Abducens Research Articles

Resection of Meningiomas Invading the Cavernous Sinus: Treatment Strategy and Clinical Outcomes

Background/Objectives: Resection of tumors invading the cavernous sinus (CS) carries a risk of injury to the cranial nerves and internal carotid artery. Therefore, radical surgery involving lesions around the CS remains challenging, especially for lesions invading the CS, optic sheath, and oculomotor cave. Here, we describe a surgical strategy for meningiomas invading these structures and report on the clinical outcomes. Methods: Surgical resection was indicated in patients with neurological symptoms or rapid tumor growth for the restoration of cranial nerve function. We investigated 13 patients who had preoperative images of CS invasion, underwent surgical resection, and were followed-up with magnetic resonance imaging for at least 1 year between July 2017 and July 2024. Their preoperative symptoms, postoperative course, adjuvant therapy, postoperative complications, degree of resection, and recurrence were evaluated. Results: The mean patient age was 59.1 years (range, 23–73 years), and 10 were female. Major preoperative symptoms included oculomotor nerve paresis in 8 patients (61.5%), abducens nerve paresis in 6 (46.2%), visual disturbance in 7 (53.8%), and brain swelling in 3 (23.1%). These symptoms improved at least partially after surgery in 7 (87.5%), 5 (83.3%), 7 (100%), and 3 (100%) patients, respectively. Major postoperative complications included contralateral visual deterioration in 1 patient (7.7%) and brief transient slight hemiparesis caused by internal carotid vasospasm or dissection in 2 (15.4%). Four patients with residual atypical meningioma in the CS underwent intensity-modulated radiotherapy (IMRT). The lesions in 6 patients recurred or regrew, resulting in additional treatment with stereotactic radiosurgery in 2 patients, IMRT in 3, and resection in 1. Conclusions: Our surgical strategy for the surgical resection of meningiomas in and around the CS for the restoration of cranial nerve function is safe and effective, with only transient acceptable injuries. Even if the tumor in the CS is too stiff to be removed, it is important to open the optic nerve sheath and oculomotor cave widely to effectively remove the tumor.

Chronic Lymphocytic Inflammation With Pontine Perivascular Enhancement Responsive to Steroids Presenting With Predominantly Neuro-Ophthalmic Features.

Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) is a rare and poorly understood inflammatory disorder of the central nervous system centered on the pons. It has a characteristic imaging appearance with enhancing and T2-hyperintense punctate and curvilinear lesions in the pons. The lesions lack restricted diffusion and have relatively little perilesional edema. Although patients typically present with gait ataxia and other sequelae of brainstem inflammation including diplopia, there is scant literature focusing on patients who present with primarily neuro-ophthalmic manifestations. Case series of 3 patients presenting with diplopia who had a final diagnosis of CLIPPERS. Case descriptions of a 71-year-old man, 61-year-old woman, and 38-year-old man are reported. Diplopia was the chief presenting complaint, owing to internuclear ophthalmoplegia, sixth nerve palsy, or skew deviation. All patients had nystagmus and gait ataxia. Brain MRI displayed punctate or curvilinear enhancement of pontine/middle cerebellar peduncle lesions without restricted diffusion. All patients achieved rapid improvement after corticosteroid treatment. In 3 patients with CLIPPERS, the main presenting complaint was diplopia. The distinctive imaging signs led to a strong presumption of CLIPPERS, permitting a truncated evaluation and early corticosteroid treatment, which provided rapid reversal of clinical and imaging manifestations.

Traumatic retroclival hematoma resulting in abducens nerve palsy: illustrative case.

Posttraumatic retroclival hematomas are rare pathologies among pediatric patients and can result in cranial nerve palsies. The authors sought to survey the literature and characterize the risk factors, treatment considerations, and overall outcomes for pediatric patients experiencing posttraumatic retroclival hematomas. A search of the Ovid Embase, Scopus, PubMed, and Web of Science databases from January 1986 to May 2024 was performed following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Additionally, the authors report a novel case of pediatric retroclival hematoma. The systematic review identified 41 eligible articles describing 64 individual cases of posttraumatic clival/retroclival hematoma in pediatric patients. The incidence of abducens nerve palsy in the setting of posttraumatic retroclival hematoma was 40%, and the rate of complete recovery of abducens nerve function was 73%. Analyses revealed that a higher initial Glasgow Coma Scale (GCS) score correlated with general neurological recovery (p < 0.05). However, no significant difference was found in GCS scores between patients with complete and those with incomplete abducens nerve recovery. There is a high rate of spontaneous recovery of abducens nerve function in patients with abducens palsy in the setting of posttraumatic retroclival hematoma. While initial GCS scores can predict general neurological recovery, factors influencing abducens nerve palsy resolution remain unclear. https://thejns.org/doi/10.3171/CASE24474.

Skull base chordomas presenting with abducens nerve deficits: clinical characteristics and predictive factors for deficit improvement or resolution.

Skull base chordomas (SBCs) often present with cranial nerve (CN) VI deficits. Studies have not assessed the prognosis and predictive factors for CN VI recovery among patients presenting with CN VI deficits. The medical records of patients who underwent resection for primary chordoma from 2001 to 2020 were reviewed. Those presenting with CN VI palsy were identified. The extent of CN VI deficit was determined to be partial or complete based on the Scott-Kraft score. The change in deficit from baseline was recorded within 3 days of surgery and at the 6-month follow-up. The postoperative course was followed until partial and/or complete deficit recovery. Univariate logistic regression models were created to predict improvement or resolution of CN VI deficit. A total of 113 patients with primary SBC were identified, 34 of whom presented with CN VI deficits: 24 (73%) with partial and 9 (27%) with complete deficits. The extent of deficit in 1 patient was unable to be determined. The median duration of deficit preoperatively was 3.6 months, and CN VI was most commonly radiographically abutted at the prepontine cistern and Dorello's canal. Twenty-three (68%) patients experienced at least partial CN VI recovery (mean 61 days, range 2-174 days). Nineteen (56%) patients experienced complete CN VI recovery (mean 162 days, range 2-469 days). No patients whose CN VI deficit worsened immediately after surgery achieved improvement in CN VI function at 6 months (p = 0.001). Preoperative partial (relative to complete) CN VI deficit was associated with greater odds of CN VI deficit improvement by 6 months (OR 7.7, p = 0.028). Factors not associated with deficit resolution included duration of deficit, CN VI involvement by tumor, total segments abutted by tumor, sex, age at diagnosis, gross-total resection, tumor volume, and adjuvant radiation therapy, although this analysis may have been underpowered to detect small differences. Overall, 68% of patients achieved at least partial recovery in CN VI function after endoscopic skull base surgery. Among patients with partial CN VI palsy at baseline, 83% achieved CN VI recovery within 6 months and 75% achieved complete recovery within 14 months. For patients who presented with a complete CN VI deficit, within those same time frames, 33% and 11% achieved partial and complete recovery, respectively. Complete preoperative CN VI deficit was associated with lower odds of CN VI recovery by 6 months. The duration of preoperative deficit does not predict functional CN VI recovery.

Cranial osteology and neuroanatomy of the late Permian reptile Milleropsis pricei and implications for early reptile evolution.

Millerettidae are a group of superficially lizard-like Permian stem reptiles originally hypothesized as relevant to the ancestry of the reptile crown group, and particularly to lepidosaurs and archosaurs. Since the advent of cladistics, millerettids have typically been considered to be more distant relatives of crown reptiles as the earliest-diverging parareptiles and therefore outside of 'Eureptilia'. Despite this cladistic consensus, some conspicuous features of millerettid anatomy invite reconsideration of their relationships. We provide a detailed description of the late Permian millerettid Milleropsis pricei using synchrotron X-ray phase-contrast micro-computed tomography focusing on the cranial anatomy of three individuals known from a burrow aggregation. Our data reveal a suite of neuroanatomical features Milleropsis shares with neodiapsids that are absent both in other 'parareptiles' and in early diverging groups of 'eureptiles'. Traits shared between Milleropsis and neodiapsids include: the presence of a tympanic emargination on the quadrate, quadratojugal and squamosal, the loss of epipterygoid contribution to the basicranial articulation suggesting a more kinetic palatoquadrate, the absence of a sphenethmoid and the pathway of the abducens nerve through the braincase. Our findings suggest that the early reptile neurocranium, a region poorly sampled in phylogenetic analyses due to relative visual inaccessibility and poor preservation, has the potential to inform the phylogenetic relationships of early reptiles.

Radiologic Clue to Cavernous Sinus Hemangioma Diagnosis

We describe a case of a 57-year-old woman presenting initially with diplopia who later developed retro-orbital and retroauricular pain. Examination showed right abducens nerve palsy and subsequent right trigeminal nerve hyperesthesia. Neuroimaging revealed a well-defined mass confined to the right cavernous sinus, with high T2 signal intensity and homogeneous enhancement on postgadolinium T1-weighted images. A meningioma was initially considered as the most likely diagnosis. The lesion grew over months, extending into the Meckel's cave and the pituitary fossa. Dynamic T1-weighted images revealed striking and progressive centripetal enhancement, leading to a revised diagnosis of cavernous sinus hemangioma (CSH). CSH is a rare benign extra-axial tumor, which is highly vascularized, and is frequently misdiagnosed as meningioma or schwannoma. The combination of very high T2 signal intensity and progressive centripetal contrast enhancement highly suggest CSH diagnosis. Given the significant risk of bleeding and mortality associated with surgical intervention, it is crucial to recognize CSH preoperatively to plan a meticulous surgical approach.

Etiology, clinical characteristics, and treatment outcome in patients with isolated sixth cranial nerve palsy

Background &amp; Objective: Isolated sixth cranial nerve palsy was the most common isolated cranial nerve palsy causing extraocular muscle dysfunction. As magnetic resonance imaging (MRI) quality had improved and knowledge had grown in recent years, the etiology previously classified as idiopathic might be re-classified to be another in the current era, and some require specific treatments. We therefore studied the etiology, clinical characteristics, and treatment outcome in patients with isolated sixth cranial palsy in recent years. Methods: The medical records of 88 patients with isolated sixth cranial nerve palsy visited at the Neurological Institute of Thailand from January 2013 to December 2020 were reviewed. Clinical and demographical data included age, gender, laterality, headache location, vascular risk factors, etiology, treatment, and prognosis were collected and analyzed. Results: The most common etiology was microvascular ischemia (29.5%), followed by inflammation (25.0%), and vascular disorders (20.5%). Neoplasm, abducens palsy mimics and false localizing sign, and idiopathic were less common (13.6%, 6.8% and 4.5%, respectively). Compared to patient with sixth cranial nerve palsy from microvascular ischemia, those with inflammatory cause were younger (p&lt;0.001), were more likely to have headache (p=0.004), and had better prognosis at 3 months (p=0.018). Conclusion: Microvascular ischemia was the most common etiology of isolated sixth cranial nerve palsy. Age at onset and presence of headache were the important clues for distinguishing sixth cranial nerve palsy due to microvascular ischemia from inflammation. Prognosis was more favorable in inflammation than microvascular ischemia group. We suggest MRI scan to exclude other causes before making a diagnosis of microvascular ischemia or idiopathic.

Deciphering Neuro-Ophthalmic Presentations of Carotid Cavernous Fistulas: A Comprehensive Analysis of Venous Flow Dynamics and Clinical Implications

Background: Carotid cavernous fistulas (CCFs) are abnormal arteriovenous connections between the carotid arterial system and the cavernous sinus, presenting with complex neuro-ophthalmic manifestations due to the redirection of arterial blood into the venous system. This study systematically reviews the diverse neuro-ophthalmic presentations of CCFs, emphasizing the influence of venous flow dynamics. Methods: A comprehensive literature search was conducted in PubMed, Scopus, and Web of Science, focusing on keywords such as "carotid cavernous fistula," "neuro-ophthalmic presentations," and "optic nerve compression." Recent and historical studies were analyzed to assess the neuro-anatomical impacts on neuro-ophthalmic symptoms from CCFs. This review aimed to consolidate knowledge and refine diagnostic and therapeutic strategies for CCF management. Results: The findings demonstrated that the neuro-ophthalmic presentations were quite distinctive, depending on the direction of venous flow. Anterior flow, overall, was associated with proptosis, conjunctival arterialization, and red, dilated vessels. In contrast, posterior flow was associated with cranial nerve complications, most notably abducens nerve palsy and trigeminal neuralgia, manifesting as double vision and facial pain, respectively. It therefore seems that the symptomatology and severity of CCFs is heavily dependent on the direction of blood flow. Conclusion: The flow direction through the veins is of significant importance in the clinical presentation and prognosis of CCFs. These dynamics must be appreciated to improve diagnosis and allow for optimal treatment, thus averting the risk of fatal complications. In this review, the need for tailored therapeutic strategies through detailed vascular and neuro-ophthalmologic analysis is outlined.

Clinical analysis of endoscopic transnasal resection of skull base chondrosarcoma

Objective:To explore the surgical techniques and clinical outcomes of endoscopic transnasal approaches in the treatment of skull base chondrosarcomas. Methods:Data from patients diagnosed with skull base chondrosarcomas and treated via endoscopic transnasal surgery at the Department of Otorhinolaryngology and Head and Neck Surgery, Xuanwu Hospital, Capital Medical University, from 2013 to 2022 were collected. This retrospective study analyzed the patients' clinical presentations, histopathological grading, involved sites and extents, and complications following the endoscopic transnasal surgery. Disease-free survival rates were calculated using the Kaplan-Meier method. Results:Complete data from 31 patients showed that the primary tumor site was in the petroclival region in 27 cases（87%）, and the anterior skull base in 4 cases（13%）. Pathological grades were Grade Ⅰ（12 cases）, Grade Ⅱ（16 cases）, and Grade Ⅲ（3 cases）. Total resection was achieved in 25 cases, with residual disease post-surgery in 6 cases. The average follow-up duration was 35.7 months（ranging from 6 to 120 months）. Among those who achieved complete resection, recurrence occurred in 5 cases（5/25）, with a five-year disease-free survival rate of 80%. Postoperative complications included transient abducens nerve palsy in 6 patients and cerebrospinal fluid rhinorrhea in 4 patients. There were no cases of death or permanent cranial nerve palsy. Total resection rate（P=0.001） and involvement of the cerebellopontine angle and jugular foramen（P=0.037） were identified as independent risk factors for residual disease and recurrence of chondrosarcoma. Conclusion:The endoscopic transnasal approach is a safe and feasible treatment option for skull base chondrosarcomas.

The Effectiveness of Steroid Versus Vitamin Therapy in the Improvement of Extraocular Movements in Patients With Diabetic Cranial Nerve Palsy: A Comparative Study.

Diabetic mononeuropathies, which are focal neuropathies, are less common than peripheral neuropathy in diabetes. They are frequently underreported or misdiagnosed due to mild or unnoticed cases. Early detection and treatment are crucial to prevent worsening nerve damage and complications. This study aims to compare the effectiveness of conventional treatment with vitamin therapy for improving these neuropathies. Fifty cases of diabetic ocular nerve palsy were stratified into two groups, 25 in each. Group A received steroids, while group B received vitamin B12 injections. Ocular movements were assessed before and after treatment initiation at 3, 6, and 10 days using the Kestenbaum limbustest. Inferential statistics were done usingthe chi-square test and the student t-test. The average age of the participants in the study was 60.5 ± 6.3 years.Thirty-eight patients had sixth nerve palsy, and 12 patients had associated third nerve palsy. Thirty-eight subjects had poorly controlled diabetes. The mean enhancement in movements was 0.75 ± 0.3 in group A and 1.04 ± 0.5 in group B, with a p value of 0.026, demonstrating the statistically significant difference between both groups. This study infers that the ocular movements were significantly improved with vitamin therapy. Treating diabetic neuropathy solely with vitamin supplementation indirectly addresses nutritional deficiencies, potentially accelerating diabetes-related complications and enhancing quality of life.

Stenting versus balloon angioplasty alone for idiopathic intracranial hypertension.

Stenting is a common approach for treating idiopathic intracranial hypertension (IIH) and venous sinus stenosis (VSS). However, studies comparing stenting with balloon angioplasty alone are lacking. This study sought to compare the clinical efficacy of balloon angioplasty and stenting in the treatment of IIH and VSS. In this single-center retrospective study, patients were divided into the following two groups: Group S, which comprised patients who underwent stenting with or without balloon angioplasty; and Group B, which comprised patients who underwent balloon angioplasty alone. From January 2018 to June 2023, the medical records of patients with IIH and VSS were evaluated to compare their postsurgical results and subsequent clinical outcomes. In total, 122 participants were included in this study; 64 in Group S, and 58 in Group B. There were no differences between the two groups in terms of their initial traits. The efficacy of Group B was similar to that of Group S in terms of headache, sixth nerve palsy, and tinnitus at discharge (all P>0.05); however, the proportion of patients with resolved symptoms was significantly greater in Group S than Group B at the 3-, 6-, and 12-month follow-up (all P<0.05). The patients in Group S had a significantly lower median papilledema Frisén grade (1 vs. 2, P<0.001), a lower mean lumbar puncture opening pressure (210.86 vs. 241.12 mmH2O, P=0.006), and a smaller mean stenosis pressure gradient (1.98 vs. 3.72 mmHg, P=0.004) than those in Group B after surgery. No statistically significant differences were detected in the complication rates between the two groups (7.8% vs. 10.3%, P=0.755). Compared with stenting, balloon angioplasty alone had limited short-term efficacy and unsatisfactory long-term results. Consequently, it is not recommended as a first-line treatment of IIH and VSS but rather as a complementary or adjunctive therapy to stenting.

Ceftazidime-Cefazolin Empiric Therapy for Pediatric Gradenigo Syndrome.

Gradenigo Syndrome (GS), a rare complication of petrous apicitis secondary to acute otitis media, is characterized by (an often incomplete) triad of otorrhea, abducens nerve palsy, and facial pain along the trigeminal nerve distribution. There are several causative pathogens of petrous apicitis, including Streptococcus and Staphylococcus species, while Pseudomonas aeruginosa is the most common. However, the case report literature often describes antibiotic management of GS with antibiotics that do not cover Pseudomonas, potentially predisposing to further intracranial complications or mortality. The purpose of this work was to describe a case of pediatric Gradenigo Syndrome, successfully treated with sufficiently broad-spectrum antibiotics. This is case report. A previously healthy 5-year-old boy with a history of swimming presented with esotropia and acute otitis media. Initial symptoms included otorrhea, otalgia, and pruritis, which were refractory to ciprofloxacin-dexamethasone drops. He subsequently developed a right sixth nerve palsy, suggestive of Gradenigo Syndrome, and neuroimaging showed evidence of petrous apicitis, clival osteomyelitis, and internal carotid artery stenosis. The causative organism was not elucidated to laboratory error. Given this uncertainty, he was successfully treated with empiric intravenous ceftazidime and cefazolin. After 16 weeks, he recovered fully without the need for surgery. In the setting of delayed or absent culture results with suspicion of skull-base infection, our case supports the use of empiric antibiotic therapy with sufficient coverage of all common pathogens including Streptococcus/Staphylococcus and Pseudomonas aeruginosa species, the latter of which is often not adequately covered by antibiotic regimens described in the literature.

Otitic hydrocephalus and papilloedema-re-evaluating a treatment paradigm.

Otitic hydrocephalus is increased intracranial pressure without ventricular dilation secondary to mastoiditis and cerebral venous sinus thrombosis (CVST). It is associated with significant visual morbidity, though more detailed data on visual outcomes is lacking. We sought to better characterize the management of increased intracranial pressure and visual outcomes in this population. Retrospective chart review at a quaternary Children's Hospital of patients <18 years of age who were diagnosed with otitic hydrocephalus from January 2009 to July 2023. Data were collected on patient demographics, clinical course, imaging, and treatment outcomes. Fifteen patients were identified with mastoiditis complicated by otitic hydrocephalus. The average age was 5.7 years (range 2-15). Eight patients were male (53%). Six patients (40%) had cranial nerve VI palsy and 14 (93%) developed papilloedema. Eleven patients (73%) developed progressively worsening papilloedema despite improving infection, clot burden, and acetazolamide; of these, three required ventriculostomy catheters. Eight were started on corticosteroids. Six had resolution of papilloedema without the need for shunt placement. Two patients had evidence of optic atrophy from increased ICP and visual loss prior to corticosteroid initiation. Both had stabilization of their condition without further visual loss. This study highlights the importance of systemic corticosteroids as part of the treatment paradigm for otitic hydrocephalus to prevent vision loss in patients otherwise unresponsive to medical management. It also identifies the risk of papilloedema progression and visual morbidity even after the initiation of appropriate medical therapy. Visual outcomes were significantly improved and invasive neurosurgical procedures were avoided with use of corticosteroids.

Microvascular decompression for abducens nerve palsy associate with neurovascular conflict

Microvascular decompression for abducens nerve palsy associate with neurovascular conflict

A challenging case of Takayasu’s arteritis in a young male with various manifestations and poor outcome

A 17-year-old boy complaining of progressive dyspnea, fever, palpitations, a 22 mm Hg blood pressure difference between the 2 arms, and arm claudication. He had a history of psoriasis-like skin lesions and bronchiectasis. Echocardiography revealed a reduced left ventricular ejection fraction, severe eccentric aortic insufficiency, circumferential aortic wall thickening, and a dilated ascending aorta with severe atherosclerotic changes. Based on imaging findings, a TA diagnosis was suggested. During his follow-up, the patient developed strabismus, blurred vision, and right sixth cranial nerve paralysis and went into a deep coma. Unfortunately, after 6 months of treatment, he expired due to COVID-19 infection.

Immediate and long-term results of microsurgical resection of tentorial meningiomas

Aim. To optimize the choice of surgical approach based on the assessment of immediate and long-term results of microsurgical treatment of cerebellar meningiomas.Materials and methods. Between 2019 and 2023 at the Department of Neurosurgery of the m.f. vladimirsky moscow Regional Research Clinical Institute, 24 patients with primary meningiomas of the cerebellum underwent microsurgical treatment. The ratio between women and men was 5:1, mean patient age was 51.5 years. mean tumor volume was 8.7 cm3. Neurological and neuroimaging data, information about concomitant disorders, surgical protocols, information on postoperative complications, functional outcomes, and catamneses of the patients were compiled.Results. Total tumor resection was achieved in 22 (91.7 %) cases, subtotal in 2 (8.3 %) cases with grade I–II radicality per the Simpson classification. Deterioration and neurologic deficit were observed in 5 (20.8 %) patients. In 2 (8.3 %) patients, dysfunction of the abducens nerve was observed, in 3 (12.5 %) – impaired hearing or deafness, in 5 (20.8 %) – ataxia aggravation. postoperative complications developed in 2 (8.3 %) patients. No deaths were registered. grade 1 meningiomas were found in 22 (91.7 %) patients, grade 2 – in 2 (8.3 %) patients.Conclusion. During microsurgical removal of tentorial meningiomas, optimal surgical approach takes into account the topographic and anatomical location of the tumor. This makes it possible to achieve safe and effective treatment with favorable functional outcomes.

RADT-42. DISSEMINATED TUMORAL AMYLOIDOSIS OF THE CRANIAL NERVES IN THE ABSENCE OF SYSTEMIC DISEASE: CASE REPORT

Abstract Tumoral amyloidosis, characterized by tumor-like deposits without systemic disease, is rare in the central nervous system. Most often located in the periventricular white matter, tumoral amyloidosis typically consist of immunoglobulin light chains (AL). While prior reports describe cases of tumoral amyloidosis isolated to the trigeminal nerve, we report herein a first known case of diffuse cranial nerve involvement. The patient is a 43-year-old man who presented with left trigeminal dysesthesias, which led to self-excoriation and erosion of the left naris. On exam, he had absent sensation in the V1-V3 distributions, left trochlear nerve palsy, and bilateral abducens nerve palsies. Imaging demonstrated significant thickening of the left trigeminal nerve and diffuse cisternal contrast enhancement of the other cranial nerves, including the oculomotor, abducens, facial, and glossopharyngeal nerves. Work-up began with a lumbar puncture that found elevated protein with otherwise benign results, including flow cytometry. He was therefore recommended to undergo open biopsy of the left trigeminal nerve and cavernous sinus. Pathology from this surgery demonstrated congo red- positive AL amyloid deposits. Following this pathologic diagnosis, he subsequently underwent a full workup for systemic amyloidosis including bone marrow biopsy, abdominal fat pad biopsy, and a PET CT scan. Biopsy of a long nodule was negative for amyloidosis. Systemic amyloid testing did not demonstrate non-CNS sites of amyloid deposition. Medical therapy with daratumumab, cyclophosphamide, bortezomib, and dexamethasone was started but then discontinued due to ineffectiveness. He underwent radiation treatment of 4500 cGy to the left cavernous sinus where the tumoral amyloidosis was most severe. He has had no further progression of his disease. Tumoral amyloidosis of the cranial nerves remains a rare and poorly-understood disease. Prior reports have described the disease isolated to the trigeminal nerve. This report raises attention to this diagnosis in cases of rare multi-nerve involvement and suggests that radiation may be a useful first-line treatment.

An evaluation of 30 years’ experience in the use of botulinum toxin injections in the management of sixth nerve palsies

ABSTRACT Intrroduction Sixth nerve palsy is the most common type of extraocular muscle palsy. The therapy options in sixth nerve palsies include monitoring with or without conservative treatment, botulinum toxin injections or strabismus surgery. The aim of this retrospective study was to compare botulinum toxin (BT) injections into the medial rectus to conservative treatment in sixth nerve palsies. The rate of patients improved after intervention and treatment outcomes for the two treatment options were be evaluated at a German tertiary referral center. Methods A service evaluation was conducted on adult patients with sixth nerve palsy. Patient files were reviewed and data including abduction deficit and size of deviation were collected retrospectively. Patients which presented between January 1987 and April 2022 were considered. Patients were allocated into two treatment groups: BT injected into medial rectus or conservative treatment, which included observation, providing occlusion and Fresnel prisms. Inclusion criteria were attendance of two visits with orthoptic assessment. Exclusion criteria included presence of further oculomotor palsies, strabismus, strabismus surgery and suppression. Non-parametric statistical analysis was conducted using IBM® SPSS Statistics. Results A total of 606 adult patients with unilateral or bilateral sixth nerve palsy attended during the named period. A total of 137 adult patients met the inclusion criteria. Of which, 36 had a bilateral palsy, 101 had a unilateral palsy. 45.26% (n = 62) were treated with BT injections and 54.75% (n = 75) were treated conservatively. The median initial abduction deficit was greater in the BT group, (−4 to −5 after Scott and Kraft) than in the conservative treatment group (−1). The initial angle of deviation at distance was significantly larger in the BT group than in the conservative treatment group (p = <0.001). The rate of improvement in the BT group was 24.19% (n = 15) and 20% (n = 15) in the conservative treatment group. When excluding longstanding palsies rates of improvement in both groups increased to 28.85%. The improvement of the angle of deviation at distance in all patients was greater in the BT group (p = <.001). The improvement of abduction in bilateral palsies were greater in the BT group (p = .016), but in unilateral palsies, there was no significant difference in abduction improvement in the two treatment groups (OD p = .3, OS p = .406). Conclusion This service evaluation found that BT injection into medial rectus in unilateral and bilateral sixth nerve palsies did not increase the rate of improvement compared to conservative treatment. But BT injections reduced the angle of deviation to a greater extent than conservative treatment. Additionally, BT was able to improve abduction in bilateral palsies to a greater extent than conservative treatment. It is recommended a BT injection is considered in symptomatic bilateral sixth nerve palsies to enable fixation and improved ocular motility. More research is needed to verify reliable clinical guidelines for the use of BT in sixth nerve palsies.

Isolated Sixth Cranial Nerve Palsy in Patients with Pituitary Apoplexy.

Pituitary apoplexy is an acute clinical syndrome constituted by headache, visual impairment, ophthalmoplegia, and altered mental status. Abducens nerve palsy due to pituitary apoplexy is a significant clinical manifestation in pituitary apoplexy cases.This study aims to investigate the rare occurrence of isolated sixth cranial nerve palsy in patients with pituitary apoplexy, a condition characterized by sudden hemorrhagic or ischemic infarction of the pituitary gland. A search was conducted on major databases, including PubMed, Web of Science, and ScienceDirect, to identify cases of isolated sixth cranial nerve palsy in patients with pituitary apoplexy. Only six cases were found in the available literature. Descriptive statistics were used to summarize the data, and relevant clinical features were compared between the cases. Among the six identified cases, isolated sixth cranial nerve palsy in patients with pituitary apoplexy predominantly affected middle-aged adults, with a prominent male preponderance. Clinical manifestations included acute-onset diplopia and headache, with the most common radiologic finding being pituitary gland enlargement or hemorrhage. Laboratory investigations revealed hormonal dysregulation in some cases. Treatment approaches varied and included conservative management and surgical intervention. Outcomes were generally favorable, with most patients experiencing partial or complete resolution of their cranial nerve palsy. Isolated sixth cranial nerve palsy in patients in the context of pituitary apoplexy is an exceptionally rare occurrence, with only six documented cases in the available literature. Further research and case reporting are essential to better understand this rare clinical entity and guide optimal management strategies.

Accuracy of the Image Interpretation Capability of ChatGPT-4 Vision in Analysis of Hess Screen and Visual Field Abnormalities.

OpenAI, the owner of ChatGPT, publicly released the GPT-4 Vision in September 2023. This multimedia chatbot has the capability to receive and analyze various images presented to it by the user. We assessed the accuracy of its interpretation of 2 of the images commonly used in neuro-ophthalmology, namely Hess screen and automated visual field images. We separately uploaded typical images of 5 abnormal Hess screen charts related to third, fourth, and sixth cranial nerve palsy, Brown syndrome, and inferior orbital wall fracture with entrapment of the inferior rectus muscle. Likewise, 5 classic images of automated visual field grayscale maps related to lesions of the optic nerve, the chiasma, the optic tract, the optic radiations, and the occipital lobe were presented. The chatbot was instructed to select the best option among the 5 choices presented in each question. The GPT-4 Vision was able to select the right choice in 2/5 questions on Hess screens and 3/5 of the visual field questions. Despite selection of the correct option, qualitative evaluation of GPT-4 responses revealed flawed analysis of certain aspects of some image findings, such as the side of involvement or the misinterpretation of the physiologic blind spot as a central scotoma. The performance of GPT-4 Vision in the interpretation of abnormalities of Hess screen and visual field involvement was highly variable, even with simple typical cases of classic disorders. As the chatbot's image recognition is currently evolving, its capacity to accurately interpret ophthalmologic images is still limited at this time.