Disease-oriented approach to botulinum toxin use

Therapy with botulinum neurotoxin for Parkinson's disease

Botulinum neurotoxin (BoNT) has been in use since the 1970's. Its effect is reached mainly by inhibiting the release of acetylcholine in the synaptic gap of motor neurons or at the motor end plate and the parasympathetic ganglia. In the case of Parkinson's disease, it is used to treat several motor and non-motor symptoms. Within recent years increasingly numerous possible fields of application of BoNT have been found for the treatment of Parkinson's disease, and for some specific symptoms it has in fact become the therapy of choice, while for others it is but one of the therapeutic options that come into consideration when others are not sufficiently effective. In the following, we intend to outline the indications, the possible side effects and also the approvals for therapies with botulinum toxin in the primary and secondary symptoms of Parkinson's disease.

Use of botulinum toxin in the management of dystonia in Parkinson's disease

Botulinum toxin is one of the most potent neurotoxins, but when injected into an overactive muscle, it can transiently alleviate an involuntary movement, such as dystonia. The primary aim of this article is to provide a comprehensive review of the various forms of dystonia observed in patients with Parkinson's disease who can benefit from a therapeutic trial of botulinum toxin. Although most of these indications are not supported by randomized controlled clinical trials and, therefore, not approved by the Food and Drug Administration, there are many open-label trials supporting a large body of empirical experience testifying to the benefits of botulinum toxin treatment in these conditions.

Botulinum toxin treatment in parkinsonism

Botulinum toxin (BoNT) was approved by the United States Food and Drug Administration (FDA) in 1989 for facial movement disorders and strabismus, but since that time its indications have been expanding beyond neurologic and ophthalmologic disorders. This article is a narrative review of the therapeutic use of BoNT in tremors, dystonia, sialorrhea, bladder and other autonomic symptoms, levodopa-induced dyskinesia and other problems occuring in the setting of parkinsonism. Though FDA approval is lacking for some of these indications, expert experiences have shown that BoNT is often beneficial in this group of patients.

Measurement Issue in Antecollis

Background:

Antecollis is defined as an involuntary forward flexion of the neck. Previous reports have measured the neck flexion angles based on the line perpendicular to the ground. This led to an inflation of the neck flexion angles in patients who had combined forward truncal flexions, especially upper camptocormia.

Methods:

We examined the neck flexion angles and the upper camptocormia angle in the published photographs of antecollis. MEDLINE search was conducted using the following search terms: antecollis OR anterocollis. Lateral-view photographs of patients diagnosed with antecollis were collected. Neck flexion angles were measured with the classic ‘perpendicular method’ and the ‘antecollis method’ we developed.

Results:

Nine patient photographs were identified. While antecollis was the only described postural abnormality in eight cases, these patients exhibited upper camptocormia angles of 45° or larger. The mean neck flexion angle measured with the antecollis method was 49.7°, while the perpendicular method yielded 103.4°.

Discussion:

Upper camptocormia should be considered in the evaluation of antecollis. We propose a new method to measure neck flexion in relation to the torso, instead of the vertical line.

[Thermoregulatory dysfunction in Parkinson's disease]

Thermoregulatory dysfunction is considered to be the least investigated among all the autonomic disorders in Parkinson disease. Pathophysiological mechanisms of this phenomena involve as central, as peripheric parts of nervous system. Dopamine deficiency in combination with peripheric autonomic dysfunction leads to temperature balance disturbance, which may be expressed by various clinical symptoms. Dopaminergic innervation of preoptic-anterior hypothalamus area plays a crucial role in thermoregulation function of central nervous system. Current thermoregulatory tests give possibility not only to reveal sudomotor and heat dissipation disorders in patients with Parkinson disease, but also to make differential diagnosis with other neurodegenerative disorders. Early detection and treatment of thermoregulatory dysfunction may improve quality of life in patients with Parkinson disease.

Botulinum Neurotoxin Type A in the Treatment of Facial Seborrhea and Acne: Evidence and a Proposed Mechanism

Intradermal injection of botulinum neurotoxin is a frequently performed procedure in aesthetic dermatology to improve facial skin tone, texture, fine wrinkles, and enlarged pores. In practice, botulinum neurotoxin type A is also used to reduce skin oiliness of the face. There is increasing evidence that acetylcholine plays specific roles in sebum production, suggesting that botulinum neurotoxin type A may reduce sebum production by interfering with cholinergic transmission between sebaceous glands and autonomic nerve terminals. Botulinum neurotoxins can also inhibit several pathogenetic components of acne development, suggesting that botulinum neurotoxins can be used as a safe and effective treatment modality for acne and other skin disorders related to overactivity of sebaceous glands. This review aims to explore the current evidence behind the treatment of facial seborrhea and acne with botulinum neurotoxin type A.

Antidepressant-Like Properties of Intrastriatal Botulinum Neurotoxin-A Injection in a Unilateral 6-OHDA Rat Model of Parkinson's Disease

Parkinson’s patients often suffer from depression and anxiety, for which there are no optimal treatments. Hemiparkinsonian (hemi-PD) rats were used to test whether intrastriatal Botulinum neurotoxin-A (BoNT-A) application could also have antidepressant-like properties in addition to the known improvement of motor performance. To quantify depression- and anxiety-like behavior, the forced swim test, tail suspension test, open field test, and elevated plus maze test were applied to hemi-PD rats injected with BoNT-A or vehicle. Furthermore, we correlated the results in the forced swim test, open field test, and elevated plus maze test with the rotational behavior induced by apomorphine and amphetamine. Hemi-PD rats did not show significant anxiety-like behavior as compared with Sham 6-OHDA- + Sham BoNT-A-injected as well as with non-injected rats. However, hemi-PD rats demonstrated increased depression-like behaviors compared with Sham- or non-injected rats; this was seen by increased struggling frequency and increased immobility frequency. Hemi-PD rats intrastriatally injected with BoNT-A exhibited reduced depression-like behavior compared with the respective vehicle-receiving hemi-PD animals. The significant effects of intrastriatally applied BoNT-A seen in the forced swim test are reminiscent of those found after various antidepressant drug therapies. Our data correspond with the efficacy of BoNT-A treatment of glabellar frown lines in treating patients with major depression and suggest that also intrastriatal injected BoNT-A may have some antidepressant-like effect on hemi-PD.

Oxybutynin-Induced Hyperthermia in a Patient With Parkinson's Disease

Impaired thermoregulation and heat intolerance may be intrinsic to autonomic dysfunction in Parkinson's disease due to disturbances in perspiration regulation. Thermoregulatory impairment leading to hyperthermia/heatstroke can be accentuated with the usage of anticholinergics, which block the ability to sweat. Oxybutynin chloride is one of the most used anticholinergic agents in clinical practice for the management of detrusor hyperreflexia secondary to neurogenic bladder dysfunction and is often used in the setting of Parkinson's disease. We present a rare instance of oxybutynin-induced heatstroke in an elderly patient with Parkinson's disease.

Use of Botulinum Neurotoxin in Parkinson's Disease: A Critical Appraisal

For well over 30 years, the botulinum neurotoxin (BoNT) has been used for a large number of indications, some of which however have not been licensed. Admittedly, approval varies in many countries and this permits a large spectrum for evaluation. Thus, BoNT is used for patients with Parkinson’s disease (PD) and other Parkinson’s syndromes (PS) in varying degrees of frequency. We have to distinguish between (1) indications that are either approved or (2) those not approved, (3) indications that might be a result of PS and (4) finally those which appear independent of PS. The most important indication for BoNT in PS patients is probably sialorrhea, for which approval has been granted in the majority of countries. Cervical dystonia is a frequent symptom in PS, with anterocollis as a specific entity. A further indication is blepharospasm in the different forms, especially the inhibition of eyelid opening in atypical PS. The use of BoNT in cases of camptocormia, the Pisa syndrome and neck rigidity is still a matter of debate. In dystonia of the extremities BoNT can be recommended, especially in dystonia of the feet. One well-known indication, for which however sufficient data are still lacking, involves treating tremor with BoNT. As to autonomic symptoms: Focal hyperhidrosis and detrusor hyperactivity can be mentioned, in this last case BoNT has already been approved. A number of further but rare indications such as freezing-of-gait, dyskinesia, and dysphagia will be discussed and evaluated.

Botulinum Toxin in Movement Disorders: An Update

Since its initial approval in 1989 by the US Food and Drug Administration for the treatment of blepharospasm and other facial spasms, botulinum toxin (BoNT) has evolved into a therapeutic modality for a variety of neurological and non-neurological disorders. With respect to neurologic movement disorders, BoNT has been reported to be effective for the treatment of dystonia, bruxism, tremors, tics, myoclonus, restless legs syndrome, tardive dyskinesia, and a variety of symptoms associated with Parkinson's disease. More recently, research with BoNT has expanded beyond its use as a powerful muscle relaxant and a peripherally active drug to its potential central nervous system applications in the treatment of neurodegenerative disorders. Although BoNT is the most potent biologic toxin, when it is administered by knowledgeable and experienced clinicians, it is one of the safest therapeutic agents in clinical use. The primary aim of this article is to provide an update on recent advances in BoNT research with a focus on novel applications in the treatment of movement disorders. This comprehensive review of the literature provides a critical review of evidence-based clinical trials and highlights recent innovative pilot studies.

Cervical Dystonia Caused by Chronic Nonunion C2 Fracture: A Case Report

Chronic nonunion cervical fracture leading to cervical dystonia (CD) is very rare. This study reports a 72-year-old man who presented with 9-month history of progressively worsening neck tilting, neck tightness, neck pain, headache, and difficulty with swallowing. The patient was referred to speech therapy and confirmed to have dysphagia on modified barium swallow study. A cervical spine radiograph showed a chronic C2 nonunion fracture. Subsequent cervical spine magnetic resonance imaging confirmed chronic C2 nonunion fracture with kyphotic deformity of the cervical canal with associated cord compression at C1-C2 and severe central canal stenosis. Needle electromyography revealed dystonic or spasmodic neck muscles, consistent with diagnosis of CD. Botulinum toxin injection resulted in marked clinical improvement. The patient finally underwent occipital to C4 posterior segmental fusion. No recurrence of CD had occurred 12 months after botulinum toxin injection and surgery, which supports the conclusion that chronic C2 nonunion fracture is most likely responsible for CD in this case. The authors suggest that all patients with CD receive dysphagia evaluation and more importantly cervical spine imaging to rule out chronic C2 nonunion fracture.

Hand, foot, and spine deformities in parkinsonian disorders

Hand and foot deformities, known as "striatal deformities", and other musculoskeletal abnormalities such as dropped head, bent spine, camptocormia, scoliosis and Pisa syndrome, are poorly understood and often misdiagnosed features of Parkinson's disease and other parkinsonian syndromes. These deformities share some similarities with known rheumatologic conditions and can be wrongly diagnosed as rheumatoid arthritis, osteoarthritis, psoriatic arthritis, Dupuytren's contracture, trigger finger, or other rheumatologic or orthopedic conditions. Neurologists, rheumatologists, and other physicians must be familiar with these deformities to prevent misdiagnosis and unnecessary diagnostic tests, and to recommend appropriate treatment options.

Botulinum Toxin Type A Injection for Cervical Dystonia in Adults with Dyskinetic Cerebral Palsy

We aimed to evaluate the efficacy and safety of injecting botulinum toxin A (BoNT-A) into the neck muscles to treat cervical dystonia (CD) in patients with dyskinetic cerebral palsy (CP). This was a randomized, double-blinded, placebo-controlled trial with cross-over design. We prospectively enrolled adults with dyskinetic CP who were over 20 years old and had been clinically diagnosed with CD for more than one year. The primary outcome measure was the change in Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) at four weeks from the baseline TWSTRS. Seventeen patients were initially enrolled, but one patient was excluded after the final evaluation because of a violation of the study protocol. At four weeks, the BoNT-A injections showed significant improvement in TWSTRS total scores compared to the saline injections (p = 0.0286 for ANCOVA). At 12 weeks, the BoNT-A injections resulted in greater improvements in TWSTRS total scores than the saline injections without statistical significance (p = 0.0783 for ANCOVA). Dysphagia occurred in three out of 16 patients: two after BoNT-A and one after saline. The dysphagia was transient and improved naturally within two weeks without any special treatment. BoNT-A injection for CD in adults with dyskinetic CP is relatively safe and improves pain and disability.

Ultrasound Guidance for Botulinum Neurotoxin Chemodenervation Procedures

Injections of botulinum neurotoxins (BoNTs) are prescribed by clinicians for a variety of disorders that cause over-activity of muscles; glands; pain and other structures. Accurately targeting the structure for injection is one of the principle goals when performing BoNTs procedures. Traditionally; injections have been guided by anatomic landmarks; palpation; range of motion; electromyography or electrical stimulation. Ultrasound (US) based imaging based guidance overcomes some of the limitations of traditional techniques. US and/or US combined with traditional guidance techniques is utilized and or recommended by many expert clinicians; authors and in practice guidelines by professional academies. This article reviews the advantages and disadvantages of available guidance techniques including US as well as technical aspects of US guidance and a focused literature review related to US guidance for chemodenervation procedures including BoNTs injection.

Pharmacological therapies for pain in Parkinson's disease - a review paper

INTRODUCTION

Parkinson's disease (PD) is a neurodegenerative movement disorder characterized by the loss of dopamine containing cells in the substantia nigra, with pain being one of the most common, yet frequently misunderstood symptoms. The prevalence of pain in PD populations ranges from 40-85% and is usually categorized under the following types: i) musculoskeletal pain ii) radicular and neuropathic pain iii) dystonia-related pain iv) akathitic pain and iv) central parkinsonian pain. Areas covered: The aim of this literature review was to document and present the common and uncommon pharmaceutical therapies that treat and/or alleviate these types of pain in PD. The PubMed database was searched with keywords: "Parkinson's disease", "Pain", and "Pharmacological Therapies". Research articles involving randomized, controlled trials were included as well as case studies and qualitative studies. Expert commentary: Given the increased prevalence of pain in PD populations, there is a need for a clear understanding of the types of pain treatments available and how they can be best combined to fit the specific needs of each patient.

The Regions on the Light Chain of Botulinum Neurotoxin Type A Recognized by T Cells from Toxin-Treated Cervical Dystonia Patients. The Complete Human T-Cell Recognition Map of the Toxin Molecule

We have recently mapped the in vitro proliferative responses of T cells from botulinum neurotoxin type A (BoNT/A)-treated cervical dystonia (CD) patients with overlapping peptides encompassing BoNT/A heavy chain (residues 449-1296). In the present study, we determined the recognition profiles, by peripheral blood lymphocytes (PBL) from the same set of patients, of BoNT/A light (L) chain (residues 1-453) by using 32 synthetic overlapping peptides that encompassed the entire L chain. Profiles of the T-cell responses (expressed in stimulation index, SI; Z score based on transformed SI) to the peptides varied among the patients. Samples from 14 patients treated solely with BoNT/A recognized 3-13 (average 7.2) peptides/sample at Z > 3.0 level. Two peptide regions representing residues 113-131 and 225-243 were recognized by around 40% of these patients. Regarding treatment parameters, treatment history with current BOTOX^® only group produced significantly lower average T-cell responses to the 32 L-chain peptides compared to treatments with mix of type A including original and current BOTOX^®. Influence of other treatment parameters on T-cell recognition of the L-chain peptides was also observed. Results of the submolecular T-cell recognition of the L chain are compared to those of the H chain and the T-cell recognition profile of the entire BoNT/A molecule is discussed. Abbreviations used: BoNT/A, botulinum neurotoxin type A; BoNT/A_i, inactivated BoNT/A; BoNT/B, botulinum neurotoxin type B; CD, cervical dystonia; L chain, the light chain (residues 1-448) of BoNT/A; LNC, lymph node cells; H chain, the heavy chain (residues 449-1296) of BoNT/A; H_C, C-terminal domain (residues 855-1296) of H chain; H_N, N-terminal domain (residues 449-859) of H chain; MPA, mouse protection assay; SI, stimulation index (SI = cpm of ³H-thymidine incorporated by antigen-stimulated T cells/cpm incorporated by unstimulated cells); TeNT, tetanus neurotoxin; TeNT_i, inactivated TeNT.

An update on new and unique uses of botulinum toxin in movement disorders

The therapeutic applications of botulinum toxin (BoNT) have grown manifold since its initial approval in 1989 by the US Food and Drug Administration (FDA) for the treatment of strabismus, blepharospasm, and other facial spasms. Although it is the most potent biologic toxin known to man, long-term studies have established its safety in the treatment of a variety of neurologic and non-neurologic disorders. This review focuses on some novel and uncommon uses of BoNT in the treatment of movement disorders, such as oromandibular dystonia, including bruxism, anterocollis, camptocormia, tremor, tics, tardive and levodopa-induced dyskinesia, and restless legs syndrome. Despite a paucity of randomized controlled trials and lack of FDA approval for these movement disorders, there is growing body of evidence that BoNT provides benefit to patients with these hyperkinetic movement disorders and that BoNT is a safe treatment when used by clinicians skilled in the administration of the drug for these conditions.

Botulinum toxin in parkinsonism: The when, how, and which for botulinum toxin injections

The aim of this article is to provide a review of the use of injections of botulinum toxin in the management of selected symptoms and signs of Parkinson's disease and other forms of parkinsonism. Sialorrhea is defined as inability to control oral secretions, resulting in excessive saliva in the oropharynx. There is a high level of evidence for the treatment of sialorrhea in parkinsonism with injections of different forms of botulinum toxin type A as well as botulinum toxin type B. Tremor can be improved by the use of botulinum toxin injections but improved tremor control often leads to concomitant motor weakness, limiting its use. Levodopa induced dyskinesias are difficult to treat with botulinum toxin injections because of their variable frequency and direction. Apraxia of eyelid opening, a sign more commonly seen in progressive supranuclear palsy and other tauopathies, often improves after botulinum toxin injections. Recent data suggest that regardless of the underlying mechanism, pain in parkinsonism can be alleviated by botulinum toxin injections. Finally, freezing of gait, camptocormia and Pisa syndrome in parkinsonism almost invariably fail to respond to botulinum toxin injections.

Histological and immunohistochemical findings of the action of botulinum toxin in salivary gland: systematic review

The treatment of sialorrhea is necessary for the constant risks posed by hypersalivation. A new therapeutic option comes up with the application of botulinum toxin in salivary glands. However, little is known about its mechanism of action in glandular tissue. Based on the above, this work had the objective to systematically review the literature about the action of botulinum toxin on submandibular and parotid salivary glands tissues. Electronic search was performed in databases of great relevance for this study (PubMed, SciELO, HighWire, Crossref, Scopus, Science Direct, MEDLINE, OLDMEDLINE, Serials Database, NLM Catalog, LILACS and IBECS). Inclusion and exclusion criteria for articles were established, and a total number of 14 articles were selected and used. There are few publications that clarify how the salivary gland acini behave with application of botulinum toxin. Although, the immunohistochemical findings were consistent among authors, showing weak immunoreactivity in glands treated with botulinum toxin. Histometric data are divergent, requiring more detailed studies to answer the questions about the efficacy and safety of botulinum toxin in salivary glands.

Occurrence of Dysphagia Following Botulinum Toxin Injection in Parkinsonism-related Cervical Dystonia: A Retrospective Study

Background

The aim was to compare the occurrence of post-injection dysphagia in parkinsonism-related cervical dystonia (PRCD) versus cervical dystonia (CD) of other etiologies (non-PRCD). A secondary objective was to explore potential clinical differences between PRCD and non-PRCD and their respective responses to botulinum toxin (BoNT).

Methods

A cross-sectional chart review was carried out of patients treated for CD with Onabotulinumtoxin A at the University of Florida. We collected demographic information, dose of BoNT injected, patient-reported presence of dysphagia as a side effect, patient-perceived duration of benefit and efficacy according to the Clinical Global Impression Scale (CGIS).

Results

Of the 144 patients included, 24 patients were diagnosed with PRCD and 120 were diagnosed as non-PRCD. Data analysis showed no significant differences in number of weeks of benefit from BoNT (PRCD 9.1±3.7 versus non-PRCD 9.4±3.7 weeks, p = 0.830), BoNT dosage (PRCD 235.0±95.6 versus non-PRCD 263.7±101.3 units, p = 0.181), median CGIS score (median = 2 or “much improved” for both groups, p = 0.88), or the presence of dysphagia after BoNT (PRCD 17% versus non-PRCD 19 %, p = 0.753, n = 132). In a subgroup analysis of the non-PRCD group, patients who experienced dysphagia were older than those who did not (63.9±8.9 years versus 58.1±14.4 years, p = 0.02).

Discussion

Despite an increased baseline risk of dysphagia in patients with PRCD, BoNT appears to be equally safe and equally beneficial in PRCD and non-PRCD patients.

Submolecular recognition regions of the HN domain of the heavy chain of botulinum neurotoxin type A by T cells from toxin-treated cervical dystonia patients

We have recently reported the submolecular T-cell recognition profile of the C-terminal half (H_C, residues 855-1296) of the heavy (H) chain of botulinum neurotoxin type A (BoNT/A) with peripheral blood lymphocytes (PBL) from 25 BoNT-treated cervical dystonia (CD) patients. In the current study, we describe the mapping of the T-cell responses of the patients to the N-terminal half (H_N, residues 449-859) of the heavy chain by using 29 synthetic overlapping peptides encompassing the entire H_N domain of BoNT/A. The profiles of the T-cell responses to the peptides varied among the patients. Samples from 14 patients treated solely with BoNT/A recognized 1-9 (average 3.7) peptides/sample at Z>3.0 level. Three peptide regions representing residues 631-649, 659-677 and 743-761 were frequently recognized by 29-64% of the patients. In patients with positive anti-BoNT/A antibody responses the overall positive T cell responses to the H_N peptides were significantly increased compared to antibody-negative patients. Influence of treatment parameters on the T-cell recognition of the H_N peptides was also observed. The results were compared with those of previously identified H_C region.

Submolecular recognition of the C-terminal domain of the heavy chain of botulinum neurotoxin type A by T cells from toxin-treated cervical dystonia patients

We determined the T-cell proliferative responses of the peripheral blood lymphocytes (PBL) from 25 botulinum neurotoxin (BoNT)-treated patients to 31 overlapping synthetic peptides encompassing the C-terminal half (residues 855-1296) of BoNT/A heavy chain. Responses of PBL to HC peptides varied among patients. Samples from 14 patients treated solely with BoNT/A recognized 2-13 (average 6.4) peptides/sample at Z>3.0 level. Six peptide regions representing residues 855-873, 1023-1041, 1051-1069, 1093-1111, 1135-1153 and 1247-1265 were frequently recognized by 36-57% of these PBLs. Influence of treatment parameters on T-cell recognition of the peptides was also investigated.

Botulinum neurotoxin type A induces TLR2-mediated inflammatory responses in macrophages

Botulinum neurotoxin type A (BoNT/A) is the most potent protein toxin and causes fatal flaccid muscle paralysis by blocking neurotransmission. Application of BoNT/A has been extended to the fields of therapeutics and biodefense. Nevertheless, the global response of host immune cells to authentic BoNT/A has not been reported. Employing microarray analysis, we performed global transcriptional profiling of RAW264.7 cells, a murine alveolar macrophage cell line. We identified 70 genes that were modulated following 1 nM BoNT/A treatment. The altered genes were mainly involved in signal transduction, immunity and defense, protein metabolism and modification, neuronal activities, intracellular protein trafficking, and muscle contraction. Microarray data were validated with real-time RT-PCR for seven selected genes including tlr2, tnf, inos, ccl4, slpi, stx11, and irg1. Proinflammatory mediators such as nitric oxide (NO) and tumor necrosis factor alpha (TNFα) were induced in a dose-dependent manner in BoNT/A-stimulated RAW264.7 cells. Increased expression of these factors was inhibited by monoclonal anti-Toll-like receptor 2 (TLR2) and inhibitors specific to intracellular proteins such as c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase (ERK), and p38 mitogen-activated protein kinase (MAPK). BoNT/A also suppressed lipopolysaccharide-induced NO and TNFα production from RAW264.7 macrophages at the transcription level by blocking activation of JNK, ERK, and p38 MAPK. As confirmed by TLR2-/- knock out experiments, these results suggest that BoNT/A induces global gene expression changes in host immune cells and that host responses to BoNT/A proceed through a TLR2-dependent pathway, which is modulated by JNK, ERK, and p38 MAPK.

Patient considerations in the treatment of cervical dystonia: focus on botulinum toxin type A

Cervical dystonia is the most common form of focal dystonia characterized by involuntary muscle contractions causing abnormal movements and posturing of the head and neck and is associated with significant pain. Botulinum toxin is considered first-line therapy in the treatment of pain and abnormal head posturing associated with cervical dystonia. There are currently three botulinum toxin type A neurotoxins and one botulinum type B neurotoxin commercially available and US Food and Drug Administration (FDA) labeled for the treatment of cervical dystonia. This review will focus on the efficacy, safety, and therapeutic use of botulinum type A neurotoxins in the treatment of cervical dystonia. We conclude with a discussion of factors influencing toxin selection including therapeutic effect, duration of effect, side effect profile, cost, and physician preference.

Comparable Botulinum Toxin Outcomes between Primary and Secondary Blepharospasm: A Retrospective Analysis

Background

Blepharospasm is a focal cranial dystonia, which could be idiopathic in origin or secondary to an underlying disorder that commonly impairs quality of life. Botulinum toxin (BoNT) injections have become the treatment of choice; however, a less favorable response to BoNT is expected in secondary blepharospasm. No studies have been conducted comparing outcomes between blepharospasm cohorts. We therefore aim to compare BoNT outcomes in primary and secondary blepharospasm subjects.

Methods

A retrospective review of 64 blepharospasm subjects receiving BoNT therapy was conducted. Demographics, BoNT treatment schedules, duration of BoNT therapy, and side effects were recorded. Outcome measures were duration of benefit, peak-dose benefit recorded with the Clinical Global Impressions Scale (CGIS), and related side effects.

Results

No difference was found between the two cohorts regarding duration of benefit from treatment (primary 9.47 weeks vs. secondary 9.63 weeks, p = 0.88). Perceived peak-dose benefit was more commonly reported as “very much improved” in secondary patients, but this was not significant (p = 0.13). Higher BoNT dosages were required in both groups over time, with a mean increase of 20.5% in primary and 26.5% in secondary blepharospasm. Ptosis (8%) and diplopia (6%) were the most common reported side effects. Mean follow-up in years was similar between groups, 3.6 years for primary vs. 2.4 years for secondary blepharospasm (p = 0.17).

Discussion

BoNT injections were effective with comparable benefits seen in both primary and secondary blepharospasm populations. Clinicians should be aware of the similar benefit from BoNT reported in secondary blepharospasm patients. The average duration of benefit in this cohort was comparable with previous reports.

Efficacy of biofeedback therapy via a mini wireless device on sleep bruxism contrasted with occlusal splint: a pilot study

The putative causes of bruxism are multifactorial and there are no definite measures for bruxism management. The aim of this study was to evaluate the efficacy of biofeedback therapy on sleep bruxism, compared with occlusal splint. Twenty-four volunteers with sleep bruxism were divided into two groups: the GTB group that were treated with biofeedback therapy (n  = 12) and the GTO group that were treated with occlusal splint (n  = 12). A mini pressure sensor integrated with a monitoring circuit by use of a maxillary biofeedback splint was fabricated. To foster the relaxation of the masticatory muscles and the nervous system, the wireless device received signals from bruxism events and vibrations alerted the bruxer when the threshold was exceeded. Total episodes and average duration of bruxism events during 8 hours of sleep were analyzed with the monitoring program (TRMY1.0). After 6 and 12 weeks, the episodes (P  =  0.001) and duration (P < 0.05) in the GTB group declined dramatically. In contrast, there were no significant differences in the GTO group after the treatment (P > 0.05). Furthermore, the episodes had significant differences between the GTB group and the GTO group after the same period of treatment (P  =  0.000). The results suggest that biofeedback therapy may be an effective and convenient measure for mild bruxers, when compared with occlusal splint therapy. The mini wireless biofeedback method may be of value for the diagnosis and management of bruxism in the future.

The use of botulinum toxin in the treatment of sialorrhea in parkinsonian disorders

Drooling is a common symptom in parkinsonian disorders. Our aim was to assess the safety and effect of botulinum toxin when applied to parotid glands without ultrasound guidance for sialorrhea in parkinsonian disorders in a retrospective study with a long-term follow-up. We evaluated 53 patients (64.2% male and 35.8% female) with a mean age of 70.18 ± 9.25 years who were treated in our centre between 2007 and 2013. We analysed the mean dose, latency, effect duration, response and adverse effects of treating sialorrhea by injecting botulinum toxin type A (Botox) into the parotid glands without ultrasound guidance. A total of 41 patients with Parkinson's disease, 6 with progressive supranuclear palsy, 4 with multiple system atrophy and 2 with corticobasal degeneration were included. The mean duration of the disease at onset was 10.51 ± 6.81 years and the mean sialorrhea duration was 1.99 ± 1.55 years. The initial dose used for each parotid gland was 14.53 ± 3.95 units of Botox, with a mean dose of 22.17 ± 8.76 units. There was an improvement after treatment in 65.22% of patients with an average score of 6.85 ± 1.58 points on a scale from 0 to 10. The duration of the treatment effect was 4.38 ± 2.11 months, with a latency period of 10.06 ± 9.63 days. Adverse effects were mild and infrequent. Botulinum toxin is a safe and effective therapy for the treatment of sialorrhea in parkinsonian disorders and there is no requirement for ultrasound guidance. It has a rapid onset and lasting effect without requiring a high dosage.

Effectiveness of BoNT A in Parkinson's disease upper limb tremor management

OBJECTIVE

One the greatest challenges of BoNT A therapy for tremor lies in the complexity and variation of components involved in tremor movement, and the lack of objective measures to determine these components. This 3 month open-label single injection study aims to couple clinician best judgment with kinematics to improve effect of BoNT A (incobotulinumtoxinA) injection in 7 patients with upper limb Parkinson's disease (PD) tremor.

METHODS

Injection was guided with clinical and kinematic assessment of tremor using angular wrist position in 3 degrees of freedom: flexion/extension, pronation/supination, and radial/ulnar deviation. Overall tremor severity and change were measured by linear finger acceleration.

RESULTS

Kinematic data from static and functional tasks demonstrate no improvement at one month post-injection, but significant improvement at two and three months. Clinical scales across UPDRS Items 20 (1, 2, 3 months post) and 21 (2 months), and spiral drawings (3 months) showed significant improvement from baseline, while line drawings did not.

CONCLUSIONS

This study suggests injection of BoNT A as a viable focal management option for upper limb PD tremor. In addition to clinical judgment, objective quantification of tremor dynamics by kinematics may be a feasible assessment and guidance tool which can be used to optimize injection conditions for focal tremor therapy. Kinematic analysis of tremor across a variety of joints in all degrees of movement may provide important insight into tremor dynamics, allowing optimized, targeted focal therapy.

Behavioral and structural effects of unilateral intrastriatal injections of botulinum neurotoxin a in the rat model of Parkinson's disease

Botulinum neurotoxin (BoNT) inhibits the release of acetylcholine from presynaptic vesicles through its proteinase activity cleaving the SNARE complex. Parkinson's disease (PD) is associated with locally increased cholinergic activity in the striatum. Therefore, the present study investigates the effect of unilateral intrastriatal BoNT-A injection in naïve rats on striatal morphology; i.e., the total number of Nissl-stained neurons and the volume of caudate-putamen (CPu) were estimated. Furthermore, stainings for markers of gliosis (glial fibrillary acidic protein) and microglia (Iba1) were performed. In addition, the potential beneficial effects of a unilateral intrastriatal injection of BoNT-A on motor activity in the rat model of hemi-PD were evaluated. Hemi-PD was induced by unilateral injection of 6-hydroxydopamine (6-OHDA) into the right medial forebrain bundle. Six weeks later, rats received an ipsilateral intrastriatal injection of BoNT-A. Behaviorally, motor performance was tested. The total number of CPu neurons and the striatal volume were not significantly different between the BoNT-A-injected right and the intact left hemispheres of naïve rats. In hemi-PD rats, intrastriatal BoNT-A abolished apomorphine-induced rotations, increased amphetamine-induced rotations, and tended to improve left forelimb usage. Forced motor function in the accelerod test was not significantly changed by BoNT-A, and open field activity was also unaltered compared with sham treatment. Thus, intrastriatal BoNT-A affects spontaneous motor activity of hemi-PD rats to a minor degree compared with drug-induced motor function. In the future, tests assessing the cognitive and emotional performance should be performed to ascertain finally the potential therapeutic usefulness of intrastriatal BoNT-A for PD.

Sympathetic skin responses from the scalp evoked by electrical stimulation in seborrheic dermatitis

Although the role of autonomic nervous system in seborrheic dermatitis (SD) is still unclear, seborrhea is sometimes accepted as a sign of autonomic dysfunction in several nervous system diseases. Therefore, we aimed to investigate the sympathetic nervous system (SNS) activity in SD by recording sympathetic skin responses (SSR) from the scalp (S-SSR). Thirty-one control subjects and 22 SD patients were studied by evoking right and left S-SSR with electrical stimulation of the right median nerve at the wrist. Mean latencies and maximum amplitudes were calculated for both sides in each group. In seven out of 31 control subjects and in 13 out of 22 patients, the S-SSR could not be elicited on either side. There were four subjects with unilateral response in the patient group. There were significantly more non-responders among the patients with SD (P < 0.000). This study suggests that in SD, the autonomic nervous system may be involved. The S-SSR is a new site for recording SSR. The responses are relatively symmetrical and can be evoked easily by electrical stimulation, and may be used to evaluate the SNS function in SD patients and also in healthy subjects.

Long-term efficacy and safety of botulinum toxin injections in dystonia

Local chemodenervation with botulinum toxin (BoNT) injections to relax abnormally contracting muscles has been shown to be an effective and well-tolerated treatment in a variety of movement disorders and other neurological and non-neurological disorders. Despite almost 30 years of therapeutic use, there are only few studies of patients treated with BoNT injections over long period of time. These published data clearly support the conclusion that BoNT not only provides safe and effective symptomatic relief of dystonia but also long-term benefit and possibly even favorably modifying the natural history of this disease. The adverse events associated with chronic, periodic exposure to BoNT injections are generally minor and self-limiting. With the chronic use of BoNT and an expanding list of therapeutic indications, there is a need to carefully examine the existing data on the long-term efficacy and safety of BoNT. In this review we will highlight some of the aspects of long-term effects of BoNT, including efficacy, safety, and immunogenicity.

Emerging opportunities for serotypes of botulinum neurotoxins

Background: Two decades ago, botulinum neurotoxin (BoNT) type A was introduced to the commercial market. Subsequently, the toxin was approved by the FDA to address several neurological syndromes, involving muscle, nerve, and gland hyperactivity. These syndromes have typically been associated with abnormalities in cholinergic transmission. Despite the multiplicity of botulinal serotypes (designated as types A through G), therapeutic preparations are currently only available for BoNT types A and B. However, other BoNT serotypes are under study for possible clinical use and new clinical indications; Objective: To review the current research on botulinum neurotoxin serotypes A-G, and to analyze potential applications within basic science and clinical settings; Conclusions: The increasing understanding of botulinal neurotoxin pathophysiology, including the neurotoxin’s effects on specific neuronal populations, will help us in tailoring treatments for specific diagnoses, symptoms and patients. Scientists and clinicians should be aware of the full range of available data involving neurotoxin subtypes A-G.

Management of pain in Parkinson's disease

Pain is a common symptom in Parkinson's disease (PD) and accounts for substantial morbidity in up to 80 % of patients. Despite contributing to disease-related discomfort and disability, pain in PD frequently goes underacknowledged and undertreated in clinical practice. Although the exact underlying neurophysiology is unclear, there is increasing understanding of the role of the basal ganglia in somatosensory processing, as well as involvement of additional brainstem structures and non-dopaminergic pathways; appreciation of these mechanisms has implications for treatment strategies. Categorizing painful symptoms based on their clinical description into musculoskeletal, dystonic, radicular-peripheral neuropathic and central pain categories provides a useful framework for management. Importantly, these symptoms should be evaluated in relation to motor symptoms and dopaminergic therapy. A multi-disciplinary approach is recommended as follows: physical therapy, liaison with pain management and consultations to rheumatological, orthopaedic and neurosurgical services should be considered.

Presynaptic neurotoxins: an expanding array of natural and modified molecules

The process of neurotransmitter release from nerve terminals is a target for a wide array of presynaptic toxins produced by various species, from humble bacteria to arthropods to vertebrate animals. Unlike other toxins, most presynaptic neurotoxins do not kill cells but simply inhibit or activate synaptic transmission. In this review, we describe two types of presynaptic neurotoxins: clostridial toxins and latrotoxins, which are, respectively, the most potent blockers and stimulators of neurotransmitter release. These toxins have been instrumental in defining presynaptic functions and are now widely used in research and medicine. Here, we would like to analyse the diversity of these toxins and demonstrate how the knowledge of their structures and mechanisms of action can help us to design better tools for research and medical applications. We will look at natural and synthetic variations of these exquisite molecular machines, highlighting recent advances in our understanding of presynaptic toxins and questions that remain to be answered. If we can decipher how a given biomolecule is modified by nature to target different species, we will be able to design new variants that carry only desired characteristics to achieve specific therapeutic, agricultural or research goals. Indeed, a number of research groups have already initiated a quest to harness the power of natural toxins with the aim of making them more specifically targeted and safer for future research and medical applications.

Application of botulinum toxin to clinical therapy: advances and cautions

The therapeutic use of botulinum toxin Type A has followed a novel and unanticipated pathway of applications, from its initial application by Scott to paralyze the extraocular muscles of the eyes to correct strabismus. In the late 1970s, Scott formed a company, called Oculinum Inc, to make botulinum toxin Type A available for this ophthalmic application. From this modest and limited beginning, it has found use for treatment of a plethora of cosmetic, neuromuscular, and skeletal disabilities, including cervical dystonia, blepharospasm, and temporary improvement in the appearance of moderate to severe glabellar lines. Botulinum toxin Type A is now being used as therapy in voiding disorders, migraine and tension-type headache, writer's cramp, and laryngeal muscle hyperactivity syndromes. It has reduced the spasm and pain associated with perianal fissures. It has found application in the reduction of glandular function in severe primary axillary hyperhidrosis and sialorrhea. Additional applications are being studied in the area of pain management based on its apparent ability to inhibit neuropeptide release from nociceptors.