The role of botulinum toxin in the management of sixth nerve palsy

Botulinum Toxin Injection for the Treatment of Third, Fourth, and Sixth Nerve Palsy: A Meta-Analysis

The efficacy of botulinum toxin injection for the treatment of third, fourth, and sixth nerve palsy was evaluated. PubMed, Scopus, EMBASE, Web of Science, and Google Scholar databases were searched. Data about the duration of palsy (acute vs chronic), cause of the palsy, type of toxin used, mean dose, and other background characteristics were collected. Outcome variables were success rate (defined by alleviation of diplopia or reduction in eye deviation) and standardized mean difference of prism diopter and abduction deficit before and after injection. The Joanna Briggs Institute checklist was implemented for the risk of bias assessment. The analysis included 38 articles, comprising 643 patients. The overall treatment success rate in acute and chronic nerve palsy was 79% and 33%, respectively. The success rate was not significantly different between different subgroups of age, type of botulinum toxin, pre-injection prism diopter, etiology of the palsy, duration of follow-up, and mean dose of botulinum toxin injection. However, in both acute and chronic palsy, diabetes etiology was accompanied by the highest success rate. Overall symptomatic response to botulinum injection was 84% (95% CI: 67% to 96%), whereas functional response was observed in 64% (95% CI: 47% to 79%) of the patients. The odds ratio for the success rate of treatment of palsies with botulinum toxin versus expectant management was 2.67 (95% CI: 1.12 to 6.36) for acute palsy and 0.87 (95% CI: 0.17 to 4.42) for chronic palsy. Botulinum toxin can be used for the treatment of acute third, fourth, and sixth nerve palsy, especially in patients with acute palsy and more severe tropia. [J Pediatr Ophthalmol Strabismus. 2024;61(3):160-171.].

A Review of Transposition Techniques for Treatment of Complete Abducens Nerve Palsy

Purpose:

To review various types of extraocular muscle transposition procedures for management of strabismus in sixth cranial nerve palsy with little lateral rectus (LR) muscle function, along with their pros and cons.

Methods:

We performed a comprehensive review of transposition procedures in sixth cranial nerve palsy, based on literature published anytime up to March 2021. A thorough search through PubMed and Cochrane databases was performed. All types of clinical studies on different transposition procedures in LR palsy, were included.

Results:

Eighty-six original articles in English, with full text or abstracts available, were included in the review, among which 16 are prospective studies, 48 retrospective, 3 review articles, 1 randomized clinical trial, 17 case reports, and 1 letter. Vertical rectus transposition has demonstrated promising results, especially in abduction improvement and expansion of binocular diplopia-free visual field, albeit the possible adverse effects such as anterior segment ischemia, especially in the presence of medial rectus contracture, and induced vertical deviation may become troublesome. Partial muscle transposition, single muscle transposition, and also transposition without tenotomy have all been introduced to reduce the risk of multiple muscle manipulation and ischemia. On the other hand, different adjustable transpositions are being utilized to manage concomitant or induced vertical deviations.

Conclusion:

Transposition procedures are highly effective in the treatment of esotropia caused by complete LR palsy. Various techniques for vertical muscle transposition have been proposed, with each of them having certain advantages and disadvantages.

A Systematic Review of Lemierre's Syndrome With a Focus on Ophthalmologic Complications

Lemierre's syndrome (LS), once known as "the forgotten disease," is a rare and potentially life-threatening condition that has had a gain in incidence over the last 30 years due to a variety of factors that could include changes in antibody prescription patterns, particularly in regard to the treatment of pharyngitis/tonsillitis. Due to its low incidence and broad spectrum of symptoms, LS does not have an obvious clinical diagnosis and can confuse the clinician managing the patient. Furthermore, it is equally difficult to treat patients suffering from LS as it requires a multidisciplinary approach from multiple subspecialties. Thus, communication between hospitalists, radiologists, otolaryngologists, neurologists, and ophthalmologists is critical towards quickly diagnosing the disease condition so that prompt antibiotics, anticoagulation, and surgical intervention can occur. Atypical presentations can also exist, making the diagnosis and management exponentially more challenging. Ophthalmologic symptoms are a particularly rare and atypical presentation of LS. These rare symptoms in LS can be terrifying for patients and providers alike; yet, there does not seem to be any modern medical literature that summarizes ophthalmologic complications for LS patients. To our knowledge, this is the first systematic review of LS with a focus on ophthalmologic complications that has been done. The main objective of this review paper is to provide an up-to-date literature review of LS epidemiology, pathophysiology, diagnosis, and treatment while also performing a novel systematic review of reported cases of LS with ophthalmological complications. We hope to bring more awareness towards LS and its atypical presentations so that physicians will be better able to rapidly diagnose and treat their patients in order to minimize long-term morbidity and mortality.

Functional and Motor Outcomes of Strabismus Surgery for Chronic Isolated Adult Sixth Nerve Palsy

Abducens nerve palsy is the most common acquired ocular motor nerve palsy in adults. Chronic cases of abducens palsy often require surgical intervention to relieve disabling diplopia. The goal of this study was to identify factors associated with surgical outcomes in isolated abducens palsy. Medical records of all adult patients from 1988 to 2012 with abducens palsies who underwent strabismus procedures were retrospectively reviewed. Motor alignment, extraocular motility, and sensory outcomes were recorded. Success was defined as absence of diplopia without prisms or face turn, vertical deviation ≤2 prism dioptres (PD), and horizontal deviation ≤10 PD. Eighty-one patients (age range: 20-86 years) met inclusion criteria. Success was achieved in 58% of patients. Final success rates for abducens palsy were 50% for neoplastic, 59% traumatic, 57% for microvascular/unknown, and 67% for other central nervous system causes (p > 0.05). Patients with an underlying neoplastic or traumatic aetiology required more than one strabismus procedure more often than those with microvascular/idiopathic or other central nervous system causes (48% vs. 24%; p = 0.03). For complete abducens palsies, patients who underwent Hummelsheim-type procedures had a higher success rate than those who underwent a full-tendon vertical rectus muscle transposition. (78% versus 35%; p = 0.049). Success rates for strabismus procedures in patients with abducens palsies are similar across all aetiologies. Frequency of re-operation is higher among those patients with neoplastic or traumatic aetiologies for their abducens palsies. Hummelsheim-type procedures have a higher success rate for complete abducens palsies than full-tendon vertical rectus transpositions.

Botulinum toxin injection with and without electromyographic assistance for treatment of abducens nerve palsy: a pilot study

PURPOSE

To compare the effects and complications of botulinum toxin injection into the medial rectus muscle with and without electromyographic (EMG) assistance for treatment of abducens nerve palsy.

METHODS

In a prospective, comparative, interventional case series, botulinum toxin was injected into the medial rectus muscle of 23 patients with esotropia secondary to abducens nerve palsy within 3 months of onset. Patients were randomly assigned to two groups. The injection was given with EMG assistance in the first (EMG group) and without EMG in the second group (no-EMG group). Success was defined as a distance esotropia of no more than 10(Delta) in the primary position. Angle of deviation was recorded preoperatively and at 1 week, 3 months, and 6 months; any postoperative complications and side effects were noted.

RESULTS

There were 11 patients in the EMG and 12 patients in the no-EMG group. The ocular deviations were significantly improved in both groups with an overall 6 month success rate of 52.2% (p = 0.008 in the EMG group, p = 0.006 in the no-EMG group). Success rates and mean changes of the angle of deviation were not statistically different between the two groups. Postinjection blepharoptosis was found to be significantly more in the EMG group (p = 0.009).

CONCLUSIONS

The effectiveness of botulinum toxin injection is the same with or without EMG assistance into the medial rectus muscle for treatment of abducens nerve palsy. EMG assistance is associated with more blepharoptosis.

Botulinum toxin treatment for acute traumatic complete sixth nerve palsy

AIMS

To investigate the benefits of botulinum toxin (BTX) injection for acute unilateral complete sixth nerve palsy caused by trauma.

METHODS

We retrospectively reviewed patients treated for acute unilateral complete sixth nerve palsy caused by head injury during a 10-year period (between March 1993 and February 2003) in our hospital. The BTX treatment group was defined as patients who received BTX injection within 3 months of injury. Patients who presented within 3 months of trauma, and had no previous BTX injection or surgery were enrolled as the conservative treatment group. Comparison of the patient demographics, palsy characteristics, angle of deviations, and recovery rates were made between the two groups.

RESULTS

In all, 33 patients were enrolled by our inclusion criteria. Of these, 19 patients were treated conservatively, and 14 patients were treated with BTX. A total of 79% of our patients presented with abduction deficit of grade -5. The results showed that there was no significant difference in the outcome for the two groups based on age, gender, time to presentation, severity, and initial angle of deviation. The BTX group had a higher recovery rate than the conservative treatment group (64.3 vs 26.3%, P=0.028). Among 26 patients with grade -5 abduction deficit, the recovery rate was higher in the BTX-treated patients than in the conservatively treated patients, which had no statistical significance (50 vs 18.8%, P=0.09).

CONCLUSION

BTX facilitates recovery of acute traumatic complete sixth nerve palsy in severely injured patients.

Management of primary hyperhidrosis: a summary of the different treatment modalities

Hyperhidrosis is a common and distressing condition involving increased production of sweat. A variety of treatment modalities are used to try to control or reduce sweating. Sweat is secreted by eccrine glands innervated by cholinergic fibers from the sympathetic nervous system. Primary hyperhidrosis most commonly affects palms, axillae and soles. Secondary hyperhidrosis is caused by an underlying condition, and treatment involves the removal or control of this condition. The treatment options for primary hyperhidrosis involve a range of topical or systemic medications, psychotherapy and surgical or non-surgical invasive techniques. Topical antiperspirants are quick and easy to apply but they can cause skin irritation and have a short half life. Systemic medications, in particular anticholinergics, reduce sweating but the dose required to control sweating can cause significant adverse effects, thus, limiting the medications' effectiveness. Iontophoresis is a simple and well tolerated method for the treatment of hyperhidrosis without long-term adverse effects; however, long-term maintenance treatments are required to keep patients symptom free. Botulinum toxin A has emerged as a treatment for hyperhidrosis over the past 5-6 years with studies showing good results. Unfortunately, botulinum toxin A is not a permanent solution, and patients require repeat injections every 6-8 months to maintain benefits. Psychotherapy has been beneficial in a small number of cases. Percutaneous computed tomography-guided phenol sympathicolysis achieved good results but has a high long-term failure rate. Surgery has also been shown to successfully reduce hyperhidrosis but, like other therapies, has several complications and patients need to be informed of these prior to undergoing surgery. The excision of axillary sweat glands can cause unsightly scarring and transthoracic sympathectomy (either open or endoscopic) can be associated with complications of compensatory and gustatory hyperhidrosis, Horner syndrome and neuralgia, some of which patients may find worse than the condition itself.

Subtenon injection of botulinum toxin for treatment of traumatic sixth nerve palsy

PURPOSE

Subtenon injection of botulinum toxin may produce results similar to intramuscular injection of the medial rectus muscle for the treatment of acute traumatic sixth nerve palsy. This study was designed to evaluate the clinical efficacy of subtenon injection and to compare our results with those in previously published reports.

METHODS

During 3 years at a single institution, 13 patients with traumatic sixth nerve palsy of less than 6 months' duration were treated with subtenon injection of botulinum toxin. The deviation angles before and after injection were recorded. A distance esotropia of less than 10 prism diopters (PD) in the primary position or absence of diplopia at 3 months was defined as recovery.

RESULTS

Of the 13 patients treated, 11 (84.5%) had unilateral palsy and 2 (15.4%) had bilateral palsy. The average pre-injection deviation was 39.5 PD of esotropia, and the average post-injection deviation was 17.0 PD. Seven patients experienced recovery and regained binocular single vision; the overall recovery rate was 53.8% (unilateral, 63.6%; bilateral, 0%). Six patients did not recover and subsequently underwent strabismus surgery.

CONCLUSION

Patients with traumatic sixth nerve palsy treated with subtenon injection of botulinum toxin showed higher recovery rates than did most patients treated with conservative measures in published reports. The result of subtenon injection of botulinum toxin without electromyography (EMG) guidance was comparable to that obtained using EMG-guided intramuscular injection of botulinum toxin. Patients with unilateral palsy demonstrated a better recovery rate than did patients with bilateral palsy.

Botulinum toxin for sixth nerve palsies in children with brain tumors

PURPOSE

Sixth nerve palsies in children with brain tumors have a low rate of spontaneous recovery. Botulinum toxin has been used to treat sixth nerve palsies. In this study, we review outcomes for children with brain tumors and sixth nerve palsies, some of whom were treated with botulinum toxin.

METHODS

To determine whether botulinum toxin effected the outcome of children with sixth nerve palsies and brain tumors, a retrospective review of charts was conducted for patients identified as having brain tumors and sixth nerve palsies after evaluation at the St Jude Children's Research Hospital Eye Clinic between 1992 and 1999. Of 48 charts identified, 19 met our inclusion criteria, having a record of brain tumor associated with sixth nerve palsy and 2 or more eye clinic visits at least 6 months apart. Children were considered recovered if they had an esotropia of less than 10 PD in primary gaze at the last follow-up visit and did not require surgical correction.

RESULTS

Of the 19 children included in the study, 10 were managed conservatively (no botulinum toxin or surgery for at least 6 months after diagnosis). Nine children received one or more botulinum toxin injections. Two (20%) of the 10 children in the conservatively managed group recovered without surgical intervention. Two (22%) of the 9 children in the botulinum toxin treatment group recovered without surgical intervention.

CONCLUSIONS

Treatment with botulinum toxin did not improve the rate of recovery in our series of children with brain tumors and sixth nerve palsies.

Botulinum A exotoxin use in clinical dermatology

Botulinum toxin (BT) prevents the release of acetylcholine at the neuromuscular junction and produces reversible paralysis of striated muscle. This effect was initially used for ophthalmologic indications, particularly strabismus. The idea of using the toxin for purely cosmetic purposes arose from the observation that therapy for facial dystonias markedly decreased lines and wrinkles in the treated areas. The ease of application, high safety profile, and impressive results from the cosmetic use of BT have led to its rapid acceptance by many clinicians. As use of BT increases and its indications expand, an understanding of this therapeutic modality is timely. This article discusses the pharmacologic aspects of BT as well as the methods for administration as they relate to its cosmetic use.

Results of a prospective randomized trial of botulinum toxin therapy in acute unilateral sixth nerve palsy

Forty-seven patients entered a prospective randomized trial to assess the effect of early botulinum neurotoxin A treatment to the ipsilateral antagonist medial rectus on the ultimate recovery rate of acute unilateral sixth nerve palsy. Twenty-two patients received injections and 25 acted as controls. The overall etiologies were microvascular (72.3%), unknown (17%), multiple sclerosis (6%), and one case each of central nervous system (CNS) sarcoidosis and basilar artery ectasia. Eighty-three percent of the patients entered the trial within 2 weeks of the onset of symptoms and 95.7% within 3 weeks. The controls had a final recovery rate of 20/25 (80%), and the injected group had a final recovery rate of 19/22 (86%). No serious side effects were encountered. We conclude that there is no evidence for a prophylactic effect of botulinum toxin in the group that we have studied.

Management of VIth nerve palsy--avoiding unnecessary surgery

Unresolved VIth nerve palsy that is not adequately controlled by an abnormal head posture or prisms can be very suitably treated by surgery. It is however essential to differentiate partially recovered palsies, which are amenable to horizontal rectus surgery, from unrecovered palsies, which must be treated initially by a vertical muscle transposition procedure. Botulinum toxin is a valuable tool in making this distinction. It also facilitates full tendon transposition in unrecovered palsies, which appears to produce the best functional outcome of all the transposition procedures, with a reduction in the need for further surgery. A study of the surgical management of 12 patients with partially recovered VIth nerve palsy and 59 patients with unrecovered palsy provides clear guidelines on how to attain a successful functional outcome with the minimum amount of surgery.

Causes and prognosis in 4,278 cases of paralysis of the oculomotor, trochlear, and abducens cranial nerves

We collected data from a large series of patients with ocular palsies and compared them with data in previous series from the Mayo Clinic. The largest group of patients among 4,278 cases was that in which the cause was undetermined for a long period of follow-up. The abducens nerve was most commonly affected. The probability of establishing a diagnosis was higher in patients younger than 50 years and among those with associated neurologic findings or multiple ocular palsies. The prognosis for recovery was best in the vascular group but was better than 50% for all groups except those with tumors. Investigation may be tailored to each patient according to clinical findings and probabilities of finding a cause, and judicious clinical judgement should be exercised.

The role of botulinum toxin in third nerve palsy

Isolated third nerve paresis is a rare diagnosis among patients presenting to the Botulinum Toxin Clinic at Moorfields Eye Hospital. Ten patients with this diagnosis are reviewed in this study. Head trauma is a common cause of third nerve palsy and is often severe enough to cause damage to fusion potential. If fusion is present and there is adequate adduction of the divergent eye, then botulinum toxin injection of the lateral rectus may induce long-term control of the ocular deviation. Three of the four patients who experienced long-term control of their ocular deviation following toxin injection shared these features. Toxin injected into the lateral rectus did not, however, reliably assess medial rectus function and therefore predict the outcome of horizontal squint surgery. Reasons for this are discussed.

Botulinum toxin therapy in dysthyroid strabismus

We report our experience with the use of Botulinum toxin injection in 38 patients (64 injections) with severe dysthyroid strabismus. Three quarters of the injections led to a decrease in the angle of the squint by a mean 75% of the initial deviation. The average duration of effect was two months. Twenty six patients went on to surgery after stabilisation of their squint and endocrine status. Six patients achieved a stable long-term result with Botulinum toxin only. We suggest these results of treatment of early dysthyroid myopathy are more consistent with the characteristics of inflammatory spasm than contracture. The value of Botulinum toxin as a temporary means of maintaining binocularity in these young patients is discussed.