Grand Rounds

Neurocysticercosis (NCC) is the most common parasitic infection of the central nervous system (CNS) caused by the larval form (Metacestode) of the Taenia solium tapeworm. It is the common identifiable cause of new onset of seizures in several regions of world including India.¹ NCC is a significant acquired cause of active epilepsy and other neurological conditions, with a prevalence estimated at 4.5 cases per 1,000 individuals in rural northwest India. It is one of the leading causes of preventable epilepsy in many developing countries, endemic regions such as Latin America, Asia, and Africa.² It is common cause of neurological disease occurs through the ingestion of parasite- Taenia solium (eggs), commonly from contaminated food or water or undercooked pork.³ The parasite’s lifecycle includes humans as definitive hosts and pigs as intermediate hosts. Humans harbour adult tapeworm in their intestines, while pigs host the larval stages. Infected humans shed eggs in faeces, contaminating the environment Tape worm which can grow upto 7 meters, release eggs within proglottids that contain 50,000-1,00,000 eggs. These eggs may be consumed by pigs and in pigs, the eggs hatch into larvae (cysticerci), which penetrate the intestinal wall and spread via bloodstream to various tissues. Humans acquire cysticerci by consuming undercooked pork. Once inside the body, larvae can travel to the brain, causing neurological symptoms.⁴ Cysticerci infection of tissues of the central nervous system causes NCC.⁵ Differential Diagnoses was Tuberculoma, Brain abscess, Metastasis, Glioma.
Radiological imaging plays a confirmative role in diagnosing NCC. In this case dietary history gives a clue for diagnosis and further investigation. Common findings on CT scans include dystrophic calcifications, while MRI with contrast reveals cystic lesions with a scolex [Figure 1 (a), (b), (c), (d)], a characteristic feature of NCC. MR spectroscopy helped to differentiate NCC from other lesions by showing elevated choline levels. Definitive diagnosis (Table 1) requires either histological confirmation, imaging of a scolex, or visualization of sub retinal parasites on fundoscopy.⁸ In this case, MRI Brain showed multi-lobulated cystic lesion in the posteromedial left temporal/occipital region. Further MRI imaging with contrast identified a nodular, ring-enhancing lesion approximately 10 mm in size in the right parieto-occipital subpial cortex, accompanied by mild to moderate perifocal edema. These findings raised suspicion of neurocysticercosis (NCC) or tuberculoma. To confirm diagnosis MR Spectroscopy was done showed mildly elevated choline levels and slightly reduced N- acetylaspartate (NAA). A choline/creatinine ratio of 1.3 (greater than 1) suggested an infective lesion in the right parietal lobe with cerebral oedema. Findings were more in favour of NCC.

[Table1]

The treatment of active NCC involves a combination of antiepileptic drugs, corticosteroids to reduce inflammation, and antiparasitic therapy with Albendazole (15 mg/kg/day) or Praziquantel (50 mg/kg/day) for 2-4 weeks.⁶ In cases involving large cysts causing mass effects, hydrocephalus, or diagnostic uncertainty, surgical intervention may be required.⁷ The treatment of active NCC involves a combination of antiepileptic drugs, hence in our case on 1^st day patient was started with Levetiracetam (20 mg/kg loading followed by 10 g/kg/day) and Clonazepam (0.25 mg/kg), 2^nd on suspecting NCC Corticosteroid- Dexamethasone was started to reduce inflammation with antiparasitic therapy with Albendazole (15 mg/kg/day) continued. A two-week course of oral albendazole, alongside antiepileptic therapy, was planned. The patient made a full recovery and was discharged in stable condition.
Neurocysticercosis (NCC) is a parasitic disease affecting the central nervous system, caused by the larval form of the pork tapeworm Taenia solium. It is a leading cause of epilepsy worldwide. Early diagnosis is crucial for improving patient outcomes and ensuring effective management. This requires a thorough patient history, particularly concerning dietary habits and lifestyle. Neuro-imaging is essential for identifying lesions and scolex within cysts. MRI and MR spectroscopy helped for the same. Preventive measures, such as promoting public sanitation and hygiene awareness, are essential to reduce the incidence of NCC. Many active forms of NCC can be successfully treated with medical therapy.

Key Takeaways:
1. Timely Diagnosis: Combining imaging findings with a detailed history is crucial.
2. Comprehensive Management: Therapy includes antiparasitics, supportive care, and symptom control.
Prevention Focus: Public education on hygiene and safe cooking practices can prevent transmission.

References :

Vedantam Rajshekhar, Neurocysticercosis -Diagnostic problems and current therapeutic strategies, Review article Indian J Med Res 144,sep 2016 Roman G. Sotelo J Brutto OD ,Flisser A ,Dumas M ,Wadia N,et al .A proposal to declare neurocysticercosisi an international reportable disease.Bull World Health Organ 2000; 78(3): 399-406 Fleury A, Trejo A, Cisneros H, García-Navarrete R, Villalobos N, Hernandez M, et al.' Taenia solium: development of an experimental model of porcine neurocysticercosis. PLoS Negl Trop Dis 2015; 9(8): e0003980; http://dx.doi.org/10.1371/ journal.pntd.0003980. Rumana Ahmad et al/Springer-Verlag Berlin Heidelberg 2016 Neurocysticercosis: a review on status in India, management, and current therapeutic interventions Syed A.A. Rizvi et al./Asian Pacific Journal of Tropical Medicine 2016 Neurocysticercosis: A case report and brief review http://dx.doi.org/10.1016/j.apjtm.2015.12.020 Garcia HH, Nash TE,Del Brutto OH.Clinical symptoms,Diagnosis and treatment of neurocysticercosis .Lancet Neurol 2014;13;1202-15. Zymberg ST. Neurocysticercosis. World Neurosurg 2013;79(2 Suppl):S24.e5-8. Del Brutto OH, Rajshekhar V, White AC Jr, et al. Proposed diagnostic criteria for neurocysticercosis. Neurology 2001;57:177-83.