Fluoroscopic, EMG-guided injection of botulinum toxin into the longus colli for the treatment of anterocollis

BackgroundAnterocollis is a form of cervical dystonia characterized by forward neck flexion. While botulinum toxin is the treatment of choice for cervical dystonia, patients with anterocollis, who receive injections into the sternocleidomastoid and anterior scalene muscles, represent a disproportionate number of treatment failures. Deep cervical muscles such as the longus colli likely play an important role in neck flexion but are not routinely injected.ObjectiveTo describe a technique for longus colli injection in cases of anterocollis and to report the clinical outcomes of 10 such injections of botulinum toxin.MethodsThree patients were referred for evaluation and treatment of anterocollis. All had previous treatment failures with sternocleidomastoid/anterior scalene injections or no activity noted on needle EMG investigation of these muscles. All patients received injections of botulinum toxin into the longus colli under fluoroscopic and EMG guidance.ResultsAll patients experienced symptomatic improvement (eight of 10 injections). Two patients reported mild dysphagia without serious complications after dose increases in botulinum toxin.ConclusionsIncomplete muscle selection may be one cause of treatment failures in anterocollis. Deep cervical flexors such as the longus colli represent an under-recognized potential target for symptomatic treatment of anterocollis.     

Change in the pattern of cervical dystonia might be the cause of benefit loss during botulinum toxin treatment

The muscular patterns of cervical dystonia were identified by polymyographic recordings in 76 patients before botulinum toxin treatment. The leading muscles were considered to be those which started dystonic movement and which showed constant and maximal activity during all dystonic movements. The dystonic muscles were repeatedly treated by local Injections of botulinum toxin. Sixteen patients showed (after repeated injections) loss of the benefit of local applications of botulinum toxin after various periods of time. Repeated polymyographic recordings were performed in these patients during the loss of the benefit of injected botulinum toxin. In four patients repeated polymyographic recordings showed an Identical pattern of cervical dystonia, but the activity of previously injected muscles was apparently decreased. In 12 patients only minimum or no activity was recorded in muscles which had previously been treated with botulinum toxin, but the pattern of cervical dystonia was changed. Different patterns of cervical dystonia with different leading muscles, but with identical directions of head deviation, were observed in six patients. In another six patients, the head deviation direction was to the opposite side and was accompanied by a change of the leading muscle and a change of the muscular pattern of dystonia. These results suggest either that dystonic activity from the cerebral generator changes to new effectors during the peripheral blockade of primary dystonic muscles, or that a change of generators at different levels of the CNS occurs. It may be neccessary to carry out repeated polymyographic recordings throughout the period of loss of benefit of previously successful local botulinum toxin injections.     

Long-term follow-up by video of cervical dystonia treated with botulinum toxin

We have analysed video recordings of 21 patients with cervical dystonia treated with botulinum toxin. Fourteen patients have a record both of their response shortly after injections were commenced and between four years five months and six years seven months later. Our analysis shows that the long term outcome is often better than the initial response. We suggest that chronic treatment with botulinum toxin allows different muscles to those initially injected to be identified as contributors to the dystonia. Subsequent injection of these muscles leads to further improvement. It implies that cervical dystonia is a more widespread disorder of motor control, rather than simply limited to a few muscles.     

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.     

Muscle selection for treatment of cervical dystonia with botulinum toxin--a systematic review

RationaleCervical dystonia, also called spasmodic torticollis, is the most common form of (primary) dystonia. Intramuscular injections with botulinum toxin are the first line of treatment for cervical dystonia. To optimise the treatment response to botulinum toxin correct muscles should be selected. Clinical evaluation is important for muscle selection but the value of additional tests to identify dystonic muscles remains unclear.ObjectiveTo evaluate all relevant literature regarding the best approach to select dystonic muscles for treatment with botulinum toxin.MethodsWe conducted a systematic review of studies that had investigated methods of selecting muscles for treatment with botulinum toxin. In addition, we compared all prospective botulinum toxin trials using either clinical evaluation or polymyographic electromyography for muscle selection.ResultsForty relevant studies were included and polymyographic electromyography recordings were most often employed. In several studies, polymyographic electromyography revealed a different pattern of muscle involvement compared to that found during clinical evaluation. In one randomized controlled trial polymyographic electromyography significantly improved the outcome of botulinum toxin treatment. A limited number of studies used positron emission tomography – computed tomography imaging or frequency analysis of the electromyography signal to identify dystonic muscles but their effect on the outcome of treatment has never been studied.ConclusionPolymyographic electromyography may improve the outcome of botulinum toxin treatment in cervical dystonia, but evidence is limited and larger studies are needed.     

Dystonic neck muscles show a shift in relative autospectral power during isometric contractions

Objective

To identify effects of a deviant motor drive in the autospectral power of dystonic muscles during voluntary contraction in cervical dystonia patients.

Cervical dystonia: Improved treatment response to botulinum toxin after referral to a tertiary centre and the use of polymyography

RationaleCervical dystonia is the most common form of (primary) dystonia. The first line of treatment for cervical dystonia is intramuscular injections with botulinum toxin. To optimise the response to botulinum toxin proper muscles selection is required. Pre-treatment polymyographic EMG in addition to clinical evaluation is hypothesised to be a good tool to improve muscle selection and treatment outcome.ObjectiveTo determine the efficacy of botulinum toxin treatment after adjacent polymyographic EMG in cervical dystonia patients referred to our tertiary referral centre with an unsatisfactory response to botulinum toxin treatment elsewhere.MethodsWe performed a retrospective analysis of 40 consecutive second opinion cervical dystonia patients. Standard polymyographic EMG was performed before treatment. We retrieved the Tsui scores and subjective evaluations from the first visit, after 12 weeks and after one year of treatment. In addition, we assessed the final outcome of treatment in our centre based on the records and asked the patients for their personal opinion about the effect of referral to our centre on their treatment response.ResultsAfter one year of treatment there was a significant improvement on both the Tsui scores (p < 0.01) and the subjective treatment evaluation (p < 0.001.) On their last visit 60% of the patients still continued treatment with a reasonable to good response.ConclusionA substantial amount of CD patients with an unsatisfactory response to botulinum toxin improved after polymyography and subsequent treatment with botulinum toxin in a tertiary referral centre.     

Botulinum toxin treatment of dystonic anterocollis: What to inject

BackgroundAnterocollis (AC) is a rare form of cervical dystonia, which responds poorly to botulinum toxin treatment.ObjectivesTo recognise the different clinical phenotypes of AC and to detail the selection of muscles from the results of treating a cohort of 15 AC patients with Botulinum Toxin.MethodsThe study was performed using prospectively collected data. We included 15 patients with cervical dystonia and AC posture, treated between 2016 and 2019 in our joint Neuro-ENT clinic. We excluded patients with posterior cervical muscle weakness and patients with Parkinsonism. We characterised the primary dystonic posture of every AC patient as posterior sagittal shift, head flexion or neck flexion, or a combination of the three.ResultsAll AC patients had a more widespread dystonic picture with a majority having Meige syndrome, but AC was the most problematic feature. Treatment with botulinum toxin required the injection not only of the deep cervical flexor (DCF), but also the sterno-cleido-mastoid (SCM) and moreover the supra-hyoid (SH) muscles. The choice between the longus capiti and the longus colli depended on the AC posture. Half of the patients had a dramatic improvement with 90% satisfaction or above.ConclusionAC posture is a complex but treatable type of CD. A joint Neuro-ENT clinic is an ideal setting in which to target all the dystonic muscles. This allows the injection of the longus capiti (under nasal endoscopic approach) as well as the supra-hyoid and SCM muscles in the same session.     

Sustained benefit of painful legs moving toes syndrome with botulinum toxin type A

Painful legs moving toes (PLMT) is a rare disorder characterized by an often-severe painful sensation in the legs associated with involuntary movement of the toes. The treatment can be challenging given the poor response to pharmacotherapy. We present a patient with PLMT who obtained substantial benefit in both pain and severity of involuntary movement with botulinum toxin type A injections for more than 3 years.     

Use of botulinum toxin in the treatment of laryngeal dystonia (spasmodic dysphonia): preliminary study of twelve patients

Laryngeal dystonia (spasmodic dysphonia) is a movement disorder characterized by involuntary contractions of laryngeal muscles involved with vocalization. The introduction of botulinum toxin in the treatment of laryngeal dystonia had a major clinical impact due to the striking improvement of symptoms. We report the preliminary results of therapeutical use of botulinum toxin in the treatment of twelve patients with laryngeal dystonia. After an extensive clinical evaluation, the patients underwent a videostroboscopic exam for diagnostic confirmation. Botulinum toxin was injected in the cricothyreoid membrane, directed towards the thyreoaritenoid muscle, with the aid of eletromyography needles. Most of patients who underwent botulinum toxin injection had a significant improvement of their symptoms (83%), with effects lasting for four months in average and without important side effects.     

Sensibilidad y dolor en distonías focales de la mano

IntroductionA growing body of evidence highlights the importance of understanding both the sensory and the motor pathophysiology of focal dystonia in order to improve its treatment. This study aims to evaluate somatosensory afferences in patients with focal or segmental dystonia affecting the upper limbs, to analyse whether the dominant limb is more frequently affected, to analyse pain tolerance, and to examine the potential association with pain perception in patients with hand dystonia.MethodsWe recruited 24 participants: 12 patients with focal hand dystonia and 12 individuals without dystonia. All participants were evaluated with a digital algometer (Somedic SenseLab AB®, Farsta, Sweden), a Semmes-Weinstein monofilament test, and the visual analogue scale for pain.ResultsAccording to our data, patients showed greater impairment in surface sensitivity than controls, both in the dominant and the non-dominant hands, as well as greater presence of pain (P > .001). Furthermore, the dystonia group showed a negative correlation between perceived pain and pressure pain tolerance threshold (rho = ?0.83; P < .001).ConclusionsPatients with focal hand dystonia presented alterations in sensitivity and more severe perceived pain than individuals without dystonia. Future studies with larger samples should aim to analyse the clinical implications and everyday impact of both objective and subjective pain.     

Association of the Val66Met polymorphism of the BDNF gene with primary cranial–cervical dystonia patients from South-west China

BackgroundThe etiology of primary dystonia remains unclear. Recent genetic studies suggest that the Val66Met polymorphism of the BDNF gene is a genetic modifier in cranial–cervical dystonia in Caucasians. However, the finding is not consistent.Patients and MethodsA total of 193 patients with primary cranial–cervical dystonia from the Department of Neurology, West China Hospital of Sichuan University was included. From the same region, 216 healthy individuals were recruited as a control group. The Val66Met SNP was identified by polymerase chain reaction-restriction fragment length polymorphism.ResultsIn the present study, cervical dystonia (59.59%) was the most common type of primary cranial–cervical dystonia. No significant difference was found in the genotype and minor allele frequencies between all patients and controls, between cervical dystonia patients and controls, and between craniocervical dystonia patients and controls. However, significant differences were found in the genotype and minor allele frequencies of Val66Met SNP between blepharospasm (BSP) patients and controls (P = 0.0080 and P = 0.0042, respectively), and between BSP patients and patients with craniocervical derived from BSP (P = 0.0010 and P = 0.0002, respectively).ConclusionMinor allele “A” of BDNF Val66Met SNP may increase the risk for developing BSP and may be a protective factor for preventing BSP progressing to craniocervical dystonia. More association studies involving a larger number of participants are needed to confirm the present findings.     

Botulinum toxin injections reduce associative plasticity in patients with primary dystonia

Botulinum toxin injections ameliorate dystonic symptoms by blocking the neuromuscular junction and weakening dystonic contractions. We asked if botulinum toxin injections in dystonia patients might also affect the integrity of sensorimotor cortical plasticity, one of the key pathophysiological features of dystonia. We applied a paired associative stimulation protocol, known to induce long‐term potentiation–like changes in the primary motor cortex hand area to 12 patients with cervical dystonia before and 1 and 3 months after botulinum toxin injections to the neck muscles. Primary motor cortex excitability was probed by measuring transcranial magnetic stimulation‐evoked motor evoked potentials before and after paired associative stimulation. We also measured the input–output curve, short‐interval intracortical inhibition, intracortical facilitation, short afferent inhibition, and long afferent inhibition in hand muscles and the clinical severity of dystonia. Before botulinum toxin injections, paired associative stimulation significantly facilitated motor evoked potentials in hand muscles. One month after injections, this effect was abolished, with partial recovery after 3 months. There were significant positive correlations between the facilitation produced by paired associative stimulation and (1) the time elapsed since botulinum toxin injections and (2) the clinical dystonia score. One effect of botulinum toxin injection treatment is to modulate afferent input from the neck. We propose that subsequent reorganization of the motor cortex representation of hand muscles may explain the effect of botulinum toxin on motor cortical plasticity. © The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.     

Botulinum toxin as treatment for focal dystonia: a systematic review of the pharmaco-therapeutic and pharmaco-economic value

Focal dystonia is a common, invalidating neurologic condition characterized by involuntary, sustained muscle contractions causing twisting movements and abnormal postures in one body part. Currently, botulinum toxin is the treatment of first choice. We performed a systematic review towards the pharmaco-therapeutic and pharmaco-economic value of botulinum toxin as treatment for focal dystonia, which yielded the following results. Botulinum toxin is the most effective treatment for reducing dystonic symptoms measured with dystonia-specific and general questionnaires, and pain in patients with focal dystonia. Seventy-one percent of patients with cervical dystonia had a reduction in neck pain compared to 12?% in placebo groups. Adverse events occur in 58?% of patients during treatment with botulinum toxin compared to 46?% treated with placebo. Especially dry mouth, neck weakness, dysphagia, and voice changes are common. Adverse events are usually mild and self-limiting. Health-related quality of life, measured with the SF-36 is 20?C50 points lower in patients with focal dystonia compared to controls and the effect of botulinum toxin on health-related quality of life is unclear. Botulinum toxin treatment is expensive because the drug itself is expensive. Yearly costs for treating a patient with focal dystonia with botulinum toxin range from EUR 347 to EUR 3,633 and the gain in QALYs with BTX treatment is small. Focal dystonia impairs the productivity and the ability to work. At start of botulinum toxin treatment only 47?C50?% was working. Botulinum toxin partly improves this. Overall, we conclude that botulinum toxin is an expensive drug with good effects. From a societal perspective, the costs may well weigh up to the regained quality of life. However, the available literature concerning costs, health-related quality of life and labor participation is very limited. An extensive cost-effectiveness study should be performed incorporating all these aspects.     

Aspects of the complexity of cervical dystonia

Most cases of cervical dystonia (CD) can easily be treated by injections of botulinum toxin A (BTX-A) into a few cervical muscles among which the splenius capitis, the semispinalis capitis the levator scapulae and the scalenii muscles are the most important ones whereras the trapezius and the sternocleidomastoideus muscles are of less importance. However, in some cases of CD the treatment of these easily injectable muscles does not lead to a satisfactory clinical outcome. Damage of and compensatory increase of connective tissue in muscles, additional activation of non-injected muscles by special motor tasks as lying, sitting, standing, walking and speaking and involvement of deep muscles remaining usually untreated may add to the complexity of treatment of cervical dystonia.     

Utility of an EMG mapping study in treating cervical dystonia

Intramuscular injections of botulinum toxin are the cornerstone of treatment for cervical dystonia. Controversy exists regarding the necessity for EMG-guided injections. We compared the clinical examination of four movement disorder specialists to an electromyographic (EMG) mapping study. Clinical predictions of individual muscle involvement were only 59% sensitive and 75% specific. Muscle hypertrophy, shoulder elevation, and dominant head vector did not bolster clinical accuracy. An EMG mapping study facilitates identification of dystonic muscles in cervical dystonia, which may enhance botulinum toxin therapy.     

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.     

Prise en charge de la crampe de l’écrivain : 14 ans d’expérience de la toxine botulique

IntroductionWriter's cramp is a focal dystonia; treatment remains disappointing. We report our 14-year experience with a population of 119 patients aged between 18 and 85 years (average age 43 years).MethodsTreatment was based on botulinum toxin injections (Dysport^®) and physiotherapy. Patients were reviewed every four to six months with clinical and video evaluation by three different observers and subjective analysis of the treatment efficiency by the patient (score of 1 to 3). The post-injection deficit, if present, was also quantified.ResultsIn the group treated with toxin and physiotherapy, cramps improved (score 2 and 3) in 61.6% of patients; a majority of patients (n = 14) reported they were moderately satisfied (score 2). In the group treated with toxin alone, 37.9% of patients were improved (score 2 and 3) with a majority (n = 18) very satisfied reporting normal writing (score 3). Age was not a predictor of therapeutic response. Good results were obtained with injections of the flexor carpi radialis followed by flexor digitorum profundus II and III and the flexor pollicis longus. Seventy-one per cent of injections caused moderate muscle weakness, minimally disabling compared to the benefit of injections. Twenty-seven patients were followed for more than two years and three patients, who had achieved score 3 with excellent response, were followed for 14 years with very efficient repeated injections. If the injections were not effective the first time, we re-assessed the situation and adjusted the injections; we considered that toxin treatment was unsuccessful after three injections without benefit.ConclusionThe choice treatment for writer's cramp remains well-targeted injections of botulinum toxin. Physiotherapy is useful when the toxin injections are ineffective in completely improving writing. This requires close cooperation between the injector, the physiotherapist and the patient.     

Botulinum toxin A is effective to treat tension-type headache caused by hemifacial spasm

ObjectiveWe examined the relationship between hemifacial spasm (HFS; a form of cranio-cervical dystonia) and chronic primary headache, including tension-type headache (TTH). We also examined whether botulinum toxin A (BoNT/A) therapy for HFS ameliorates concomitant TTH.MethodsFifty-one HFS patients receiving BoNT/A therapy were recruited. Patients’ characteristics (including age, gender, chronic headache history, exercise habits, stiff neck, cervical spondylolysis history), stress factors, worsening/new onset of headache associated with HFS, and dose of BoNT/A were examined. We diagnosed headache types according to The International Classification of Headache Disorders, 3rd edition, beta. Numerical Rating Scale (NRS) and Headache Impact Test-6 (HIT-6) scores for headache severity were compared between the 6-week baseline before BoNT/A therapy and 6-week follow-up after BoNT/A therapy.ResultsOf 51 patients with HFS, 17 (33.3%) reported worsening or new onset of headache (especially TTH) associated with HFS (Group-S), and 34 were not aware of headache (Group-N). Twelve patients (70.6%) in group-S reported improvement of headache after BoNT/A therapy. NRS (from 7 [5–9] to 0 [0–5], p < 0.01) and HIT-6 (from 55 [54–64] to 44 [36–52], p < 0.001) scores were significantly improved after BoNT/A therapy. Logistic regression analysis revealed significant interaction between TTH associated with HFS and the presence of stress factors (odds ratio 43.11: 2.95–629.39, p < 0.001) and history of chronic headache (odds ratio 28.53: 2.96–275.10, p < 0.001).ConclusionsPrimary headache, especially TTH, is associated with HFS. BoNT/A therapy for HFS may also be indirectly effective for treatment of TTH.     

Treatment of spasmodic torticollis with local injections of botulinum toxin

Summary Thirty-seven patients with spasmodic torticollis (cervical dystonia) who received repeated local injections of botulinum toxin have been followed up for a mean period of 12.3 (10–29) months, during which time 138 treatment sessions were performed. Mean doses per muscle averaged 320 mouse units (mu; range 160–1000 mu botulinum toxin A prepared by CAMR, Porton Down, UK). Eighty-six per cent of patients experienced significant improvement of posture and 84% of those with pain had relief following the first injection. Muscular patterns of recurrent torticollis were relatively constant and in most patients efficacy was maintained with subsequent injections, while 15% of all follow-up sessions failed. Only 2 of 37 patients were consistent non-responders; 22% and 10% of all sessions were complicated by transient dysphagia and weakness of neck muscles, respectively. It is concluded that local botulinum toxin injections can be a safe and efficaceous long-term treatment of spasmodic torticollis and that optimal doses should be between 200 and 400 mu/muscle.