Superior Oblique Palsy Research Articles

Isolated Sudden-Onset Trochlear Nerve Palsy Associated with Mild Novel Coronavirus Disease (COVID-19) Infection

ABSTRACT Purpose To present a case of sudden isolated unilateral trochlear nerve palsy of new onset associated with a COVID-19 infection without a severe course. Methods A 49-year-old previously healthy man suddenly noticed seeing double while going down the stairs to go out for the first time the day after the completion of medical treatment and home isolation for COVID-19. There was no systemic disease or history of trauma. Results Magnetic resonance imaging of the brain and orbits was normal and the neurology examination revealed no pathology. The acute onset of the diplopia, the small vertical fusion amplitude, and the lack of facial asymmetry supported acquired trochlear nerve palsy. Conclusions Trochlear nerve palsy has rarely been reported in association with the various types of viral infections. To the best of our knowledge, this is the first case of isolated unilateral trochlear nerve palsy with no additional neurological finding or any radiological finding that is possibly associated with mild SARS-CoV-2 infection.

Neuro-ophthalmological manifestations of diabetes mellitus during COVID-19-related lockdown in India.

The coronavirus disease 19 (COVID-19) pandemic has resulted in a huge impact on the health care system. Diversion of health care workforce toward management of a high number of COVID-19 cases and lockdown restrictions have affected the follow-up of patients. The objective of this study was to analyze the impact of this situation on the control of diabetes, eventually resulting in related neuro-ophthalmological complications. This retrospective case series included diabetic patients visiting the neuro-ophthalmology clinic at a tertiary care eye center in India from 25 March 2020 to 25 September 2020 during the lockdown. The incidence of diabetes-related neuro-ophthalmological complications, including third, fourth, sixth nerve palsies and non-arteritic anterior ischemic optic neuropathy (NAION) was evaluated and compared with that of the same period during 2019. Overall disease incidence rate was significantly higher in the year 2020 (60.2%) compared to the previous year of 2019 (29.8%). The proportion of third nerve palsy (4.8% vs 16.3%, P < 0.001) and NAION (0.3% vs 14.3%, P < 0.001) had increased. Even though the percentage of sixth nerve palsy was 25% in 2020, this was not significantly different from 2019. There was a reduction in the percentage of fourth nerve palsy cases from the year 2019 to 2020. There was a significant increase in diabetes-related neuro-ophthalmic complications during the COVID-19 lockdown. This can possibly be attributed to worsening of glycemic control in diabetic patients.

Disinsertion-distal myectomy and tucking of inferior oblique combined with superior oblique full tendon advancement in superior oblique palsy.

To assess the preliminary outcomes of inferior oblique (IO) disinsertion-distal myectomy and tucking combined with superior oblique (SO) full tendon advancement in patients with Knapp II or III superior oblique palsy. This single-centered retrospective study included 16 eyes from 13 patients with Knapp Class II or III SO palsy. All patients underwent IO disinsertion-distal myectomy and tucking combined with SO full tendon advancement while under general anesthesia. Pre- and post-operative levels of vertical deviation in the primary position, abnormal head position, IO hyperfunction and SO hypofunction, torsion, as well as the presence of diplopia, were all measured, and the differences were statistically compared. Pre-operatively, 12 patients had abnormal head positions, and two had diplopia. The pre-and post-operative levels of IO hyperfunction and SO hypofunction, as well as a vertical deviation in the primary position and torsion, all differed statistically significantly (p < 0.01). Inferior oblique disinsertion distal myectomy and tucking combined with SO full tendon advancement surgery appears to be an effective procedure in patients with congenital and acquired Knapp Class II or III SO palsy.

This issue of ACTA

This issue of ACTA

Candidate Genes in Testing Strategies for Linkage Analysis and Bioinformatic Sorting of Whole Genome Sequencing Data in Three Small Japanese Families with Idiopathic Superior Oblique Muscle Palsy.

Idiopathic superior oblique muscle palsy is a major type of paralytic, non-comitant strabismus and presents vertical and cyclo-torsional deviation of one eye against the other eye, with a large vertical fusion range and abnormal head posture such as head tilt. Genetic background is considered to play a role in its development, as patients with idiopathic superior oblique muscle palsy have varying degrees of muscle hypoplasia and, rarely, the complete absence of the muscle, that is, aplasia. In this study, whole genome sequencing was performed, and single nucleotide variations and short insertions/deletions (SNVs/InDels) were annotated in two patients each in three small families (six patients in total) with idiopathic superior oblique muscle palsy, in addition to three normal individuals in one family. At first, linkage analysis was carried out in the three families and SNVs/InDels in chromosomal loci with negative LOD scores were excluded. Next, SNVs/InDels shared by the six patients, but not by the three normal individuals, were chosen. SNVs/InDels were further narrowed down by choosing low-frequency (<1%) or non-registered SNVs/InDels in four databases for the Japanese population, and then by choosing SNVs/InDels with functional influence, leading to one candidate gene, SSTR5-AS1 in chromosome 16. The six patients were heterozygous for 13-nucleotide deletion in SSTR5-AS1, except for one homozygous patient, while the three normal individuals were wild type. Targeted polymerase chain reaction (PCR) and direct sequencing of PCR products confirmed the 13-nucleotide deletion in SSTR5-AS1. In the face of newly-registered SSTR5-AS1 13-nucleotide deletion at a higher frequency in a latest released database for the Japanese population, the skipping of low-frequency and non-registration sorting still resulted in only 13 candidate genes including SSTR5-AS1 as common variants. The skipping of linkage analysis also led to the same set of 13 candidate genes. Different testing strategies that consisted of linkage analysis and simple unintentional bioinformatics could reach candidate genes in three small families with idiopathic superior oblique muscle palsy.

Temporal Slant Recession of the Inferior Rectus Muscle: A Simple Surgical Treatment for Diplopia Caused by Small Vertical Deviations.

To evaluate the therapeutic effect of temporal slant recession of the inferior rectus muscle (TSRIRM) for the treatment of small vertical deviations in patients with vertical diplopia, with consideration of the theoretical additive effects of this procedure on ocular torsion and horizontal incomitance. Retrospective review of 11 patients who were treated with TSRIRM. Eight patients with vertical diplopia and small hyperdeviations (up to 6 prism diopters (PDs)) were treated with isolated TSRIRMs. Three patients with vertical diplopia from unilateral superior oblique palsies with large hyperdeviations (>15 PDs) were treated with TSRIRMs in conjunction with contralateral inferior oblique recessions. Six of the 8 patients with small vertical deviations had successful vertical realignment with elimination of symptomatic diplopia after an isolated TSRIRM. Two of the eight patients had residual hypertropia with symptomatic diplopia. Three additional patients with unilateral superior oblique palsy had successful vertical realignment with elimination of symptomatic diplopia after ipsilateral inferior oblique recession and contralateral TSRIRM. In total, 9 of 11 patients had successful surgical results after TSRIRM. TSRIRM provides an effective and reliable treatment for small angle vertical strabismus. Its ease of surgical access renders it useful for implementation in an outpatient neuro-ophthalmology setting.

Twenty-first century century superior oblique palsy meets artificial intelligence

Superior oblique (SO) palsy is a diagnostic consideration in most cases of cyclovertical strabismus. Participants will learn if they can beat artificial intelligence to distinguish actual SO palsy from another common diagnosis using only patient alignment measurements, in all cases objectively verified by imaging.

Small tuck for superior oblique palsy

Some surgeons only treat superior oblique (SO) palsy with a tuck when the SO tendon is lax, either for fear of creating a secondary Brown syndrome or out of belief that a lax tendon signifies a distinct etiology that uniquely responds to SO tuck. This study reports a series of patients with SO palsy treated by small SO tuck in whom lack of tendon laxity precluded a larger tuck.

Can machine learning (ML) distinguish hypertropia (HT) in sagging eye syndrome (SES) from superior oblique palsy (SOP)?

Can machine learning (ML) distinguish hypertropia (HT) in sagging eye syndrome (SES) from superior oblique palsy (SOP)?

Surgical outcomes of combined ipsilateral inferior oblique and superior rectus recession for superior oblique palsy with hypertropia in abduction

To assess surgical outcomes of simultaneous inferior oblique (IO) and ipsilateral superior rectus (SR) recessions for superior oblique palsy (SOP) with hypertropia in abduction despite negative forced ductions.

Recurrent Painful Ophthalmoplegic Neuropathy with Unilateral Oculomotor and Trochlear Nerve Palsy in an 8-year-old Girl

ABSTRACT Background Recurrent painful ophthalmoplegic neuropathy (RPON) is a rare disorder with a unilateral headache accompanied by ipsilateral episodes of painful ocular cranial nerve neuropathy, which typically occurs in childhood. Case report We report an 8-year-old female with four episodes of RPON involving unilateral third and fourth cranial nerves. Right eye exotropia and complete ptosis were detected on examination. Brain MRI images revealed right third nerve enhancement where it exits from the brainstem. She completely recovered after 5 weeks with the administration of prednisolone and indomethacin. Discussion and conclusion Due to the rarity of this condition in children, recurrent painful ophthalmoplegic neuropathy should be considered as a differential diagnosis of unilateral or bilateral painful ophthalmoplegia, particularly with a history of migrainous headache. Since it is a treatable entity, and repeated attacks may lead to permanent sequela, early intervention is crucial.

A Case with Bilateral Dural Arteriovenous Fistulae Manifesting as Sequential Trochlear, Oculomotor Nerve Palsies

Purpose: We report a patient with bilateral dural arteriovenous fistulae (DAVF) who initially presented with unilateral, isolated trochlear nerve palsy; and later with contralateral, oculomotor nerve palsy.Case summary: A 72-year-old male without any underlying disease or a trauma history visited with sudden vertical diplopia in both eyes that had developed 5 days prior. Brain magnetic resonance imaging (MRI) performed before his first visit was unremarkable. The eye movement test revealed hyperdeviation and limitation of downgaze in the left eye; we thus suspected unilateral, ischemic trochlear nerve palsy and this was indeed observed. However, the diplopia did not improve and limitations of the upper, medial gaze of the right eye developed after 3 months. Follow-up examinations (orbital computed tomography, brain MRI, and cerebral angiography) revealed bilateral DAVF running from the left to the right. He underwent gamma-knife radiosurgery; then the eye movement limitations and diplopia improved.Conclusions: Diplopia manifesting as paralysis in an elderly patient may be caused by DAVF; the diplopia may not always be the common ischemic paralytic strabismus. DAVF should be considered during differential diagnosis and further radiological examinations may be needed.

Function of oculumotor, trochlear and abducens nerves in patients with cerebral aneurysms undergoing endovascular treatment

Background. Functional impairment of nerves, which move an eyelid, is a serious problem in patients with aneurysms, especially concerning enlarging number of endovascular procedures on cerebral aneurysms.Aim. To evaluate frequency of malfunction of oculomotor, trochlear, abducens nerves in patients with cerebral aneurysms.Methods. From 2019 to 2021 189 patients with 202 aneurysms underwent endovascular treatment. Location of the aneurysms: cavernous, clinoid and communicating segments of the internal carotid arteries, superior cerebellar arteries, P1 and P2 segments of the posterior cerebral arteries. Patients did not have dislocation syndrome as a result of a stroke. There were 37 male patients and 152 female patients. The age of patients ranged from 17 to 78 years, the mean age was 52±12 years. Distribution of aneurysm location: 42 (21%) – cavernous segment of the internal cerebral artery, 25 (12%) – clinoid segment, 110 (55%) – communicating segment, 18 (9%) – superior cerebellar arteries, 7 (3%) – P1 and P2 segments of the posterior cerebral arteries. Morphologically 11 (5%) of the aneurysms were fusiform, 191 (95%) of the aneurysms were saccular. 43 aneurysms (21%) were embolized with coils, 49 (24%) were treated using assisted coiling (balloon- and/or stent-assistance), 83 (42%) of the aneurysms were treated with flow-diverters. 27 (13%) patients underwent several endovascular procedures, including a combination of aforementioned techniques. Function of oculomotor, trochlear and abducens nerves was evaluated at the admission, during the hospitalization and at the discharge. Follow-up was achieved in 102 (54%) patients with 115 aneurysms, the mean follow-up period in June 2022 is 13 months. Checking cerebral angiography was performed 8months after the operation on the average.Results. In 89 (77%) patients checking cerebral angiography showed complete obliteration of the aneurysms, in 26 (23%) filling part of the aneurysm was found out to be smaller. 11 patients had preoperative oculomotor nerve paresis, after the procedure 1 patient had no oculomotor nerve impairment and made a complete recovery, 2 patients had partial improvement, 7 patients had no changes, in 1 patient paresis worsened. In our group we did not observe any case of trochlear nerve palsy either prior or after the operation during follow-up. 6 patients had preoperative abducens nerve paresis, after the treatment 1 patients had a complete recovery of abducens nerve function, 3 patients had partial improvement, 2 patients had no changes.Conclusion. In patients with cerebral aneurysms without cerebral dislocation as result of a stroke function of trochlear nerve did not suffer either prior or after endovascular treatment. Endovascular treatment in this category of patients may positively affect the oculomotor and abducens nerve impairment, but in rare cases it can lead to deterioration of neurological deficit.

Pearls & Oy-sters: Vertical Diplopia and Ocular Torsion: Peripheral vs Central Localization.

We describe a case with torsional deviation of the eyes from a brainstem lesion. Torsional eye movement refers to changes in the position of the eyes in the roll plane around the visual axis. When the head is tilted laterally (that is, rolled toward the shoulder), the eyes roll in the opposite direction as part of the torsional vestibulo-ocular reflex known as the ocular counter-roll. Pathologies that affect the otolith-ocular pathway can lead to a torsional deviation of the eyes as part of the ocular tilt reaction (OTR) that also causes vertical deviation of the eyes (skew deviation) and head tilt. Lesions caudal to the pontomedullary junction (such as the labyrinth, eighth cranial nerve, or vestibular nucleus) result in an OTR with ipsiversive torsional deviation, whereas lesions rostral to the junction result in an OTR with contraversive torsional deviation. Furthermore, torsional deviation of the eyes in the OTR is conjugate (incyclotorsion in the higher eye and excyclotorsion in the lower eye), whereas torsional deviation from ocular palsy in peripheral lesions is disconjugate (e.g., exyclotorsion only in the higher eye with superior oblique palsy). Therefore, the pattern of torsional eye deviation can be helpful in localizing the lesion. Several techniques including fundus photography, double Maddox rod testing, optical coherence tomography, and video-oculography are used to measure torsional eye position.

Masquerading Superior Oblique Palsy

We evaluated patients with hypertropia compatible with a diagnosis of superior oblique (SO) palsy to ascertain whether the 3-step test (3ST) can distinguish SO atrophy characteristic of trochlear nerve pathology from masquerading conditions. Prospective cross-sectional study. In an academic practice, we performed quasi-coronal plane, surface coil magnetic resonance imaging in 83 patients clinically diagnosed with SO palsy. We evaluated alignment, SO cross-sectional area, SO contractility, and rectus muscle pulley positions. A total of 57 patients with mean age 39 years (SD = 21 years) had unilateral SO palsy manifested by SO atrophy (22 congenital and 35 acquired). There was normal SO size in 26 patients with an average age of 39 years (SD =16 years) considered masquerades (8 congenital and 18 acquired). Maximum palsied SO cross-section averaged 9.5 ± 3.8 mm2, less than 18.4 ± 3.9 mm2 contralaterally (P < 10-24). In masquerades, maximum hypertropic SO cross-section was 20.7 ± 3.1 mm2, which was not different from the hypotropic SO or the contralesional muscle in SO palsy. Head tilt testing in masquerades was indistinguishable from SO palsy. In SO palsy, central hypertropia averaged 13.2 ± 9.4Δ, increasing to 21.1 ± 14.0Δ in ipsilateral tilt, and decreasing to 4.3 ± 5.3Δ in contralateral tilt. In masquerades, central hypertropia averaged 13.1 ± 8.7Δ, and was 17.7 ± 11.1Δ in ipsilateral and decreasing to 4.9 ± 5.1Δ in contralateral tilt. Upright hypertropia was larger at 17.7 ± 9.9Δ in congenital than 12.0 ± 8.4Δ in acquired SO palsy (P = 0025) but was indistinguishable from congenital masquerades. Contractile change in SO cross-section was bilaterally similar in masquerades. Relevant coordinates of rectus pulleys were similar bilaterally in masquerades. The 3ST pattern characteristic of unilateral SO palsy may be mimicked in all respects by masquerades.

Diplopia following microvascular decompression surgeries: illustrative cases

BACKGROUNDMicrovascular decompression is an effective treatment strategy for trigeminal neuralgia. However, there may be inadvertent complications involving adjacent cranial nerves during or months after the operation. This case lesson highlights the potential manifestations, both optical and nonneurologic (monocular) and binocular diplopia, after microvascular decompression in two patients. Neurosurgeons should recognize monocular versus binocular causes of diplopia after neurosurgical microvascular decompression.OBSERVATIONSThe authors reported on two patients who presented with diplopia after microvascular decompression for trigeminal neuralgia. The first patient had binocular diplopia with a paradoxical head tilt potentially due to a contiguous trochlear nerve palsy. The second patient had monocular diplopia due to dry eye syndrome from trigeminal nerve dysfunction. However, within 2 years after their operations, both patients had resolution of their diplopia without additional surgical intervention.LESSONSBoth monocular and binocular diplopia can be presenting symptoms of cranial neuropathies after microvascular decompression for trigeminal neuralgia. Most cases of postoperative diplopia (both monocular and binocular) resolve spontaneously over time without additional neurosurgical treatment.

Differences in gene expression between the primary and secondary inferior oblique overaction.

BackgroundThis study sought to define different adaptive changes in the molecular levels of the overacting inferior oblique muscle in primary and secondary inferior oblique overaction.MethodsThe inferior oblique muscles of patients with congenital superior oblique palsy (SOP) and those of patients with congenital esotropia were collected during surgery. RNA-seq technology was performed to detect the differentially expressed genes (DEGs) between the two groups. A comprehensive analysis of the gene expression profiles was then conducted, including the identification of DEGs, a Gene Ontology (GO) analysis, and a gene set enrichment analysis (GSEA). Finally, a protein-protein interaction (PPI) network was constructed with Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) and Cytoscape software.ResultsWe identified 221 DEGs, of which 104 were significantly upregulated and 117 were downregulated in the SOP group. Additionally, several isoforms of the myosin heavy chain (MyHC) gene were found to be significantly and differentially expressed in the SOP group, including 3 upregulated fast-twitch MyHC isoforms (i.e., MYH1, MYH4, and MYH13) and 1 downregulated slow-twitch MyHC isoform (i.e., MYH3). The GO analysis indicated that the upregulated DEGs were mainly enriched in the muscle system process and muscle contraction. The GSEA analysis revealed that the upregulated pathways of ribosome, proteasome, oxidative phosphorylation, fatty acid metabolism, viral myocarditis, and cardiac muscle contraction were enriched.ConclusionsOur findings provide insights into the different molecular changes of inferior oblique muscle overaction secondary to SOP and suggest the potential pathological mechanisms of inferior oblique overaction (IOOA) in SOP. The results suggest that upregulated fast-twitch MyHC isoforms and downregulated slow-twitch MyHC isoform in SOP may contribute to the increased force of its inferior oblique muscle.

Recurrent Ophthalmoplegia Associated with Hyperhomocysteinemia

Purpose: This report describes a case of recurrent ophthalmoplegia associated with hyperhomocysteinemia due to methylenetetrahydrofolate reductase (MTHFR) gene polymorphism.Case summary: A 40‐year‐old healthy man presented with acute diplopia. He had a history of diplopia due to left sixth nerve palsy 2 years ago. Prism and alternate cover tests revealed left hypertropia in the primary position. Examination of ductions and versions showed mild elevation of the left eye on adduction. Brain and orbit magnetic resonance imaging were normal. Laboratory studies revealed an elevated level of erythrocyte sedimentation rate (ESR) and homocysteine. A diagnosis of left fourth nerve palsy associated with hyperhomocysteinemia was made. Symptoms were completely resolved within 2 weeks. Two years later, the patient again had diplopia associated with esotropia and limited abduction of the right eye. ESR and homocysteine level were normal. Analysis for MTHFR gene polymorphisms, which contribute to variable hyperhomocysteinemia, revealed 677TT homozygote variant. A diagnosis of recurrent paralytic strabismus associated with hyperhomocysteinemia, caused by MTHFR gene polymorphism, was made. Symptoms resolved within 1 month, and the patient did not have any further recurrence in 6 months.Conclusions: Patients with hyperhomocysteinemia may present with ophthalmoplegia. An analysis for MTHFR gene polymorphisms is needed to diagnose hyperhomocysteinemia.

Clinical features of excyclotorsion in the non-paretic eye of patients with congenital unilateral superior oblique palsy

BackgroundTo investigate preoperative clinical features and postoperative results according to the correspondence between excyclotorsion and the paretic eye in patients with congenital unilateral superior oblique palsy (USOP).MethodsA retrospective review of medical charts was performed. The patients were divided into the accordance (ocular excyclotorsion in the paretic eye) and disaccordance (ocular excyclotorsion in the non-paretic eye) groups. The degree of excyclotorsion (scale, 0–4) was measured. Age, sex, hypertropia at the primary position, fixation preference, inferior oblique overaction, and degree of excyclotorsion were measured.ResultsNinety-eight patients were included in this study. There were 70 (71.4%) and 28 patients (28.6%) in the accordance and disaccordance groups. Sixteen patients (22.9%) in the accordance group and 12 patients (42.9%) in the disaccordance group were aged under 2 years (p = 0.04). A fixation preference of the paretic eye was observed in 2 (2.9%) and 8 (28.6%) patients in the accordance and disaccordance groups (p < 0.01). The postoperative degree of excyclotorsion in the accordance group (0.14 ± 0.39) was lower than that in the disaccordance group (0.28 ± 0.71) (p = 0.01). The residual postoperative excyclotorsion (> 1) were observed in the disaccordance group (14 patients, 50%) and accordance group (16 patients, 22.9%) (p = 0.01).ConclusionPreoperative disaccordance between excyclotorsion and the paretic eye was observed in patients who were under 2 years of age and preferred fixation of the paretic eye. The postoperative degree of excyclotorsion was lower in the accordance group.

Hypopituitarism and cranial nerve involvement mimicking Tolosa-Hunt syndrome as the initially presenting feature of diffuse large B-cell lymphoma: a case report

BackgroundEarly diagnosis of lymphoma involving the central nervous system is sometimes difficult but emergent to avoid the delay of therapeutic initiation. Pituitary insufficiencies are usually associated with lymphoma in the pituitary gland. There have been no cases of lymphoma originating from extra pituitary gland with hypopituitarism that simultaneously presenting unilateral upper cranial nerve palsies and ophthalmalgia. These symptoms are mostly caused by neoplastic involvement of the skull base or benign diseases such as Tolosa-Hunt syndrome (THS). We report a case of lymphoma with unique clinical courses initially presenting hypopituitarism and symptoms mimicking THS with a mass in sphenoidal and cavernous sinuses accompanying sphenoidal bone erosion.Case presentation.A 71-year-old woman visited our hospital with left ophthalmalgia, ptosis, and diplopia. Neurological findings revealed left oculomotor, trochlear and abducent nerve palsies. Endocrine tests indicated partial hypopituitarism. Initial CT and MRI revealed that a mass in sphenoidal and cavernous sinuses had invaded the sella with osteolysis of the sphenoid bone. At around four weeks, almost all the symptoms of cranial nerve palsies were relieved. Seven weeks later, she had a high fever and cervical lymph node (CLN) swellings. CLN biopsy revealed CD20-positive B-cells. She was diagnosed with diffuse large B-cell lymphoma (DLBCL). 18F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) revealed elevated uptake at the erosion lesion of the sphenoidal bone, but not the pituitary gland. After chemotherapy, all the symptoms related to systemic lymphoma were relieved, but partial hypopituitarism remained. The mass in sphenoidal and cavernous sinuses and elevated uptake by PET/CT were dissolved.ConclusionThis case of DLBCL had a unique clinical course; initial presentation of hypopituitarism and symptoms mimicking THS. There was also rare demonstration of mass lesions related to DLBCL in the sphenoidal and cavernous sinuses compressing the pituitary gland through an eroded area of the sphenoidal bone. It should be clinically cautioned that DLBCL can be associated with erosion of the sphenoidal bone and cause both hypopituitarism and THS-mimicking symptoms.