High-flow carotid cavernous fistula and 'white eye': A rare and easily misdiagnosed presentation - A case report and literature review

The three classic symptoms of carotid cavernous fistula (CCF) are pulsating exophthalmos, bruit and conjunctival chemosis. Here, we present a clinical case of isolated abducens nerve palsy due to a high-flow CCF in an 84-year-old woman, without the typical congestive orbito-ocular features. It was a diagnostic challenge because, for patients older than 50 years with cardiovascular risk factors, ischaemic mononeuropathy is the most frequent aetiology. This case illustrates the least common type of CCF that can be easily misdiagnosed. Physicians should consider fistula as a possible diagnosis in a patient with isolated abducens nerve palsy even without the classic triad.

Abducens Nerve Palsy as a Rare Complication of Herpes Zoster Ophthalmicus: A Case Report

Herpes zoster ophthalmicus (HZO) is a condition resulting from the reactivation of dormant varicella zoster virus within the sensory nerve ganglion in the ophthalmic branch of the trigeminal nerve. The tell-tale rash along one side of the nerve tract accompanied by pain, a burning sensation, and itching alerts health practitioners on the right path to diagnosis. Conversely, HZO can present with other rarer complications such as intraocular and extraocular manifestations. This case report deals with a seemingly healthy 45-year-old female who developed left abducens nerve palsy within one week of developing a vesicular rash on the same side. Curiously, those afflicted are usually of an advanced age or suffer from an immunocompromised state; this patient however suffered from no other comorbidities nor did she report having been in contact with anyone of a similar affliction. In this case, the classical treatment regime of antivirals and corticosteroids resulted in the complete resolution of the infection and the return of full ocular function. Being able to recognize and appreciate these typical and atypical signs and symptoms of HZO can aid in the further propagation of good outcomes and timely resolutions.

Transient recurrent episodes of abducens nerve palsy and cheiro-oral syndrome in a sub-occlusive carotid bulb atherosclerotic stenosis

We report the case of a male in his 50s with a history of smoking admitted to our hospital for three transient recurrent episodes of less than 60 min of cheiro-oral paresthesias and binocular horizontal diplopia with convergent strabismus. On admission, his neurological examination was normal. Cerebral magnetic resonance imaging showed no cerebral lesion. Computed tomography angiography showed a sub-occlusive right carotid bulb atherosclerotic stenosis, the absence of abnormality of the subclavian arteries and the origin of the vertebral arteries, and no stenosis of the basilar artery or posterior cerebral arteries. Routine blood tests were normal with glycated hemoglobin of 6.5%. The patient underwent right carotid endarterectomy. One year after carotid endarterectomy, the patient has had no other cerebrovascular events.

Rare Combination of Abducens Nerve Palsy and Optic Neuritis on the Same Side: Case Report and Review of 8 Patients in Literature

The concurrent development of abducens nerve palsy and optic neuritis on the same side is rare. Here we presented an 82-year-old man who developed the combination of abducens nerve palsy and optic neuritis on the left side 2 months after the sixth inoculation of COVID-19 mRNA vaccine. In past history at 45 years old, he experienced subarachnoid hemorrhage and underwent surgery for the clipping of intracranial aneurysm. The patient had no systemic symptoms, such as general fatigue, fever, arthralgia, and skin rashes. Physical and neurological examinations were also unremarkable. Since the aneurysmal metal clip used at that time was not compatible with magnetic resonance imaging, he underwent computed tomographic (CT) scan of the head and showed no space-occupying lesion in the orbit, paranasal sinuses, and brain. As an old lesion, the anterior temporal lobe on the left side had low-density area with metallic artifact on the left side of the skull base, indicative of metal clipping. In 4 weeks of observation from the initial visit, he showed complete recovery of visual acuity and became capable of abducting the left eye in full degrees. We also reviewed 8 patients with the combination of abducens nerve palsy and optic neuritis in the literature to reveal that the combination of signs did occur in mild meningitis with rare infectious diseases and in association with preceding herpes zoster in the first branch of the trigeminal nerve. The course of the present patient suggested that the combination of signs might be vaccine-associated.

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.

Electromyographic predictors of abducens nerve palsy after endoscopic skull base surgery

OBJECTIVE

Recovery of abducens nerve palsy (ANP) after endoscopic endonasal skull base surgery (ESBS) has been shown to be potentially predicted by postoperative ophthalmological examination. Triggered electromyography (t-EMG) and free-run electromyography (f-EMG) activity provide an intraoperative assessment of abducens nerve function, but associations with long-term ANP outcomes have not been explored. The objective of this study was to describe intraoperative abducens EMG characteristics and determine whether these electrophysiological profiles are associated with immediately postoperative and long-term ANP outcomes after ESBS.

METHODS

The authors conducted a 5-year (2011-2016) retrospective case-control study of patients who underwent ESBS in whom the abducens nerve was stimulated (t-EMG). Electrophysiological metrics were compared between patients with a new postoperative ANP (cases) and those without ANP (controls). Pathologies included chordoma, pituitary adenoma, meningioma, cholesterol granuloma, and chondrosarcoma. Electrophysiological data included the presence of abnormal f-EMG activity, t-EMG stimulation voltage, stimulation threshold, evoked compound muscle action potential (CMAP) amplitude, onset latency, peak latency, and CMAP duration at various stages of the dissection. Controls were selected such that pathologies were similarly distributed between cases and controls.

RESULTS

Fifty-six patients were included, 26 with new postoperative ANP and 30 controls without ANP. Abnormal f-EMG activity (28.0% vs 3.3%, p = 0.02) and lack of response to stimulation (27% vs 0%, p = 0.006) were more frequent in patients with immediately postoperative ANP than in controls. Patients with immediately postoperative ANP also had a lower median CMAP amplitude (35.0 vs 71.2 μV, p = 0.02) and longer onset latency (5.2 vs 2.8 msec, p = 0.04). Comparing patients with transient versus persistent ANP on follow-up, those with persistent ANP tended to have a lower CMAP amplitude (12.8 vs 57 μV, p = 0.07) and higher likelihood of not responding to stimulation at the end of the case (45.5% vs 7.1%, p = 0.06). Abnormal f-EMG was not associated with long-term ANP outcomes.

CONCLUSIONS

The presence of f-EMG activity, lack of CMAP response to stimulation, decreased CMAP amplitude, and increased CMAP onset latency were associated with immediately postoperative ANP. Long-term ANP outcomes may be associated with t-EMG parameters, including whether the nerve is able to be stimulated once identified and CMAP amplitude. Future prospective studies may be designed to standardize abducens nerve electrophysiological monitoring protocols to further refine operative and prognostic utility.

A Case of Mycoplasma Infection with an Atypical Presentation of Abducens Nerve Palsy, Erythema Multiforme and Polyarthritis without Respiratory Manifestations

Mycoplasma pneumoniae is a self-propagating microorganism that commonly causes respiratory tract infections. It can also cause a variety of extrapulmonary symptoms with or independently of respiratory symptoms, such as skin lesions, arthralgia, myalgia, hemolysis, cardiac lesions, gastrointestinal symptoms, and central nervous system lesions, which are rare manifestations reported in approximately 0.1% of cases. In this study, we present a unique case of Mycoplasma-related abducens nerve palsy, polyarthritis, and erythema multiforme without respiratory disease. The patient was a 69-year-old woman who presented to our hospital with a skin rash, fever, arthralgia, and diplopia without respiratory symptoms. Brain magnetic resonance imaging showed optic neuritis on the right side, suggesting the diplopia was caused by right abducens nerve palsy. However, the etiologies of abducens nerve palsy were not revealed by the physical examination, blood biochemistry tests, or bacteriological examinations, including the cerebrospinal fluid examination obtained at admission. Mycoplasma infection was suspected from erythema multiforme revealed by a skin biopsy and polyarthralgia, and it was finally diagnosed according to elevated Mycoplasma particle agglutination (PA) antibodies in paired serum. Though minocycline did not improve her diplopia, the daily administration of 30 mg of prednisolone gradually improved her symptoms, and the Mycoplasma PA antibody titer, which was regularly measured in the clinical course, also decreased, suggesting a relationship between Mycoplasma infection and abducens nerve palsy. This is the first case of isolated abducens nerve palsy, which was reported as the only central neurological symptom in an adult patient with Mycoplasma infection. The mechanism or pathogenesis of CNS manifestations caused by Mycoplasma pneumoniae remains to be elucidated, and further investigation is needed. Hence, Mycoplasma infection is a common disease. Clinicians should be aware of the diverse manifestations, including abducens nerve palsy, of Mycoplasma infection and should consider Mycoplasma infection even in the absence of typical respiratory symptoms.

Neurosurgical Intervention in the Treatment of Gradenigo Syndrome: A Case Report

Gradenigo syndrome comprises a clinical triad: retro-orbital pain, sixth cranial nerve palsy, and purulent otorrhea. This clinical syndrome often arises secondary to petrous apicitis, which is an infection of the petrous apex that may result from the contiguous spread of infection from the ear or mastoid. This syndrome is very rare, and based on the existing literature, the initial approach for treatment involves long-term administration of IV antibiotics, which may resolve the underlying infection related to petrous apicitis, mastoiditis, and/or otitis media. In this case, the patient, a 69-year-old male, had a progression of several symptoms, including recurrent headaches, diplopia, hearing loss, and dysphagia, despite long-term antibiotic therapy and a prior mastoidectomy. Thus, the neurosurgical team decided to intervene via anterior petrous bone resection via the Kawase approach, which unfortunately did not result in the resolution of the patient's symptoms. The patient continued to have symptoms of Gradenigo syndrome, including sixth cranial nerve palsy and was subsequently referred to outpatient follow-up for further management. In this report, we present the patient's case and a brief review of the literature concerning various treatment modalities for Gradenigo syndrome.

Isolated Abducens Nerve Palsy Following Spinal Anesthesia

A healthy 28-year-old lady, para 1, presented to the emergency department with persistent frontal headache, nausea, and vomiting following an emergency cesarean section four days ago. She experienced difficulties with six failed attempts of spinal anesthesia intrapartum before conversion to general anesthesia. A 25-gauge Whitacre needle was utilized for administering spinal anesthesia under a sitting position. The anesthetist noticed a loss of resistance upon needle insertion, but only a negligible amount of cerebrospinal fluid was obtained upon removing the stylet. The patient underwent an emergency cesarean section due to fetal distress, and she was not in labor during the attempts of spinal anesthesia. Otherwise, the cesarean section lasted for an hour and was uneventful. No intrapartum eclampsia or pre-eclampsia. She was diagnosed with post-dural puncture headache, and her symptoms improved after receiving intravenous hydration, oral caffeine, and non-steroidal anti-inflammatory drug (NSAIDs). However, on the sixth day after the spinal anesthesia, she suddenly developed double vision. Examination showed bilateral visual acuity was measured at 6/7.5. No proptosis or ptosis was noted. The relative afferent pupillary defect was negative with no anisocoria. Both eyes were orthophoria with normal head posture. Extraocular muscles revealed a right abduction restriction of -1 with the patient complaining of binocular horizontal diplopia at the right gaze, consistent with right abducens nerve palsy. Systemic neurological findings were normal, and imaging results were unremarkable. Diagnosis of right abducens nerve palsy post-dural puncture was made clinically. The patient was keen on conservative management instead of blood patch therapy. Hence, she was treated supportively via uni-ocular patching to relieve diplopia. Spontaneous complete recovery of the right abducens nerve palsy was observed after three weeks. Cranial nerve palsy is a rare complication reported following spinal anesthesia, with the abducens nerve being the commonest nerve involved. Although it is not always benign, the presented case showed spontaneous complete recovery of the right abducens nerve palsy after three weeks. Awareness of this uncommon complication will avoid unnecessary distress and investigative burden to both the patient and the doctor.

Sixth Nerve Palsy From Multiple Myeloma in Central Nervous System: Case Series and Review of Current Literature

We reported two cases of the central nervous system (CNS) multiple myeloma (MM) with unusual presentation of sixth nerve palsy. The first patient developed in the setting of newly diagnosed MM and the second patient in the relapsed refractory setting. One underwent surgery, and the other received radiation. Both patients received systemic chemotherapy and noted improvement. We also performed a comprehensive literature review of previously published cases of sixth nerve palsy from MM. This review highlights the importance of recognizing this presentation of CNS multiple myeloma to avoid delays in diagnosis and to get appropriate management in time.

Occurrence of the ossification of petrosphenoid ligament: a retrospective radiologic study from computed tomographic images

BACKGROUND

Various ligaments present in the skull base are of clinical and surgical importance. One among them, is the petrosphenoid ligament (PSL). PSL may ossify either in a partial or complete form and forms the roof of Dorello's canal underneath which the abducens nerve passes. Studies argued both protective and adverse effects of the ossified PSL. Hence, the incidence of PSL ossification has become a relevant subject in clinical practice to radiologists, neurologists and neurosurgeons for understanding its potential role in abducens nerve compression.

MATERIALS AND METHODS

We have undertaken this study to investigate the incidence of PSL ossification from multidetector computed tomography (MDCT) images of the patients who had been referred to the Medical Imaging Department of Mubarak Al-Kabeer Hospital in Kuwait. We retrospectively assessed a total of 200 patients' head CT scans (400 petroclival regions) between January 2021 and June 2022 in which 59% were males (n = 118) and 41% were females (n = 82) aged between 18 and 91 years.

RESULTS

A total of 37 patients (26 male, 11 female) aged between 18-84 years were presented with ossification of PSL. Among these 37 patients, 28 patients were presented with unilateral ossified PSL, and 9 patients were presented with bilateral ossified PSL, amounting to the total of 46 ossified PSL from 400 CT images of the petroclival regions (11.5%). The genderwise and sidewise occurrence of the PSL ossification seen in different age groups were not statistically significant (p > 0.05). Among all the ossified cases, there was no patient presented with abducens nerve palsy.

CONCLUSIONS

We believe our results provide baseline data in the region for understanding PSL ossification and its impact on the abducens nerve palsy.

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.

A Case of a Ruptured Microaneurysm at the Tip of the Basilar Artery With Right Abducens Nerve Palsy at the Time of the Initial Rupture and Rerupture During an Outpatient Follow-Up

The presentation of abducens nerve palsy after each occurrence of subarachnoid hemorrhage (SAH) is rare. Herein, we report the case of a patient with a ruptured microaneurysm at the tip of the basilar artery who presented with right abducens nerve palsy at the time of the initial rupture and rerupture during an outpatient follow-up. A 52-year-old woman developed SAH with right abducens nerve palsy, which was treated with coil embolization. One year after the initial SAH, there was a relapse of the SAH and paresis of the right abducent nerve palsy. This may have been caused by the location of the abducens nerve in relation to the surrounding structures, which were susceptible to the effects of hematoma or intracranial pressure fluctuations. Stent-assisted coil embolization is an effective treatment for regrowth that appears after endovascular therapy of microaneurysms.

Simultaneous Unilateral Abducens Nerve Palsy and Contralateral Anterior Ischaemic Optic Neuropathy as the Presenting Signs of Giant Cell Arteritis

Ischaemic optic neuropathy is the most common, feared, and recognised ocular manifestation of giant cell arteritis (GCA), while extraocular muscle palsy rarely occurs in the disease. Overlooking the diagnosis of GCA in aged patients with acquired diplopia and strabismus is not only sight- but also life-threatening. Here, we present, for the first time, a case of unilateral abducens nerve palsy and contralateral anterior ischaemic optic neuropathy as the presenting signs of GCA in a 98-year-old woman. Prompt diagnosis and treatment prevented further visual loss and systemic complications and allowed for rapid resolution of the abducens nerve palsy. We also aim to discuss the possible pathophysiological mechanisms of diplopia in GCA and to emphasise that acquired cranial nerve palsy must raise suspicion of this severe disease in elderly patients, particularly in association with ischaemic optic neuropathy.

Atypical Gradenigo Syndrome in an Elderly Man Resolved with Mastoidectomy and Petrous Apicectomy

Gradenigo syndrome (GS) was described primarily in the paediatric population, especially in the pre-antibiotic era. GS is rarely reported in the elderly population, especially in the post-antibiotic era. We present the rare case of a 67-year-old man who presented with an incomplete triad of symptoms (without abducens nerve palsy) of GS that failed medical therapy and was successfully treated with surgical intervention (mastoidectomy and petrous apicectomy). Physicians should be familiar with atypical presenting symptoms of GS as it can lead to life-threatening complications, especially in the elderly. GS cases resistant to medical therapy may require prompt appropriate imaging studies and surgical intervention.

LEARNING POINTS

Gradenigo syndrome may present with an incomplete triad (without abducens nerve palsy), especially in the post-antibiotic era.Gradenigo syndrome can rarely affect immunocompromised elderly patients.Gradenigo syndrome cases resistant to medical therapy may require prompt appropriate imaging studies and surgical intervention (mastoidectomy and petrous apicectomy).

Isolated Abducens Nerve Palsy in a Patient With COVID-19: A Case Report and Literature Review

INTRODUCTION

The pandemic of coronavirus disease 2019 (COVID-19) stands as a major global health and social burden. As cases are growing, several other symptoms, besides the typical respiratory ones, are emerging. The involvement of the nervous system is increasingly recognized with manifestations ranging from hyposmia to meningoencephalitis and cranial neuropathies.

CASE REPORT

We report the case of a 41-year-old female patient who presented to the emergency department complaining of diplopia and headache over the last 2 days. She denied any medical history, as well as any other neurological or respiratory symptom. A detailed neurological and ophthalmological examination revealed a limitation to the abduction of the right eye due to palsy of the right lateral rectus muscle causing painless, horizontal diplopia in the right gaze. The computed tomography of the brain was normal. Based on the detected lymphopenia, she was tested for COVID-19 and was positive. The cerebrospinal fluid analysis showed no abnormalities, while also a repeated head computed tomography was similarly normal. The patient received no specialized medical treatment, and after 6 days, she was discharged home having a minimal degree of persistent diplopia. Two weeks later, brain magnetic resonance imaging was performed that was similarly unrevealing.

CONCLUSIONS

Isolated abducens nerve palsy can be the only presenting symptom in COVID-19. Although several pathophysiological mechanisms have been proposed, the exact nature of this manifestation has not been clarified yet. Vigilance is required by neurologists to detect and manage patients with such subtle clinical presentations.

The Immediate Onset of Isolated and Unilateral Abducens Nerve Palsy Associated with COVID-19 Infection: A Case Report and Literature Review

Cranial nerve palsy associated with coronavirus disease 2019 (COVID-19) is rare. We herein report the first Asian case of the immediate onset of isolated and unilateral abducens nerve palsy (ANP) accompanied with COVID-19 infection. A 25-year-old man developed diplopia one day after the COVID-19 symptom onset. Neurological examination revealed limitation of left eye abduction without ataxia and hyporeflexia. Negative anti-ganglioside antibody results and mild albuminocytological dissociation were noted. The patient was diagnosed with left ANP accompanied by COVID-19 infection. The ANP spontaneously recovered without treatment. ANP can develop during the early phase of COVID-19 infection and adversely affect patients' quality of life.

Seropositive Muscle-Specific Tyrosine Kinase Myasthenia Gravis Presenting as a Late-Onset Isolated Sixth Nerve Palsy: A Case Report and a Brief Review of Subtypes of Myasthenia Gravis

Autoimmune myasthenia gravis (MG) is a well-characterized post-synaptic disorder of neuromuscular transmission. Immunologically, there is complement activation with autoantibodies binding to the acetylcholine receptor (AChR), leading to cross-linking and internalization of the receptor. The diminished functional clustering leads to impaired folding of the post-synaptic membrane. The antibodies generated by the autoimmune process are directed at the various components of the post-synaptic membrane and its scaffolding, including the AChR, muscle-specific tyrosine kinase (MuSK), low-density lipoprotein receptor-related protein 4 (LRP4), and the other recently described epitopes including the extracellular membrane proteins agrin and collagen Q (ColQ). MuSK MG is phenotypically different from classic AChR-antibody-mediated MG by a more frequent presentation of bulbar weakness, less responsiveness to symptomatic therapy with acetylcholinesterase inhibitors, the absence of a thymoma, and a better therapeutic response to a cluster of differentiation (CD-20) B-cell therapy such as rituximab. The pleiotropic ocular findings of ocular MG include ptosis, fluctuating and variable involvement of cranial nerves III, IV, and VI, pseudo-internuclear ophthalmoplegia (INO), near-complete or complete ophthalmoplegia, and variable gaze palsies. To our knowledge, we present one of the very few reported cases of MuSK MG presenting as isolated sixth nerve palsy. The localization of a sixth nerve palsy with lateral rectus muscle weakness can be due to disease anywhere along its path from the abducens nucleus, coursing at the skull base through Dorello's canal, through the cavernous sinus, and along its path through the superior orbital fissure and into the orbits. A painless sixth nerve palsy should alert the clinician to MuSK-MG as we outline in this case report.

Outcomes of half-width vertical rectus transposition augmented with posterior fixation sutures for sixth cranial nerve palsy

AIM

To describe the experience with half-width vertical muscles transposition (VRT) augmented with posterior fixation sutures.

METHODS

The clinical charts of all patients, who underwent half-width VRT augmented with posterior fixation sutures for sixth cranial nerve palsy from January 2003 to December 2018, were retrospectively reviewed. For each patient, pre- and post-operatively, the largest measured angle was used for the calculations, usually resulting with the angle for distance, except in young infants, where measurements were made at near fixation using the Krimsky test.

RESULTS

Fifteen patients met the inclusion criteria for the study, of them 9 (60.0%) had also medial rectus muscle recession at the time of surgery. Mean follow-up period was 21.4±23.2mo (range 1.5-82mo). Preoperative mean esotropia was 51.3±19.7 prism diopter (PD; range 20-90 PD). Postoperative mean deviation on final follow-up was 7.7±20.2 PD (range -40 to 35 PD; P=0.018). In all patients with preoperative abnormal head position, improvement was noted. Ten (66.7%) patients had improvement in abduction and 10 (66.7%) patients reported improvement in their diplopia, by final follow-up. The addition of medial rectus recession was correlated with a larger change in postoperative horizontal deviation compared to baseline (P=0.026). Two (13.3%) patients developed a vertical deviation in the immediate postoperative period which had resolved in one of them.

CONCLUSION

Half-width VRT augmented with posterior fixation suture, with or without medial rectus muscle recession, is an effective and safe procedure for esotropia associated with sixth cranial nerve palsy. A major improvement in the angle of deviation is expected. Most patients will have improvement in their abnormal head position and diplopia.

Clinical Course of Abducens Nerve Palsy in Patients with Ruptured Vertebral Artery Dissecting Aneurysms

Objective

There are few detailed reports on abducens nerve palsy due to a ruptured vertebral artery dissecting aneurysm (VADA). We investigated the clinical characteristics and long-term course of abducens nerve palsy in ruptured VADA patients treated by endovascular surgery.

Methods

Of the 51 cases of ruptured VADA treated by endovascular intervention from 2011 to 2019, 31 with a good/fair outcome, in which ocular motility disorder was able to be followed, were included and investigated.

Results

In all, 11 patients (35.5%) had abducens nerve palsy, and the World Federation of Neurological Surgeons (WFNS) grade and Hunt & Hess (H&H) grade at the time of arrival of patients with abducens nerve palsy were significantly higher than those of patients without abducens nerve palsy. Of the 10 patients who were able to be followed, abducens nerve palsy in 3 completely recovered in 7-180 days. Abducens nerve palsy improved in five patients and remained in two patients.

Conclusion

More severe neurological findings on admission reflect a higher rate of abducens nerve palsy. Diplopia induced by abducens nerve palsy is one of the most important sequelae of ruptured VADA, which impairs the daily activities of the patients. Some cases of abducens nerve palsy improve over a long period. Therefore, appropriate diagnosis and follow-up should be concerned.

Herpes Simplex Virus-2 Meningoencephalitis With Abducens Nerve Palsy With Literature Review

Herpes simplex virus (HSV), a human alpha herpes virus, is responsible for most infections caused by herpes viruses worldwide. Among the herpes simplex viruses, both HSV 1 and 2 cause significant morbidity. HSV-2 accounts for most genital infections with extragenital complications involving the groin, thigh, or other pelvic areas. HSV-2 is the leading viral cause of sexually transmitted diseases. Viral dissemination via the blood or the cutaneous route during primary infection can affect joints, liver, lungs, spinal cord, and brain. HSV-2, by nature of its higher reactivation frequency, leads to clinical reactivation or subclinical shedding, resulting in increased transmission risk during unprotected sexual encounters. HSV-2 reactivation can result in lesions involving the fingers, skin, eyes, brain, and visceral organs such as the esophagus, lung, and liver. Ocular involvement results in keratitis, blepharitis, conjunctivitis, and rarely necrotizing retinitis. Oculomotor cranial nerve involvement by HSV is a rare entity even in patients with human immunodeficiency virus infection. Clinical features associated with reactivation are seen in primary infections, especially in children and adolescents. A medical literature search resulted in a few cases caused by a varicella-zoster virus but none by HSV. Here we describe a young female with a newly diagnosed meningoencephalitis and abducens nerve palsy (first case) due to a primary HSV infection. She came to the emergency department with headache, confusion, abnormal behavior and later developed diplopia as an inpatient. She was treated successfully with two weeks of acyclovir.

The diagnostic dilemma of a pregnant woman presenting with an isolated sixth nerve palsy: A case report

Pregnant women presenting with isolated cranial palsies are uncommon. Isolated sixth nerve (abducens nerve) palsy can occur for a variety of reasons and neuroimaging is often performed to identify an underlying cause. We report a case of a woman in her third pregnancy with preeclampsia who presented with an isolated sixth nerve palsy. The diagnosis of aseptic cavernous sinus thrombosis was made and she subsequently made a full recovery.

IgG4-related hypophysitis diagnosed by retroperitoneal mass biopsy in a patient presenting with abducens nerve palsy: A case report (CARE-compliant article)

RATIONALE

Immunoglobulin G4 (IgG4)-related hypophysitis is a rare disorder which often requires invasive pituitary gland biopsy to confirm its diagnosis. We present a case whereby peripheral organ lesion biopsy and imaging findings were sufficient for the diagnosis.

PATIENT CONCERNS

A 77-year-old man with diplopia was referred to our department by an opthomologist who had diagnosed the patient with right abducens nerve palsy.

DIAGNOSES

Head magnetic resonance imaging revealed enlargement of the pituitary gland and pituitary stalk, while hormonal analysis revealed panhypopituitarism, thereby indicating a diagnosis of hypophysitis. Abdominal computed tomography imaging revealed a solid mass that encompassed the left kidney ureter. Although the patient did not have an increase in serum IgG4, a biopsy of the periureteral mass revealed infiltrating plasma cells that were positive when stained for IgG4.

INTERVENTIONS

The patient was given corticosteroid pulse therapy (methylprednisolone: 1 g × 3 days), followed by oral corticosteroids (prednisolone, 0.5 mg/kg/d).

OUTCOMES

The right abducens nerve palsy improved and the pituitary lesion shrank after the initiation of corticosteroid treatment.

CONCLUSION

Based on the diagnosis of IgG4-related disease in the retroperitoneal organ and response to corticosteroid treatment, this patient was diagnosed with IgG4-related hypophysitis. This hypophysitis caused enlargement of the pituitary gland with resulting nerve compression, causing abducens nerve palsy. When IgG4-related hypophysitis is suspected, a thorough examination of other organ lesions and biopsy should be considered.

CyberKnife Radiotherapy for Skull Base Petroclival Metastases Including Dorello's Canal: Report of 10 Cases

Skull base petroclival metastases cause diplopia due to abducens nerve palsy. Diplopia is visually disabling, and skull base metastasis is extremely difficult to treat even with microscopic surgery. However, stereotactic radiotherapy with CyberKnife (Accuray Incorporated, Sunnyvale, California) has been very successful in 10 cases. As the abducens nerve runs through Dorello’s canal in the skull base, the radiation dose and fraction were adjusted to avoid damage to the nerve. Since these metastases are not located inside the brain but in the skull base, contrast magnetic resonance imaging (MRI) combined with fluorodeoxyglucose-positron emission tomography (FDG-PET) was essential to detect the cancers.

Iatrogenic Dural Puncture-induced Abducens Nerve Palsy: Treatment with Epidural Blood Patch

Iatrogenic dural puncture (IDP) is a known complication of epidural anesthesia. While operator experience is certainly critical in preventing inadvertent dural punctures, it can happen even in the hands of a skilled operator. Often, IDP presents as post-dural puncture headache (PDPH) without the involvement of cranial nerves; however, infrequent excessive loss of cerebrospinal fluid (CSF) can lead to intracranial hypotension causing compression of the cranial nerves, in particular, the abducens nerve. Here, we describe the case of a patient who suffered from an atypical headache with neurological sequalea from an IDP. Epidural blood patch (EBP) is an effective treatment for PDPH, especially in cases that are not responsive to conservative therapy. However, it may be the first line of defense in patients with neurological symptoms arising from low intracranial hypotension. In our case report, as well as others reported in the literature, there was a complete resolution of the neurological symptoms after the EBP was placed.

Herpetic optic perineuritis presenting as classic abducens nerve palsy

Optic perineuritis is a rare manifestation of herpes zoster ophthalmicus (HZO). Relative afferent pupillary defect (RAPD) is an important early clue to an impending nerve involvement, and robust clinical examination allows early detection of such rare metachronous manifestation of cutaneous HZ and institution of timely management for such sight-threatening conditions.

Using Botulinum Toxin A as an Adjunct in the Surgery of Large-Angle Sensory Exotropia and Abducens Nerve Palsy

Regarding the review article by Escuder AG, Hunter DG, entitled "The Role of Botulinum Toxin in the Treatment of Strabismus" Seminars in Ophthalmology. 2019;34(4): 198-204, we cannot agree with you more with your point of view about the dosage preparation for botulinum toxin A (BTA) in the strabismus surgery. Moreover, we also included a case series that used BTA as an adjunct in the surgery for large-angle sensory exotropia and abducens nerve palsy.

An unusual presentation of sixth nerve palsy: neurobrucellosis

Abducens nerve palsy is generally seen in older patients with diabetes and hypertension. It is relatively rare in young and otherwise healthy patients. An extensive differential diagnosis is considered in patients younger than 50 years of age who develop a sixth nerve palsy. We report here a 25-year-old patient from Turkey who was admitted with sixth nerve palsy as a component of neurobrucellosis. She was referred to our clinic because she had double vision and restricted right eye abduction. During the ophthalmic examination, both pupils were round and reactive to light and accommodation. Extraocular movements were intact with the exception that the right eye was unable to abduct. Magnetic resonance imaging revealed no pathology. She also had a diagnosis of brucellosis and her abducens nerve palsy was a form of clinical manifestation of neurobrucellosis. We conclude that neurobrucellosis should be considered in patients with sixth cranial nerve palsy especially in areas where brucellosis is endemic.

Convergent strabismus fixus after bilateral abducens nerve palsies due to aneurysms: A case report

RATIONALE

Convergent strabismus fixus is an ocular motor abnormality in which the eye is fixed in adduction. This condition is mostly associated with high myopia and is caused by a displacement of the extraocular muscles. We report a nonmyopic woman with convergent strabismus fixus due to aneurysms.

PATIENT CONCERNS

A 79-year-old woman complained of progressive worsening of esotropia about 50 years prior to her visit. Neuroimaging showed that the eye was not dislocated, and the extraocular muscles were not displaced. However, aneurysms were found bilaterally from the intracavernous carotid arteries and the location was on both abducens nerves.

DIAGNOSES

Chronic bilateral abducens nerve palsies due to aneurysms.

INTERVENTIONS

Endovascular treatment was successfully performed for the aneurysms.

OUTCOMES

Convergent strabismus fixus still remained.

LESSONS

Chronic abducens nerve palsies may develop to nonmyopic convergent strabismus fixus without displacement of extraocular muscles, and mass lesions in the brain including aneurysms should be ruled out when orbital MRI cannot explain the condition.

Cranial nerve palsies due to incidental durotomy in lumbar Spine surgery: a case report

We present a 65-year old man who underwent a partial laminectomy at L4. During surgery an incidental durotomy (ID) appeared. Postoperatively he developed cranial nerve palsies. Subsequent to surgical closure of the ID, symptoms completely resolved within three months.

Abducens Nerve Palsy as Initial Presentation of Multiple Myeloma and Intracranial Plasmacytoma

Central Nervous System (CNS) involvement in multiple myeloma and/or multifocal solitary plasmacytoma is rare. Although they are unique entities, multiple myeloma (MM) and plasmacytoma represent a spectrum of plasma cell neoplastic diseases that can sometimes occur concurrently. Plasmacytomas very often present as late-stage sequelae of MM. In this case report, we report a 53-year-old female presenting with right abducens cranial nerve (CN) VI palsy as an initial presentation secondary to lesion of the right clivus.

Temporal Arteritis Presenting as an Isolated Bilateral Abducens Nerve Palsy: A Rare Case of a 65-year-old Male

Giant cell arteritis (GCA) or temporal arteritis (TA) is a granulomatous inflammation of medium to large-sized arteries. It may have a diverse presentation. The most common presenting symptoms of GCA are fever, malaise, unilateral headache, jaw claudication, polymyalgia rheumatica (PMR) and ophthalmoplegia. Most severe sequelae of GCA could be blindness. We report a case of a 65-year-old Caucasian male who presented for the third time with recurrent episodes of diplopia. Neurologic exam showed bilateral cranial nerve (CN) VI palsy, slightly worse on the right than the left side. Other focal neurological deficits were absent. GCA was considered and biopsy of the temporal artery was performed which showed necrotizing pan-arteritis, consistent with GCA. The patient was empirically treated with intravenous (IV) methylprednisolone while awaiting the biopsy results which resulted in the resolution of the symptoms. As far as we know, this is the second case in the literature about the bilateral sixth CN involvement in the background of GCA.

[Cerebrospinal fluid leakage and abducens nerve palsy caused by bowling activity]

Cerebrospinal fluid leakage can develop due to traffic trauma or lumbar puncture; however, in many cases, it develops spontaneously without any obvious cause. This report describes a case of cerebrospinal fluid leakage caused by bowling activity. A 57-year-old woman adjusted her bowling form, which led to the development of an orthostatic headache and double vision. Cerebrospinal fluid leakage and right abducens nerve palsy was diagnosed, which was resistant to conservative treatment. An epidural blood patch was performed, leading to an improvement in the headache and abducens nerve palsy. The hypotension and nerve palsy may have been caused by small amounts of cerebrospinal fluid leakage due to repeated traction of the brachial plexus and nerve root resulting from an irregular bowling form. To the best of our knowledge, there are no reported cases of cerebrospinal fluid leakage caused by bowling; therefore, this is a valuable case to investigate the mechanism of onset. Similar mechanisms may have remained undiscovered in other cases of spontaneous intracranial hypotension.

Bilateral abducens nerve palsies and urinary retention caused by the rupture of a vertebral artery aneurysm: A case report and literature review

RATIONALE

Bilateral abducens nerve deficits caused by vertebral artery (VA) aneurysm have been reported, but there have been no reports regarding accompanying urinary retention.

PATIENT CONCERNS

In this report, we describe an unusual case with bilateral abducens nerve palsy and urinary retention due to rupture of a vertebral aneurysm.

DIAGNOSES

Subarachnoid hemorrhage caused by the rupture of a left VA aneurysm.

INTERVENTIONS

The VA aneurysm was successfully controlled by coil embolization.

OUTCOMES

Urinary retention was improved after embolization and recovered by the day the patient left hospital. The bilateral abducens nerve palsy gradually recovered 6 months later.

LESSONS

This case emphasizes the importance of maintaining a broad, open mind in approaching the diagnosis and management of urinary retention associated with cranial nerve symptoms and reacting quickly to the clinical developments.

Isolated abducens nerve palsy associated with subarachnoid hemorrhage: a localizing sign of ruptured posterior inferior cerebellar artery aneurysms

OBJECTIVE Compressive cranial nerve syndromes can be useful bedside clues to the diagnosis of an enlarging intracranial aneurysm and can also guide subsequent evaluation, as with an acute oculomotor nerve (cranial nerve [CN] III) palsy that is presumed to be a posterior communicating artery aneurysm and a surgical emergency until proven otherwise. The CN VI has a short cisternal segment from the pontomedullary sulcus to Dorello's canal, remote from most PICA aneurysms but in the hemodynamic pathway of a rupturing PICA aneurysm that projects toward Dorello's canal. The authors describe a cranial nerve syndrome for posterior inferior cerebellar artery (PICA) aneurysms that associates subarachnoid hemorrhage (SAH) and an isolated abducens nerve (CN VI) palsy. METHODS Clinical and radiological data from 106 surgical patients with PICA aneurysms (66 ruptured and 40 unruptured) were retrospectively reviewed. Data from a group of 174 patients with other aneurysmal SAH (aSAH) were analyzed in a similar manner to control for nonspecific effects of SAH. Univariate statistical analysis compared incidence and risk factors associated with CN VI palsy in subarachnoid hemorrhage. RESULTS Overall, 13 (4.6%) of 280 patients had CN VI palsy at presentation, and all of them had ruptured aneurysms (representing 13 [5.4%] of the 240 cases of ruptured aneurysms). CN VI palsies were observed in 12 patients with ruptured PICA aneurysms (12/66 [18.1%]) and 1 patient with other aSAH (1/174 [0.1%], p < 0.0001). PICA aneurysm location in ruptured aneurysms was an independent predictor for CN VI palsy on multivariate analysis (p = 0.001). PICA aneurysm size was not significantly different in patients with or without CN VI palsy (average size 4.4 mm and 5.2 mm, respectively). Within the PICA aneurysm cohort, modified Fisher grade (p = 0.011) and presence of a thick cisternal SAH (modified Fisher Grades 3 and 4) (p = 0.003) were predictors of CN VI palsy. In all patients with ruptured PICA aneurysms and CN VI palsy, dome projection and presumed direction of rupture were directed toward the ipsilateral and/or contralateral Dorello's canal, in agreement with laterality of the CN palsy. In patients with bilateral CN VI palsies, a medial projection with extensive subarachnoid blood was observed near bilateral canals. CONCLUSIONS This study establishes a localizing connection between an isolated CN VI palsy, SAH, and an underlying ruptured PICA aneurysm. CN VI palsy is an important clinical sign in aSAH and when present on initial clinical presentation may be assumed to be due to ruptured PICA aneurysms until proven otherwise. The deficit may be ipsilateral, contralateral, or bilateral and is determined by the direction of the aneurysm dome projection and extent of subarachnoid bleeding toward Dorello's canal, rather than by direct compression.

Post-traumatic Unilateral Avulsion of the Abducens Nerve with Damage to Cranial Nerves VII and VIII: Case Report

Traumatic injuries of the abducens nerve as a consequence of facial and/or head trauma occur with or without associated cervical or skull base fracture. This is the first report on unilateral avulsion of the abducens nerve in a 29-year-old man with severe right facial trauma. In addition, he exhibited mild left facial palsy, and moderate left hearing disturbance. Magnetic resonance imaging (MRI) using fast imaging employing steady-state acquisition (FIESTA) revealed avulsion of left sixth cranial nerve. We recommend thin-slice MR examination in patients with abducens palsy after severe facial and/or head trauma.

Sensorimotor Characteristics of Neuro-Ophthalmology and Oculo-Plastics Patients

BACKGROUND AND PURPOSE

Certified orthoptists are routinely required, as a standard component of outpatient care, to examine and identify the cause of double vision described by neuro-ophthalmology and oculo-plastics patients. Peer-reviewed articles in the strabismus literature describing the significance of this role of the orthoptists, especially in more complex cases of strabismus, do exist, but are outdated. The importance of creating a differential diagnosis in the understanding of the disease process is a well-recognized component of medical education and modern medicine.

PATIENTS AND METHOD

This work was a retrospective chart review and descriptive study of the most common clinical characteristics of adult neuro-ophthalmology and oculo-plastics patients seen over a 9-year period by an orthoptist in a large, urban academic institution in the United States. History and clinical data obtained included demographic information; whether the subjects were neuro-ophthalmology or oculo-plastic patients or both; chief complaint; past medical history and associated medical risk factors; past ocular history of strabismus or amblyopia; whether reported diplopia was monocular or binocular; visual acuities; sensorimotor examination and fusion status information; presence or absence of ptosis; pupil size and reactivity; basic accommodative function; orthoptist and physician diagnoses; and suggested treatment of diplopia.

RESULTS

Five hundred seventy-five subjects were identified based on inclusion criteria. Racial demographics matched that of the state of Maryland, with the majority of the patients being Caucasian. The minority were of Hispanic origin. Ninety-one percent of the study cohort was referred by the department of neuro-ophthalmology at the institution. Hypertension was a statistically significant medical risk factor for acquired strabismus and diplopia in this adult cohort. Etiology for the strabismus and associated diplopia suggested by the orthoptist was in close agreement with the final diagnosis made by the referring physician. Pupil-sparing oculomotor palsy (third cranial nerve, CN3) occurred as frequently as pupil-involving CN3, with tumor occurring more frequently as an etiology than aneurysm in both groups. Trochlear nerve palsy (CN4) was more often associated with hydrocephalus than abducens nerve palsy (CN6), and trauma remained a common association with acquired CN4 palsy. In patients with thyroid eye disease (TED), eso- and exo-deviations occurred with similar frequency. As has been reported in the literature, concomitant myasthenia gravis (MG) remained rare in these patients, although occurring with similar frequency in patients with both types of horizontal deviation. In patients with ptosis, asymmetry was not statistically more predictive of MG than symmetry. Prism was used most frequently, followed by surgery, to address diplopia symptoms. Lastly, there was a statistically significant association of acquired strabismus and diplopia in female subjects with breast cancer and no past ocular history of childhood strabismus or amblyopia.

CONCLUSION

The thorough assessment of sensorimotor function, fusion, and visual acuity provided by the orthoptist is an important clinical adjunct in developing the differential required to make an accurate final diagnosis, which sometimes may not subscribe to accepted clinical norms reported in the literature. The orthoptist also plays an important role in the nonsurgical treatment of acquired diplopia due to strabismus. Fresnel Press-On™ or ground-in spectacle prism was a commonly used treatment for diplopia.

Solitary Osteochondroma of the Skull Base: A Case Report and Literature Review

We report a case of an osteochondroma in the posterior clinoid process that occurred in a 43-year-old man with trochlear nerve palsy. Although the potential preoperative diagnoses based on computed tomography and magnetic resonance imaging included other intracranial tumors such as calcified meningioma, thallium-201 single-photon emission computed tomography effectively differentiated osteochondroma from those possibilities. Via an orbitozygomatic approach, a subtotal resection was achieved with a good relief of symptoms. Twenty-two cases of solitary osteochondromas in the skull base have been reported that have demonstrated little risk of recurrence or malignant transformation. However, surgery for skull base osteochondromas does carry a significant risk with a reported mortality > 10%. Although some previous reports advocate complete resection as the only curative method for skull base osteochondromas, the risks of total resection should be weighed against the chance for recurrence; our review of the literature demonstrated a relatively high mortality and an extremely low incidence of recurrence.

A Case of the Internal Carotid Artery-Posterior Communicating Artery Aneurysm Mimicking Tolosa-Hunt Syndrome

A 53-year-old woman experienced a right retrobulbar pain followed by ipsilateral extraocular palsies in all directions without dilated pupils or ptosis. Because a plain head computed tomography (CT) scan obtained on her initial visit showed no abnormal findings, such as subarachnoid hemorrhage or a giant cavernous aneurysm, her condition was provisionally diagnosed as Tolosa–Hunt syndrome and elective magnetic resonance (MR) imaging was scheduled. The day after her initial visit, however, she suddenly developed complete ptosis and a dilated pupil on the right side. Emergency MR imaging and angiography revealed a clover leaf-shaped aneurysm projecting to the cavernous sinus at the junction of the internal carotid artery and the posterior communicating artery. Her condition was diagnosed as impending rupture of the aneurysm, and she underwent emergency open surgery. Her symptoms completely resolved within the following 2 weeks. Our case demonstrated that a medium-sized internal carotid artery–posterior communicating artery aneurysm can cause simultaneous oculomotor and abducens nerve palsies with retrobulbar pain if the shape of the aneurysm is complicated. Although these symptoms are very similar to those of Tolosa–Hunt syndrome, we believe that prompt radiological examinations such as MR or 3D CT angiography should be performed to prevent subsequent rupture of the aneurysm.

Epidural Blood Patch for the Treatment of Abducens Nerve Palsy due to Spontaneous Intracranial Hypotension -A Case Report-

Intracranial hypotension is characterized by a postural headache which is relieved in a supine position and worsened in a sitting or standing position. Although less commonly reported than postural headache, sixth nerve palsy has also been observed in intracranial hypotension. The epidural blood patch (EBP) has been performed for postdural puncture headache, but little is known about the proper timing of EBP in the treatment of sixth nerve palsy due to intracranial hypotension. This article reports a case of sixth nerve palsy due to spontaneous intracranial hypotension which was treated by EBP 10 days after the onset of palsy.

Cryptococcal meningitis presenting with isolated sixth cranial nerve palsy in a patient with systemic lupus erythematosus

Cryptococcal meningitis is a rare complication of systemic lupus erythematosus (SLE). The nonspecific neurologic findings associated with this infection delays accurate diagnosis because initial neuropsychiatric manifestations of SLE are in instances indistinguishable from that of crytococcal meningitis. We report a case of cryptococcal meningitis presenting with unilateral sixth cranial nerve palsy in a male patient with SLE, which was successfully treated with antifungal agents.