Comparison of head tilt test between sagging eye syndrome and acquired unilateral trochlear nerve palsy.

PURPOSE: To investigate the distinction between sagging eye syndrome (SES group) and acquired unilateral trochlear nerve palsy (Trochlear group) in the Bielschowsky head tilt test (BHTT). METHODS: Fifteen patients in the SES group (mean age 74.6 ± 5.2 years) and 14 patients in the Trochlear group (55.2 ± 15.9 years) visited the Department of Ophthalmology, Hyogo Medical University Hospital between November 2016 and October 2022 for treatment of their diplopia. Eye position was measured with the alternate prism cover test, and values for fixation of the dominant eye, or unaffected eye, were used. Cyclodeviation was measured with the synoptophore and the Glaucoma Module Premium Edition of the SPECTRALIS optical coherence tomography. In the BHTT, eye position was measured in three head postures: primary position (PP), head tilt to the side with hypertropia (Hyper), and head tilt to the side with hypotropia (Hypo). The differences in vertical deviation between PP and Hyper (Hyper - PP), PP and Hypo (PP - Hypo) and Hyper - Hypo were measured and compared. RESULTS: Vertical deviation in primary position was 7.3 ± 4.5 PD in the SES group and significantly larger (17.1 ± 8.4 PD) in the Trochlear group (p = 0.002). The vertical deviation in Hyper was significantly larger in the Trochlear group with 7.7 ± 4.7 PD and 22.1 ± 9.4 PD, respectively (p < 0.001), whereas the that in Hypo was not significantly different between the two groups with 6.5 ± 3.4 PD and 8.4 ± 6.6 PD, respectively (p = 0.725). The SES group showed no significant difference according to the 3 head postures (p = 0.311), while the Trochlear group showed a significantly different with smaller mean values in vertical deviation in Hypo (p < 0.001). The difference in the vertical deviation for the 3 head postures was the largest in Hyper - Hypo (1.7 ± 2.1 PD and 13.6 ± 7.1 PD, respectively), and the accuracy of SES was at the cutoff value of 6 PD, and it was considered not to be SES if the value was 6PD or higher. The accuracy of SES determination was 100% sensitivity and 100% specificity, and the area under the curve was 1.0. CONCLUSION: The difference in Hyper - Hypo in the BHTT may be the most useful index in differentiating SES from acquired unilateral trochlear nerve palsy; if the difference was more than 6 PD, the probability of SES was very low.

Case report: isolated trochlear nerve palsy associated with posterior cerebral artery aneurysm.

We describe a case of isolated trochlear nerve palsy caused by an unruptured posterior cerebral artery (PCA) aneurysm in an 82-year-old male who consulted an ophthalmologist after developing diplopia. Magnetic resonance angiography showed a left PCA aneurysm in the ambient cistern, and T2WI showed an aneurysm compressing the left trochlear nerve to the cerebellar tentorium. Digital subtraction angiography revealed that the lesion was located between the left P2a segment. We attributed this isolated trochlear palsy to left PCA unruptured aneurysm pressure. Thus, we performed stent-assisted coil embolization. The aneurysm was obliterated, and trochlear nerve palsy improved completely.

Cranial Polyneuropathy Secondary to Remote Iophendylate Myelography.

A 68-year-old woman with controlled hypertension, and degenerative joint disease of the spine for which she had undergone several myelograms and three surgeries 30-32 years earlier, presented with a 2 year history of painless, oblique, binocular diplopia. Her prior ophthalmic evaluations were consistent with an isolated left trochlear nerve paresis. She had magnetic resonance imaging (MRI) showing multiple foci of T1-weighted hyperintensities around the midbrain and brainstem thought to represent subarachnoid fat from a ruptured dermoid cyst. An extensive evaluation revealed a left trochlear nerve paresis as well as diminished sensation in the distributions of the first and second divisions of the left trigeminal nerve. Review of her MRI and history of myelograms raised the possibility of focal inflammation from intrathecal iophendylate (Pantopaque®). Repeat MRI was obtained that showed T1-weighted hyperintensities similar to her previous MRI, but in this study, T1-weighted fat suppression imaging also was performed and revealed these foci to be of low signal intensity, consistent with retained iophendylate.

Unusual manifestation of heat stroke: Isolated trochlear nerve palsy.

Heat stroke is a life-threatening disease characterized by hyperthermia and neurological dysfunction. The central nervous system is highly sensitive to hyperthermia, which causes neurological complications due to the involvement of the cerebellum, basal ganglia, anterior horn cells, and peripheral nerves. Several studies reported about clinical symptoms and brain image findings of heat stroke. Isolated cranial nerve dysfunction caused by lacunar infarction is an extremely rare condition in patient with heat stroke. We experienced a rare case of trochlear nerve palsy due to midbrain infarction caused by heat stroke.

Isolated Fourth Nerve Palsy in Tuberculous Meningitis.

Tuberculous meningitis is a type of subacute meningitis and like other intracranial processes can compromise ocular motor nerves, causing palsies. Trochlear nerve is an unusual isolated manifestation in this type of pathology. The authors report a 5-year-old boy presented in their clinic with a trochlear nerve palsy as unique neurological manifestation of tuberculous meningitis. Treatment with complete anti-tuberculous therapy and botulinum A toxin was needed to get the complete resolution of the nerve palsy. In tuberculous meningitis, the presence of high protein levels and higher number of cells in cerebrospinal fluid is associated with cranial nerve involvement. Usually cranial nerve palsies occur in combination. VI cranial nerve alone or a combined disorder of VI and III cranial nerves are the palsies most frequently presented. Much less common is an isolated disorder of IV cranial nerve in the course of meningitis. The length of full treatment with anti-tuberculous therapy in this case was of 1 year. The persistence of palsy 1 month after the beginning of the symptoms indicated the possibility of a botulinum toxin injection with complete resolution of the process without disability, ocular motility has remained normal on follow-up.

The Development of Hypertrophic Inferior Olivary Nucleus in Oculopalatal Tremor.

Oculopalatal tremor is an acquired clinical condition resulting from the interruption of the dentato-rubro-olivary neuronal pathway. The signal change in inferior olivary nucleus and its hypertrophy on magnetic resonance imaging (MRI) can be observed prior to the development of symptomatic oculopalatal tremor. This is a case of the fourth cranial nerve palsy followed by oculopalatal tremor, and increased signal intensity in inferior olivary nucleus on MRI was observed in 7 months after damage to the dentate-rubro-olivary pathway and 5 months prior to the development of oscillopsia and oculopalatal tremor.

Compressive lesions of the head and neck: Common and uncommon must-know entities.

There are many lesions that cause compression of nerves and vessels in the head and neck, and they can often be overlooked in the absence of adequate history or if not suspected by the radiologist. Many of these lesions require a high index of suspicion and optimal positioning for imaging. While a multimodality approach is critical in the evaluation of compressive lesions, an MRI utilizing high-resolution (heavily weighted) T2-weighted sequence is extremely useful as a starting point. In this review, we aim to discuss the radiological features of the common and uncommon compressive lesions of the head and neck which are broadly categorized into vascular, osseous, and miscellaneous etiologies.

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

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.

COVID-19 and sudden-onset ocular neurogenic palsy in prior healthy patients: a systematic review.

BACKGROUND: The aim of this systematic review is to identify cases of neurogenic ocular palsy in the presence of COVID-19 and to document patient characteristics, type of palsy and possible aetiologies. METHODS: A systematic search of PubMed, Medline and CINAHL databases was conducted on the 6th of January 2023 to identify cases of neurogenic ocular palsy in patients with current or previous COVID-19 infection. Data were pooled to summarise the neurogenic palsy, patient clinical characteristics and proposed palsy mechanisms. RESULTS: The combined database search yielded 1197 articles. Of these, 23 publications consisting of 25 patients met the inclusion criteria. Most patients were male (68%) and ranged in age from 2 to 71 years (median=32.7, SD=21.4). Seven patients (28%) were children aged 2 to 10 years old. Abducens palsies were most common (68%) and the most common ocular presentation was diplopia (76%) with an average time of onset 15 days from testing positive to COVID-19 or having symptoms of the virus. Proposed mechanism of development of a neurogenic palsy secondary to COVID-19 infection was classified into one of three categories: vascular/thrombotic, a viral neuro-invasive or inflammatory virus-mediated immune response. DISCUSSION: This study suggests that COVID-19 infection may be linked to oculomotor, trochlear and abducens nerve palsies and the underlying mechanisms may vary but are difficult to definitively establish. Further studies investigating the onset of neurogenic palsy secondary to COVID-19 infection is required.

Skull Base Metastasis of Breast Cancer With Oculomotor and Trochlear Nerve Palsy.

Skull base metastatic tumors are rare. Breast cancer in particular can cause bone metastases after a long period of time. A 70-year-old woman presented with multiple cranial nerve palsy. Magnetic resonance imaging revealed a lesion that extended from the orbit to the base of the skull, and the patient was referred to our department. Ophthalmological evaluation showed left visual acuity impairment, left oculomotor nerve palsy, and left trochlear nerve palsy. Endoscopic biopsy performed 5 years after the completion of breast cancer treatment revealed skull base metastases. In unilateral multiple cranial nerve palsy, the possibility of skull base metastases should be considered.

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

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.

Unilateral Isolated Trochlear Nerve Palsy due to Ipsilateral Midbrain Infarction.

Ischemic stroke is a very rare etiology in cases of isolated trochlear nerve palsy, and no reports of ipsilateral trochlear nerve palsy caused by unilateral stroke have so far been published. However, we now report a case of isolated trochlear nerve palsy due to ipsilateral dorsal small midbrain infarction in a 70-year-old woman who presented with acute onset of diplopia. There were no other clinical manifestations, but brain magnetic resonance imaging revealed a small ischemic lesion in the right dorsal midbrain, showing that isolated trochlear nerve palsy can be caused by stroke.

Rapid progression from trochlear nerve palsy to orbital apex syndrome as an initial presentation of advanced gastric cancer.

The most cases with orbital metastases have been reported in patients with a prior established diagnosis of cancer and widespread systemic involvement. However, ocular symptoms can be developed as an initial presentation of cancer in patients without cancer history. We report a case of rapid progression from trochlear nerve palsy to orbital apex syndrome as an initial presentation of advanced gastric cancer.

Isolated Trochlear Nerve Palsy in a Patient with Superior Cerebellar Rete Mirabile.

BACKGROUND: Rete mirabile is a very rare vascular malformation and superior cerebellar artery (SCA) rete mirabile is not reported previously. We report a new case of rete mirabile of SCA initially detected by magnetic resonance imaging and transfemoral cerebral angiography. CASE DESCRIPTION: This report illustrates the case of a 58-year-old man who presented with vertical diplopia. Brain magnetic resonance angiography and transfemoral cerebral angiography revealed a rete mirabile of SCA and 3-dimensional volume isotropic turbo spin echo acquisition, brain magnetic resonance imaging sequence, demonstrated that the cisternal segment of the ipsilateral trochlear nerve was compressed by this vascular malformation. We assumed that his cranial nerve palsy was caused by the rete mirabile of the right SCA. During the 8 weeks presence of diplopia, the patient was observed and the symptom was relieved spontaneously. CONCLUSIONS: We provide a first report in the literature of rete mirabile involving the SCA and suggest a descriptive knowledge of rete mirabile for clinicians during decision-making of treatment.

Imaging of Cranial Nerves III, IV, VI in Congenital Cranial Dysinnervation Disorders.

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.

Imaging demonstration of trochlear nerve agenesis in superior oblique palsy emerging during the later life.

BACKGROUND: Congenital trochlear palsy may manifest with sudden vertical diplopia due to decompensation during the later life, which may bring a diagnostic challenge. CASE PRESENTATION: Two men with vertical diplopia for several years after age of 50 were referred with persisting or suddenly aggravating diplopia. Findings were consistent with unilateral superior oblique palsy (SOP) in both patients with a contraversive head tilt. Facial asymmetry was suggestive of a congenital cause in a patient. High resolution magnetic resonance image (MRI)s disclosed atrophic superior oblique and absent trochlear nerve in the side of SOP in both patients. CONCLUSION: Imaging demonstration of superior oblique atrophy and absent trochlear nerve may aid in diagnosis of congenital SOP presenting sudden vertical diplopia during the later life due to delayed decompensation.