Trial Design for Mixed Urinary Incontinence: Midurethral Sling Versus Botulinum Toxin A

IMPORTANCE

Mixed urinary incontinence (MUI) is common and can be challenging to manage.

OBJECTIVES

We present the protocol design and rationale of a trial comparing the efficacy of 2 procedures for the treatment of women with MUI refractory to oral treatment. The Midurethral sling versus Botulinum toxin A ( MUSA) trial compares the efficacy of intradetrusor injection of 100 U of onabotulinimtoxinA (an office-based procedure directed at the urgency component) versus midurethral sling (MUS) placement (a surgical procedure directed at the stress component).

STUDY DESIGN

The MUSA is a multicenter, randomized trial of women with MUI electing to undergo procedural treatment for MUI at 7 clinical centers in the NICHD Pelvic Floor Disorders Network. Participants are randomized to either onabotulinumtoxinA 100 U or MUS. OnabotulinimtoxinA recipients may receive an additional injection between 3 and 6 months. Participants may receive additional treatment (including crossover to the alternative study intervention) between 6 and 12 months. The primary outcome is change from baseline in Urogenital Distress Inventory (UDI) at 6 months. Secondary outcomes include change in UDI at 3 and 12 months, irritative and stress subscores of the UDI, urinary incontinence episodes, predictors of poor treatment response, quality of life and global impression outcomes, adverse events, use of additional treatments, and cost effectiveness.

RESULTS

Recruitment and randomization of 150 participants is complete and participants are currently in the follow-up phase.

CONCLUSIONS

This trial will provide information to guide care for women with MUI refractory to oral treatment who seek surgical treatment with either onabotulinumtoxinA or MUS.

Facial Apocrine Chromhidrosis: A Case Report

Apocrine chromhidrosis is a rare disease that is characterized by colored sweating. Here, we present a rare case that was successfully treated for this condition. A 32-year-old woman presented with dark blue discharge from her cheeks. She was diagnosed with apocrine chromhidrosis and was treated successfully with botulinum toxin type A.

Use of Botulinum Toxin A to Manage Hamstring-Induced Flexion Contracture Following Total Knee Arthroplasty: A Case Series

Introduction Flexion contractures following total knee arthroplasty (TKA) greatly affect patient function and satisfaction. Botulinum toxin A (BTX) has been described in the literature as a means of addressing post-operative flexion contractures due to hamstring muscle rigidity. Methods We retrospectively report a case series of eight patients with range of motion (ROM) who developed a flexion contracture status post-TKA and were managed with the use of physical therapy, diagnostic hamstring lidocaine injections, and therapeutic hamstring BTX injections. Results All patients had an improvement in extension ROM following diagnostic lidocaine hamstring injections and were therefore considered candidates for therapeutic hamstring BTX injections. Prior to therapeutic hamstring BTX injections, patients had an average flexion contracture of 19° (range: 15°-22°). All patients had an improvement in extension ROM two to four weeks following the therapeutic hamstring BTX injection, with an average improvement in ROM of 7° (range: 2°-19°). At the final follow-up, all patients continued to sustain an improvement in extension ROM with an average deficit of 9° (range: 0°-17°). Conclusion Our case series highlights the use of diagnostic hamstring lidocaine injections to confirm hamstring rigidity as an etiology for flexion contracture following TKA. In addition, we showed a persistent improvement in flexion contracture for all patients after hamstring BTX injections. Therefore, when the appropriate patient is selected, BTX may provide an additional treatment option for a flexion contracture following TKA.

Clinical presentation of patients with lower limb spasticity undergoing routine treatment with botulinum toxin: baseline findings from an international observational study

OBJECTIVE

Describe how people with lower limb spasticity present for treatment in routine clinical practice.

METHODS

Prospective, observational study (Clinicaltrials.gov: NCT04050527) of ambulatory adult patients (≥ 18 years) with unilateral lower limb spasticity (able to take ≥ 5 steps with or without assistance) presenting for routine spasticity management, including treatment with abobotulinumtoxinA.

RESULTS

The study population included 430 adults with lower limb spasticity. Despite their relatively young age (mean ± standard deviation 53.7 ± 13.9 years), only 20% of patients were employed. Most patients had an acquired brain injury due to cerebrovascular disease; 84.1% reported having concomitant upper limb spasticity. Using the Leg Activity Measure, most patients reported no or only mild difficulties in performing hygiene/positioning tasks, while 80.7% had at least mild difficulty with indoor ambulation and 90.5% had at least mild difficulty with walking outdoors. Sensory, communication and/or cognitive impairments were also common. At the first treatment cycle, 50.7% of patients set active function primary goals, including locomotion transferring or standing.

CONCLUSION

These observations highlight the complexity of presentation that must be considered when setting treatment goals for lower limb spasticity and emphasize the types of impairment and activity (functional) limitations that treating teams may expect to encounter in their patients and should cover in their initial and follow-up assessments.

Cyclic Esotropia Managed With Botulinum A Toxin Injections: A Report of Four Cases and Literature Review

Cyclic strabismus is a rare entity and is unique in that patients follow variable but reliable time cycles where they alternate between orthotropia or "straight" eyes and strabismus, most commonly in the form of esotropia. Despite many theories on the underlying etiology and unique features of this diagnosis, none have been proven and its pathophysiology remains unknown. Four cases of cyclic esotropia diagnosed by pediatric ophthalmologists have been included in this report. The ages of the patients ranged from 10 months to eight years. The time duration from the onset of deviation to presentation to an ophthalmologist ranged from 1-52 weeks with three of the four patients presenting in the cyclic phase and the fourth presenting with a constant esotropia after a clear history and photographically documented cyclic esotropia for the preceding two months. All four patients were followed for periods ranging from one to four months to confirm their diagnosis or obtain multiple readings of the maximal deviation on the strabismic days before any intervention. The angle of esotropia when present ranged from 25 to 35 prism diopters and the cycle duration was 48 hours for all four cases (24 hours of esotropia followed by 24 hours of orthotropia). All patients were treated with botulinum toxin A injections to both medial recti, which resulted in an end to their cyclic deviation with excellent alignment obtained during follow-up periods ranging from 12-36 months for all cases. Cyclic esotropia is an elusive diagnosis that can be easily overlooked. When identified, classical treatment is usually extraocular muscle surgery targeting the largest angle of deviation. Many non-surgical treatments have been tried to no avail. However, in recent times, botulinum toxin A has been seen as a viable alternative.

A study of combination unilateral subcutaneous botulinum toxin a treatment for androgenetic alopecia

OBJECTIVE

To observe the efficacy of unilateral subcutaneous injection of botulinum toxin A combined with finasteride and minoxidil in the treatment of androgenic alopecia.

METHODS

Thirty-seven patients with androgenic alopecia were treated with finasteride and minoxidil as standard therapy and were randomly assigned to subcutaneous injections of botulinum toxin A in one hemisphere of the head at the beginning of a 6-month treatment. Before treatment, 3 months after treatment, and 6 months after treatment, the patient's head hair growth was photographed and evaluated.

RESULTS

After 3 and 6 months of treatment, hair density of the treated androgenic alopecia patients was higher than before treatment (p < 0.05), and the hair density of the botulinum toxin A injection side was higher than that of the control side (p < 0.05). After 6 months of treatment, the response rate of botulinum toxin A combined with finasteride and minoxidil was 77.5%, with no significant side effects observed.

CONCLUSION

Finasteride and minoxidil have a significant effect on androgenic alopecia, and the effect is further increased after combined with botulinum toxin A subcutaneous injection.

Injection Botulinum Toxin A in Treatment of Resistant Chronic Low Back Pain: A Prospective Open-Label Study

Objective

The aim of this study was to evaluate the effect of botulinum toxin A (BTX-A) injection on patients with chronic low back pain (CLBP).

Design

In this open-label prospective study, patients with CLBP who satisfied inclusion and exclusion criteria received 100 units of BTX-A injection. Patients were followed up at four weeks, three months, and six months after injection. Pain and function were assessed with visual analog scale (VAS), Roland-Morris Disability Scale (RMS), and Oswestry Disability Index (ODI) at baseline and subsequent visits.

Results

A total of 19 participants with a mean age of 41.11 years completed the study. Compared to baseline, a significant improvement in all scores was observed that persisted up to six months post-injection (P<0.001). Only two patients reported transient injection site pain that improved over two to three days without any treatment.

Conclusion

BTX-A injection is safe and improves pain and function in patients with resistant CLBP. The effects are more beneficial when the population is more homogenous in diagnosis and devoid of negative predictors for the outcome.

Closing Difficult Laparostomies With the Aid of Botulinum Toxin A: An Audit of 12 Cases

Background

Obtaining primary fascial closure following laparostomy can be difficult; especially with fascial retraction or large pre-existing fascial defects. Various techniques have been described in the literature which attempt to improve reapproximation rates. Most techniques described comprise the use of adjuncts including Bogota Bags, negative pressure dressings, anchor devices and various types of mesh. While most techniques achieve primary closure, less achieve primary fascial closure. Botulinum toxin A (BTA) has proven a beneficial adjunct in repairing large ventral herniae. While there is limited research in the use of BTA in the acute setting of laparostomy closure its benefits in elective repair may prove transferrable with the appropriate protocols.

Method

This retrospective study reviewed 12 cases where BTA was used as an adjunct to close laparostomy. It compared primary fascial closure rates to historical controls at the same institution. 

Results

Seven males and five females. Median age 63.5 years. Median BMI 32.95. Median days from BTA injection to primary fascial closure 9.5. Median 18 days from primary operation to primary fascial closure. 83% of patients achieved primary fascial closure with the rest achieving partial closure with the residual defect bridged with biological mesh. At the time of review, there was only one resulting ventral hernia in a patient with a BMI of 51.7 at the time of surgery.

Conclusion

While BTA does not guarantee primary fascial closure in laparostomy this study would indicate it improves primary fascial closure rates and can be added to any other existing method for managing the open abdomen. As BTA can be injected via the open abdomen or with ultrasound guidance it can be performed by any appropriately trained surgeon, anaesthetist or radiologist making its use widely achievable. Retrospectively registered.

Evaluation of the efficiency and safety of botulinum toxin A injection on improving facial scars: A protocol for systematic review and meta-analysis

BACKGROUND

Botulinum toxin A injection is an established method of treatment. Clinical practitioners use it widely in their practice to prevent the occurrence of facial scars. However, the effectiveness and safeness of has not been comprehensively established. The objective of the current systematic review is to evaluate the efficacy and safety of using botulinum toxin A injection to improve facial scars.

METHODS AND ANALYSIS

This systematic review involves browsing a number of electronic databases to search for related articles. The search will include databases in both English (PubMed, EMBASE, Web of Science, Spocus, and Cochrane Central Register of Controlled Trials) and Chinese (WanFang database, China Nation Knowledge Infrastructure, and VIP database), the periods of searching will be from inception till the 15th of September 2020. Completing the search in databases allows to consider randomized controlled studies that compares botulinum toxin A interventions to any comparison interventions in those who have facial scars. The review will be inclusive of papers in both languages, English and Chinese. The independent screening of studies for eligibility is conducted by 2 independent authors. Discussion was used to resolve discrepancies between the authors. The Cochrane Risk of Bias Tool V.2.0 is adopted for evaluating the methodological quality of each study. Data extraction was performed by 2 independent authors. For dichotomous outcomes, the were expressed as relative risk (RR) with 95% confidence intervals (CI). For continuous outcomes the results were expressed as the mean difference (MD) or standardized mean difference (SMD) with 95% CI. The statistical analysis of the present study is carried out in RevMan 5.3 software.

RESULTS

This study will output a comprehensive synthesis of existing evidence in relation to botulinum toxin A. Moreover, the results will also provide an interpretation of the effectiveness and safety of botulinum toxin A.

CONCLUSION

The present review contributes to the existing body of knowledge by adding more evidence to evaluate if botulinum toxin A is effective and safe to be used as an intervention for improving facial scars.

OSF REGISTRATION NUMBER

DOI 10.17605/OSF.IO/94TXP (https://osf.io/94TXP/).

Calcitonin gene-related peptide antagonists versus botulinum toxin A for the preventive treatment of chronic migraine protocol of a systematic review and network meta-analysis: A protocol for systematic review

BACKGROUND

Although calcitonin gene-related peptide antagonists and botulinum toxin A have been shown efficacy in preventing chronic migraine, there is no direct evidence for their comparative effectiveness. This review is to assess the comparative effectiveness and safety of calcitonin gene-related peptide antagonists and botulinum toxin A for chronic migraine using network meta-analysis.

METHODS

OVID MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials will be searched for relevant randomized controlled trials from their inception to December 2019 without language restriction. We will include trials testing the effectiveness of calcitonin gene-related peptide antagonists or botulinum toxin A in patients with chronic migraine. The outcomes are mean change from baseline in the number of headache days, the mean change from baseline in the number of migraine days, the mean change from baseline in headache hours, responder rate, and adverse events rate. The methodological quality of the included randomized controlled trials will be evaluated using Cochrane Collaboration's risk of bias tool. Standardized mean difference will be used to synthesize continuous variables and risk ratio will be used to synthesize categorical variables. Pairwise and network meta-analysis will be performed using a frequentist method in netmeta package (R 3.5.0, www.r-project.org).

RESULTS

Ethical approval and informed consent are not required for this systematic review. The results will be submitted to a peer-reviewed journal and conference abstracts for publication.

CONCLUSION

The result of the review will systematically provide suggestions for clinicians, patients, and policy makers in the treatment of chronic migraine.PROSPERO registration number: CRD42018089201.

Clinical effectiveness of ultrasound guided subacromial-subdeltoid bursa injection of botulinum toxin type A in hemiplegic shoulder pain: A retrospective cohort study

Hemiplegic shoulder pain (HSP), which occurs in most patients with hemiplegia, causes considerable distress and worsens outcomes in rehabilitation. Although they have received the treatments such as anti-inflammatory drugs or physical therapy, many of the individuals remain suffering from shoulder pain 6 months after acute stroke event. In this retrospective study, we evaluated the effectiveness of ultrasound guided subacromial-subdeltoid (SASD) bursa injections with botulinum toxin type A (BoNT/A) compared to steroids for refractory HSP.The data were collected retrospectively by reviewing the patient's medical records and pain questionnaires in our rehabilitation center. In total, 38 patients who received ultrasound guided SASD bursa injection (BoNT/A group, n = 18; corticosteroid group, n = 20) were included. The pain visual analog scale (VAS) score at rest and during arm passive abduction, Fugl-Meyer score of upper limbs (F-M score) were evaluated before, 2, 4, 8, and 12 weeks after injection.Both 2 groups obtained a significant improvement of VAS score at rest or during arms passive abduction compared to baseline score (within group compare, P < .05). There were no significant differences of pain score improvement between two groups at week 2, 4, 8, and 12 after injection either at rest or during passive arm abduction (between 2 groups compare, P > .05). There were also no differences in results of the post treatment F-M score between 2 groups (between 2 groups compare, P > .05). Similarly, during the follow-up period no collateral effects were reported after BoNT/A injection.SASD bursa BoNT/A injection can substantially reduce the pain as corticosteroid in patients with HSP. BoNT/A injection could be a useful strategy for replacing steroids as a treatment for refractory HSP especially in the patients who cannot tolerate the steroids injection.

Treatment of focal dystonia involving multiple muscles with a single injection of botulinum toxin A to 1 muscle: A case report

RATIONALE

Botulinum toxin A (BTX-A) injection is effective in treating focal dystonia. However, there are no prior reports regarding the treatment of progressive focal dystonia by a single BTX-A injection that affect a distant muscle.

PATIENT CONCERNS

A 19-year-old male was referred to the rehabilitation clinic with a complaint of involuntary movement in his left big toe. The involuntary movement pattern was initially observed in the abduction direction only; however, it progressed to irregular mixed patterns in the flexion and abduction directions.

DIAGNOSES

In needle electromyography, abnormal dystonic patterns were observed in the left abductor hallucis (AH), flexor hallucis longus, and flexor hallucis brevis muscles.

INTERVENTIONS AND OUTCOMES

These symptoms resolved with a single BTX-A injection to the AH muscle.

LESSONS

In this case, a single BTX-A injection to 1 muscle for treating progressive focal dystonia was effective on a distant noninjected muscle.

A randomized controlled trial of botulinum toxin A for treating neuropathic pain in patients with spinal cord injury

BACKGROUND

To assess the effect of botulinum toxin A (BTA) for treating neuropathic pain in patients with spinal cord injury (SCI).

METHODS

A total of 44 patients with SCI with neuropathic pain were randomly divided into the intervention group and the placebo group, each group 21 patients. The subjects in the intervention group received BTA (200 U subcutaneous injection, once daily) at the painful area, whereas those in the placebo group were administered a saline placebo. This study was conducted from December 2014 to November 2016. The primary outcome was measured using the visual analog scale (VAS). The secondary outcomes were measured using the short-form McGill Pain Questionnaire (SF-MPQ), and World Health Organization quality of life (WHOQOL-BREF) questionnaire. All outcome measurements were performed before and after 4 and 8 weeks of intervention.

RESULTS

Forty-one participants completed the study. The intervention with BTA showed greater efficacy than placebo in decreasing the VAS score after week 4 and week 8 of treatment. Significant differences in the SF-MPQ and WHOQOL-BREF were also found between the 2 groups.

CONCLUSION

The results of this study demonstrated that BTA might decrease intractable neuropathic pain for patients with SCI.

[Effect of botulinum toxin A injection in the treatment of gastrocnemius spasticity in children aged 9-36 months with cerebral palsy: a prospective study]

OBJECTIVE

To investigate the long-term clinical efficacy and adverse effects of botulinum toxin-A (BTX-A) injection in the treatment of gastrocnemius spasticity in children aged 9-36 months with cerebral palsy.

METHODS

Eighty children aged 9-36 months with cerebral palsy and gastrocnemius spasticity were selected and randomly divided into a BTX-A injection group and a conventional treatment group (n=40 each). The children in the BTX-A injection group received injections of BTX-A guided by color Doppler ultrasound and 4 courses of rehabilitation training after injection. Those in the conventional treatment group received 4 courses of the same rehabilitation training alone. Before treatment and at 1, 2, 3, and 6 months after treatment, the modified Tardieu scale (MTS) was applied to assess the degree of gastrocnemius spasticity, the values in the passive state measured by surface electromyography (sEMG) were applied to evaluate muscle tension, and the Gross Motor Function Measure (GMFM) was used to evaluate gross motor function.

RESULTS

Compared with the conventional treatment group, the BTX-A injection group had significantly greater reductions in MTS score and the values in the passive state measured by sEMG (P<0.05), as well as significantly greater increases in joint angles R1 and R2 in MTS and gross motor score in GMFM (P<0.05). No serious adverse reactions related to BTX-A injection were found.

CONCLUSIONS

BTX-A injection is effective and safe in the treatment of gastrocnemius spasticity in children aged 9-36 months with cerebral palsy.

Muscle loading is necessary for the formation of a functional tendon enthesis

Muscle forces are essential for skeletal patterning during development. Eliminating muscle forces, e.g., through paralysis, leads to bone and joint deformities. Botulinum toxin (BtxA)-induced paralysis of mouse rotator cuffs throughout postnatal development closely mimics neonatal brachial plexus palsy, a significant clinical condition in infants. In these mice, the tendon-to-bone attachment (i.e., the tendon enthesis) presents defects in mineral accumulation and fibrocartilage formation, presumably impairing the function of the tissue. The objective of the current study was to investigate the functional consequences of muscle unloading using BtxA on the developing supraspinatus tendon enthesis. We found that the maximum endurable load and stiffness of the supraspinatus tendon attachment decreased after four and eight weeks of post-natal BtxA-muscle unloading relative to controls. Tendon cross-sectional area was not significantly reduced by BtxA-unloading, while, strength, modulus, and toughness were decreased in the BtxA-unloaded group compared to controls, indicating a decrease in tissue quality. Polarized-light microscopy and Raman microprobe analysis were used to determine collagen fiber alignment and mineral characteristics, respectively, in the tendon enthesis that might contribute to the reduced biomechanical performance in BtxA-unloaded shoulders. Collagen fiber alignment was significantly reduced in BtxA-unloaded shoulders. The mineral-to-matrix ratio in mineralized fibrocartilage was not affected by loading. However, the crystallographic atomic order of the hydroxylapatite phase (a measure of crystallinity) was reduced and the amount of carbonate (substituting for phosphate) in the hydroxylapatite crystals was increased. Taken together, these micrometer-scale structural and compositional changes partly explain the observed decreases in the mechanical functionality of the tendon enthesis in the absence of muscle loading.

Botulinum toxin effects on gasatrocnemius strength and plantar pressure in diabetics with peripheral neuropathy and forefoot ulceration

BACKGROUND

High forefoot plantar pressure is associated with plantar ulcers in people with diabetes and peripheral neuropathy. The purpose of this pilot study was to determine the safety and efficacy of botulinum toxin A injected into the gastrocnemius-soleus muscles to reduce muscle strength and plantar pressure.

METHODS

This double blind, randomized clinical trial studied 17 people with diabetes mellitus, peripheral neuropathy and a forefoot plantar ulcer. Subjects were randomized into one of three groups receiving gastrocnemius-soleus muscle injections on the involved side with; 1) Saline (n = 5, weight =99± 21 kg), 2) 200-units of Botox® (n = 7, weight = 101± 5 kg), or 3) 300-units of Botox® (n = 5, weight = 129± 22 kg). Botox® dose was converted to units/kg, the majority received between 1.9 and 2.4 units/kg (n = 11) and one 3.2 units/kg. Plantarflexor peak torque and forefoot peak plantar pressure were quantified prior and 2 weeks post-injection.

RESULTS

There were no complications from the injections. Plantarflexor peak torque on the involved side increased in the placebo and 300 groups (3± 4 Nm and 6± 10 Nm, respectively) and decreased -8± 11 Nm in the 200 group. There was no relationship between units/kg of Botox® for each subject and change in plantarflexor peak torque. Forefoot peak plantar pressure did not change in the placebo and 300 groups (0± 11 and 0± 5 N/cm(2), respectively) and decreased -4± 16 N/cm2 (4%) for the 200 group.

CONCLUSION

There were no adverse events associated with the Botox® injections. This study was unable to determine the dose to consistently reduce plantarflexor strength and forefoot plantar pressure. Additional research is needed to investigate diabetes mellitus specific physiological changes and their impact of BoNT-A effectiveness in order to guide appropriate dosing.

Botulinum toxin use as an adjunctive modality in a patient with multiple flexor tendon ruptures

Botulinum toxin A has been described in treatment protocols for several disease processes, from primary axillary hyperhydorosis to esophageal dysfunction. It is best known for its use in plastic and dermatological practices. Botulinum toxin has a straightforward mechanism of action. The toxin inhibits acetylcholine release at the neuromuscular junction causing a chemical denervation, which ceases contractions of the muscle. With its minimal side effect profile, botulinum toxin should be considered when muscle spasm is a detriment. This case involves an injury to the hand of a patient with a history of intermittent diffuse muscle spasms. Subsequently, due to the patient's previous upper extremity muscle spasms, repeated flexor tendon repair ruptures of the index finger occurred until botulinum toxin was administered to the offending muscle. The patient has not required any additional surgical interventions for the repaired tendon and is now actively flexing all digits. This case report demonstrates how botulinum toxin can be used in a clinical scenario when decreased muscle activity is desired to promote tendon healing.

Botulinum toxin A during pregnancy: a survey of treating physicians

Botulinum toxin A (btxA) is widely used for cosmetic purposes, headaches, dystonia, spasticity, pain and other on and off label uses. Despite the widespread use of btxA in women of childbearing potential, there are few data on the effects of this drug on pregnant women and the fetus. The goal of this study was to survey physicians who use btxA, to determine their experience with pregnant women. We surveyed 900 physicians who used commercially available btxA. The questionnaire asked treating physicians if they had knowingly or unknowingly injected pregnant women and what was the outcome of each pregnancy. In total, 396 physicians (44%) returned questionnaires, of whom only 12 physicians reported injecting pregnant women with btxA. Sixteen pregnant women were injected, mostly in the first trimester, and only one patient, who had prior spontaneous abortions, suffered a miscarriage. Another woman had a therapeutic abortion. All other pregnancies went to term and there were no fetal malformations. Based on this limited survey of treating physicians in the USA, btxA appears to be relatively safe for both expectant mother and fetus. We need further data, however, and we would recommend that physicians and patients carefully consider the risks and benefits before using btxA in pregnant women.

Botulinum toxin A treatment in patients suffering from blepharospasm and dry eye

BACKGROUND

Many patients with essential blepharospasm also show dry eye signs and symptoms. Botulinum toxin A is an effective treatment for reducing spasms in these patients. In this investigation, the effect of botulinum toxin A injections on tear function and on the morphology of the ocular surface in patients suffering from blepharospasm in combination with a dry eye syndrome was investigated.

METHODS

Botulinum toxin A injections were applied to 16 patients with blepharospasm. All patients complained of dry eye symptoms and had reduced tear break up time values. A subjective questionnaire and ocular examinations including tear break up time, Schirmer test without local anaesthesia, and rose bengal staining were evaluated before, 1 week, 1 month, and 3 months after injection. Impression cytology was performed before, 1 month, and 3 months after botulinum toxin A treatment.

RESULTS

Although all patients were relieved of blepharospasm after botulinum toxin injections, only three noticed an improvement in dry eye symptoms. Eight patients noticed no difference and five complained of worsening. Tear break up time was found to be increased 1 week and 1 month after injections. Schirmer test measurements were reduced up to 3 months. Rose bengal staining slightly increased 1 week after injections. Impression cytology showed no definite change in conjunctival cell morphology 1 month and 3 months after botulinum toxin A injections.

CONCLUSION

In the patients presented here suffering from blepharospasm and dry eye, botulinum toxin A injections were effective in relieving blepharospasm but were not successful in treating dry eye syndrome.

Early and selective loss of neuromuscular synapse subtypes with low sprouting competence in motoneuron diseases

The addition or loss of synapses in response to changes in activity, disease, or aging is a major aspect of nervous system plasticity in the adult. The mechanisms that affect the turnover and maintenance of synapses in the adult are poorly understood and are difficult to investigate in the brain. Here, we exploited a unique anatomical arrangement in the neuromuscular system to determine whether subtypes of synapses can differ in anatomical plasticity and vulnerability. In three genetic mouse models of motoneuron disease of diverse origin and severity, we observed a gradual and selective loss of synaptic connections that begun long before the onset of clinical deficits and correlated with the timing of disease progression. A subgroup of fast-type (fast-fatiguable) neuromuscular synapses was highly vulnerable and was lost very early on. In contrast, slow-type synapses resisted up to the terminal phase of the disease. Muscle-specific differences were also evident. Similar selective losses were detected in aged mice. These selective vulnerability properties of synapses coincided with hitherto unrecognized major differences in stimulus-induced anatomical plasticity that could also be revealed in healthy mice. Using paralysis and/or growth-associated protein 43 overexpression to induce synaptic sprouting, we found that slow-type, disease-resistant synapses were particularly plastic. In contrast, fast-type synapses with the highest vulnerability failed to exhibit any stimulus-induced change. The results reveal pronounced subtype specificity in the anatomical plasticity and susceptibility to loss of neuromuscular synapses and suggest that degenerative motoneuron diseases involve a common early pathway of selective and progressive synaptic weakening also associated with aging.