Caregiver burden and health-related quality of life in idiopathic dystonia patients under botulinum toxin treatment: a cross-sectional study.

Dystonia is a chronic movement disorder that is associated with a reduction in health-related quality of life (HR-QoL) and restriction of activities of daily living. Botulinum neurotoxin (BT) improves disease-specific HR-QoL by reducing abnormal movements, postures, and pain. We examined the burden of the corresponding primary caregiver as a potential important factor for disease management and HR-QoL of dystonia patients under treatment with BT. 114 patients with focal, segmental, or generalized dystonia were recruited, together with 93 corresponding caregivers, whose burden was investigated using the Caregiver Burden Inventory. In addition, all participants were assessed for cognitive impairment, depression, anxiety, alexithymia, and HR-QoL. Only a small proportion of caregivers suffered from caregiver burden. Despite BT therapy, patients' HR-QoL was decreased compared to the age-matched general German population. Psychological symptoms, notably anxiety, and depression correlated significantly with reduced HR-QoL. Our data imply that caregiver burden emerged to be an issue in subgroups of dystonia patients. Furthermore, HR-QoL of dystonia patients is reduced even under optimized BT treatment in a specialized center.

Validating the Parkinson's disease caregiver burden questionnaire (PDCB) in German caregivers of advanced Parkinson's disease patients.

BACKGROUND: Advanced Parkinson's disease (PD) may place a high burden on patients and their caregivers. Understanding the determinants of caregiver burden is of critical importance. This understanding requires the availability of adequate assessment tools. Recently, the Parkinson's disease caregiver burden questionnaire (PDCB) has been developed as a PD-specific measure of caregiver burden. However, the PDCB has only been evaluated in a sample of Australian caregivers of patients at a less advanced stage of the disease. OBJECTIVE: We tested whether a German translation of the PDCB qualifies as an adequate measure of caregiver burden in a German sample of caregivers of advanced patients with PD. METHODS: We collected PDCB data from 65 caregivers of advanced patients with PD. Reliability of the scale was assessed and compared against the original version. To validate the German version of the PDCB, we examined the correlations with the caregiver burden inventory (CBI), the short form 36 health survey (SF-36), the Parkinson's disease quality of life questionnaire 39 (PDQ-39), disease duration, and the amount of caregiving time. RESULTS: The total PDCB score proved to be reliable and to be significantly related to CBI and SF-36 scores. PDCB scores also increased with increasing amounts of caregiving time. CONCLUSIONS: The German version of the PDCB appears to be an adequate measure of caregiver burden in caregivers of advanced PD patients.

[Treatment goals in patients with post-stroke upper limb spasticity following injection of botulinum toxin A : Results of the German-Austrian subgroup of the ULIS-II study]. / Therapieziele bei Patienten mit Armspastik nach Schlaganfall nach Injektion mit Botulinumtoxin A : Ergebnisse der deutsch-österreichischen Subgruppe der ULIS-II-Studie.

BACKGROUND: The ULIS-II was an international cohort study (NCT01020500) evaluating current treatment of upper limb spasticity in post-stroke adult patients with botulinum toxin A (BoNT-A) in real-life practice. OBJECTIVE: Post hoc analysis to compare current management of post-stroke adult patients regarding goal setting and attainment with BoNT-A in Germany (D) and Austria (A) with the full cohort of ULIS-II. MATERIAL AND METHODS: The ULIS-II was a global, open-label, prospective, multicenter observational study with 2 visits conducted in 84 centers worldwide. A total of 468 patients aged ≥18 years with post-stroke upper limb spasticity were included. The primary outcome measure was the responder rate defined as achievement of a goal attainment scale (GAS) score of 0, 1 or 2 after 1 cycle of BoNT-A. RESULTS: A total of 57 patients from D/A were included in the efficacy analysis. The number of patients in D/A and the full cohort achieving the primary (78.9% vs. 79.6%) and secondary treatment goal (76.8% vs. 75.6%), respectively, was comparable. Deviating from the full cohort, the most common primary treatment goal in D/A was related to impairment (33.3%). Compared to baseline there was a marked reduction in concomitant therapies at the follow-up visit after 3-5 months in the D/A group: patients receiving oral anti-spastic medication 61.4% vs. 40.4%, positioning 50.9% vs. 36.8% and splinting 43.9% vs. 31.6%. Injection control techniques were less frequently used in the D/A group compared to the global study cohort (electrical stimulation: 26.3% vs. 45.8% and electromyography: 12.3% vs. 29.2%). No adverse events were documented in the D/A cohort. CONCLUSION: A single injection of BoNT-A in adult patients with post-stroke spasticity of the arm led to a high response rate of approximately 80% in both cohorts. The BoNT-A injections in post-stroke adult patients contributed to an improvement in the daily life of patients and their carers beyond simple reduction of muscle tone or spasticity.

Impaired heart rate variability in cervical dystonia is associated to depression.

Causes of cardiovascular autonomic dysfunction in cervical dystonia (CD) are poorly understood. Studies examining effects of botulinum neurotoxin (BoNT) therapy on heart rate variability (HRV) yielded contradictory results. There is compelling evidence that depression shifts autonomic balance towards sympathetic predominance. As depression is the most frequent non-motor symptom in CD, we sought to determine if it is associated to dysfunction of cardiovascular autonomic regulation. Standardized interviews, clinical examinations, self-rating forms, autonomic symptom questionnaire, and automated autonomic testing in outpatients with idiopathic CD were used. Cardiovascular autonomic screening encompassed five different analyses of HRV, and testing of orthostasis. 85 CD patients participated in the study. 21% of them had HRV impairment, 14% orthostatic hypotension. 30% of CD patients had symptoms of depression. In those, decreased HRV was more frequent than in CD patients without mood disturbance (40 vs. 13%; p = 0.008). CD patients with and without depression had no other significant differences, including demographics, dystonia severity, comorbidity, medication, or BoNT therapy. Cardiovascular autonomic imbalance with sympathetic predominance is a non-motor manifestation of CD, associated to depression. Impaired HRV is a cardiovascular risk factor, moreover, emphasizing the need to identify and treat depression in dystonia.

Botulinum toxin drugs: brief history and outlook.

The global botulinum toxin (BT) market is currently undergoing rapid changes: this may be the time to review the history and the future of BT drug development. Since the early 1990s Botox(®) and Dysport(®) dominated the international BT market. Later, Myobloc(®)/NeuroBloc(®), a liquid BT type B drug, came out, but failed. Xeomin(®) is the latest major BT drug. It features removal of complexing proteins and improved neurotoxin purity. Several new BT drugs are coming out of Korea, China and Russia. Scientific challenges for BT drug development include modification of BT's duration of action, its transdermal transport and the design of BT hybrid drugs for specific target tissues. The increased competition will change the global BT market fundamentally and a re-organisation according to large indication groups, such as therapeutic and cosmetic applications, might occur.

Intrathecal Baclofen therapy in Germany: Proceedings of the IAB-Interdisciplinary Working Group for Movement Disorders Consensus Meeting.

Continuous intrathecal Baclofen application (ITB) through an intracorporeal pump system is widely used in adults and children with spasticity of spinal and supraspinal origin. Currently, about 1200 new ITB pump systems are implanted in Germany each year. ITB is based on an interdisciplinary approach with neurologists, rehabilitation specialists, paediatricians and neurosurgeons. We are presenting the proceedings of a consensus meeting organised by IAB-Interdisciplinary Working Group for Movement Disorders. The ITB pump system consists of the implantable pump with its drug reservoir, the refill port, an additional side port and a flexible catheter. Non-programmable pumps drive the Baclofen flow by the reservoir pressure. Programmable pumps additionally contain a radiofrequency control unit, an electrical pump and a battery. They have major advantages during the dose-finding phase. ITB doses vary widely between 10 and 2000 µg/day. For spinal spasticity, they are typically in the order of 100-300 µg/day. Hereditary spastic paraplegia seems to require particularly low doses, while dystonia and brain injury require particularly high ones. Best effects are documented for tonic paraspasticity of spinal origin and the least effects for phasic muscle hyperactivity disorders of supraspinal origin. Oral antispastics are mainly effective in mild spasticity. Botulinum toxin is most effective in focal spasticity. Myotomies and denervation operations are restricted to selected cases of focal spasticity. Due to its wide-spread distribution within the cerebrospinal fluid, ITB can tackle wide-spread and severe spasticity.

The dystonia discomfort scale (DDS): a novel instrument to monitor the temporal profile of botulinum toxin therapy in cervical dystonia.

BACKGROUND AND PURPOSE: Conventional scales measure the effect of botulinum toxin (BT) therapy only at specific points in time. The Dystonia Discomfort Scale (DDS), a novel, easy-to-use, self-assessment scale to record temporal profiles of the effect of BT therapy in cervical dystonia (CD), is introduced and evaluated against the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS). METHODS: Seventy-six patients with CD (age 54.4 ± 10.9 years, 34% male) receiving ≤5 cycles of incobotulinumtoxinA (Xeomin); Merz Pharmaceuticals, Frankfurt am Main, Germany) injections at intervals ≥10 weeks used DDS to record the severity of their symptoms daily. DDS data were compared with TWSTRS-Total scores and patients' subjective estimation (SE) of the onset (TO) and waning (TW) of the treatment effect. RESULTS: The Toronto Western Spasmodic Torticollis Rating Scale - Total scores correlated significantly with DDS (P ≤ 0.028 at all visits evaluated). TO-DDS and TO-SE were 7.9 ± 8.6 and 7.1 ± 4.1 days, respectively; TW-DDS and TW-SE were 41.8 ± 19.2 and 45.1 ± 21.5 days, respectively. CONCLUSION: The Dystonia Discomfort Scale is a novel, easy-to-use, self-assessment scale for valid and sensitive monitoring of the temporal profile of the effect of BT therapy in patients with CD. DDS provides important additional information about onset, duration, waning, stability and reproducibility of the effects of BT therapy.

Sonographic detection of basal ganglia abnormalities in spasmodic dysphonia.

BACKGROUND AND PURPOSE: Abnormalities of the lenticular nucleus (LN) on transcranial sonography (TCS) are a characteristic finding in idiopathic segmental and generalized dystonia. Our intention was to study whether TCS detects basal ganglia abnormalities also in spasmodic dysphonia, an extremely focal form of dystonia. METHODS: Transcranial sonography of basal ganglia, substantia nigra and ventricles was performed in 14 patients with spasmodic dysphonia (10 women, four men; disease duration 16.5 ± 6.1 years) and 14 age- and sex-matched healthy controls in an investigator-blinded setting. RESULTS: Lenticular nucleus hyperechogenicity was found in 12 spasmodic dysphonia patients but only in one healthy individual (Fisher's exact test, P < 0.001) whilst other TCS findings did not differ. The area of LN hyperechogenic lesions quantified on digitized image analysis correlated with spasmodic dysphonia severity (Spearman test, r = 0.82, P < 0.001). CONCLUSION: Our findings link the underlying pathology of spasmodic dysphonia to that of more widespread forms of dystonia.

Five-year experience with incobotulinumtoxinA (Xeomin(®) ): the first botulinum toxin drug free of complexing proteins.

In 2005, incobotulinumtoxinA (Xeomin(®) ), a new botulinum toxin (BT) type A drug without complexing proteins (CPs), became available. This paper reviews the specific features of Xeomin(®) and the experience gathered with it during the last 5 years. Compared with conventional BT drugs, Xeomin(®) 's extended shelf live and its simplified temperature restrictions indicate that CPs are not necessary for BT drug stability. Its reduced molecular size does not translate into diffusion differences, and its potency labelling is identical to that of onabotulinumtoxinA (Botox(®) ). With a reduced content of inactivated botulinum neurotoxin, Xeomin(®) should have reduced antigenicity. Lack of CP's may further reduce antigenicity. Xeomin(®) 's therapeutic efficacy against cervical dystonia, blepharospasm and spasticity has been proven in large randomised, double-blind and placebo-controlled studies leading to registrations in many countries. Additional successful clinical use in axillary hyperhidrosis, hemifacial spasm, re-innervation synkinesias and hypersalivation as well as in dystonia and spasticity in extended doses and throughout extended observation periods has been documented meanwhile. Lack of reported cases of antibody-induced therapy failure (ABF), as to date, support the hypothesis of an improved antigenicity.

[Pharmacology of botulinum toxin drugs]. / Pharmakologie der Botulinumtoxinmedikamente.

Botulinum toxin (BT) is used with remarkable success to treat various disorders caused by muscle hyperactivities or exocrine gland overactivity. Its use for treatment of non-muscular pain conditions is currently being explored. In Germany, BT type A is available as Botox®, Dysport® and Xeomin®, BT type B as NeuroBloc®. In aesthetic medicine they are called Vistabel®, Azzalure® and Bocouture®. Numerous other BT drugs are used worldwide. Often, their origin is dubious. BT drugs consist of botulinum neurotoxin, complexing proteins and adjuvants. Their manufacturing process is highly complex. BT drugs vary in many aspects. By no means are they generics. Clinically relevant differences include their potency labeling, antigenicity, presence of complexing proteins, storage conditions, pH value of the reconstituted drug and pharmaceutical preparation.

Botulinum toxin for treatment of dystonia.

Botulinum toxin (BT) is used in various medical specialties. However, dystonia is still one of the most important indications for BT therapy. BT drugs consist of botulinum neurotoxin, complexing proteins and excipients. Botox, Dysport and Xeomin are BT type A drugs and produce similar therapeutic and adverse effects (AE). Neurobloc/MyoBloc is based upon BT type B. Its use is limited by substantial systemic anticholinergic AE. The potency of BT drugs may be compared as follows: Botox:Xeomin:Dysport:Neuobloc/MyoBloc = 1:1:3:40. BT selectively blocks the cholinergic innervation of striate and smooth muscles and exocrine glands. It can produce obligate, local and systemic AE. However, its overall AE profile including long-term safety is excellent. BT can be blocked by antibodies. Risk factors include single doses, interinjection intervals and the immunological quality of the BT drug applied. Planning of BT therapy is based upon target muscle identification and estimation of their dystonic involvement. For planning of BT therapy and BT placement, electromyography and imaging techniques may be used additionally. So far, total Xeomin and Botox doses of up to 840 MU have been used without clinically detectable systemic AE. BT can be used to treat focal dystonias including cranial, pharyngolaryngeal, cervical and limb dystonias. In segmental and generalized dystonias, BT therapy has to be focussed on the most relevant target muscles. Combinations with all other treatment options including deep brain stimulation are possible. Recent safety data and availability of immunologically improved BT drugs are now allowing higher BT doses thus expanding the use of BT into more widespread dystonias.

On muscle spindles, dystonia and botulinum toxin.

Dystonia may produce co-contractions and constant strain in numerous muscle fibers, including those of the muscle spindles. As proprioceptors, muscle spindles detect dynamic or static changes in muscle length and their afferent projections to the spinal cord play a central role in control of antagonistic muscles. Their parallel arrangement with extrafusal muscle fibers and association with the earlier recruited oxidative motor units allow them to conveniently sample the activity of all motor units and effectively modulate movement. At the same time, fusimotor muscle spindle innervation contracts the striated polar portions of the intrafusal muscle fibers and prevents their slackening during extrafusal muscle contractions. Botulinum toxin remains the most efficient therapy of dystonia. Its muscular mechanism of action is hinged on cholinergic blockade not only of extrafusal, but also of intrafusal muscle fibers. Besides being a targeted muscular therapy, the alteration of the corresponding sensory input following an effect of botulinum toxin on the intrafusal muscle fibers is pivotal in modulating loss of pre-synaptic inhibition in dystonia, including suppression of the tonic vibration reflex. Whether or not trans-synaptic botulinum toxin migration occurs, a modification of the central motor programming is bound to happen in dystonia, with botulinum toxin acting either as another 'sensory trick' or as a form of 'short-term plasticity'. Knowledge of the muscle spindle anatomy and function is key to unify our understanding of abnormal movements and of effects of botulinum toxin therapy. Thus, in dystonia, overactivity of muscles and increased spindle sensitivity are germane to botulinum toxin targets of action.

Association of Motor and Cognitive Symptoms with Health-Related Quality of Life and Caregiver Burden in a German Cohort of Advanced Parkinson's Disease Patients.

Parkinson's disease (PD) is a chronic progressive movement disorder with severe reduction in patients' health-related quality of life (HR-QoL). Motor and cognitive symptoms are especially linked with decreased PD patients' HR-QoL. However, the relationship of these symptoms to caregiver burden is relatively unclear. Influence of the Montreal Cognitive Assessment scale (MoCA) as a cognitive screening tool and Movement Disorders Society Unified Parkinson's disease Rating Scale MDS-UPDRS symptoms in relation to patients' HR-QoL and caregivers` burden was analyzed. PD patients (n = 124) completed MDS-UPDRS, MoCA, and the PD questionnaire 8 (PDQ-8) as a measure of quality of life. Caregivers (n = 78) were assessed by the PD caregiver burden inventory (PDCB). PDQ-8 and PDCB scores were regressed on MDS-UPDRS subscales and MoCA subscores. PDQ-8 correlated with attention (R 2 0.1282; p < 0.001) and executive (R 2 0.0882; p 0.001) MoCA subscores and all parts of the MDS-UPDRS. PDCB correlated most strongly with MDS-UPDRS part III motor symptoms (R 2 0.2070; p < 0.001) and the MoCA attention subscore (R 2 0.1815; p < 0.001). While all facets of PD symptoms assessed by the MDS-UPDRS relate to PD patients' quality of life, motor symptoms are the most relevant factor for the prediction of caregiver burden. In addition, patients' attentional symptoms seem to affect not only them, but also their caregivers. These findings show the potential of a detailed analysis of MDS-UPDRS and MoCA performance in PD patients.

A potential noninvasive neurobiological test for Alzheimer's disease.

Currently Alzheimer's disease, which affects more than 20 million people worldwide, can only be definitely diagnosed by histological examination of brain tissue obtained at autopsy or biopsy. There is a great need for an early, noninvasive, sensitive, and easily administered diagnostic test of Alzheimer's disease. Here it is reported that patients diagnosed with probable Alzheimer's disease by standard clinical criteria exhibited a marked hypersensitivity in their pupil dilation response to a cholinergic antagonist, tropicamide, placed in their eyes. It was possible to distinguish 18 of 19 individuals (95%) either clinically diagnosed with Alzheimer's disease or classified as suspect Alzheimer's individuals by neuropsychological screening from 30 of 32 normal elderly controls (94%).

Routine use of Xeomin in patients previously treated with Botox: long term results.

BACKGROUND AND PURPOSE: Based upon large and carefully performed studies Xeomin was first registered in 2005. However, its real potential can only be assessed, when it is used outside of study design restrictions, in an independent setting, in off-label indications and during continued use. METHODS AND RESULTS: Two hundred and sixty-three patients (91 with dystonia, 84 with spasticity, 17 with hemifacial spasm and re-innervation synkinesias, 64 with hyperhidrosis, 7 with hypersalivation), who were previously treated with Botox for at least 1 year under stable conditions, were converted in a blinded fashion to Xeomin using a 1:1 conversion ratio and identical treatment parameters. Therapeutic outcome and adverse effects were monitored by neurological examination and structuralised interviews. In 223 patients (all except those with axillary hyperhidrosis) Xeomin was used continuously throughout a 3 year period. Altogether 1050 injection series were performed. Patients with dystonia received 261.5 +/- 141.0 MU Botox/Xeomin, patients with spasticity 450.5 +/- 177.1 MU, patients with hemifacial spasm and reinnervation synkinesias 44.7 +/- 19.5 MU and patients with hyperhidrosis 286.9 +/- 141.6 MU. The maximum botulinum toxin dose applied was 840 MU. There were no subjective or objective differences between Botox and Xeomin treatments with respect to onset latency, maximum and duration of their therapeutic effects and their adverse effect profiles. Long-term use did not reveal additional safety relevant aspects. None of the patients lost therapeutic efficacy during the observation period. CONCLUSIONS: Xeomin can be used safely in doses of up to 840 MU. Even when applied in high doses it did not produce secondary therapy failure. There were no diffusion differences between Botox and Xeomin. Using a conversion ratio of 1:1 Xeomin and Botox can easily be exchanged in a continued treatment.

[Botulinum toxin: from drug to poison]. / Botulinum Toxin: vom Medikament zum Toxin ...

For most of its time, the history of botulinum toxin (BT) has been the history of botulism, i. e. of an intoxication with BT. By the end of the 1960's a paradigm shift took place which in this radicalness had never occurred before in the history of mankind. At that time BT was first used therapeutically to treat strabismus. From ophthalmology BT rapidly spread into numerous medical specialties. For most of its indications BT is the therapy of choice, for some it has revolutionized their treatment altogether. The widespread therapeutic use of BT allowed detailed clinical and technical investigations of BT's action upon the human body. Applying this knowledge we diagnosed for the first time chronic botulism in adults living on a farm with chronic bovine botulism. This constitutes another radical paradigm shift. The history of BT is the history of a dual paradigm shift each time induced by a complete reversal of the viewing perspective. Knowledge gain can be a linear process. It can, however, also be a circular one. Changes of the viewing perspective are crucial. Changing the viewing perspective may facilitate knowledge gain. This might be used to develop an instrument to facilitate knowledge gain.

[An improved model of a catheterised human bladder for screening bactericidal agents]. / Verbessertes Modell der humanen katheterisierten Blase für das Screening antibakteriell wirksamer Agenzien.

PURPOSE: Catheter encrustation and associated blockage by a crystalline Proteus mirabilis biofilm constitute a continuous problem in long-term catheterised patients. The objective of the present work was to verify a new, physiological bladder model possessing the ability to show that triclosan-blocking solutions exert bactericidal and bacteriostatic activities. MATERIAL AND METHODS: Catheterised sterile infusion bags served as human bladder models. Artificial urine inoculated with Proteus mirabilis was administered by a further aperture. Samples for measurement of pH value and microbial count were collected at intervals of 24 h. Upon completion of testing catheter encrustation was assessed and visualised by scanning electron microscopy. RESULTS: In contrast to the application of placebo solution, in models filled with triclosan-blocking solution the catheters drained freely for the experimental period. Similar results were obtained for pH values and microbial count. The pH of the artificial urine did not exceed a critical value of pH 7 and the numbers of organisms correspond approximately to the initially inoculated number of organisms. CONCLUSION: In the model developed here, triclosan inhibits the growth of Proteus mirabilis over the test period by diffusing into the artificial urine through the catheter balloon. Thus, triclosan acts against the pH increase as well as the formation of a crystalline biofilm. Taken together, the adaptability of this new, physiological model of the human bladder could be shown.

Overactive bladder in Parkinson's disease: alteration of brainstem raphe detected by transcranial sonography.

Urinary dysfunction is very common in idiopathic Parkinson's disease (PD) and manifests primarily with symptoms of overactive bladder (OAB). Affection of central serotonergic systems has been suggested to play a role in OAB. The objective of this study was to evaluate whether in PD patients with OAB symptoms a specific alteration of the brainstem raphe (BR), which contains serotonergic neurons, can be detected with transcranial sonography (TCS). Of 116 PD patients enrolled, 19 had PD-related OAB symptoms (OAB+) unlike remaining 97 patients (OAB-). Patients were examined by a sonographer blinded to the clinical data. Reduced echogenicity of BR was found in 12 (63%) OAB+ patients but only in 18 (19%) of 93 assessable OAB- patients (Mann-Whitney U-test, P < 0.001). In OAB+ patients, lower raphe echogenicity score was associated with longer duration of OAB symptoms (anova, P = 0.033). Other TCS findings such as echogenicity of substantia nigra, thalami, lenticular and caudate nuclei, and widths of third and lateral ventricles did not differ between OAB+ and OAB- patients. TCS findings suggest a pathogenetic role of BR in OAB related to PD. Alterations may reflect disturbance of its central serotonergic system.

Clinical use of non-A botulinum toxins: botulinum toxin type B.

Botulinum neurotoxin type B (BT, BT-B) has been used as NeuroBloc/MyoBloc since 1999 for treatment of cervical dystonia, hyperhidrosis, spastic conditions, cerebral palsy, hemifacial spasm, bladder dysfunction, spasmodic dysphonia, sialorrhoea, anal fissures, piriformis syndrome, various pain conditions and cosmetic applications. Generally, its therapeutic effects are comparable to BT type A (BT-A). The adverse effect profiles of BT-B and BT-A, however, differ considerably. BT-B has been found to produce more regional as well as systemic anticholinergic adverse effects, such as dryness of mouth, accommodation difficulties, conjunctival irritation, reduced sweating, dysphagia, heartburn, constipation, bladder voiding difficulties and dryness of nasal mucosa. In BT-B the relationship between autonomic and motor effects known from BT-A is substantially shifted towards autonomic effects. BT-B, therefore, should be used carefully in patients with autonomic disorders and in patients with concomitant anticholinergic therapy. If NeuroBloc/MyoBloc is used to treat cervical dystonia patients with antibody-induced failure of BT-A therapy, 86% of those will develop complete secondary therapy failure after five applications. If NeuroBloc/MyoBloc used to treat cervical dystonia patients without prior exposure to BT, 44% of those will develop complete secondary therapy failure after nine applications. NeuroBloc/MyoBloc, therefore, is associated with substantial antigenicity problems originating from a particular low specific biological potency. Systemic anticholinergic adverse effects and high antigenicity limits the clinical use of NeuroBloc/MyoBloc considerably.

Clinical use of non-A botulinum toxins: botulinum toxin type C and botulinum toxin type F.

Botulinum neurotoxin (BoNT) serotype A is commonly used in the treatment of focal dystonia, but some patients are primarily or become secondarily resistant to it. Consequently, other serotypes have to be used when immuno-resistance is proven. In the literature, patients with focal dystonia have been treated with BoNT serotype F with clinical benefit but with short lasting effects. Recently, BoNT serotype C has been used with positive clinical outcome. An update on the clinical use of BoNT serotype F and BoNT serotype C is provided.