素对于口下颌肌张力障碍的治疗是有效、安全的。熟悉本病的临床特点及分型,选择正确的靶肌肉及注射适宜剂量的肉毒毒素是治疗本病的关键。     

Responsiveness to botulinum toxin type A in muscles of complex regional pain patients with tonic dystonia

Tonic dystonia of the limbs in complex regional pain syndrome (CRPS) is associated with considerable disability. Treatment options are scarce. Botulinum toxin (BoNT) is sometimes used, but the effect is often said to be disappointing. However, this notion stems from case reports and clinicians’ opinions but has never been formally studied. We therefore investigated responsiveness to BoNT in CRPS patients with tonic dystonia. We injected the extensor digitorum brevis (EDB) muscle with BoNT-A in 17 patients with CRPS and tonic dystonia to compare the response between affected and unaffected legs. We also investigated the right legs of 17 healthy controls. Responsiveness was defined as a decrease of the amplitude of the compound muscle action potential (CMAP) of >20 % from baseline 2 weeks after BoNT-A injection. We controlled for a temperature effect on BoNT efficacy by measuring skin temperature hourly directly above the EDB muscle in the first 2 weeks. CMAP amplitude decreased >20 % after injection on the affected side in 16 of 17 CRPS patients, similar to the response in unaffected legs (12/13) or legs of controls (17/17). The degree of CMAP reduction was significantly smaller in patients than in controls (56.0 ± 22.3 vs. 70.6 ± 14.6 %; p = 0.031). This may be due to a lower physical activity level and a greater difficulty to localize the EDB muscle properly in affected legs. The decrease in CMAP amplitude was not related to skin temperature. Contrary to the prevailing opinion, BoNT-A has a normal, although perhaps slightly lower efficacy in CRPS patients with dystonia.     

Neutralizing botulinum toxin type a antibodies: clinical observations in patients with cervical dystonia

Neutralization of antibodies poses a problem for a substantial number of cervical dystonia (CD) patients treated with botulinum toxin type A (BoNT/A). Presence of these antibodies may lead to a secondary nonresponse to BoNT/A treatment. In this study, we compared 6 antibody-positive (Ab+) with 12 antibody- negative (Ab-) CD patients treated with BoNT/A (Dysport) and matched for du- ration of treatment, number of BoNT/A injections, and severity of clinical symptoms. The two groups differed in cumulative BoNT/A dose (Ab+, 5984 mouse units [MU ], SD = 3151 MU; Ab-, 3143 MU, SD =1294 MU; P <.05), in addition, ab+ patients were significantly younger (ab+ mean age = 41.3 y, sd =5.9 y; ab - mean age = 56.8 y, sd = 15.3 y; p <.05), in or- der to avoid formation of neutralizing antibodies, doses of bont/a should be kept as low as possible, the risk of antibody formation seems to be higher in younger patients.     

Sustained attention in cranial dystonia patients treated with botulinum toxin

BACKGROUND: Primary cranial dystonia (PCD) is related to a functional disorder in basal ganglia usually accompanied by impaired executive function. AIM: To investigate symptom relief and neurocognitive change in response to treatment with botulinum toxin (BTX) in a group of patients with PCD. METHODS: We assessed nine patients with PCD and nine age- and educationally matched healthy individuals using tests of memory, sustained attention, span of auditory attention, and perceptual flexibility. RESULTS: Despite well-preserved intellectual skills relative to controls, we identified a sustained attention deficit in patients with PCD. After BTX treatment, there was an increase in the scores of the concentration endurance test (sustained attention) and the values did not differ significantly from control group patients' scores. CONCLUSION: The results support the view that executive dysfunction in PCD is secondary to the disrupting effects of the symptoms. Treatment with BTX alleviates the symptoms and, consequently, improves sustained attention.     

Long-term follow-up of cervical dystonia patients treated with botulinum toxin A.

We followed the course in 100 consecutive patients with cervical dystonia (CD) after they were initially treated with botulinum toxin (BTX) in the form of Dysport 10 to 12 years ago. A total of 4 patients had died, and 6 were lost to follow-up. Of the remaining 90 patients, 57 (63%) were still treated with BTX. In the patients treated at one centre over the whole period with Dysport, mean dose used during each treatment session was 833 (SD +/- 339) units Dysport with a cumulative dose of 20,943 (SD +/- 9462) units Dysport over a mean of 26.8 (SD +/- 8.6) treatment cycles. Secondary nonresponse was detected in 3 of the 90 patients. During follow-up, 12 patients developed blepharospasm, 13 oromandibular dystonia, and 17 patients writer's cramp. We conclude that BTX remains effective and safe for approximately 60% of CD patients for more than 10 years.     

Autonomic cardiovascular function and baroreflex sensitivity in patients with cervical dystonia receiving treatment with botulinum toxin type A

OBJECTIVE: To investigate possible changes in autonomic cardiovascular regulation and cardiopulmonary baroreflex sensitivity in patients with primary cervical dystonia receiving chronic treatment with botulinum toxin type A. METHODS: Short-term power spectral analysis of heart rate and systolic blood pressure variability, high-frequency and low-frequency oscillations of heart rate variability, low frequency/high frequency ratio and baroreflex sensitivity (alpha index) were measured in 12 patients with cervical dystonia before and 2-4 weeks after botulinum toxin type A injection and compared with normative data. RESULTS: Before treatment, at rest, patients had significantly lower high frequency power than healthy subjects (p < 0.01), whereas no differences were found in low frequency power. Botulinum toxin injection in patients induced no changes in either power frequency. In patients before treatment and healthy subjects the low frequency oscillatory components increased similarly from rest to tilt (p < 0.01), but tilt induced lower low frequency values in patients than in healthy subjects (p < 0.01). In patients before treatment, the high frequency variations from rest to tilt remained unchanged, whereas in healthy subjects they decreased significantly (p < 0.01). Botulinum toxin type A injection in patients induced no changes in low frequency or high frequency powers. In patients before treatment the low frequency/high frequency ratio increased slightly from rest to tilt, but in healthy subjects increased significantly (p < 0.01). Botulinum toxin type A left the pretreatment low frequency/high frequency ratio unchanged. The alpha-index measured at rest in patients before treatment was lower than in healthy subjects (p<0.05), whereas during tilt was similar in both groups. The alpha-index measured after botulinum toxin injection in patients remained unchanged at rest and during tilt. CONCLUSIONS: Patients with cervical dystonia receiving treatment with botulinum toxin type A have mild, subclinical abnormalities in autonomic cardiovascular regulation and cardiopulmonary baroreflex sensitivity. These changes do not worsen after acute botulinum toxin type A injection.     

Jaw-opening oromandibular dystonia secondary to Wilson's disease treated with botulinum toxin type A

We have reported a case series of five patients with jaw-opening oromandibular dystonia secondary to Wilson's disease (WD), in which the patients were treated with botulinum toxin type A (BTX-A). In all cases, dystonia score was partially reduced three weeks after injections. The most common side effect was transient mild dysphagia. This preliminary study showed that jaw-opening oromandibular dystonia in WD may be partially responsive to the use of BTX-A.     

Personalized botulinum toxin type A therapy for cervical dystonia based on kinematic guidance

Background

Botulinum toxin type A (BoNT-A) injections is the accepted first-line therapy for cervical dystonia (CD), however, numerous patients discontinue treatment early due to perceived sub-optimal relief. To improve BoNT-A therapy for CD, proper assessment of neck motion and selection of relevant muscles and dosing must be met. Kinematic technology may improve treatment outcomes by guiding physicians to better tailor muscle selection and BoNT-A dosing for CD therapy.

Methods

28 CD participants were placed into either group: expert injector determined injection patterns by visual assessment (“vb”) versus injection patterns based on kinematics interpreted by an expert injector (“kb”). Injections occurred at weeks 0, 16 and 32 with follow-ups at weeks 6, 22 and 38. Kinematics utilized four sensors to capture the severity of multiaxial, static neck posturing (e.g., torticollis) and dynamic, spasmodic/tremor movements while participants were seated. Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) score changes were evaluated over 38 weeks.

Results

For the “kb” participants, there was a significant 28.8% (? 11.25 points) reduction in TWSTRS total score at week 6, as well as significant reduction in severity and disability TWSTRS sub-scores (parts I and II) with maintained improvement at subsequent visits. As for the “vb” participants had a significant reduction in total TWSTRS score by 28.5% (? 9.84 points) after week 22. Disability score for the “vb” group trended towards improvement over 38 weeks.

Conclusion

Clinical judgement guided by kinematic analysis of CD biomechanics can result in faster optimal muscle selections and minimize use of higher BoNT-A doses as compared to visual determination, thereby achieving comparable and potentially better treatment outcomes.

     

A型肉毒毒素治疗头颈部肌张力障碍的临床观察

目的观察A型肉毒毒素(BTXA)治疗偏侧面肌痉孪、睑痉孪、Meige’s综合征、痉孪性斜颈的疗效。方法治疗组(A组)用BTXA对86例患者进行头颈部肌肉多点注射,对照组(B组)50例根据诊断选用不同的药物或/和针灸、理疗、中医药治疗。观察两组疗效及副作用。结果A组治疗后当日至3d内开始见效,7～15d达高峰,疗效维持2～6月。总有效率为100%,疗效明显高于B组(P<0.001)。BTXA重复注射疗效无下降,1例HFS患者第三次注射产生耐药性,少数患者有轻微的局部副反应,未见全身副作用。B组62%(31例)的患者疗效维持5～15月后减退,需逐渐增加剂量,少数患者出现白细胞减少、肝功能损害、皮疹、共济失调等不良反应。结论A型肉毒毒素局部注射是治疗头颈部肌张力障碍的一种安全、有效、简便的方法。     

Lack of effect of botulinum toxin on cortical excitability in patients with cranial dystonia

The aim of this study was to verify whether botulinum toxin (BTX)-induced clinical improvement of cranial dystonia is associated with changes in the cortical silent period (SP), a measure of cortical excitability. By transcranial magnetic stimulation (TMS), high-intensity stimuli were delivered with a round coil centered at the vertex during a maximal muscle contraction of the orbicularis oculi. Motor evoked potentials (MEPs) and SPs were obtained from surface electrodes placed over the orbicularis oculi muscle before and 2 to 3 weeks after BTX-A injection into the affected muscles in 10 patients with cranial dystonia and 8 age-matched control subjects. BTX injection improved blepharospasm in all patients. Facial muscle SPs were significantly shorter in patients than in control subjects and did not significantly change after treatment, at the time of maximal clinical improvement. We conclude that the clinical improvement induced by BTX in patients with cranial dystonia is largely symptomatic. It does not appear to result from modulation of abnormal aspects of intracortical excitability, although these may play a role in craniofacial dystonia.     

Treatment of upper limb dystonia with botulinum toxin

The use of botulinum toxin A (BTX A) in upper limb dystonia is gaining increasing acceptance and it has recently been suggested that it be considered as first line treatment.(1) We have reviewed our experience since 1991 of treating 20 cases of upper limb dystonia. 14 patients had task-specific dystonias (6 simple writer's cramp, 5 dystonic writer's cramp, 3 musician's cramp) and 6 had secondary focal or segmental dystonias (4 with early cortico-basal degeneration). All patients had electromyography to both determine and guide muscle selection. Pre- and post-treatment video as well as questionnaires formed the basis for outcome assessment. Botulinum toxin therapy was clearly beneficial in about two-thirds of those with primary upper limb dystonia, a condition affecting young adults (mean onset 32.9 years). In contrast, BTX A was far less effective in secondary upper limb dystonias which occurred in the elderly (mean onset 71.7 years). Optimal treatment strategies are discussed. In conclusion, botulinum toxin is an effective form of treatment for primary upper limb dystonia; its role in late onset secondary dystonia is mainly palliative.     

Clinico-immunologic aspects of botulinum toxin type B treatment of cervical dystonia

In this multicenter study of 100 patients with cervical dystonia, we examined the immunogenicity of botulinum toxin type B (BTX-B) and correlated the clinical response with the presence of blocking antibodies (Abs) using a novel mouse protection assay. One-third of the patients who were negative for BTX-B Abs at baseline became positive for BTX-B Abs at last visit. Thus, the high antigenicity of BTX-B limits its long-term efficacy.     

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

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

The complex relationship between antibody titers and clinical outcome in botulinum toxin type A long-term treated patients with cervical dystonia

Journal of Neurology - Repeated injections with abo- or onabotulinumtoxin type A (aboBoNT/A, onaBoNT/A) may lead to induction of neutralizing antibodies (NABs) and/or a secondary treatment failure...     

A new botulinum toxin type A free of complexing proteins for treatment of cervical dystonia

A new botulinum toxin type A free of complexing proteins (NT 201) was compared with BOTOX in patients with cervical dystonia by means of a double-blind noninferiority trial. Four hundred sixty-three patients received IM injections of 70 to 300 U of NT 201 or BOTOX and were followed up over 16 weeks. The study clearly shows that NT 201 is at least as effective and safe as BOTOX.     

肌电图下局部注射A型肉毒毒素治疗痉挛性斜颈临床观察

目的探讨肌电图引导下局部注射A型肉毒毒素治疗痉挛性斜颈的疗效。方法在肌电图引导下采用A型肉毒毒素局部多点注射治疗痉挛性斜颈42例,治疗前后的病情采用Tsui量表进行评分比较。结果症状基本缓解20例,占47.62%,明显缓解18例,占42.86%,部分缓解4例,占9.52%,无效0例,有效率90.48%。疗效平均持续约6月左右,最长达1~3年。复发者重复注射仍有效且剂量无增加,局部不良反应轻微短暂。结论肌电图引导下局部注射A型肉毒毒素治疗痉挛性斜颈是一种安全有效且简便易行的方法,可重复注射。     

Treatment of cervical dystonia hand spasms and laryngeal dystonia with botulinum toxin

Summary One hundred and twenty-six patients with different forms of focal dystonia (89 with cervical dystonia, 12 with hand cramps and 25 with laryngeal dystonia) were treated with localised injections of botulinum toxin. Mean doses per muscle were 200 mouse units (m.u.) for treating cervical dystonia, 40–120 m.u. for forearm muscles in writers' cramp and 3.7 m. u. for the thyroarytenoid muscle in laryngeal dystonia. Responder rates have been above 80% in all patient groups and beneficial effects could be reproduced over follow-up periods of up to 4 years. The commonest side-effects were dysphagia after treatment of spasmodic torticollis, weakness of neighbouring muscles after injections for hand cramps and breathiness and hypophonia following laryngeal injections. All these were transient and generally well tolerated. It is concluded that botulinum toxin injections are a safe and effective treatment in all three types of focal dystonia.