Surgical management of chronic sixth cranial nerve palsy: case report and literature review.

Background: Esotropia resulting from sixth cranial nerve palsy can substantially impact an individual's visual acuity and overall quality of life. If the condition does not resolve in 6-10 months, surgical intervention may be necessary. Various muscle surgeries may be considered, with vertical rectus muscle transposition emerging as the primary option for treatment of complete palsy. However, this technique carries the risk of anterior segment ischemia and post-surgery deviations. Herein, we present a successful treatment of chronic complete sixth nerve palsy using a modified Nishida procedure, without splitting or tenotomy, and an adjunct botulinum toxin A (BTA) injection in the ipsilateral medial rectus muscle. Case Presentation: A 59-year-old woman with a history of traumatic sixth nerve palsy had previously undergone horizontal muscle strabismus surgeries. Following multiple left medial rectus recessions, lateral rectus resection, and BTA injections, esotropia persisted. The worsening of her condition led to emotional distress and impaired social interaction. Initial examination revealed marked esotropia and limited left eye abduction. Magnetic resonance imaging (SIGNA MR750w, GE Healthcare, Waukesha, WI, USA) of the left eye revealed a contracted medial rectus muscle and substantial atrophy of the left lateral rectus muscle. A modified Nishida procedure was performed with an injection of 3 units of BTA into the ipsilateral medial rectus muscle, resulting in improved ocular alignment and stable findings after nine postoperative months. Furthermore, we supported our successful outcome with a summary of similar reported cases of sixth nerve palsy managed using the modified Nishida procedure with or without adjunctive procedures. Conclusions: Following the modified Nishida procedure, the patient experienced a reduction in diplopia, improved ocular alignment and stability, and an increased binocular diplopia-free field. This case underscores the importance of an individualized approach to complex strabismus cases and highlights the modified Nishida procedure as a valuable tool in such circumstances. In the future, strabismus management will focus on refining personalized treatment and exploring innovative techniques for complex cases. Our success in using a combination of Nishida procedure and BTA injection should be further investigated in large-scale studies.

Tuberculoma Masquerading as a Sixth Cranial Nerve Palsy in a Young Patient: A Case Report.

Tuberculosis is a worldwide health concern with a wide range of clinical manifestations. Rarely, it can involve the central nervous system in the form of tuberculomas. Although cranial nerve palsies or localized neurological signs are the most frequent presentations of tuberculoma, isolated sixth nerve palsy is unusual and rare. We report the case of a 17-year-old female who presented with isolated sixth nerve palsy, an unusual early manifestation of intracranial tuberculoma. We established the diagnosis through clinical, radiological, and laboratory evaluations and successfully managed the patient with antitubercular therapy. This case highlights the importance of considering tuberculoma as a differential diagnosis in cases of isolated cranial nerve palsies, especially in regions with a high prevalence of tuberculosis.

Scrub Typhus Presenting as Bilateral Sixth Nerve Palsy.

Scrub typhus, a tropical rickettsial infection, can have various neurological manifestations. Here, we present the case of an otherwise healthy 19-year-old female who presented to the emergency department with fever, headache, and diplopia. On examination, she was found to have bilateral sixth nerve palsy and bilateral papilledema. Initial unenhanced CT of the brain and CT venogram were unremarkable. The cerebrospinal fluid study was normal. Later, bloodwork revealed high titers of Orientia tsutsugamushi antibody. A thorough physical examination revealed no evidence of any eschar. She was treated with doxycycline and had significant clinical improvement with partial recovery of bilateral lateral rectus function. We want to highlight the importance of maintaining a high index of suspicion for atypical neurological presentations of scrub typhus.

Isolated pseudo­abducens palsy and contralateral occipital headache with thalamic stroke: A case report and mini­review of the literature.

The abducens nerve (sixth cranial nerve) is essential for lateral eye movement, and its malfunction can cause a variety of issues with vision. Pseudo-abducens palsy is a rare neurological condition that causes a limitation in eye abduction, while the abducens nerve is still functioning. Thalamic pain syndrome, a severe complication of cerebrovascular events, presents as intense neuropathic pain provoked by temperature fluctuations. Although thalamic strokes are infrequently associated with ocular abnormalities, some studies suggest an association between isolated pseudo-abducens palsy and thalamic infarctions. The present study describes the case of a 38-year-old male patient with 1-day progressive diplopia and occipital headache who had abducens palsy on the left side as a result of a right thalamic infarction. The patient had a 10-year history of smoking and a 1-year history of hypertension, which was poorly controlled. The diagnosis was supported by a neurological examination, imaging and stroke etiology investigations. The patient recovered well within 5 days, highlighting the good prognosis of an acute thalamic presentation. In addition, a mini-review of the literature was performed and two similar reports were identified upon searching the literature using the Embase, Google Scholar, Lilacs, Medline, SciELO and ScienceDirect databases. On the whole, the present study demonstrates that understanding the complex neuronal connections inside the thalamus is critical for a proper diagnosis and appropriate intervention strategies in patients with thalamic stroke with oculomotor impairments. Further research is required to elucidate the underlying causes and develop treatment techniques for thalamic infarction consequences.

Bilateral Sequential Abducens Nerve Palsy After Pfizer-BioNTech COVID-19 Vaccine (BNT162b2): A Case Report and Literature Review.

This case report details the occurrence of bilateral sequential abducens nerve palsy in a previously healthy 42-year-old woman two days after receiving her first dose of the Pfizer-BioNTech COVID-19 vaccine (BNT162b2). Despite the widespread global administration of COVID-19 vaccines, instances of abducens palsy following vaccination are limited in the available literature. Considering the temporal association between vaccination and symptom onset, the absence of underlying medical conditions predisposing to such neurological manifestations, normal brain imaging results, the occurrence of other cranial palsies post-vaccination, and analogous occurrences after different vaccinations, we propose a plausible connection between the patient's abducens palsy and the COVID-19 vaccination. Our findings contribute to the growing body of evidence regarding the side effects and safety profile of COVID-19 vaccines. Importantly, the resolution of symptoms with conservative management and the uneventful administration of the second vaccine dose suggest that the observed abducens palsy may be a transient and isolated reaction.

Outcomes of "a new modification of Jensen technique combined with medial rectus recession" in patients with complete sixth cranial nerve palsy.

BACKGROUND: To report the outcomes of "our modified Jensen technique" for treating esotropia in cases with complete sixth cranial nerve (CN VI) palsy. METHODS: This study is a 30-year case series of isolated complete CN VI palsy who underwent combined medial rectus recession and our modified Jensen operation. We modified the original technique by anchoring the muscle-unifying sutures to the sclera near the equator using a non-absorbable suture. Major outcomes such as postoperative diplopia, face turn, horizontal and vertical eye deviations, and abduction limitation were assessed. Successful surgery was defined as orthotropia or esotropia equal to or less than 8 prism diopters (PD) and the absence of any vertical deviation. RESULTS: Fifty-three cases with a mean age of 28 years old were included in this study. The male-to-female ratio was 3 to 1. Forty-five cases (85%) presented with unilateral palsy, whereas 8 patients (15%) had bilateral palsy. Trauma was the most common etiology (85%). Diplopia or face turn, presented in 42 patients before the operation, remained in seven cases after the operation. Primary position esotropia, which was the main complaint in all patients, decreased from 49 PD to 4 PD in unilateral palsy and from 101 PD to 10 PD in bilateral palsy. The mean reduction of abduction deficit was 1.78 in unilateral and 1.75 in bilateral palsy. The success rate was 76% in unilateral and 62% in bilateral palsy. CONCLUSION: Our modified Jensen operation was effective in treating patients with complete CN VI palsy, producing no significant permanent complications.

Preliminary Results of New Modification of Vertical Muscle Transposition to Enhance Abducting Force in Sixth Nerve Palsy.

Introduction: Since 1907, multiple transposition procedures have been established for the treatment of abducens paralysis. The purpose of the study was to determine where the transposed muscle should be reattached in order to increase the tangential force necessary to improve abduction. Methods: Retrospective case review of 12 consecutive patients with abducens paralysis who underwent transposition procedures between 2016 and 2019 was conducted. Vertical rectus muscles are transposed to the insertion of lateral rectus muscle; the temporal parts are joined and sutured to the sclera on top of the lateral rectus muscle in the middle of the insertion. The nasal parts are sutured to the sclera following the spiral of Tillaux. The muscle junction suture is placed 8 mm from the insertion, with the temporal parts of the vertical muscles bellies joined and sutured to the lateral rectus muscle. A full-tendon transposition was performed on 11 patients, a half-tendon transposition procedure on 1 patient. The minimum follow-up was 3 months. Results: The mean preoperative deviation was ET of 37° (range: ET 24° to ET 51°). The mean preoperative abduction limitation was 5 mm from midline (range: 7 to 1 mm). The postoperative mean deviation was ET of 2° (range: 0° to ET 5°). The postoperative mean abduction improvement was 5 mm past midline (range: 2-6 mm). There were no complications or signs of anterior segment ischemia. Conclusion: To achieve the maximal abductive force from the transposed muscles, we suggest that the vertical muscles be reattached as close as possible to the middle of the lateral rectus insertion.

Isolated Abducens Nerve Palsy in the Setting of Isolated Sphenoid Sinusitis: A Case Report.

The cranial nerves (CNs) are responsible for multiple functions, including extraocular mobility, facial sensation and movement, hearing, mastication, tongue movement and sensation, and swallowing. Beyond these vital roles, they can also demonstrate importance in their diagnostic value. Isolated or combined palsies provide insights into potential localizations and various underlying etiologies, including stroke, tumor, and infections that may guide further neurological evaluation. CN VI, the abducens nerve, singularly innervates the lateral rectus muscle, which is responsible for the abduction of the eyes. Despite its long anatomic trajectory, making it susceptible to intracranial injury, an isolated abducens nerve palsy is extremely rare. The most common clinical presentation includes headache, diplopia, and the inability to abduct the afflicted eye. This case report introduces a 71-year-old female with a medical history of malignancy and pancytopenia who presented to the emergency room with complaints of ear pain and swelling and subsequently developed diplopia secondary to unilateral CN VI palsy. Magnetic resonance imaging (MRI) revealed isolated sphenoid sinusitis for which she was clinically asymptomatic. She was treated with a regimen of ampicillin-sulbactam, an oral anti-inflammatory agent, and a tapered course of methylprednisolone with a rapid and complete resolution of the abducens nerve palsy and sinusitis. Acute isolated diplopia is an unusual neurologic condition prompting the need for rapid and thorough investigation. Although exceedingly rare and infrequently cited in the literature, isolated abducens nerve palsies secondary to sphenoid sinusitis should be entertained in the differential diagnosis of this presentation.

Acute Cranial Nerve VI Palsy Following Prolonged Prone Positioning in an Adolescent With Neurofibromatosis Type 1: A Rare Complication of Spinal Surgery in the Prone Position.

The abducens or sixth cranial nerve provides motor innervation to the lateral rectus muscle, which abducts the ipsilateral eye with secondary innervation of the contralateral medial rectus muscle to allow for coordinated movement of both eyes. Various acute and chronic pathologic conditions, most importantly pontine infarctions and increased intracranial pressure, can result in acute sixth cranial nerve palsies. We report the uncommon occurrence of acute abducens nerve palsy following spinal fusion surgery in an 18-year-old male patient with a history of multiple neurological and orthopedic conditions. Postoperatively, the patient presented with symptoms that included left diplopia with restricted upward and downward gaze, indicative of abducens nerve palsy. The anatomy of the sixth cranial nerve is discussed, potential etiologies of sixth nerve palsy presented, and a proposed diagnostic workup reviewed. Our report emphasizes the need for comprehensive exploration of ocular symptoms following spinal surgery, given the various potential etiologies of sixth nerve palsy.

Isolated Sixth Cranial Nerve Palsy as Initial Presentation of Pituitary Apoplexy: A Case Report.

Pituitary apoplexy is a serious condition, which if left untreated, might lead to irreversible life-long complications. Hence, pituitary apoplexy should always be included in the differential diagnoses of a patient with an isolated sixth cranial nerve (CN) palsy. This report highlights the case of a patient presenting with isolated CN palsy associated with pituitary apoplexy. Although pituitary adenomas are common, they seldom present with isolated abducent nerve palsy without any other CN involvement. The 47-year-old female patient presented with acute right eye pain, diplopia, and a squint. Examination revealed an isolated unilateral sixth CN palsy. Brain MRI showed a sellar and suprasellar mass suggestive of hemorrhagic pituitary apoplexy. The patient was transferred to neurosurgery and underwent transsphenoidal resection of a pituitary macroadenoma. Postoperative follow-up showed clinical improvement. It is, thus, imperative for physicians to have the knowledge to recognize an isolated sixth cranial nerve palsy and its associated causes.

Persistent Trigeminal Artery Causing an Abducens Nerve Palsy: A Case Report.

We present a case of a 50-year-old female who was diagnosed with an isolated right abducens nerve palsy and was found to have a persistent trigeminal artery (PTA). The trigeminal artery is the most common persistent embryological carotid-vertebrobasilar anastomosis. A PTA can be picked up as an incidental finding on magnetic resonance imaging (MRI) or angiography. It has been reported that a PTA can be found in 0.1 to 0.6% of all cerebral angiograms. PTA has been linked to several rare abnormalities such as vascular aneurysms and cranial nerve compression. Our patient presented with diplopia and was found to have a paresis of the right lateral rectus muscle consistent with a right abducens nerve palsy. MRI found a right-sided PTA indenting the ventral surface of the pons. This case investigates and highlights that neurovascular compression from a PTA can cause an isolated abducens nerve palsy. Further research is required to investigate if surgical intervention for non-aneurysmal PTA would be beneficial for patients.

A Potentially Adjustable Modification of the Nishida Procedure.

For patients with a complete, chronic abducens nerve palsy and resulting abduction deficit, a transposition procedure is often the procedure of choice. One such transposition procedure involves transposing the superior rectus (SR) and inferior rectus (IR) laterally without disinserting or splitting either muscle. While effective, this procedure - like many transposition procedures - carries with it the risk of induced torsional or vertical misalignment. Here, we describe an adjustable variation of the above transposition procedure, one which potentially would allow for post-operative correction of induced vertical or torsional deviations.

Inflammatory Sixth Nerve Palsy Post-COVID-19 Vaccination: Magnetic Resonance Imaging Findings.

Sixth nerve palsy is the most common post-vaccination oculomotor palsy. It is generally transient with most patients making a complete recovery. We report the case of a 46-year-old healthy male patient who presented with a painless sixth nerve palsy after the second dose of the Pfizer BioNTech COVID-19 vaccine, which recovered over the course of the next month. We confirmed the lesion localisation by demonstrating enhancement of the root exit zone and the cisternal portion of the sixth nerve on sequential magnetic resonance imaging during the symptomatic period. Here, a temporal relationship between vaccine application and diplopia onset suggests an aetiologic relationship. Moreover, the lack of pre-existing medical conditions suggests a post-vaccination inflammatory process.

Computational method for aid in the diagnosis of sixth optic nerve palsy through digital videos.

The sixth cranial nerve, also known as the abducens nerve, is responsible for controlling the movements of the lateral rectus muscle. Palsies on the sixth nerve prevent some muscles that control eye movements from proper functioning, causing headaches, migraines, blurred vision, vertigo, and double vision. Hence, such palsy should be diagnosed in the early stages to treat it without leaving any sequela. The usual methods for diagnosing the sixth nerve palsy are invasive or depend on expensive equipment, and computer-based methods designed specifically to diagnose the aforementioned palsy were not found until the publication of this work. Therefore, a low-cost, non-invasive method can support or guide the ophthalmologist's diagnosis. In this context, this work presents a computational methodology to aid in diagnosing the sixth nerve palsy using videos to assist ophthalmologists in the diagnostic process, serving as a second opinion. The proposed method uses convolutional neural networks and image processing techniques to track both eyes' movement trajectory during the video. With this trajectory, it is possible to calculate the average velocity (AV) in which each eye moves. Since it is known that paretic eyes move slower than healthy eyes, comparing the AV of both eyes can determine if the eye is healthy or paretic. The results obtained with the proposed method showed that paretic eyes move at least 19.65% slower than healthy ones. This threshold, along with the AV of the movement of the eyes, can help ophthalmologists in their analysis. The proposed method reached 92.64% accuracy in diagnosing the sixth optic nerve palsy (SONP), with a Kappa index of 0.925, which highlights the reliability of the results and gives favorable perspectives for further clinical application.

Childhood hypertension, sixth nerve palsy, and renal artery stenosis.

This short report demonstrates an uncommon presentation of intracranial bleeding and sixth nerve palsy in a child with systemic hypertension due to long-standing unilateral renal artery stenosis of unknown etiology that resulted in contracture of the affected kidney and compensatory hypertrophy of the contralateral kidney. Structural renal damage and cardiac ventricular hypertrophy suggested the pathology and ensuing hypertension to be long-standing; however, renal function tests were normal at presentation. The importance of routine outpatient evaluation of systemic blood pressure in children, similar to adults, so as to diagnose and treat secondary hypertension and its causes early, before further systemic and neurological complications set in, is emphasized. The primary neuro-ophthalmological clinical presentation of the child with subsequent confluence of major pediatric domains of medicine, surgery, neurology, cardiology, nephrology, interventional radiology, and ophthalmology toward optimum multidisciplinary etiological and symptomatic management of the condition and its sequelae and subsequent rehabilitation is described.

Bilateral sixth cranial nerve palsy, the first presenting feature of hemorrhagic apoplexy of pituitary macroadenoma: A case report.

INTRODUCTION AND IMPORTANCE: We report on apoplexy of undiagnosed pituitary macroadenoma presenting as sudden onset bilateral sixth nerve palsy. CASE PRESENTATION: A 36-year-old male patient presented with a complaint of sudden onset diplopia for one week associated with chronic headache for two years. On further investigations, isolated bilateral sixth cranial nerve palsy was found to cause diplopia in lateral gaze and at distance. Magnetic resonance imaging of the brain showed a well-defined lobulated mass of 19 × 22 × 24 mm in the sellar and suprasellar region with hemorrhage, compressing optic chiasma superiorly with extension into the superior cavernous sinus compartment on the left side. The neurosurgery team excised the tumour through an endoscopic endonasal transsphenoidal approach. Abducens nerve palsy recovered within one week. CLINICAL DISCUSSION: In our case diplopia due to bilateral sixth cranial nerve palsy was the first clinical presentation of hemorrhagic apoplexy of pituitary macroadenoma which is a potentially life-threatening condition. There was no other significant ocular symptoms. High index of suspicion, prompt diagnosis and multidisciplinary team management resulted into favourable outcome. CONCLUSION: Sudden onset diplopia and isolated bilateral sixth nerve palsy should be added to the spectrum of clinical presentations of hemorrhagic apoplexy of previously undiagnosed pituitary macroadenoma.

Augmented inferior rectus transposition with medial rectus recession in treatment of chronic unilateral sixth nerve palsy.

BACKGROUND: to report the results of augmented inferior rectus muscle transposition (IRT) in management of chronic sixth nerve palsy. METHODS: a retrospective review of medical records of patients with chronic complete sixth nerve palsy who were treated by augmented full thickness IRT to the lateral border of the paralyzed lateral rectus muscle. Patients were selected for IRT if there was more limitation of abduction in inferior gaze associated with V- pattern esotropia. Medial rectus recession (MRRc) was performed in case of positive intraoperative forced duction. Effect on primary position esotropia, face turn, amount of V-pattern and limitation of ocular ductions were reported and analyzed. RESULTS: the review revealed 11 patients (7 males) with chronic unilateral sixth nerve palsy who were treated by simultaneous augmented IRT and MRRc. Causes of sixth nerve palsy were trauma (6 cases), vascular (3 cases), inflammation and congenital (one case each). Mean age of the patients at the time of surgery was 35.6 years (range; 11-63) and mean follow up was 8.6 months (range; 6-13). Postoperatively, average correction of esotropia, V-pattern, face turn and limited abduction were 35.9 PD, 11.4 PD, 25.9° and 2.2 unit, respectively (p < .00). Postoperative complications in the form anterior segment ischemia, symptomatic induced vertical deviations were not found. CONCLUSIONS: In cases of chronic unilateral sixth nerve palsy associated with more limitation of abduction in downgaze and V-pattern esotropia, augmented IRT could be considered as an effective and safe modality.

Facial and Abducens Nerve Palsies Following COVID-19 Vaccination: Report of Two Cases.

A broad spectrum of neurological side effects has been reported after immunisation for COVID-19, including functional neurological disorders, cerebral vascular events, cerebral venous thrombosis, intracerebral haemorrhage, neuroleptic malignant syndrome, cranial nerve palsies, and otologic manifestations. Multiple cranial neuropathies have also been reported following vaccination in which involvement of VII nerve is the most prevalent, followed by the VI, III, and IV nerves. We describe two male patients, one with with facial nerve palsy and the other with abducens nerve palsy following COVID-19 vaccination. The patient with facial nerve palsy received the AstraZeneca vaccine 2 days before the symptoms began. In contrast, the patient with the abducens palsy had received his first dose of the Sinopharm vaccine 7 days previously. Both patients demonstrated a gradual recovery within the next 2 months. Further studies are required to investigate the proper relationship between cranial nerve palsies and vaccinations.

Diplopia due to a neurovascular compression.

A 36-year-old female patient presented to our clinic with a two months history of diplopia and dizziness. The symptoms appeared gradually and increased in frequency and intensity. She had no significant medical history and she did not take any medication. A full ophthalmological consult was performed, which revealed restricted ocular motility in the left eye (LE), in left gaze. Otherwise, the examination showed no pathological findings: best corrected visual acuity (BCVA) both eyes (OU) 1 (Snellen chart), normal slit lamp examination and pupillary reflexes, normal intraocular pressure (IOP) and fundus aspect. Diplopia tests revealed a horizontal diplopia, exacerbated in left gaze. Sixth nerve palsy suspicion was raised and the patient was directed to the neurology department. Following magnetic resonance imaging, with angiographic sequence, a complex intracerebral vascular malformation that interacted with the cranial nerves and determined horizontal diplopia, was found. For a correct diagnosis, we needed a good collaboration between various medical specialties, especially ophthalmology and neurology, because patients with diplopia often present for the first time at the ophthalmologist. Abbreviations: BCVA = best corrected visual acuity, IOP = intraocular pressure, LE = left eye, RE = right eye.

Simultaneous and Sequential Development of Sixth Nerve Palsy and Horner's Syndrome from Carotid Cavernous Sinus Fistulas.

The combination of ipsilateral sixth nerve palsy (6NP) and Horner's syndrome (Horner's) is a localizing sign of an injury to the posterior cavernous sinus. The presentation and clinical course of 3 patients presenting with coexisting ipsilateral 6NP and Horner's as a result of carotid cavernous sinus fistulas (CCFs) are discussed in this case series. We highlight these cases to show the possible sequence of events: (i) simultaneous discovery of 6NP and Horner's, (ii) 6NP followed by Horner's, and (iii) Horner's followed by 6NP. It is important to carefully assess for Horner's in patients with 6NP as this has high localizing value. In patients with a red eye consistent with a CCF, identifying Horner's also has high localizing value and can confirm the suspicion of a CCF. Clinicians should recognize that although 6NP and Horner's localize to the cavernous sinus and may be due to a CCF, they may appear in isolation or sequentially. It is also important to understand that Horner's and 6NP have different prognoses: 6NP usually resolves over time, whereas Horner's tends to persist.