Case report: Bilateral optic nerve sheath meningocele: clinical aspects.

Optic nerve sheath meningocele is an enlargement of the sheath itself, consisting of a collection of cerebrospinal fluid along the perineural space. It should be considered primary if it is not associated with orbital-cerebral neoplasm or with cranio-orbital junction malformations. We report three cases of bilateral primary idiopathic optic nerve sheath meningocele, two of them with gradual vision loss. The first case presented a history of monocular blurred vision of the right eye and headache. It was initially treated with acetazolamide without any improvement, after which optic nerve sheath fenestration was required. The second case showed intermittent binocular diplopia with central 24-2 perimetry defects in the left eye. The third case was first presented as a subacute bilateral conjunctivitis with a suspected orbital pseudotumor. An incidental bilateral optic nerve sheath meningocele was found in the orbital imaging, being totally asymptomatic. In all the cases, orbital and cranial magnetic resonance with contrast and fat suppression was crucial in the diagnosis.

Uncovering the Diagnostic Challenge of Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease: A Case Study of Acute Bilateral Vision Loss.

We discuss a perplexing case of a 51-year-old female with a history of asthma and morbid obesity, presenting with acute bilateral vision loss of unknown etiology. The patient's clinical course was marked by a constellation of symptoms, including blurry vision, eyeball pain, photophobia, headache, nausea, and dizziness, prompting a multidisciplinary approach for diagnostic evaluation. Despite a comprehensive workup and a temporal artery biopsy ruling out large vessel arteritis, the etiology of vision loss remained elusive until myelin oligodendrocyte glycoprotein (MOG) antibody testing returned positive, implicating myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). High-dose corticosteroid therapy was initiated. However, the patient had worsening visual symptoms and was started on plasmapheresis and subsequent administration of Rituximab to prevent relapses, along with a long-term steroid taper regimen. This case underscores the diagnostic challenge of optic neuritis, particularly in MOGAD. It emphasizes the importance of a thorough evaluation and multidisciplinary collaboration.

Bilateral optic disc collaterals secondary to high-flow dural arteriovenous fistula: a diagnostic dilemma.

A man in his 80s, with a history of diabetes, hypertension and coronary artery disease, presented with bilateral painless progressive vision loss 2 years prior. His examination showed subnormal best corrected visual acuity of 20/50 and 20/80 in the right eye and left eye (LE), respectively, grade II relative afferent pupillary defect in LE, normal anterior segment, intra-ocular pressure (IOP) and defective colour vision in both eyes (BE). Fundus examination revealed optic disc pallor, disc collaterals and grade 2 hypertensive retinopathy in BE. Automated perimetry showed advanced field loss in BE. MRI of the brain and orbits with contrast showed signs of raised intracranial pressure, and magnetic resonance angiogram of the brain showed multiple arterio-venous channels along with the right transverse and sigmoid sinuses. The patient was referred to a neuroradiologist for further evaluation, and cerebral angiogram confirmed multifocal high-flow dural arterio-venous fistulae at right jugular foramen, transverse and sigmoid sinuses. He underwent Onyx liquid embolization.

Severe papilloedema with vision loss secondary to Guillain-Barré syndrome.

We discuss a patient who presented with bilateral VI and VII cranial nerve palsies, symmetric upper and lower limb weakness and areflexia, 2 weeks following an flu-like illness. At presentation, there was no papilloedema, and her visual function was normal. Cerebrospinal fluid analysis and electrophysiology supported the diagnosis of Guillain-Barré Syndrome (GBS). She received intravenous immunoglobulins. She subsequently developed headaches and vision loss. Funduscopy demonstrated severe papilloedema with visual acuity of 6/18 right eye, 6/12 left eye with bitemporal visual field depression. Lumbar puncture revealed elevated opening pressure with high protein and normal cell count. She received acetazolamide. There was resolution of papilloedema and normal visual function at 3 months. Of note, the patient's body mass index was 17 kg/m2Our case highlights the rare occurrence of papilloedema in GBS, reiterating the importance of performing funduscopy on patients with any neurological diagnosis. Early detection and prompt management of papilloedema can prevent permanent vision loss.

Clinical, electrophysiologic and serologic evidence of cancer associated retinopathy preceding a diagnosis of breast cancer.

We report the case of a woman in her 50s who presented headaches, blurred vision, diplopia and loss of peripheral vision. She was treated for normal tension glaucoma based on optic nerve cupping prior to the development of diplopia. Records demonstrated visual field constriction over 4 months despite well-controlled intraocular pressures. Examination revealed decreased visual acuity and visual field constriction. The multifocal electroretinogram was abnormal. After a thorough review of her medical and family history, a concern for cancer-associated retinopathy developed. Blood samples were positive for antiretinal antibodies against 23 kDA and 46 kDA proteins. Cancer screening was recommended as the aetiology for retinopathy was unknown and revealed a left breast lump. Following lumpectomy with adjuvant chemoradiation, her visual acuity normalised and visual field defects completely resolved. This case serves to provide an example that distant systemic symptoms may be a manifestation of the underlying malignancy and the importance of clinical suspicion with prompt evaluation.

Toxic optic neuropathy associated with lamotrigine and levetiracetam dual therapy.

We report the case of an early adolescent male on lamotrigine and levetiracetam therapy with a 1-month history of progressive, bilateral, painless visual loss which resolved on cessation of lamotrigine. To our knowledge, we present the first case of lamotrigine and levetiracetam dual therapy associated with toxic optic neuropathy, supported by electrophysiology and optical coherence tomography (OCT) changes. Electrophysiology findings were consistent with retinal ganglion cell dysfunction, with bilateral optic nerve involvement. Macula OCT showed mild retinal ganglion cell loss in all inner quadrants bilaterally. This case highlights the importance of asking patients with epilepsy treated with lamotrigine and levetiracetam about visual problems and considering early dose reduction or cessation of treatment.

Bilateral non-arteritic posterior ischaemic optic neuropathy following COVID-19 vaccination.

We report a case of bilateral posterior ischaemic optic neuropathy, which followed vaccination with ChAdOx1 nCoV-19 for COVID-19 prophylaxis. A man in his early 60s was initially assessed for bilateral acute vision loss following 3 days of frontal headaches. The patient denied any other preceding visual concerns or symptoms of giant cell arteritis. The patient received his first dose of the ChAdOx1 nCoV-19 vaccination 10 days before the onset of his symptoms.At initial presentation, visual acuity was counting fingers bilaterally. Blood work found normal erythrocyte sedimentation rate (6 mm/hour) and C reactive protein (<5 mg/L) as well as a negative infectious and autoimmune serology. He was negative for COVID-19 with PCR testing. Diffusion-weighted MRI showed restricted diffusion along both optic nerves. After 5 months, the patient's visual acuity remained counting fingers bilaterally with pale optic nerves. Isolated bilateral posterior ischaemic optic neuropathy has not been reported in association with the ChAdOx1 nCoV-19 vaccine.

Chondrosarcoma of the petrous apex with nerve abducens involvement in a woman with pre-existing contralateral amblyopia.

We report about a case of a woman in her 50s with a chondrosarcoma of the petrous apex. She has a strabism due to a right-sided amblyopia since childhood and noticed a slowly progressive squint angle in the last months. Her general practitioner (GP) referred her to an ophthalmologist who diagnosed a left abducens paresis and initiated an MRI demonstrating a mass in the left petrous apex. A transnasal endoscopic transsphenoidal biopsy revealed a grade I chondrosarcoma. The patient underwent an endoscopic transsphenoidal anterior petrosectomy approach with complete removal of the tumour. After surgery the squint angle gradually improved to previous levels, so that the patient was able to resume her work. This report demonstrates that even slight changes of a squint angle without diplopia, in this case because of pre-existing amblyopia, could be a hallmark of an intracranial process.

Neurosyphilis Mimicking Connective Tissue Disease.

A male in his 60s developed a pruritic, maculopapular rash on his torso and arms, sparing his palms and soles. He tested positive for ANA and an initial skin biopsy identified "bullous lupus," supporting the diagnosis of a connective tissue disease. Additional symptoms included headaches, facial nerve palsy and hearing loss, which partially responded to oral corticosteroids. He subsequently developed a steroid-dependent left eye scotoma, neuroretinitis and optic nerve papillitis. Mycophenolate mofetil was added but an attempted oral steroid taper led to a worsening rash, progressive retinitis and papillitis. Neurosyphilis was confirmed by serum positive rapid plasma reagin test, reactive treponema pallidum antibodies, positive cerebrospinal fluid venereal disease research laboratory and positive spirochete immunostain of skin biopsy of lesional (rash) tissue. Treatment with intravenous ceftriaxone resolved his rash and visual symptoms. It is important to consider syphilis as a mimicker of connective tissue diseases.

Sixth cranial nerve palsy and dense cerebral venous sinus thrombosis in a child with nephrotic syndrome.

Nephrotic syndrome (NS) is a common glomerular disease characterised by massive proteinuria, hypoalbuminaemia, oedema and hyperlipidaemia. Cerebral venous sinus thrombosis (CVST) is a rare complication in children with NS. Here, we report a case of relapsing NS on steroid therapy, in a male in early childhood who presented with symptoms of headache, vomiting and double vision. On prism cover test there was 25 PD esotropia with abduction restriction in the left eye. Fundus examination showed bilateral papilloedema. He was diagnosed as sixth cranial nerve palsy of left eye. Neuroimaging reported dense CVST. He was managed with subcutaneous low molecular weight heparin and steroids. After 2 months of treatment, there was a complete resolution of esotropia and optic disc oedema. This case highlights the importance of early diagnosis of acute onset esotropia and sagittal sinus thrombosis in a case of NS.

Optic atrophy secondary to minocycline-induced idiopathic intracranial hypertension.

An early adolescent female presented with blurry vision, ocular 'fullness', pulsatile tinnitus and gait difficulty due to poor vision. She was found to have florid grade V papilloedema, 2 months after the use of minocycline for the treatment of confluent and reticulated papillomatosis for 2 months. MRI of the brain without contrast showed fullness of the optic nerve heads concerning for increased intracranial pressure, which was confirmed on lumbar puncture with an opening pressure greater than 55 cm H2O. She was initially started on acetazolamide, but due to high opening pressure and severity of visual loss, a lumboperitoneal shunt was placed in 3 days. This was complicated by a shunt tubal migration 4 months later, leading to worsening vision of 20/400 in both eyes for which she underwent shunt revision. By the time she presented to the neuro-ophthalmology clinic, she was legally blind with her exam consistent with bilateral optic atrophy.

Antiglutamate acid decarboxylase seropositive brain stem encephalitis.

This is a case of a previously healthy female in her fourties presenting with a subacute presentation of bilateral horizontal gaze restriction, with bilateral lower motor facial palsy. The patient's daughter has type 1 diabetes. On investigation, the patient's MRI revealed a lesion in the dorsal medial pons. Cerebrospinal fluid analysis revealed albuminocytological dissociation, with a negative autoimmune panel. The patient was treated with intravenous immunoglobulin, and methylprednisolone for a total of 5 days and showed mild improvement. The patient had raised serum antiglutamic acid decarboxylase (anti-GAD) levels, and the final diagnosis of GAD seropositive brain stem encephalitis was made.

Bickerstaff's brainstem encephalitis mimicking herpetic encephalomyelitis in a liver transplant patient with anti-GQ1b antibodies.

A woman in her late 70s with a history of liver transplant presented with ophthalmoplegia, ataxia, areflexia, positive Babinski's sign and reduced consciousness. This followed an antecedent illness in the form of a herpes zoster infection. MRI of the brain/spinal cord, cerebrospinal fluid analysis with viral PCR and routine blood tests were normal, and tacrolimus neurotoxicity was ruled out. Serum anti-GQ1b antibodies were positive. A diagnosis of Bickerstaff's brainstem encephalitis was made, forming part of the continuum that involves Miller-Fisher syndrome, entitled the 'anti-GQ1b syndrome'. Complete recovery ensued without intravenous immunoglobulins or plasma exchange. The role of monitoring anti-ganglioside pattern change to predict or confirm disease recurrence and disease severity is further discussed.

Complete ophthalmoplegia diagnosed as Tolosa-Hunt syndrome on interval MRI.

Tolosa-Hunt syndrome is a rare cause of painful ophthalmoplegia, most commonly presenting with retro-orbital pain and eye motor nerve palsy, most often affecting a single eye. The condition is characterised by an idiopathic process causing granulomatous inflammation to the cavernous sinus affecting, one or multiple cranial nerves that pass therein. The mechanism underlying the inflammation is not well understood, but patients have been observed to respond to steroids during a flare. We present this as a unique case where a multidisciplinary team diagnosed Tolosa-Hunt syndrome despite non-specific MRI findings in the cavernous sinus 1 day following an initially normal MRI.

Acute retinal ischaemia associated with paracentral acute middle maculopathy detected on multimodal imaging: a premonitory sign of severe carotid occlusive disease.

A man in his 60s presented with a subacute paracentral scotoma and preserved visual acuity in the left eye. He was found to have a very subtle area of deep retinal whitening at the macula and multiple retinal cholesterol emboli. Optical coherence tomography (OCT) with En face imaging revealed globular paracentral acute middle maculopathy (PAMM). A diagnosis of PAMM associated with branch artery occlusion was made and the patient was immediately transferred to the nearest stroke centre. Investigations revealed severe carotid occlusive disease for which the patient underwent carotid endarterectomy. Paracentral scotomas in patients with little clinical findings on fundus examination should raise the suspicion for PAMM, which is easily identifiable on OCT. Eye care professionals must recognise PAMM as a possible sign of acute retinal arterial ischaemia-an ocular and systemic emergency that requires immediate referral to specialised stroke centres.