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Annals of Indian Academy of Neurology Oct 2022Ocular nerve palsies are among the most common cranial neuropathies in neurological practice. Nerves can get affected anywhere along their path from the brainstem to the...
Ocular nerve palsies are among the most common cranial neuropathies in neurological practice. Nerves can get affected anywhere along their path from the brainstem to the orbit. There can be isolated involvement of multiple cranial nerves together. The etiologies differ according to the type of presentation. The steps toward the diagnosis need to be strategically planned and must be based on clinical localization. It is crucial to make proper localization to plan further investigations and thus treatment of the etiology. This review covers the approach toward the diagnosis, etiologies involved, and management of ocular cranial neuropathies.
PubMed: 36589037
DOI: 10.4103/aian.aian_167_22 -
AJNR. American Journal of Neuroradiology Feb 2023The trochlear nerve has traditionally been difficult to identify on MR imaging. The advent of 7T MR imaging promises to greatly benefit visualization of small structures...
BACKGROUND AND PURPOSE
The trochlear nerve has traditionally been difficult to identify on MR imaging. The advent of 7T MR imaging promises to greatly benefit visualization of small structures due to gains in the signal-to-noise ratio allowing improved spatial resolution. We investigated the utility of a clinically feasible ultra-high-resolution 7T MR imaging protocol for identification of the trochlear nerve, as well as assessment of normal trochlear nerve anatomy.
MATERIALS AND METHODS
Coronal high-resolution 2D T2-weighted TSE images used in a 7T epilepsy protocol of 50 subjects at our institution were reviewed by 2 independent radiologists for visualization of the trochlear nerve at the nerve origin and cisternal, tentorial, and cavernous segments. The frequency of nerve visibility within these segments and their anatomy were documented, and disagreements were resolved by joint review.
RESULTS
Of the 100 nerves reviewed in 50 subjects, at least 2 segments of the trochlear nerve from the brainstem to the cavernous sinus were identified in 100% of cases. The origins from the brainstem and cisternal segment were visible in 65% and 93% of nerves, respectively. The trochlear nerve was identified at the trochlear groove in 100% of cases and in the posterior wall of the cavernous sinus in 74% of cases.
CONCLUSIONS
Coronal high-resolution 2D TSE at 7T reliably identified the trochlear nerve throughout its course and is a promising tool for imaging patients with suspected trochlear nerve pathology.
Topics: Humans; Trochlear Nerve; Magnetic Resonance Imaging; Brain Stem
PubMed: 36657953
DOI: 10.3174/ajnr.A7774 -
Korean Journal of Ophthalmology : KJO Jun 2017Congenital cranial dysinnervation disorders are a group of diseases caused by abnormal development of cranial nerve nuclei or their axonal connections, resulting in... (Review)
Review
Congenital cranial dysinnervation disorders are a group of diseases caused by abnormal development of cranial nerve nuclei or their axonal connections, resulting in aberrant innervation of the ocular and facial musculature. Its diagnosis could be facilitated by the development of high resolution thin-section magnetic resonance imaging. The purpose of this review is to describe the method to visualize cranial nerves III, IV, and VI and to present the imaging findings of congenital cranial dysinnervation disorders including congenital oculomotor nerve palsy, congenital trochlear nerve palsy, Duane retraction syndrome, Möbius syndrome, congenital fibrosis of the extraocular muscles, synergistic divergence, and synergistic convergence.
Topics: Abducens Nerve; Cranial Nerve Diseases; Duane Retraction Syndrome; Humans; Magnetic Resonance Imaging; Oculomotor Nerve; Trochlear Nerve
PubMed: 28534340
DOI: 10.3341/kjo.2017.0024 -
Indian Journal of Ophthalmology May 2021The aim of this study was to describe epidemiological and clinical characteristics of pediatric ocular motor cranial nerve palsy.
PURPOSE
The aim of this study was to describe epidemiological and clinical characteristics of pediatric ocular motor cranial nerve palsy.
METHODS
This was a retrospective record-based study, carried out at a tertiary eye care hospital in India, between January 2011 and January 2015 and included patients up to 16 years of age at the time of presentation, diagnosed with third, fourth, sixth nerve palsy or a combination of these with other cranial nerve palsy. Data analyzed included demographic details, etiologies, presence or absence of amblyopia, relevant investigations, and management.
RESULTS
A total of 90 cases were included in the study. Eighty patients (88.88%) presented with isolated nerve palsy. Forty-three patients (47.77%) had congenital nerve palsy. The most common nerve involved was third (n = 35, 38.88%) followed by sixth (n = 23, 25.55%) and fourth nerve (n = 22, 24.44%). Most common cause of third and fourth cranial nerve palsy was congenital (n = 18, 51.42% and n = 17, 77.30%, respectively), while it was trauma for the sixth nerve (n = 7, 30.40%). Amblyopia was most frequently associated with third cranial nerve palsy (n = 27, 77.14%). The radio-imaging yield was maximum (n = 7, 70%) for combined cranial nerve palsy. Overall 44 (48.88%) patients were managed conservatively, while 46 (51.11%) patients needed squint with or without ptosis surgery.
CONCLUSION
The most common ocular motor cranial nerve involved in the pediatric population was the third cranial nerve, and it was found to be the most amblyogenic in this age group. The neuroimaging yield was maximum for combined cranial nerve palsy. The most common conservatively managed nerve palsy in this study group was the fourth nerve palsy.
Topics: Abducens Nerve Diseases; Child; Cranial Nerve Diseases; Demography; Humans; India; Oculomotor Nerve Diseases; Retrospective Studies; Trochlear Nerve Diseases
PubMed: 33913847
DOI: 10.4103/ijo.IJO_1803_20 -
Journal of Clinical Pathology Sep 1996A case of neurocytoma arising in the rostral pontine region of an 18 year old man is reported. The patient developed a right trochlear nerve palsy and was shown to have...
A case of neurocytoma arising in the rostral pontine region of an 18 year old man is reported. The patient developed a right trochlear nerve palsy and was shown to have a well circumscribed, contrast enhancing mass on magnetic resonance imaging. The tumour was characterised histologically by a uniform population of medium sized round nuclei and slightly eosinophilic cytoplasm or occasional perinuclear halos, with delicate branching capillaries, patches of fibrillary matrix, and occasional perivascular pseudorosettes. Immunohistochemical studies demonstrated strong reactivity for synaptophysin in the fibrillary processes and cytoplasm of tumour cells. The present tumour is an exceptional case of neurocytoma arising in the pons.
Topics: Adolescent; Brain Neoplasms; Humans; Immunohistochemistry; Male; Neurocytoma; Pons; Synaptophysin
PubMed: 9038764
DOI: 10.1136/jcp.49.9.764 -
Anatomical Record (Hoboken, N.J. : 2007) Mar 2019The oculomotor (OM) complex is a combination of somatic and parasympatethic neurons. The correct development and wiring of this cranial pair is essential to perform...
The oculomotor (OM) complex is a combination of somatic and parasympatethic neurons. The correct development and wiring of this cranial pair is essential to perform basic functions: eyeball and eyelid movements, pupillary constriction, and lens accommodation. The improper formation or function of this nucleus leads pathologies such as strabismus. We describe the OM organization and function in different vertebrate brains, including chick, mouse, and human. The morphological localization is detailed, as well as the spatial relation with the trochlear nucleus in order to adjust some misleading anatomical topographic descriptions. We detailed the signaling processes needed for the specification of the OM neurons. The transcriptional programs driven the specification and differentiation of these neurons are partially determined. We summarized recent genetic studies that have led to the identification of guidance mechanisms involved in the migration, axon pathfinding, and targeting of the OM neurons. Finally, we overviewed the pathology associated to genetic malformations in the OM development and related clinical alterations. Anat Rec, 302:446-451, 2019. © 2018 Wiley Periodicals, Inc.
Topics: Animals; Cell Differentiation; Cell Movement; Chickens; Cranial Nerves; Eye Movements; Humans; Mice; Motor Neurons; Neural Pathways; Oculomotor Nerve
PubMed: 29663710
DOI: 10.1002/ar.23827 -
Frontiers in Oncology 2022Schwannomas of the trochlear nerve with the absence of systemic neurofibromatosis are considerably uncommon, especially complicated by intra-tumoral hemorrhage. Due to...
BACKGROUND
Schwannomas of the trochlear nerve with the absence of systemic neurofibromatosis are considerably uncommon, especially complicated by intra-tumoral hemorrhage. Due to the lack of typical clinical manifestations and imaging findings, a definite diagnosis of trochlear schwannomas before surgery is particularly difficult.
CASE PRESENTATION
We report the case of a 64-year-old female patient who presented with a unilaterally intermittent headache of 2-month duration and without a remarkable neurological deficit at admission. Imaging studies revealed a well-demarcated cystic-solid lesion with mixed signals beside the brainstem and suprasellar cisterna. The patient underwent a surgical operation with total resection of the tumor by a subtemporal surgical approach. The tumor was intraoperatively found to originate from the trochlear nerve and was pathologically confirmed as a hemorrhagic schwannoma with cystic degeneration.
CONCLUSIONS
We describe this case in detail and conduct a concomitant survey of the literature, summarizing the clinical presentations, radiological features, surgical treatment, and the possible mechanisms of hemorrhage in relevance to trochlear nerve schwannoma.
PubMed: 36713505
DOI: 10.3389/fonc.2022.1097155 -
Cureus Oct 2022Simultaneous oculomotor and trochlear nerve palsy in Herpes Zoster Ophthalmicus (HZO) is rare. We report a 78-year-old lady who presented with right ptosis while...
Simultaneous oculomotor and trochlear nerve palsy in Herpes Zoster Ophthalmicus (HZO) is rare. We report a 78-year-old lady who presented with right ptosis while receiving treatment for HZO keratouveitis. Examination showed crusted vesicular lesions on the right V dermatome with right complete ptosis and limited right eye extraocular movement on adduction, supraduction, infraduction, and intorsion. There was mild right eye anterior chamber inflammation, while bilateral fundus examinations were normal. Other neurological and systemic examinations were unremarkable. Neuroimaging was also normal. Corticosteroids treatment was started, in addition to oral acyclovir, given for a total course of six weeks. Her ocular motor cranial neuropathy (OMCN) was partially resolved during the follow-up at one year. OMCN can be an isolated complication of HZO, or it may be associated with other neurological complications. Although recovery for OMCN is anticipated, the patient should be closely monitored for the possibility of developing other devastating neurological complications.
PubMed: 36447705
DOI: 10.7759/cureus.30755 -
Neurology India 2020Trochlear nerve cavernous hemangioma (CH) is a rare disease. There have been only five such cases reported in the world literature till date. The authors report a case... (Review)
Review
Trochlear nerve cavernous hemangioma (CH) is a rare disease. There have been only five such cases reported in the world literature till date. The authors report a case of trochlear nerve CH in the Asian population and review the relevant literature. A 49-year-old Asian woman presented with gradually worsening double vision for 6 years. Physical examination identified a complete paralysis of left trochlear nerve. In imaging, a circular lesion measuring about 1 cm in diameter was found in the left ambient cistern. The lesion was completely excised through the left-side subtemporal approach, with a diagnosis of trochlear nerve CH confirmed by pathological examination. Further nerve anastomosis was not adopted, and the patient remained clinically stable in a two years' follow-up. This report provides more information about the history characteristics, imaging features, and surgical treatment strategies for trochlear nerve CH.
Topics: Cranial Nerve Neoplasms; Diplopia; Female; Hemangioma, Cavernous; Humans; Magnetic Resonance Imaging; Middle Aged; Neurosurgical Procedures; Trochlear Nerve
PubMed: 33109877
DOI: 10.4103/0028-3886.299168 -
Journal of AAPOS : the Official... Aug 2016Progressive strabismus initially considered idiopathic may be caused by isolated schwannomas of motor nerves to extraocular muscles, detectable only on careful imaging....
BACKGROUND
Progressive strabismus initially considered idiopathic may be caused by isolated schwannomas of motor nerves to extraocular muscles, detectable only on careful imaging. This study reviewed clinical experience of a referral practice in identifying schwannomas on magnetic resonance imaging (MRI).
METHODS
We reviewed 647 cases imaged for strabismus to identify presumed cranial nerve schwannomas, identified by gadodiamide-enhanced, high-resolution surface coil orbital MRI and thin-section cranial MRI. Clinical features and management were correlated with MRI.
RESULTS
Schwannomas were identified as fusiform intraneural enlargements in 8 cases: 1 affecting the trochlear nerve; 2, the abducens nerve; and 5 the oculomotor nerve. Involved muscles were atrophic. Both abducens schwannomas, 1 superior oblique, and 1 oculomotor schwannoma were subarachnoid; 3 were intraorbital, and bilateral oculomotor lesions of 1 case extended from cavernous sinus to orbit. Associated strabismus progressed for 3-17 years. Abducens schwannoma caused esotropia; trochlear schwannoma caused hypertropia and cyclotropia. Intracranial oculomotor schwannoma caused mydriasis and exotropia. Intraorbital schwannoma caused exotropia with or without hypertropia. Since lesion diameters were 3-9 mm, 6 had been previously missed on routine MRI.
CONCLUSIONS
Progressive, acquired strabismus may be caused by isolated cranial nerve schwannomas, representing about 1% of strabismus cases in this study, involving the oculomotor more than abducens nerve. Because most schwannomas are small and deep in the orbit, findings could be readily missed by routine imaging, leading to a possible diagnosis of idiopathic strabismus. Schwannomas should be suspected when extraocular muscles are atrophic, but the causative lesions themselves are identifiable only using targeted, high resolution MRI.
Topics: Humans; Magnetic Resonance Imaging; Neurilemmoma; Oculomotor Muscles; Oculomotor Nerve; Retrospective Studies; Strabismus; Trochlear Nerve
PubMed: 27424045
DOI: 10.1016/j.jaapos.2016.05.015