Orbital cysticercosis--an ultrasonic diagnosis

An Interesting Case Report on a Myocysticercosis Cyst

One of the most dangerous parasite infections, cysticercosis, is found practically everywhere in the world. Cysticercus cellulosae is the larval stage of the swine tapeworm Taenia solium, which causes cysticercosis. Orbital or ocular cysticercosis (OOC) is an avoidable cause of blindness. There are two types of ocular cysticercosis: intraocular (in the anterior chamber, subretinal space, or vitreous) and extraocular (in the orbital tissues or subconjunctival space). Here, we report a rare case of extraocular muscle cysticercosis that presented as a solitary, well-defined lobulated mass near the medial canthus in the right eye and was well managed medically with antihelminthic drugs and corticosteroid therapy. The key to diagnosing myocysticercosis is orbital imaging. Although brain and ocular involvement in cysticercosis is common, extraocular muscle cysticercosis is extremely uncommon and mainly affects young people and children. Orbital pseudotumor, idiopathic myositis, and hydatid cysts are a few differential diagnoses for ocular cysticercosis. It is critical to recognize and treat such illnesses as early as feasible to avoid serious consequences. Public health measures are essential to eradicate this disease in the area.

Orbital cysticercosis, case report and review

Orbital cysticercosis is secondary to an infestation by cysticercus cellulosae, the larval form of Taenia solium.Orbital cysticercosis may present with a wide spectrum of clinical findings and result in significant ocular morbidity. Although traditionally thought to be only prevalent in endemic regions with poor sanitation, immigration requires even ophthalmologists practicing in industrialised counties to be aware of this masquerading condition's presentation and treatment.We report the clinical manifestation of a case of orbital cysticersosis that presented with recurrent orbital inflammation for almost a year. We also present a literature review of the different ocular manifestations, diagnostic and treatment modalities.

Extraocular muscle cysticercosis: clinical features and management outcome

BACKGROUND

Extraocular muscle cysticercosis is rare and can be classified based on the stage of evolution as viable, degenerating, and inactive. A tailored approach to therapy using a combination of albendazole and steroids has been proposed. In this study, we have evaluated the clinical features and response of "viable" extraocular muscle cysticercosis to a tailored therapy with oral albendazole and steroids.

METHODS

A retrospective review of 32 patients with viable extraocular muscle cysticercosis was performed over a 3-year period. Ultrasound examination was performed at 3 weeks and 6 weeks for resolution of the cyst and clinical signs following treatment with oral albendazole and prednisolone. The clinical presentation, ocular alignment, motility restriction, and ultrasound examination details were recorded on serial visits.

RESULTS

The mean age was 19.5 years. The most common presenting signs included limitation of ocular motility in 75%, conjunctival mass in 37.5%, diplopia in 28.1%, and proptosis in 28.1% of the patients, respectively. Ocular alignment evaluation revealed esotropia in 3.1%, exotropia in 12.5%, and hypertropia in 6.25%. Restriction of abduction and abduction in elevation was present in two patients each. The average time for complete resolution was 65.9 days. All the patients had resolution, except four, who had residual motility limitation but were asymptomatic.

CONCLUSIONS

Combination therapy with oral albendazole and steroids is effective in the management of viable extraocular muscle cysticercosis. However, residual motility restriction may persist despite treatment.

Taenia coenurus in the orbit of a chinchilla

A 4-year old, male intact, captive-bred chinchilla (Chinchilla lanigera) was presented due to progressive exophthalmos of the right eye over a 5-month period. Ophthalmic examination revealed exophthalmos with dorsal displacement of the right globe. Retropulsion was decreased and a fluctuant, subcutaneous mass could be palpated posterior and dorsal to the central aspect of the zygomatic bone. Transdermal ultrasonography revealed a fluid-filled mass consistent with a cyst located within the ventral right orbit. Computed tomography demonstrated dorsal displacement of the globe, lateral displacement of the zygomatic arch, and numerous mineral-dense foci within the lumen of the cyst. The cyst was removed en bloc by ventral transpalpebral orbitotomy. Histopathology revealed a single capsulated cyst with multiple invaginated protoscolices, characterized by a prominent scolex with refractile hooklets, suckers, and abundant calcareous corpuscles consistent with a Taenia coenurus. Exophthalmos resolved with surgical therapy and there was no evidence of recurrence or postoperative complications over a period of 2 years. To the authors' knowledge, this is the first reported case of an orbital cyst of parasitic origin in a chinchilla.

Disseminated cysticercosis involving orbit, brain and subcutaneous tissue

Human cysticercosis is caused by dissemination of embryos of Taenia solium from the intestine via the hepatoportal system to the tissues and organs of the body. We report, probably the first case, where orbital cysticercosis was associated with multiple Cysticercus cellulosae cysts in the brain and subcutaneous tissue. Thorough screening for all the sites of involvement by the cyst is extremely useful for knowing the extent of dissemination, infection control, and for epidemiological purposes.

Extraocular muscle cysticercosis: clinical presentations and outcome of treatment

PURPOSE

To report various clinical presentations and treatment outcomes in a series of patients with extraocular muscle cysticercosis.

METHODS

This retrospective study reviewed the charts of 43 patients diagnosed with extraocular muscle cysticercosis with computed tomography and orbital B-scan ultrasonography between January 1991 and December 2002. Clinical presentation, results of investigations, treatment, and outcome were recorded.

RESULTS

The superior rectus was the most commonly affected extraocular muscle. Restricted ocular motility was present in 88% of patients, and inflammatory signs were noted in the involved quadrant in 70% of patients. Eleven patients were treated with oral albendazole alone and 31 patients were treated with oral albendazole and prednisolone. Four extraocular muscle cysts were excised surgically, and five extruded spontaneously. Inflammatory signs subsided in all patients, and residual restriction of ocular motility was seen in 16 (50%) of 32 patients at a mean follow-up of 5 months. Type of treatment made no significant difference in the ocular motility outcome.

CONCLUSIONS

Extraocular muscle cysticercosis should be considered in patients who present with restricted ocular motility and inflammatory signs. The direction of motility restriction does not indicate the muscle involved. Residual restriction of ocular motility is common despite the addition of corticosteroids to albendazole therapy.

CT in the diagnosis of isolated cysticercal infestation of extraocular muscle

AIM

To evaluate the use of computed tomography (CT) and ultrasound (US) to diagnose orbital cysticercosis, and present the diagnostic features.

METHOD

US and CT were used to evaluate patients with proptosis. Four patients were diagnosed as having orbital myocysticercosis and treated with oral albendazole and corticosteroid. Follow-up was undertaken with US and CT.

RESULT

US features were confirmatory of myocysticercosis in two eyes where as CT was effective in diagnosing the condition in all four eyes. In two patients the medial rectus was involved, in one the superior rectus and, in the other, the inferior rectus muscles. Serial US and CT revealed complete resolution of the lesions in 3 months.

CONCLUSION

CT is useful method in diagnosing isolated orbital myocysticercosis. Our report demonstrated that ophthalmic signs and symptoms in the presence of proptosis, especially in an endemic region, should alert the clinician to the possibility of myocysticercosis. Though CT is superior, US can be used as a economical follow-up investigation.

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.

Ultrasonological characteristics of extraocular cysticercosis

Cysticercosis is a common ophthalmic parasitosis wherein humans are the intermediate hosts in the life cycle of the tape worm Taenia solium. While intraocular cysticercosis is more common and is more readily diagnosed clinically, recognition of extraocular cysticercosis needs supplementary imaging. Computed tomography (CT) and magnetic resonance imaging (MRI) have been extensively used to diagnose and characterize neurocysticercosis. Since the orbit is easily accessible to ultrasonography (USG), we evaluated its role in the diagnosis and management of extraocular cysticercosis. Serial A- and B- scan ultrasonograms from 24 patients with extraocular cysticercosis were analyzed to determine features at various stages of evolution of the lesion and an attempt was made to classify the lesion on this basis. Of 24 patients, 23 had a cyst clearly demonstrable by USG: 22 within or attached to an extraocular muscle (with or without myositis) and one free in the orbit. One patient had an optic nerve cyst not detected by USG but by CT scan. Cysts at various stages of evolution were found - viable, degenerating and inactive. The therapeutic response of the cyst to treatment with oral albendazole could be effectively studied and monitored by sequential USG. Orbital ultrasound is a practical, precise and cost-effective imaging modality to diagnose, manage and monitor extraocular cysticercosis, although it can not completely replace CT and MRI.

Socio-demographic trends in ocular cysticercosis

There has been a gradual change in the socio-demographic trends of ocular/adnexal cysticerosis. We present the results of a 5-year study of 33 cases of ocular/adnexal cysticercosis and compare our observations with those reported by previous authors. The male:female ratio in our study was 2:1 and maximum number of patients (45%) belonged to the age-group of 31-40 years. Seventy percent of our patients were of low socio-economic status and 70% were strictly vegetarians. The most common location of cysticerci was in the vitreous (50% of all cases); orbital cysts were present in 5% and subconjunctival cyst in 3%. Most common extraocular site for associated cysticercosis was the brain (18%): Ultrasonography proved to be an effective and economical alternative to magnetic resonance imaging and computerized tomographic scanning for the detection of cysticerci in the orbit and in eyes with hazy media.