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Journal of AAPOS : the Official... Apr 2020Townes-Brocks syndrome (TBS) is a rare genetic syndrome associated with heterozygous mutations in SALL1 and characterized by abnormalities of the anus, ear, and thumb....
Townes-Brocks syndrome (TBS) is a rare genetic syndrome associated with heterozygous mutations in SALL1 and characterized by abnormalities of the anus, ear, and thumb. Ophthalmic findings have been rarely reported and include congenital cataract, microphthalmia, optic nerve atrophy, coloboma, epibulbar dermoid, and dysinnervation patterns, such as Duane syndrome and gustatory lacrimation. We report a case of genetically confirmed TBS showing a spectrum of ocular anomalous innervations, including bilateral type 1 Duane syndrome and Möbius sequence, left-sided Marcus Gunn jaw winking, left eye gustatory lacrimation, and lack of emotional tearing bilaterally. Magnetic resonance imaging of brain and orbit showed absence of the abducens nerve bilaterally and of the left facial nerve.
Topics: Abnormalities, Multiple; Anus, Imperforate; Hearing Loss, Sensorineural; Humans; Thumb; Transcription Factors
PubMed: 31981611
DOI: 10.1016/j.jaapos.2019.12.004 -
Journal of Neuroendovascular Therapy 2022There are few detailed reports on abducens nerve palsy due to a ruptured vertebral artery dissecting aneurysm (VADA). We investigated the clinical characteristics and...
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.
PubMed: 37502345
DOI: 10.5797/jnet.oa.2021-0060 -
Folia Morphologica 2023The microanatomy of the central myelin portion and transitional zone of several cranial nerves including trigeminal, facial, vestibulocochlear, glossopharyngeal, and...
BACKGROUND
The microanatomy of the central myelin portion and transitional zone of several cranial nerves including trigeminal, facial, vestibulocochlear, glossopharyngeal, and vagus nerves have been clearly demonstrated to provide information for neurovascular compression syndrome such as trigeminal neuralgia and hemifacial spasm. However, the study of oculomotor and abducens nerve is limited.
MATERIALS AND METHODS
Oculomotor and abducens nerves were harvested with a portion of brainstem and embedded in paraffin. Longitudinal and serial sections from ten of each cranial nerve were stained and a photomicrograph was taken to make the following observations and measurements: 1) patterns of central myelin portion, 2) length of central myelin portion, and 3) depth of central myelin- peripheral myelin transitional zone.
RESULTS
For oculomotor nerve, the longest central myelin bundle was always seen on the first nerve bundle and that the length of central myelin decreased gradually. For abducens nerve, morphological patterns were classified into four types based on number of nerve rootlets emerging from the brainstem and number of nerve bundles in each rootlet. Length of central myelin portion was between 0.36-6.10 mm (2.75 ± 0.83 mm) and 0.13-5.01 mm (1.66 ± 1.39 mm) for oculomotor and abducens nerves, respectively. The oculomotor nerve transitional zone depth was 0.07-058 mm (0.23 ± 0.07 mm), while for abducens nerve, depth was 0.05-0.40 mm (0.16 ± 0.07 mm). Positive weak correlations between central myelin and depth of TZ were found in oculomotor nerve (r +0.310, p < 0.05) and abducens nerves (r +0.413, p < 0.05).
CONCLUSIONS
Detailed microanatomy of the central myelin and transitional zone might be beneficial for locating the site of compression in neurovascular conflicts at oculomotor and abducens nerves.
Topics: Humans; Abducens Nerve; Myelin Sheath; Brain Stem; Trigeminal Neuralgia; Spinal Nerve Roots
PubMed: 35692113
DOI: 10.5603/FM.a2022.0057 -
Pediatrics in Review Oct 2023
Topics: Female; Humans; Infant; Abducens Nerve Diseases
PubMed: 37777223
DOI: 10.1542/pir.2022-005571 -
Brain Sciences May 2021The present study aims to provide detailed observations on the cavernous segment of the abducens nerve (AN), emphasizing anatomical variations and the relationships...
The present study aims to provide detailed observations on the cavernous segment of the abducens nerve (AN), emphasizing anatomical variations and the relationships between the nerve and the internal carotid plexus. A total of 60 sides underwent gross-anatomical study. Five specimens of the AN were stained using Sihler's method. An additional five specimens were subjected to histological examination. Four types of AN course were observed: a single nerve along its entire course, duplication of the nerve, division into separate rootlets at the point of contact with the cavernous part of the internal carotid artery (ICA), and early-branching before entering the orbit. Due to the relationships between the ICA and internal carotid plexus, the cavernous segment of the AN can be subdivided into a carotid portion located at the point of contact with the posterior vertical segment of the cavernous ICA and a prefissural portion. The carotid portion of the cavernous AN segment is a place of angulation, where the nerve always directly adheres to the ICA. The prefissural portion of the AN, in turn, is the primary site of fiber exchange between the internal carotid plexus and either the AN or the lateral wall of the cavernous sinus.
PubMed: 34065668
DOI: 10.3390/brainsci11050649 -
The Laryngoscope Mar 2021While abducens nerve palsy (ANP) is a known risk in the setting of some endoscopic endonasal skull base surgery (ESBS), frequency and prognosis of post-operative palsy...
OBJECTIVES
While abducens nerve palsy (ANP) is a known risk in the setting of some endoscopic endonasal skull base surgery (ESBS), frequency and prognosis of post-operative palsy remain unknown. Our goals were to determine the frequency and prognosis of ANP after high-risk ESBS, and identify factors associated with recovery.
METHODS
Retrospective case series of all patients with pathology at highest risk for abducens nerve injury (pituitary adenoma, chordoma, meningioma, chondrosarcoma, cholesterol granuloma) generated a list of patients with abducens nerve palsy after ESBS performed from 2011-2016. A validated ophthalmologic clinical grading scale measuring lateral rectus duction from 0 to -5 (full motion to inability to reach midline) was measured at multiple time points to assess recovery of ANP.
RESULTS
Of 655 patients who underwent ESBS with increased risk of abducens injury, 40 (6.1%) post-operative palsies were identified and 39 patients with dedicated examination at multiple time points were included in subsequent analysis. Complete resolution was noted in 25 patients (64%) within 12 months. While 19 of 23 (83%) with a partial palsy had complete resolution, only six of 16 (38%) with a complete palsy resolved entirely (P = .005; Fisher's exact test). All six patients with delayed onset of palsy resolved (P = .070; Fisher's exact test). Meningioma and chordoma had higher rates of both temporary and permanent post-operative ANP (P < .0001; Fisher's exact).
CONCLUSIONS
The frequency of post-operative ANP following ESBS is low, even in high-risk tumors. While only a minority of complete abducens nerve palsies recover, patients with partial or delayed palsy post-operatively are likely to recover function without intervention.
LEVEL OF EVIDENCE
IV Laryngoscope, 131:513-517, 2021.
Topics: Abducens Nerve; Abducens Nerve Injury; Adult; Diagnostic Techniques, Ophthalmological; Endoscopy; Female; Humans; Intraoperative Complications; Male; Middle Aged; Predictive Value of Tests; Preoperative Care; Recovery of Function; Retrospective Studies; Skull Base; Treatment Outcome
PubMed: 32809233
DOI: 10.1002/lary.29008 -
Turkish Journal of Ophthalmology Aug 2022Multiple sclerosis (MS) is a chronic disorder characterized by demyelination of the central nervous system. It often presents in women aged 18-35 with neurological...
Multiple sclerosis (MS) is a chronic disorder characterized by demyelination of the central nervous system. It often presents in women aged 18-35 with neurological symptoms such as visual loss, paresthesia, focal weakness, and ataxia. Demyelination in the brainstem can result in internuclear ophthalmoplegia causing binocular horizontal diplopia. Our report details a patient with horizontal diplopia from an isolated abducens (sixth) nerve palsy as the initial symptom of MS. While rare, this demonstrates the importance of including MS in the differential diagnosis for an isolated abducens nerve palsy, especially in younger patients with no known vascular risk factors.
Topics: Abducens Nerve Diseases; Brain Stem; Diplopia; Female; Humans; Multiple Sclerosis; Ocular Motility Disorders
PubMed: 36017545
DOI: 10.4274/tjo.galenos.2022.13245 -
Neuro-ophthalmology (Aeolus Press) Jun 2020Pembrolizumab is a checkpoint inhibitor targeting the programmed cell death 1 receptor of lymphocytes and is used in the treatment of solid tumours including melanoma....
Pembrolizumab is a checkpoint inhibitor targeting the programmed cell death 1 receptor of lymphocytes and is used in the treatment of solid tumours including melanoma. The authors report a 64-year-old man treated with pembrolizumab for stage IV cutaneous melanoma (primary cutaneous melanoma of the right lower back) with liver metastases. The patient developed a horizontal binocular diplopia due to an isolated unilateral cranial nerve VI palsy. Following 1 week of high dose oral steroid therapy and cessation of the drug, the patient's nerve palsy and associated diplopic symptoms improved dramatically, and after 6 weeks of oral steroid taper and drug cessation, the palsy resolved completely. Few reports of checkpoint inhibitor autoimmune-induced isolated cranial nerve palsies have been described, and this is the first report of drug-induced isolated cranial nerve VI palsy.
PubMed: 32395170
DOI: 10.1080/01658107.2019.1566385 -
Journal of Neuro-ophthalmology : the... Dec 2022
Topics: Humans; Paralysis; Abducens Nerve Diseases
PubMed: 35482436
DOI: 10.1097/WNO.0000000000001543 -
Journal of Neurosurgery Nov 2022The petrosal process of the sphenoid bone (PPsb) is a relevant skull base osseous prominence present bilaterally that can be used as a key surgical landmark, especially...
OBJECTIVE
The petrosal process of the sphenoid bone (PPsb) is a relevant skull base osseous prominence present bilaterally that can be used as a key surgical landmark, especially for identifying the abducens nerve. The authors investigated the surgical anatomy of the PPsb, its relationship with adjacent neurovascular structures, and its practical application in endoscopic endonasal surgery.
METHODS
Twenty-one dried skulls were used to analyze the osseous anatomy of the PPsb. A total of 16 fixed silicone-injected postmortem heads were used to expose the PPsb through both endonasal and transcranial approaches. Dimensions and distances of the PPsb from the foramen lacerum (inferiorly) and top of the posterior clinoid process (PCP; superiorly) were measured. Moreover, anatomical variations and the relationship of the PPsb with the surrounding crucial structures were recorded. Three representative cases were selected to illustrate the clinical applications of the findings.
RESULTS
The PPsb presented as a triangular bony prominence, with its base medially adjacent to the dorsum sellae and its apex pointing posterolaterally toward the petrous apex. The mean width of the PPsb was 3.5 ± 1 mm, and the mean distances from the PPsb to the foramen lacerum and the PCP were 5 ± 1 and 11 ± 2.5 mm, respectively. The PPsb is anterior to the petroclival venous confluence, superomedial to the inferior petrosal sinus, and inferomedial to the superior petrosal sinus; constitutes the inferomedial limit of the cavernous sinus; and delimits the upper limit of the paraclival internal carotid artery (ICA) before the artery enters the cavernous sinus. The PPsb is anterior and medial to and below the sixth cranial nerve, forming the floor of Dorello's canal. During surgery, gentle mobilization of the paraclival ICA reveals the petrosal process, serving as an accurate landmark for the location of the abducens nerve.
CONCLUSIONS
This investigation revealed details of the microsurgical anatomy of the PPsb, its anatomical relationships, and its application as a surgical landmark for identifying the abducens nerve. This novel landmark may help in minimizing the risk of abducens nerve injury during transclival approaches, which extend laterally toward the petrous apex and cavernous sinus region.
PubMed: 35276642
DOI: 10.3171/2021.12.JNS212024