Optic nerve cysticercosis: a case report

Amyloid-β42/40 ratio drives tau pathology in 3D human neural cell culture models of Alzheimer's disease

The relationship between amyloid-β (Aβ) species and tau pathology in Alzheimer’s disease (AD) is not fully understood. Here, we provide direct evidence that Aβ42/40 ratio, not total Aβ level, plays a critical role in inducing neurofibrillary tangles (NTFs) in human neurons. Using 3D-differentiated clonal human neural progenitor cells (hNPCs) expressing varying levels of amyloid β precursor protein (APP) and presenilin 1 (PS1) with AD mutations, we show that pathogenic tau accumulation and aggregation are tightly correlated with Aβ42/40 ratio. Roles of Aβ42/40 ratio on tau pathology are also confirmed with APP transmembrane domain (TMD) mutant hNPCs, which display differential Aβ42/40 ratios without mutant PS1. Moreover, naïve hNPCs co-cultured with APP TMD I45F (high Aβ42/40) cells, not with I47F cells (low Aβ42/40), develop robust tau pathology in a 3D non-cell autonomous cell culture system. These results emphasize the importance of reducing the Aβ42/40 ratio in AD therapy.

The relationship between amyloid-β species and tau pathology in Alzheimer’s disease is not fully understood. Here, the authors show that it is the increased ratio of amyloid-β42 and 40 isoforms drives tau pathology in 3D human neural cell culture models of the disease.

Optic Nerve Cysticercosis at the Orbital Apex Presenting as Optic Neuritis

Purpose:

To describe an unusual presentation of ocular cysticercosis and highlight the role of imaging in diagnosis.

Case Report:

A 33-year-old female presented with loss of vision in her right eye and features suggesting optic neuritis. Magnetic resonance imaging (MRI) of the brain and orbits revealed a cystic lesion with peripheral rim enhancement in the optic nerve substance at the orbital apex. An enzyme-linked immunosorbent assay test for cysticercosis further established the diagnosis as optic nerve cysticercosis. She was treated with oral albendazole and steroids, resulting in remarkable improvement in visual acuity and resolution of the lesion.

Conclusion:

A high index of clinical suspicion along with appropriate imaging methods can help diagnose rare presentations of ocular cysticercosis. With timely management, successful outcomes can be obtained.

Cysticercosis of the eye

Cysticercosis is a preventable and eradicable cause of blindness endemic in the Indian subcontinent, South-East Asia and other developing countries. Ocular and orbital cysticercosis has varied presentations depending upon the site of involvement, number of lesion and the host immune response. In this article we present a review of the various clinical manifestations, diagnosis and management protocol for orbital and ocular cysticercosis. Owing to its varied presentation, cysticercosis may pose a diagnostic challenge to the health professionals. Early diagnosis and management can prevent the vision loss and optimize visual outcomes.

Minimally invasive bone-saving orbitotomy for removal of optic nerve cysticercosis

A 32-year-old man previously being managed for multiple neurocysticercosis presented with a reduction in vision and pain on eye movement. Fundus examination revealed disc edema with venous dilatation. MRI showed a localized hypointensity on T1 weighted images and hyperintensity on T2 weighted images suggestive of a cyst in the optic nerve sheath. Medical therapy with albendazole and steroids did not improve vision. Surgical removal of the cyst was achieved by a modified lateral orbital exploration using a lateral canthal incision without bone removal, with full recovery of vision. Histopathological examination confirmed cysticercosis.

Optic nerve cysticercosis: case report and review of current management

The authors present a case of optic nerve cysticercosis in a 32-year-old patient who presented with sudden blurring of vision in the left eye and a transient visual improvement on systemic steroids. The ocular findings were unremarkable other than a relative afferent pupillary defect (RAPD). An ultrasound of the orbit, CT and MRI scans revealed a cystic lesion in the orbital portion of the optic nerve close to the eyeball. A presumed diagnosis of optic nerve cysticercosis was made on the basis of imaging and a positive serum ELISA. The patient improved dramatically on a 4-week therapeutic trial of albendazole and oral steroids. The post-treatment ultrasound and CT scan showed an involution of the cyst with some residual thickening of the optic nerve.

Neurocysticercosis: evaluation with advanced magnetic resonance techniques and atypical forms

Neurocysticercosis (NCC) is the most common helminthic infection of the central nervous system, but its diagnosis remains difficult. The purpose of this article is to perform a critical analysis of the literature and show our experience in the evaluation of NCC. We discuss the advanced MR technique applications such as diffusion and perfusion-weighted imaging, spectroscopy, cisternography with FLAIR, and supplemental O2 and 3D-CISS. The typical manifestations of NCC are described; emphasis is given to the unusual presentations. The atypical forms of neurocysticercosis were divided into: intraventricular, subarachnoid, spinal, orbital, and intraparenchymatous. Special attention was also given to reactivation of previously calcified lesions and neurocysticercosis associated with mesial temporal sclerosis.

Optic nerve cysticercosis

Optic nerve cysticercosis is rare but causes significant visual morbidity. A high index of suspicion is warranted for patients in endemic areas who present with sudden vision loss. Visual morbidity can be prevented by early imaging studies and therapeutic interventions.

Orbital and adnexal cysticercosis

Orbital and adnexal cysticercosis is emerging as a far commoner disease than previously considered, both in endemic and nonendemic areas of cysticercosis. A review of the literature on orbital and adnexal cysticercosis found that it has a predilection for children and young adults with no definite sex predilection. The extraocular muscle form is the commonest type of orbital and adnexal cysticercosis. Lodgement of cysts in the subconjunctival space is another common site, followed by the eyelid, optic nerve, retro-orbital space and lacrimal gland. Association of orbital cysticercosis with systemic cysticercosis is quite rare. The clinical manifestations of orbital or adnexal cysticercosis are entirely different and depend on the location, size, relation to adjacent structures and stage of evolution of the cyst. Diagnosis of cysticercosis is based mainly on orbital imaging because of its highly specific appearance. Tissue diagnosis is not essential for initiating treatment. Medical therapy is the recommended treatment for the extraocular muscle form and retro-orbital cysticer-cosis. Surgical removal is advocated for subconjunctival and eyelid cysticercosis. Because of the limited number of cases of optic nerve and lacrimal gland cysticercosis, their treatment is controversial.

Optic nerve cysticercosis

Cysticercosis of the optic nerve is an extremely rare entity and only seven cases have been reported in the world literature. A case of optic nerve cysticercosis in a 25-year-old woman is reported, along with a review of literature. The patient presented with two episodes of pain, diminution of vision and proptosis. Computed tomography and ultrasonography revealed an intraneural cyst with scolex in the retrobulbar portion of the optic nerve. A positive enzyme-linked immunosorbent assay test for cysticercosis further confirmed the diagnosis. Medical therapy in the form of oral albendazole and steroids resulted in complete resolution of the cyst, with few visual sequelae.

Bilateral cysticercosis of the optic nerve

Bilateral cysticercosis of the optic nerves affected a man who presented with features suggestive of optic neuritis. Ultrasonography revealed bilateral sonolucent cystic lesions with central echo-dense, highly reflective structures behind the optic nerve heads. A subretinal cyst was present in one eye. Magnetic resonance imaging of the brain and orbit revealed multiple cysticerci in the brain, orbit, and eye. The subretinal cyst was removed by pars plana vitrectomy, and the other cysts resolved on treatment with albendazole.

Ocular and orbital cysticercosis

PURPOSE

To study the demographic factors, clinical diagnosis, results of investigation, modalities of treatment and their outcome in ocular and extraocular cysticercosis.

METHOD

A total of 20 patients were recruited for the study. Ultrasonography and computed tomography were done for all the patients. Serial ultrasound was obtained in patients receiving medical treatment. Therapy was individualized according to the location of the cyst.

RESULTS

The commonest clinical presentation was proptosis (9 of 20) with restriction of ocular movements, followed by subconjunctival cyst, subretinal cyst, papilloedema, atypical optic neuritis, lid nodule and intraretinal cyst. Ultrasonography was comparable with computed tomographic scan for detection of scolex. Two of the twenty patients had associated cysts in the brain parenchyma. Medical or surgical therapy as indicated, had a satisfactory outcome.

CONCLUSION

Cysticerci can lodge themselves in any part of the ocular and extra ocular tissue. Associated brain parenchyma involvement is quite rare. The clinical presentation, treatment and outcome mainly depends on the location of the cyst.

Optic nerve cysticercosis: imaging findings

We present the imaging findings of retrobulbar optic nerve cysticercosis in a 50-year-old woman with a 6-month history of vision loss. Contrast-enhanced CT revealed an approximately 7-mm ring-enhancing cyst with a mural nodule located in the anterior portion of the left optic nerve. A contrast-enhanced MR imaging study revealed a cystic lesion with peripheral enhancement of the mural nodule. Sonography showed a cystic mass with a focal area of increased echogenicity corresponding to the mural nodule.

Retrobulbar optic nerve cysticercosis with surgical removal: a case report

A 15-year-old boy presented with diminution of vision which rapidly progressed to no perception of light. In the ocular fundus, a neuroretinitis-like picture was seen. On CT-scan & ultrasonography, an optic nerve swelling was detected with a shadow of scolex. Medical therapy in the form of steroids along with albendazole was ineffective. Surgical removal by lateral orbitotomy was done and a complete cyst with scolex was removed, which was confirmed histopathologically as a case of retrobulbar optic nerve cysticercosis.

Big muscles and big nerves

For 11 years, a 50-year-old woman with euthyroid Graves' disease experienced intermittent exacerbations of her orbitopathy associated with a decline in visual acuity. On each occasion, treatment with systemic corticosteroids led to prompt recovery of vision. Upon referral for consideration for orbital decompressive surgery, computed tomography and magnetic resonance imaging scanning detected bilateral optic-nerve sheath meningiomas, as well as typical findings of Graves' disease. Orbital radiation therapy led to stabilization of visual function and orbital findings, eliminating the need for systemic steroids. To our knowledge, this is the first reported case of Graves' disease associated with bilateral optic nerve sheath meningiomas.

Retrobulbar optic nerve cysticercosis. Case report

The authors report a first case of intraoptic neurocysticercosis in a 12-year-old boy living on Reunion Island. Cysticercosis of the retrobulbar portion of the optic nerve is rare. Because of the patient's age and disturbances in both visual acuity and visual field, it was initially believed to be an optic nerve tumor. Computerized tomography scans and surgical aspects were confirmed by pathological findings. A conservative removal using en bloc orbitotomy showed good functional and aesthetic results.