The role of Botulinum toxin in management of acute traumatic third-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.].

Oculomotor Cranial Neuropathies: Diagnosis and Management

Ocular nerve palsies are among the most common cranial neuropathies in neurological practice. Nerves can get affected anywhere along their path from the brainstem to the orbit. There can be isolated involvement of multiple cranial nerves together. The etiologies differ according to the type of presentation. The steps toward the diagnosis need to be strategically planned and must be based on clinical localization. It is crucial to make proper localization to plan further investigations and thus treatment of the etiology. This review covers the approach toward the diagnosis, etiologies involved, and management of ocular cranial neuropathies.

Success rates of botulinum toxin in different types of strabismus and dose effect

OBJECTIVE

To determine the effect of botulinum toxin in different types of strabismus and analyze its dose effect.

DESIGN

This was an interventional clinical study performed in a tertiary care university hospital.

METHODS

Eighty six patients treated with botulinum toxin for strabismus were included. Main outcome measures involved success of botulinum toxin, alignment change per unit of toxin, and dose effect on complications and outcomes.

RESULTS

Success rates were 31% for infantile esotropia, 25% for partially accommodative esotropia, 61.5% for residual esotropia, 25% for third cranial nerve paralysis, 13.3% for sixth cranial nerve paralysis, 75% for Duane retraction syndrome, and 38.5% for nonaccomodative esotropia. Improvement in deviation size after botulinum toxin treatment was significant in patients with infantile esotropia (p = 0.001), residual esotropia (p = 0.001), and nonaccomodative esotropia (p = 0.03). Mean deviation change per 1 unit of toxin was 2.7 ± 2.4 prism diopters (PD) with a single injection and 2.1 ± 1.9 PD with multiple injections. A 3.32 PD of early deviation change with botulinum toxin corrected 1 PD of final deviation. Success rate was not correlated with age (r = 0.040, p = 0.8), sex (r = -0.083, p = 0.6), mean dose (r = -0.149, p = 0.35), or total dose (r = 0.165, p = 0.29) but was significantly correlated with deviation size (β = -0.077, p = 0.0001). Complications were not associated with the dose of botulinum toxin (p > 0.05).

CONCLUSIONS

Botulinum toxin has variable outcomes in different types of strabismus. Still, it reduces the deviation size in most patients, thus allowing for a smaller amount of subsequent muscle surgery. Early overcorrection is a more powerfull indicator of better outcome than postinjection duction deficit.

Isolated Oculomotor Nerve Palsy in Mild Traumatic Brain Injury

BACKGROUND

Isolated oculomotor nerve palsy is rarely encountered after mild traumatic brain injury. It is difficult to offer patients accurate management strategies or prognostic assessments because only a few reports have described the management of oculomotor nerve palsy.

METHODS

We performed a search for all clinical studies of isolated oculomotor nerve palsy after mild traumatic brain injury published up to July 9, 2019. We placed no restrictions on language or year of publication in our search, and we searched the following key words: traumatic brain injury, isolated oculomotor nerve palsy, mild head trauma, management, and prognosis.

RESULTS

We identified 14 cases of isolated oculomotor nerve palsy after mild traumatic brain injury. In three cases, steroids were used to manage the oculomotor nerve palsy. Five patients who had underlying brain lesions underwent surgery, and seven patients were observed and followed up. The time to partial or complete resolution was 6.0 ± 5.3 mos with a range of 0.5-18 mos.

CONCLUSIONS

This review includes a survey of surgical treatment for the management of traumatic brain injury that underlies oculomotor nerve palsies, steroid therapy to reduce related brain edema, and oculomotor rehabilitation with training eye movement behavior.

Clip Compression Injury of the Oculomotor Nerve: Its Prevention and Recovery

Clip compression injury of oculomotor nerve (ON) is a preventable complication of aneurysm microsurgery. The author illustrates this condition in which ON was inadvertently occluded by the clip during repairing posterior communicating artery (PcoA) aneurysm. The report indicates that the surgeon should be meticulous in identifying and protecting ON at clipping stage when PcoA aneurysm prematurely bursts.

The Use of Botulinum Toxin in Strabismus Treatment

There is a long and extensive experience with the use of Botulinum Toxin type A (BoNT-A) injection in the treatment of different types of strabismus and oculomotor palsies. The frequency of its use varies depending on the country and institution. It is a short procedure, may reduce general anesthesia exposure, causes minimal scarring compared to surgery, and can be proposed as an early treatment in unstable strabismus. Over many years, the experience of using BoNT-A indications has been refined and new applications have been reported. The use of BoNT-A in the postoperative period, after strabismus surgery or during surgery, can also be beneficial.

Intramuscular Distribution of the Abducens Nerve in the Lateral Rectus Muscle for the Management of Strabismus

AIMS

To elucidate the intramuscular distribution and branching patterns of the abducens nerve in the lateral rectus (LR) muscle so as to provide anatomical confirmation of the presence of compartmentalization, including for use in clinical applications such as botulinum toxin injections.

METHODS

Thirty whole-mount human cadaver specimens were dissected and then Sihler's stain was applied. The basic dimensions of the LR and its intramuscular nerve distribution were investigated. The distances from the muscle insertion to the point at which the abducens nerve enters the LR and to the terminal nerve plexus were also measured.

RESULTS

The LR was 46.0 mm long. The abducens nerve enters the muscle on the posterior one-third of the LR and then typically divides into a few branches (average of 1.8). This supports a segregated abducens nerve selectively innervating compartments of the LR. The intramuscular nerve distribution showed a Y-shaped ramification with root-like arborization. The intramuscular nerve course finished around the middle of the LR (24.8 mm posterior to the insertion point) to form the terminal nerve plexus. This region should be considered the optimal target site for botulinum toxin injections. We have also identified the presence of an overlapping zone and communicating nerve branches between the neighboring LR compartments.

CONCLUSION

Sihler's staining is a useful technique for visualizing the entire nerve network of the LR. Improving the knowledge of the nerve distribution patterns is important not only for researchers but also clinicians to understand the functions of the LR and the diverse pathophysiology of strabismus.

Botulinum Toxin Injection for Treatment of Acute Traumatic Superior Oblique Muscle Palsy

Purpose:

To evaluate the outcomes of botulinum toxin injection into the inferior oblique (IO) muscle for management of unilateral acute traumatic superior oblique (SO) palsy.

Methods:

In this prospective case series, 10-20 units of botulinum toxin A (Dysport, Ipsen, Biopharm Ltd., Wrexham, UK) was injected into the ipsilateral IO muscle of 13 consecutive patients with unilateral acute traumatic SO palsy. All patients received injections within four weeks of the incident.

Results:

Mean age was 29 ± 15 years and 12 (92%) subjects were male. Mean amount of hypertropia (in primary position) was decreased from 10.0 ± 3.9^Δ at baseline to 4.6 ± 8.9^Δ, one month after the injection, and to 1.5 ± 2.7^Δ at final follow-up (P = 0.001). IO overaction improved from 2.7 ± 0.6 to 1.0 ± 1.2 and 0.6 ± 0.9 (P ≤ 0.001), and subjective torsion from 5.3 ± 3.9 to 3.2 ± 3.4 and 1.6 ± 2.5 degrees (P ≤ 0.001), at the same time intervals respectively. One month after the injection as well as at final follow-up, 10 (77%) patients were diplopia-free in primary and reading positions. Subgroup analysis showed that patients who recovered had less baseline hypertropia as compared to those who failed (8.3^Δ vs. 15.7^Δ, respectively; P = 0.01). All patients with a favorable outcome had baseline hypertropia of 10^Δ or less.

Conclusion:

A single injection of BTA into the IO muscle can rapidly and safely resolve symptomatic diplopia in patients with acute traumatic SO palsy, while waiting for spontaneous recovery.

[Third cranial nerve palsy and Purtscher retinopathy in a child with multiple injuries]

CASE REPORT

A 4 year-old girl was referred to our hospital after have suffered a severe accident. The patient was diagnosed with complete third nerve palsy in her right eye and Purtscher retinopathy in her left eye.

DISCUSSION

Purtscher retinopathy is a rare condition. The diagnosis is made on clinical ground and its treatment is not well defined although it is believed that systemic steroids could improve the visual outcome. Traumatic third nerve palsy has a poor spontaneous recovery. The use of botulinum toxin might be useful in children to improve the recovery rate, maintaining binocularity, and avoiding amblyopia in other cases.

Managing the patient with oculomotor nerve palsy

PURPOSE OF REVIEW

To provide clinically relevant information regarding the evaluation and current treatment options for oculomotor nerve palsies. We survey recent literature and provide some insights into these studies.

RECENT FINDINGS

Recent case reports highlight emerging new causes of oculomotor cranial nerve palsies, including sellar chordoma, odontogenic abscess, nonaneurysmal subarachnoid hemorrhage, polycythemia, sphenoiditis, neurobrucellosis, interpeduncular fossa lipoma, metastatic pancreatic cancer, leukemia, and lymphoma. Surgical studies have focused on modifications and innovations regarding strabismus surgery for this condition. New globe fixation procedures may include fixation to the medial orbital wall by precaruncular and retrocaruncular approaches, apically based orbital bone periosteal flap fixation and the suture/T-plate anchoring platform system.

SUMMARY

Management of oculomotor nerve palsy depends in part upon the underlying cause and anatomical location of the lesion. Careful clinical evaluation and appropriate imaging can identify a definitive cause in most cases. Surgical options depend on the number, extent, and severity of the muscles involved as well as the presence or absence of signs of aberrant regeneration. The clinician should also address issues that arise due to involvement of the pupil and accommodation. Strabismus surgery can be challenging but also rewarding with appropriate selection and staging of procedures.

Nonsurgical treatment of neurologic diplopia

The ocular motor pathways are complex and disorders of these pathways can be devastating for patients, in some cases leading to loss of employment and independence. Surgical intervention for these cases is not always warranted, possible, or even safe for some patients, and nonsurgical and orthoptic treatments can provide significant relief. This paper will discuss various treatment options, including eye exercises, prisms, optical manipulation, occlusion, and lifestyle changes.