CT in the diagnosis of isolated cysticercal infestation of extraocular muscle

Cysticercosis in ophthalmology

Cysticercosis is caused by Taenia solium, a cestode or tapeworm that preferentially affects the subcutaneous tissue, brain, muscle, and the eye. It is traditionally a disease of low socioeconomic regions, but large-scale population migration has made it a matter of global concern. Its ocular invasion is a potentially blinding disease. In the last two decades, there has been considerable discussion of cysticercosis; however, most comes from a limited number of case observations. Thus, to overcome this limitation, we summarize and analyse twenty years of medical literature (from 2000 to 2020) on cysticercosis in ophthalmology.

The burden of parasitic zoonoses in Nepal: a systematic review

Background

Parasitic zoonoses (PZs) pose a significant but often neglected threat to public health, especially in developing countries. In order to obtain a better understanding of their health impact, summary measures of population health may be calculated, such as the Disability-Adjusted Life Year (DALY). However, the data required to calculate such measures are often not readily available for these diseases, which may lead to a vicious circle of under-recognition and under-funding.

Methodology

We examined the burden of PZs in Nepal through a systematic review of online and offline data sources. PZs were classified qualitatively according to endemicity, and where possible a quantitative burden assessment was conducted in terms of the annual number of incident cases, deaths and DALYs.

Principal Findings

Between 2000 and 2012, the highest annual burden was imposed by neurocysticercosis and congenital toxoplasmosis (14,268 DALYs [95% Credibility Interval (CrI): 5450–27,694] and 9255 DALYs [95% CrI: 6135–13,292], respectively), followed by cystic echinococcosis (251 DALYs [95% CrI: 105–458]). Nepal is probably endemic for trichinellosis, toxocarosis, diphyllobothriosis, foodborne trematodosis, taeniosis, and zoonotic intestinal helminthic and protozoal infections, but insufficient data were available to quantify their health impact. Sporadic cases of alveolar echinococcosis, angiostrongylosis, capillariosis, dirofilariosis, gnathostomosis, sparganosis and cutaneous leishmaniosis may occur.

Conclusions/Significance

In settings with limited surveillance capacity, it is possible to quantify the health impact of PZs and other neglected diseases, thereby interrupting the vicious circle of neglect. In Nepal, we found that several PZs are endemic and are imposing a significant burden to public health, higher than that of malaria, and comparable to that of HIV/AIDS. However, several critical data gaps remain. Enhanced surveillance for the endemic PZs identified in this study would enable additional burden estimates, and a more complete picture of the impact of these diseases.

Various parasites that infect humans require animals in some stage of their life cycle. Infection with these so-called zoonotic parasites may vary from asymptomatic carriership to long-term morbidity and even death. Although data are still scarce, it is clear that parasitic zoonoses (PZs) present a significant burden for public health, particularly in poor and marginalized communities. So far, however, there has been relatively little attention to this group of diseases, causing various PZs to be labeled neglected tropical diseases. In this study, the authors reviewed a large variety of data sources to study the relevance and importance of PZs in Nepal. It was found that a large number of PZs are present in Nepal and are imposing an impact higher than that of malaria and comparable to that of HIV/AIDS. These results therefore suggest that PZs deserve greater attention and more intensive surveillance. Furthermore, this study has shown that even in settings with limited surveillance capacity, it is possible to quantify the impact of neglected diseases and, consequently, to break the vicious circle of neglect.

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.

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.

Epidemiology, clinical manifestations and diagnosis of zoonotic cestode infections: an update

This paper reviews the literature on zoonotic cestode infections with specific reference to the years 1999-2003. The sources and prevalence of various zoonotic tapeworm infections caused by adult and larval stages of the genera Taenia, Echinococcus, Diphyllobothrium, Hymenolepis and Dipylidium continue to be an important cause of morbidity and mortality, not only in most underdeveloped countries but also in industrialized countries, particularly in rural areas or among immigrant groups from endemic areas. The review gives a detailed report on recent molecular epidemiological studies on the taxonomy and phylogenetic variations in Echinococcus granulosus, immunological tests and imaging techniques used in epidemiological surveys and clinical investigations of important adult and larval tapeworm infections of animals and humans. Larval stages or metacestodes of Taenia solium, Echinococcus spp. and pseudophyllidean tapeworms (Spirometra syn. Diphyllobothrium spp.) may reside in various tissues of their intermediate hosts, including humans. In particular, Cysticercus cellulosae (T. solium) and the larvae of E. granulosus, and E. multilocularis, which are predominantly located in the liver, lungs and central nervous system forming various types of cysts, lead to a complex of systemic diseases such as cysticercosis, cystic echinococcosis and alveolar echinococcosis, respectively. Relatively rare clinical manifestations are seen in the muscles, subcutaneous tissue, spleen, kidneys, bones and body cavities.