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Journal of Korean Neurosurgical Society Mar 2021Electrooculography (EOG) records eyeball movements as changes in the potential difference between the negatively charged retina and the positively charged cornea. We...
OBJECTIVE
Electrooculography (EOG) records eyeball movements as changes in the potential difference between the negatively charged retina and the positively charged cornea. We aimed to investigate whether reliable EOG waveforms can be evoked by electrical stimulation of the oculomotor and abducens nerves during skull base surgery.
METHODS
We retrospectively reviewed the records of 18 patients who had undergone a skull base tumor surgery using EOG (11 craniotomies and seven endonasal endoscopic surgeries). Stimulation was performed at 5 Hz with a stimulus duration of 200 μs and an intensity of 0.1-5 mA using a concentric bipolar probe. Recording electrodes were placed on the upper (active) and lower (reference) eyelids, and on the outer corners of both eyes; the active electrode was placed on the contralateral side.
RESULTS
Reproducibly triggered EOG waveforms were observed in all cases. Electrical stimulation of cranial nerves (CNs) III and VI elicited positive waveforms and negative waveforms, respectively, in the horizontal recording. The median latencies were 3.1 and 0.5 ms for craniotomies and endonasal endoscopic surgeries, respectively (p=0.007). Additionally, the median amplitudes were 33.7 and 46.4 μV for craniotomies and endonasal endoscopic surgeries, respectively (p=0.40).
CONCLUSION
This study showed reliably triggered EOG waveforms with stimulation of CNs III and VI during skull base surgery. The latency was different according to the point of stimulation and thus predictable. As EOG is noninvasive and relatively easy to perform, it can be used to identify the ocular motor nerves during surgeries as an alternative of electromyography.
PubMed: 33353290
DOI: 10.3340/jkns.2020.0179 -
Asian Journal of Neurosurgery 2018Abducens nerve palsy associated with subarachnoid hemorrhage (SAH) has rarely been reported. Its frequency, mechanism of palsy, association with aneurysmal location, and...
BACKGROUND
Abducens nerve palsy associated with subarachnoid hemorrhage (SAH) has rarely been reported. Its frequency, mechanism of palsy, association with aneurysmal location, and clinical course are poorly described. The purpose of our study was to evaluate patients with abducens nerve palsy caused by SAH occurring from ruptured vertebral artery (VA) dissecting aneurysm and to find aneurysmal location using initial computed tomography (CT) and its association with clinically detected cranial nerve palsy.
METHODS
Fourteen patients of SAH due to ruptured VA dissecting aneurysm were treated at our hospital from January 2011 to May 2015. The clinical courses and CT findings were reviewed retrospectively.
RESULTS
Abducens nerve palsy was observed in 77.8% of cases after excluding patients with decreased levels of consciousness. Clots within the prepontine cistern were significantly thicker in cases of VA dissecting aneurysm than in case of supratentorial aneurysm ( = 0.002).
CONCLUSION
The findings of our study indicated that ruptured VA dissecting aneurysms, even in cases of angio-negative SAH, are likely to present with abducens nerve palsy.
PubMed: 30283507
DOI: 10.4103/ajns.AJNS_156_16 -
Current Oncology (Toronto, Ont.) Jul 2022Abducens nerve palsy is a severe dysfunction after petroclival meningioma (PC MNG) surgery. The objective of this investigation was to analyze abducens nerve outcomes in...
Abducens nerve palsy is a severe dysfunction after petroclival meningioma (PC MNG) surgery. The objective of this investigation was to analyze abducens nerve outcomes in patients who underwent the retrosigmoid approach in relation to the MIB-1 index. Thirty-two patients with primary sporadic PC MNG were retrospectively analyzed. Mean follow-up was 28.0 months. Analysis of the MIB-1 index was performed to evaluate the abducens nerve outcome. An optimal MIB-1 index cut-off value (<4/≥4) in the association with postoperative CN VI palsy was determined by ROC analysis (AUC: 0.74, 95% CI: 0.57−0.92). A new-onset CN VI palsy was present in 7 cases (21.88%) and was significantly associated with an increased MIB-1 index (≥4%, p = 0.025) and a peritumoral edema in the brachium pontis (p = 0.047) which might be caused by the increased growth rate. Tumor volume, cavernous sinus infiltration, auditory canal invasion, and Simpson grading were not associated with new CN VI deficits. Six (85.7%) of the 7 patients with both an increased MIB-1 index (≥4%) and new abducens nerve palsy still had a CN VI deficit at the 12-month follow-up. A peritumoral edema caused by a highly proliferative PC MNG with an elevated MIB-1 index (≥4%) is associated with postoperative abducens nerve deficits.
Topics: Abducens Nerve; Abducens Nerve Diseases; Humans; Meningeal Neoplasms; Meningioma; Morbidity; Paralysis; Retrospective Studies
PubMed: 35877258
DOI: 10.3390/curroncol29070398 -
IDCases 2022An isolated cranial nerve VI palsy is a rare initial manifestation of undiagnosed neurosyphilis. A 33-year-old male presented with a one month history of progressive...
An isolated cranial nerve VI palsy is a rare initial manifestation of undiagnosed neurosyphilis. A 33-year-old male presented with a one month history of progressive headache and diplopia. Neurologic examination only revealed an isolated abducens palsy on the left. Cranial imaging was unremarkable. Examination of his cerebrospinal fluid revealed lymphocytic predominant leukocytosis and elevated protein. Microbiologic work-up were all negative. Further work-up revealed the patient to be serum Rapid Plasma Reagin and Enzyme Immunoassay reactive. Enzyme-linked immunosorbent assay for Human Immunodeficiency Virus also tested positive. His cerebrospinal fluid was then sent for Rapid Plasma Reagin to confirm the diagnosis of neurosyphilis. He completed 14 days of intravenous penicillin and was eventually discharged with partial resolution of the abducens palsy. We describe the second case of neurosyphilis presenting only with an isolated cranial nerve VI involvement. On further review, ours was the first case documented on an individual who had an undiagnosed Human Immunodeficiency Virus infection. There are various differentials for an isolated cranial neuritis but infectious causes, particularly neurosyphilis, should be considered among young individuals with known risk factors despite their apparently benign medical history.
PubMed: 35036319
DOI: 10.1016/j.idcr.2022.e01377 -
Cephalalgia : An International Journal... Mar 2023Based on expert opinion, abducens nerve palsy and a neuroimaging criterion (≥3 neuroimaging signs suggestive of elevated intracranial pressure) were added to the...
BACKGROUND
Based on expert opinion, abducens nerve palsy and a neuroimaging criterion (≥3 neuroimaging signs suggestive of elevated intracranial pressure) were added to the diagnostic criteria for idiopathic intracranial hypertension. Our objective was to validate this.
METHODS
This prospective study included patients with new-onset idiopathic intracranial hypertension for a standardized work-up: interview, neuro-ophthalmological exam, lumbar puncture, neuroimaging. Neuroimaging was evaluated by a blinded neuroradiologist.
RESULTS
We included 157 patients classified as idiopathic intracranial hypertension (56.7%), probable idiopathic intracranial hypertension (1.9%), idiopathic intracranial hypertension without papilledema (idiopathic intracranial hypertension-without papill edema; 0%), suggested idiopathic intracranial hypertension-without papill edema (4.5%), or non-idiopathic intracranial hypertension (36.9%). Moderate suprasellar herniation was more common in idiopathic intracranial hypertension than non-idiopathic intracranial hypertension (71.4% versus 47.4%, p < 0.01), as was perioptic nerve sheath distension (69.8% versus 29.3%, p < 0.001), flattening of the globe (67.1% versus 11.1%, p < 0.001) and transverse sinus stenosis (60.2% versus 18.9%, p < 0.001). Abducens nerve palsy was of no diagnostic significance. Sensitivity of ≥3 neuroimaging signs was 59.5% and specificity was 93.5%.
CONCLUSION
Moderate suprasellar herniation, distension of the perioptic nerve sheath, flattening of the globe and transverse sinus stenosis were associated with idiopathic intracranial hypertension. We propose that idiopathic intracranial hypertension can be defined by two out of three objective findings (papilledema, opening pressure ≥25 cm cerebrospinal fluid and ≥3 neuroimaging signs).
Topics: Humans; Papilledema; Constriction, Pathologic; Prospective Studies; Magnetic Resonance Imaging; Pseudotumor Cerebri; Intracranial Hypertension; Abducens Nerve Diseases
PubMed: 36786317
DOI: 10.1177/03331024231152795 -
Journal of Pediatric Ophthalmology and... 2023To report the incidence and outcomes of pulled-in-two syndrome during strabismus surgery and investigate the clinical features and management of the disease.
PURPOSE
To report the incidence and outcomes of pulled-in-two syndrome during strabismus surgery and investigate the clinical features and management of the disease.
METHODS
The medical records of patients who underwent strabismus surgery and developed pulled-in-two syndrome between July 2013 and October 2020 were reviewed retrospectively. The demographic characteristics, intraoperative details (including surgery type and management), and subsequent and final outcomes were extracted from the records.
RESULTS
Of the 11,824 strabismus surgeries during the study period, 4 cases of pulled-in-two syndrome were documented, accounting for an overall incidence of 0.034%. The average age of the patients with pulled-in-two syndrome was 61.75 ± 8.99 years. All 4 patients were women; 2 had abducens nerve palsy and the other 2 had myopic strabismus fixus. The inferior rectus muscle was involved in 1 patient and the medial rectus muscle was involved in 3 patients. All of the involved extraocular muscle was lost. One patient achieved orthotropia, and the others were undercorrected after the surgery.
CONCLUSIONS
Pulled-in-two syndrome is one of the rarest and most severe complications of strabismus surgery. Cranial nerve palsy, advanced age, prior surgery, thyroid-associated ophthalmopathy, and degenerative conditions of the extraocular muscle are risk factors for pulled-in-two syndrome. Therefore, the prevention of pulled-in-two syndrome in patients with these risk factors should be investigated further. .
PubMed: 35938640
DOI: 10.3928/01913913-20220627-01 -
Journal of Neurological Surgery. Part... Dec 2020The anatomy and definition of the petroclinoid ligament (PCL) and its relationship with the abducens nerve are variably described. The goal of this study was to clarify...
The anatomy and definition of the petroclinoid ligament (PCL) and its relationship with the abducens nerve are variably described. The goal of this study was to clarify the anatomy of the PCL and better elucidate its relationship with the abducens nerve. Thirty-six sides from 18 fresh-frozen adult cadaveric heads were used in this study. Specimens were all Caucasian and derived from 10 males and 8 females. The mean age at death was 79 years. Dissection of the PCL and abducens nerve was performed using a surgical microscope. The anterior and posterior attachments of the PCL, and position of the abducens nerve were noted. Subsequently, the width, thickness, and length of the ligament, and diameter of the abducens nerve were measured. Thirty-one sides (86.1%) were found to have a PCL, on two sides (5.6%), the PCL was ossified, and on three sides (8.3%), the PCL was absent. The width, thickness, and length of the PCL ranged from 0.54 to 3.39, 0.07 to 0.49, and 3.27 to 17.85 mm, respectively. No PCL had an anterior attachment onto the posterior clinoid process but rather, the clivus. Therefore, based on our findings, the PCL would be better described as the petroclival ligament.
PubMed: 33381363
DOI: 10.1055/s-0039-1692699 -
Journal of Neurosurgery. Case Lessons May 2024Unilateral cranial nerve (CN) VI, or abducens nerve, palsy is rare in children and has not been reported in association with Chiari malformation type 1 (CM1) in the...
BACKGROUND
Unilateral cranial nerve (CN) VI, or abducens nerve, palsy is rare in children and has not been reported in association with Chiari malformation type 1 (CM1) in the absence of other classic CM1 symptoms.
OBSERVATIONS
A 3-year-old male presented with acute incomitant esotropia consistent with a unilateral, left CN VI palsy and no additional neurological symptoms. Imaging demonstrated CM1 without hydrocephalus or papilledema, as well as an anterior inferior cerebellar artery (AICA) vessel loop in the immediate vicinity of the left abducens nerve. Given the high risk of a skull base approach for direct microvascular decompression of the abducens nerve and the absence of other classic Chiari symptoms, the patient was initially observed. However, as his palsy progressed, he underwent posterior fossa decompression with duraplasty (PFDD), with the aim of restoring global cerebrospinal fluid dynamics and decreasing possible AICA compression of the left abducens nerve. Postoperatively, his symptoms completely resolved.
LESSONS
In this first reported case of CM1 presenting as a unilateral abducens palsy in a young child, possibly caused by neurovascular compression, the patient's symptoms resolved after indirect surgical decompression via PFDD.
PubMed: 38710112
DOI: 10.3171/CASE23539 -
Indian Journal of Otolaryngology and... Aug 2022To address the management of complications after temporal bone fractures and the outcomes. A prospective clinical study of 100 patients from the Department of Trauma...
To address the management of complications after temporal bone fractures and the outcomes. A prospective clinical study of 100 patients from the Department of Trauma (Surgery + E.N.T.), P.D.U. Medical College, Rajkot between the time period of 2017-2019. Among 100 patients, 79 were males and 21 were females. The most affected age group was 16-45 years (72). The longitudinal fracture (90) is the most common type of fracture, in which non-petrous type is the most prevalent (88) as low impact injuries are more common. The most common presentations of temporal bone fracture are ear bleed (59) and decreased hearing (59), mostly over the side of trauma. The most common clinical finding is hearing impairment (59), followed by haemotympanum (20) and facial palsy (15), more common over the side of trauma. Facial palsy had been easily managed conservatively by steroids and physiotherapy in most of the cases. 12 out of 15 patients had good recovery i.e. upto grade I and II by conservative management, 3 had undergone facial nerve decompression, following which 1 had recovered completely, i.e. grade 1; 1 upto grade II while 1 did not show any improvement. Other complications included giddiness (18), trigeminal neuralgia (1) and abducens nerve palsy (1). The temporal bone is more prone to injury and complications following trauma like hearing impairment, cerebrospinal fluid leak and facial palsy resolve either spontaneously or with conservative management. Surgeries must be undertaken only if adequate conservative treatment fails and after proper investigations.
PubMed: 36032853
DOI: 10.1007/s12070-020-02068-5 -
PloS One 2016We have previously reported that the presence of the abducens nerve was variable in patients with type 3 Duane's retraction syndrome (DRS), being present in 2 of 5 eyes...
BACKGROUND
We have previously reported that the presence of the abducens nerve was variable in patients with type 3 Duane's retraction syndrome (DRS), being present in 2 of 5 eyes (40%) and absent in 3 (60%) on magnetic resonance imaging (MRI). The previous study included only 5 eyes with unilateral DRS type 3.
OBJECTIVES
To supplement existing scarce pathologic information by evaluating the presence of the abducens nerve using high resolution thin-section MRI system in a larger number of patients with DRS type 3, thus to provide further insight into the pathogenesis of DRS.
DATA EXTRACTION
A retrospective review of medical records on ophthalmologic examination and high resolution thin-section MRI at the brainstem level and orbit was performed. A total of 31 patients who showed the typical signs of DRS type 3, including abduction and adduction deficit, globe retraction, narrowing of fissure on adduction and upshoot and/or downshoot, were included. The abducens nerve and any other extraocular muscle abnormalities discovered by MRI were noted.
RESULTS
DRS was unilateral in 26 patients (84%) and bilateral in 5 patients (16%). Two out of 5 bilateral patients had DRS type 3 in the right eye and DRS type 1 in the left eye. Of the 34 affected orbits with DRS type 3 in 31 patients, the abducens nerve was absent or hypoplastic in 31 eyes (91%) and present in 3 eyes (9%). Patients with a present abducens nerve showed more limitation in adduction compared to patients with an absent abducens nerve (P = 0.030).
CONCLUSIONS
The abducens nerve is absent or hypoplastic in 91% of DRS type 3. Patients with a present abducens nerve showed more prominent limitation of adduction. As DRS type 3 partly share the same pathophysiology with type 1 and 2 DRS, the classification of DRS may have to be revised according to MRI findings.
Topics: Abducens Nerve; Adolescent; Adult; Aged; Child; Child, Preschool; Duane Retraction Syndrome; Female; Humans; Infant; Magnetic Resonance Imaging; Male; Middle Aged
PubMed: 27352171
DOI: 10.1371/journal.pone.0150670