Isolated abducens nerve palsy following upper respiratory infection in a patient with ipsilateral chronic sphenoid sinusitis.

The abducens nerve, which is vulnerable because of its complex anatomy at the skull base, is seldom affected by acute or severe sphenoid sinusitis. Notably, abducens nerve palsy following asymptomatic chronic rhinosinusitis (CRS) in a healthy young individual after a mild upper respiratory infection (URI) remains undocumented in the literature. Herein, we report a case of acute unilateral abducens neuropathy in a healthy 35-year-old woman with CRS in the ipsilateral sphenoid sinus, following a mild URI 2 weeks earlier. She presented with sudden-onset diplopia, was afebrile, and had normal serum inflammatory biomarkers. Comprehensive ophthalmological and neurological exams revealed no abnormalities except limited lateral gaze in the left eye. Imaging revealed mucosal swelling on the hyperpneumatized left sphenoid sinus, which thinned the clivus and positioned the inflamed mucosa close to the Dorello's canal, likely facilitating the spread of inflammation to the ipsilateral abducens nerve. Urgent endoscopic sinus surgery combined with systemic corticosteroids and antibiotics led to complete resolution by postoperative day 10. The present case demonstrates acute abducens nerve neuropathy from URI-induced exacerbation of sphenoid sinus CRS with specific anatomical predispositions.

Isolated Sixth Nerve Palsy and COVID-19: A Recurrent Case in a 7-Month-Old Child and Analysis of Reported Cases.

BACKGROUND: With the SARS-CoV-2 pandemic (COVID-19), data on central and peripheral nervous system involvement, including those causing cranial nerve 6 (CN6) palsy, have been limited to case reports. To extract clinically relevant features of COVID-19-related CN6 palsy, we report on a recurrent pediatric case and analysis of reported cases associated with infection or immunization. METHODS: A PubMed search revealed 18 cases of isolated CN6 palsy in addition to the index case (n = 19). Clinical characteristics, workup, and temporal associations between systemic symptoms onset or vaccination, symptoms onset, and resolution were compiled and analyzed. RESULTS: The median age of CN6 onset was 43 years (interquartile range [IQR]: 28-52). Sixteen cases (84.2%) were associated with COVID-19 illness and 3 (15.8%) were associated with COVID-19 vaccination. Four cases (23.5%) had positive neuroimaging findings. The median latency from first COVID-19 symptoms or vaccination to onset of CN6 palsy was 6 days (IQR: 2.3-16), and the median time from onset to resolution was 30 days (IQR: 14-60). Latency to onset of CN6 palsy was significantly and directly associated with time to resolution (R 2 = 0.401, P = 0.010). Patients who had a positive SARS-CoV-2 antibody test had significantly longer days from symptoms to onset (6.0 vs 24.5, P = 0.030), and patients with a positive SARS-CoV-2 polymerase chain reaction test had a significantly shorter time to resolution (17.50 vs 90, P = 0.042). CONCLUSIONS: Isolated CN6 palsy from COVID-19 is rare, can occur in infants as young as 7 months, and can be recurrent. Longer latency from systemic symptoms onset portends greater recovery times, and this relationship may reflect multiple mechanisms by which COVID-19 (and/or an immune response thereto) causes cranial neuropathies with direct clinical relevance.

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.

Fusobacterium necrophorum an Underrecognized Cause of Petrous Apicitis Presenting with Gradenigo Syndrome: A Case Report.

BACKGROUND With the advent of antibiotics, petrous apicitis (PA), inflammation of the petrous temporal bone, has become a rare complication of otitis media. Even more uncommon is Gradenigo syndrome (GS), a result of PA, characterized by a triad of otitis media or purulent otorrhea, pain within the regions innervated by the first and second division of the trigeminal nerve, and ipsilateral abducens nerve palsy. Recent literature has demonstrated increasing reports of Fusobacterium necrophorum isolated in cases of GS. CASE REPORT A 21-year-old man presented with otalgia, reduced hearing, and severe headache. Examination revealed right-sided purulent otorrhea, anesthesia within the trigeminal nerve distribution, and an ipsilateral abducens nerve palsy. F. necrophorum was isolated from an ear swab and a blood culture. Computed tomography and magnetic resonance imaging (MRI) demonstrated otomastoiditis, PA, cavernous sinus thrombosis, and severe stenosis of the petrous internal carotid artery. He was treated with intravenous benzylpenicillin, underwent a mastoidectomy and insertion of a ventilation tube, and was started on a 3-month course of dabigatran. Interval MRI showed improved internal carotid artery caliber, persistent petrous apex inflammation, and normal appearance of both cavernous sinuses. Follow-up clinical review noted persistent abducens and trigeminal nerve dysfunction. CONCLUSIONS We identified 190 cases of PA; of these, 80 presented with the classic Gradenigo triad. Fusobacterium sp. were cultured in 10% of GS cases, making them the most frequent isolates. Due to the fastidious nature of F. necrophorum, it may be underrepresented in the historical literature, and we recommend that empiric antibiotics cover anaerobic organisms.

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.

Do infants with isolated congenital sixth nerve palsy require comprehensive work-up? A retrospective cohort and review of the literature.

PURPOSE: The purpose of this study is to describe a case series of infants with isolated congenital sixth nerve palsy (ICSNP) and suggest a management algorithm based on our experience and a review of the literature. METHODS: A retrospective cohort design was used. The clinical database of a single tertiary medical center was reviewed to identify all patients diagnosed with ICSNP from January 2020 to November 2022. Data were collected as follows: demographic parameters, age at initial presentation, presenting symptoms and signs, findings on ophthalmic and neurologic examinations, findings on follow-up, and outcome. RESULTS: Six patients were included. All were born at term. The average gestational weight was 3675.7 ± 262.7 g. Three mothers had gestational diabetes. Five deliveries necessitated labor induction either by oxytocin (n = 4) or by membrane stripping followed by oxytocin (n = 1). One had also gone a forceps assisted delivery. Symptoms were noticed in all newborns by their parents within the first week of life. Ophthalmological and neurological examinations were otherwise unremarkable apart of one patient with a head turn to the side of the involved eye. Four patients underwent brain imaging that were unremarkable. All abduction deficits resolved by 1 to 3 months of age. Follow up examinations were unremarkable (mean follow up 14.3 ± 5.0 months, range 4-23). CONCLUSIONS: This case series, together with previous reports, support ICSNP's benign nature. We suggest an initial basic work-up that solely includes ophthalmological and neurological examinations which will be elaborated in case of any additional pathologic findings or if ICSNP does not fully resolve by 3 months.

Magnetic Resonance Imaging of Globe Translation in Abducens Palsy.

PURPOSE: It has been supposed that rectus muscle paralysis would cause proptosis due to the reduction in active posterior tension. This study aimed to test this proposition by evaluating globe translation during horizontal duction in patients with abducens palsy. DESIGN: Prospective, single-center, fellow-eye controlled, case series. METHODS: Horizontal globe rotation and translation were quantified using orbital magnetic resonance imaging of patients with isolated unilateral abducens nerve palsy without other ocular motility disorders. Unaffected fellow eyes served as the control group. Digital image analysis was performed. RESULTS: The study included 5 female and 2 male patients with a mean ± standard deviation age of 52 ± 15 years. The average esotropia was 39.0 ± 9.6 diopters. Mean adduction was similar at 54.9 ± 10.4° in palsied eyes and 52.0 ± 7.1° in fellow eyes. However, abduction in palsied eyes was significantly less at 11.4 ± 7.1° than 37.1 ± 11.4° in fellow eyes (P = .0023). Average anterior translation in adduction was 0.46 ± 0.42 mm in palsied orbits, similar to 0.35 ± 0.47 mm in fellow orbits (P = .90). Anterior translation in abduction averaged 0.17 ± 0.53 mm in palsied orbits, similar to 0.27 ± 0.73 mm in fellow orbits (P = .80). Average medial translation in adduction at 0.32 ± 0.23 mm in palsied orbits was statistically similar to 0.12 ± 0.44 mm in fellow orbits (P = .54). Average lateral translation in abduction at 0.19 ± 0.18 mm in palsied orbits was similar to 0.33 ± 0.15 mm in control orbits (P = .38). CONCLUSION: Abducens palsy does not alter normal eye translation during horizontal duction.

Sixth cranial nerve palsy and trigeminal neuropathic pain due to a space-occupying lesion.

Various neuropathies of the cranil nerves can accompany trigeminal neuropathic pain attributed to space-occupying lesions. In this case report, the patient presented with persistent intraoral pain and numbness on the right side of the face. Cranial nerve examination revealed dysfunctional eye movements, diplopia, and mechanical hyposensitivity in the mandibular region. The patient was diagnosed with neuropathy due to intracranial lesions and referred to the Department of Neurosurgery and Otorhinolaryngology. The patient was suspected of having malignant lymphoma and is currently undergoing neurosurgical intervention. This article discusses the importance of the examination of the cranial nerve for patients with persistent pain in the trigeminal nerve distribution.

Case Report: Unilateral Cranial Nerve VI Palsy Secondary to Intracranial Hypotension.

SIGNIFICANCE: Intracranial hypotension is a condition that occurs from a cerebrospinal fluid leak. Various visual symptoms have been associated with this condition. Cranial nerve VI (CN VI) palsies are the most common ocular manifestation, as the abducens nerve is prone to injury because of its intracranial anatomical course. PURPOSE: This case report presents a CN VI palsy secondary to intracranial hypotension from ventriculoperitoneal shunt overfiltration. Diagnosis, treatment, and management considerations are discussed. No identifiable health information was included in this case report. CASE REPORT: A 70-year-old White man was referred to the eye clinic for evaluation of binocular horizontal diplopia. The patient had a recent history of a left ventriculoperitoneal shunt for a persistent cerebrospinal fluid leak after complex mastoid surgery. The patient was also symptomatic for positional headaches, which improved in a recumbent position. He was diagnosed with a left CN VI palsy secondary to intracranial hypotension from a ventriculoperitoneal shunt overfiltration. The patient was followed up by neurosurgery for shunt adjustments to resolve the overfiltration. Binocular horizontal diplopia was managed conservatively with Fresnel prism. CONCLUSIONS: Intracranial hypotension should be considered in patients presenting with cranial nerve palsies and positional headaches. Obtaining neuroimaging and comanaging with neurology or neurosurgery are advised to make prompt diagnosis and treatment. Careful clinical monitoring and conservative diplopia therapy are recommended as visual symptoms improve upon resolution of the cerebrospinal fluid leak.

Etiologic distribution of isolated abducens nerve palsy: Analysis of 807 patients and literature review.

BACKGROUND AND PURPOSE: The etiologies of abducens nerve palsy have shown a large variability among studies. This study aimed to establish the clinical features and underlying etiologies of isolated abducens nerve palsy by recruiting patients from all departments in a referral-based university hospital. METHODS: We reviewed the medical records of 807 patients with a confirmed diagnosis of isolated abducens nerve palsy at all departments of Seoul National University Bundang Hospital, Seongnam, Republic of Korea, from 2003 to 2020. We also compared the proportion of etiology with that of the patients pooled from the previous studies. RESULTS: The most common etiology was microvascular (n = 296, 36.7%), followed by idiopathic (n = 143, 17.7%), neoplastic (n = 115, 14.3%), vascular anomalies (n = 82, 10.2%), inflammatory (n = 76, 9.4%), and traumatic (n = 35, 4.3%). Patients were mostly managed by ophthalmologists (n = 576, 71.4%), followed by neurologists (n = 479, 59.4%), emergency physicians (n = 278, 34.4%), neurosurgeons (n = 191, 23.7%), and others (n = 72, 8.9%). The proportion of etiology significantly differed according to the age and sex of the patients and the specialties involved in the management (p < 0.001). Compared to the pooled data from the previous reports, the current study showed a higher prevalence of microvascular cause but a lower occurrence of traumatic and neoplastic causes. CONCLUSIONS: The results of previous studies on etiologic distribution of isolated abducens nerve palsy should be interpreted with consideration of the demographic features of patients recruited and the specialties involved.

Vertebrobasilar dolichoectasia and other arterial abnormalities leading to abducens nerve palsy.

INTRODUCTION: Dolichoectatic vessels can cause cranial nerve dysfunction by either direct compression or ischemia. Abducens nerve palsy due to neurovascular compression by elongated, enlarged, tortuous or dilated arteries is an uncommon but important cause. AIM: To highlight neurovascular compression as a cause of abducens nerve palsy and discuss various diagnostic techniques. METHODS: Manuscripts were identified using the National Institutes of Health PubMed literature search system. Search terms included abducens nerve palsy, neurovascular compression, dolichoectasia and arterial compression. Inclusion criteria required that the articles were written in English. RESULTS: The literature search identified 21 case reports where abducens nerve palsy was due to vascular compression. Out of these 18 patients were male and the mean age was 54 years. Eight patients had unilateral right abducens nerve involvement; eleven patients had unilateral left nerve involvement and two patients had bilateral involvement. The arteries causing the compression were basilar, vertebral and anterior inferior cerebellar arteries. A compressed abducens nerve is not usually clearly detected on CT (Computed Tomography) or MRI (Magnetic Resonance Imaging). MRA (Magnetic Resonance Angiography), Heavy T2- WI (weighted imaging), CISS (constructive interference in steady state) and FIESTA (Fast Imaging Employing Steady-state Acquisition) are essential to demonstrate vascular compression of the abducens nerve. The various treatment options included controlling hypertension, glasses with prisms, muscle resection and microvascular decompression.

Isolated Sixth Nerve Palsies in a Child With Familial Hemophagocytic Lymphohistiocytosis Type 2.

ABSTRACT: A previously healthy 2-year-old boy presented with a left sixth cranial nerve palsy. There was a family history of multiple sclerosis and optic neuritis. Neuroimaging showed multiple foci of T2/FLAIR hyperintense signal abnormality in both cerebral hemispheres and in the brainstem. The initial diagnosis was suspicious for demyelinating disease. However, there was no clinical improvement after a course of corticosteroids, and there was no change in his follow-up MRI. He later developed bilateral sixth nerve palsies, with esotropia addressed with bilateral medial rectus botulinum toxin injections. A brain biopsy was planned. However, his 3-month-old sister was separately admitted for fever and pancytopenia. She had markedly elevated ferritin, D-dimer, triglycerides, sIL-2R, CXCL9, and IL-18 and low fibrinogen. Her bone marrow biopsy showed hemophagocytosis. Genetic testing of both siblings revealed biallelic mutations in the PRF1 locus. The final diagnosis of familial hemophagocytic lymphohistiocytosis Type 2 was made. Both siblings underwent chemotherapy. The boy's sixth nerve palsies and MRI abnormalities resolved. Both siblings then went on to undergo bone marrow transplant.

Ocular Motor Nerve Palsy After Traumatic Brain Injury: A Claims Database Study.

BACKGROUND: Traumatic brain injury (TBI) is one of the common causes of ocular motor nerve (oculomotor nerve [CN3], trochlear nerve [CN4], and abducens nerve [CN6]) palsies, but there has been no large study of ocular motor nerve palsy caused by TBI. This study aimed to investigate the characteristics of and differences in ocular motor nerve palsy after TBI, according to patient age and severity of TBI. METHODS: This was a population-based retrospective cohort study that included patients who had ocular motor nerve palsy after TBI with ≥6 months of continuous enrollment using claims data from the IBM MarketScan Research Databases (2007-2016). We assessed sex, age at the first diagnosis of TBI, the severity of TBI, and the rates of strabismus procedures according to the age and severity of TBI. The rates of muscle transposition surgery and chemodenervation in CN3, CN4, and CN6 palsy were investigated. RESULTS: A total of 2,606,600 patients with TBI met the inclusion criteria. Among them, 1,851 patients (0.071%) had ocular motor nerve palsy after TBI. The median age of the patients was 39 (Q1-Q3: 19-54) years, and 42.4% of the patients were female. The median continuous enrollment period after the first diagnosis of TBI was 22 (Q1-Q3: 12-38) months. Of the 1,350,843 children with TBI, 454 (0.026%) had ocular motor nerve palsy. Of the 1,255,757 adults with TBI, 1,397 (0.111%) had ocular motor nerve palsy. Among these 1,851 patients, CN4 palsy (697, 37.7%) occurred most frequently, and strabismus procedures were performed in 237 patients (12.8%). CN6 palsy developed most frequently in children. More children (16.5%) underwent strabismus surgeries than adults (11.6%) ( P = 0.006). The proportion of CN4 palsy (52.3%) was higher while the proportion of CN3 palsy (15.5%) was lower in patients with mild TBI than in patients with moderate-to-severe TBI ( P < 0.001). CONCLUSIONS: CN4 palsy developed most frequently among patients of all ages, and only approximately 13% of the patients underwent strabismus procedures for ocular motor nerve palsy after TBI. The rate of development of ocular motor nerve palsy was approximately 4.3 times lower in children than adults, and children most frequently had CN6 palsy after TBI.

MRI Diagnosis of Clival Cancer and Sixth Nerve Palsy.

BACKGROUND: Imaging diagnosis of clival cancer may be difficult, in part because of normal variation in marrow signal with aging. Identifying whether clival cancer has damaged the sixth cranial nerve is a further challenge because minimal clival abnormalities could impinge on the nerve, which travels very close to the clivus. METHODS: Two neuroradiologists, who were unaware of previous imaging and clinical diagnoses, reviewed MRI studies of 25 patients with cancer but no clival involvement and no sixth nerve palsy, 24 patients with clival cancer but without sixth nerve palsy, and 31 patients with clival cancer and sixth nerve palsy. The radiologists were tasked with determining whether there was clival cancer, whether there was a sixth nerve palsy and its laterality, and with indicating the pulse sequences used to make those determinations. RESULTS: Both neuroradiologists correctly identified all 25 cases with a normal clivus. In about half of those cases, they depended on finding a homogeneously bright marrow signal; in the remaining cases, they excluded cancer by determining that the clivus was not expanded and that there were no focal signal abnormalities. Both neuroradiologists correctly identified clival cancer in 54 (98%) of the 55 cases with and without sixth nerve palsy. In doing so, they relied mostly on clival expansion but also on focal signal abnormalities. Both neuroradiologists were at least 80% correct in identifying a sixth nerve palsy, but they often incorrectly identified a palsy in patients who did not have one. When there was a one-sided signal abnormality or the clivus was expanded in one direction, both neuroradiologists were accurate in identifying the side of the sixth nerve palsy. CONCLUSION: Current MRI pulse sequences allow accurate differentiation of a normal from a cancerous clivus. When the marrow signal is not homogeneously bright in adults, cancer can be diagnosed on the basis of clival expansion or focal signal abnormalities. MRI is less accurate in predicting the presence of a sixth nerve palsy. However, the side of a unilateral palsy can be predicted when the clivus is clearly expanded in one direction or there is a focal signal abnormality on one side.