The Nepalese Shepherd

Mrinal M. Patnaik MD, Radha Rajasingham MD, Alaka Deshpande MD, Gurdeep Parmar MD, William Stauffer MD
DOI: 68-71 First published online: 1 January 2009


Neurocysticercosis is one of the most common causes of seizures in the developing world. Due to the high volumes of immigration from South America and Asia, American physicians are increasingly encountering this condition. This case report attempts to present a brief overview of some of the difficulties associated with the treatment of patients with a high disease burden.

Case report

A 35‐year‐old Nepalese shepherd was brought to the Sir J.J Hospital in Mumbai, India, by his father, for evaluation of 3 months of intense headaches, cognitive decline, “bizarre” behavior, and visual changes. The gentleman had lived in Nepal all his life and had worked on his farm tending cows and pigs. He had been seen by physicians in Nepal, but due to a lack of response to treatment, he was brought to Mumbai for further evaluation. The patient’s headaches were notably worse in the morning, and more recently, the patient had developed bowel and bladder incontinence. There was no history of seizures, focal neurological deficits, cranial nerve abnormalities, sensory changes, fevers, weight loss, or skin rashes.

On examination, the patient was afebrile and his vital signs were stable. He was conscious but disoriented to time and place. There were no meningeal signs, no lymphadenopathy, rashes, or subcutaneous nodules. The cardiovascular, pulmonary, and abdominal examinations were normal. On a detailed neurological examination, the pupils were equal, round, and reactive to light, and extraocular movements were intact bilaterally. Fundoscopic examination revealed bilateral papilledema with optic atrophy. There were no other cranial nerve abnormalities. Muscle tone and strength were normal. Reflexes were symmetric but exaggerated bilaterally. The plantar reflexes were upgoing bilaterally, and the sensory examination was unobtainable due to the patient’s mental status.


The patient’s diffuse, nonfocal neurological symptoms, with evidence of papilledema and upgoing plantar reflexes, warranted immediate head imaging and a computed tomography (CT) scan was performed. The head CT revealed multiple ring‐enhancing lesions throughout the brain, highly suggestive for neurocysticercosis (NCC). The main differential diagnosis of multiple ring‐enhancing lesions in an immune‐competent host is either NCC or tuberculomas (Table 1). It is believed that NCC lesions are usually round in shape and 20 mm or less in size, with ring enhancement and/or the presence of a visible scolex.1,2 On the other hand, tuberculomas are usually irregular and solid in consistency and tend to be greater than 20 mm in size. 1,2 Because the patient had a large number of brain lesions, a magnetic resonance imaging (MRI) was performed to better identify the structural location of these lesions with regard to the brain stem and the fourth ventricle. The MRI demonstrated invaginated scolices in the numerous lesions and helped to better delineate their number and location (Figure 1). It was incidentally noted on the lower cervical images that the patient’s neck muscles also contained similar cysts. The presence of soft tissue cysts spurred further imaging that revealed profound soft tissue involvement (Figure 2). The diagnosis was confirmed by the retrieval of an intact cysticercus obtained by a skeletal muscle biopsy (Figure 3).

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Table 1

Differential diagnosis of multiple ring‐enhancing lesions in the brain

Neurocysticercosis—lesions tend to be round, often cystic, less than  or equal to 20 mm in size. The lesions can often demonstrate the  presence of a visible scolex.
Tuberculomas—lesions tend to be irregular, solid, and usually  greater than 20 mm in size.
Toxoplasmosis—usually an opportunistic infection in immune‐ compromised hosts. These lesions tend to be distributed in the  region of the basal ganglia and sometimes in the frontal and  parietal lobes. The lesions are generally greater than 20 mm in size.
Cryptococcomas—occasionally seen in patients with cryptococcal  meningitis and immune‐compromised states. These lesions are  irregular and heterogeneous and often found in the basal ganglia  region.
CNS metastases—most commonly from lung, breast, renal  cancers, and malignant melanoma.
Cerebral abscesses.
Primary CNS lymphoma—tends to be seen in immune‐ compromised hosts. The lesions are most often located in the  periventricular region.
Coenurosis—a rare cestodal infection caused by Taenia multiceps (dog tapeworm).
  • CNS = central nervous system.

Figure 1

T1‐weighted coronal magnetic resonance imaging of the brain showing numerous hypointense lesions with invaginated scolices highly suggestive for neurocysticercosis.

Figure 2

T1‐weighted coronal magnetic resonance imaging of the body showing numerous hypointense cystic lesions within the skeletal muscles.

Figure 3

Intact cysticercus cellulosae recovered from a skeletal muscle biopsy.


NCC, caused by the Taenia solium or pork tapeworm, is the most common central nervous system (CNS) parasitic disease in humans. Endemic in the developing world, it is the most frequent cause of secondary epilepsy in developing countries. 3,4 An estimated 30% to 50% of seizures in South and Central America are secondary to NCC. 5,6 In India, one study demonstrated that 40% of patients with seizures showed evidence of active NCC, prior cysticercosis, or cysticercal granulomas on head CT scan. 7 With increasing rates of immigration from endemic areas, seizures secondary to NCC are occurring with much more frequency in the United States. A study from Los Angeles found that 10% of patients presenting with seizures were found to have the diagnosis of NCC. 8

Humans acquire cysticercosis by fecal–oral contamination with T solium eggs from a human tapeworm carrier who has eaten contaminated pork. Although the cyst may develop in virtually any body tissue, there is a predilection for the CNS, skeletal muscle, eye, and skin. 9 When found beneath the skin, they clinically manifest as subcutaneous small, painless nodules. In the muscles, the cysts form small circular calcifications and can cause pseudohypertrophy of skeletal muscle in extreme cases. 3 Cysticercosis is frequently asymptomatic when located outside the CNS. The most common clinical manifestation of NCC is seizure activity. 10 Intraparenchymal cysts often lead to seizures, whereas extraparenchymal cysts can result in hydrocephalus and are associated with a poorer prognosis. 4,11

Although the exact pathogenesis is not known, the patient often becomes symptomatic years after CNS invasion. The parasite can remain in the CNS, evading the host immune system through various inherent defense mechanisms, causing no clinical symptoms. 3 Symptomatic disease, especially seizures, occurs when the parasite dies or is killed by antiparasitic agents, causing acute inflammation and localized edema. 4

Diagnosis is established with neuroimaging but may also be confirmed by means of serological assay. Absolute criteria for diagnosis include CT or MRI evidence of the scolex, direct visualization of subretinal parasites by fundoscopic examination, or histological demonstration of the parasite by brain biopsy. 11 Both CT and MRI can elucidate the scolex. However, CT is more sensitive for detecting calcifications, while MRI is more sensitive for perilesional edema, degenerative changes of the parasite, cysts that are small or located in the ventricles, brain stem, or cerebellum. 9 The diagnostic criteria for human cysticercosis have been listed in Table 2.

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Table 2

Diagnostic criteria for human cysticercosis 11

Absolute criteria
 Histological demonstration of the parasite
 Direct visualization of the parasite by fundoscopic examination
 Evidence of cystic lesions showing scolex on CT/MRI
Major criteria
 Lesions suggestive of NCC on neuroimaging studies
 Positive immunological tests
 Plain X‐ray films showing calcification in thigh and calf muscles
Minor criteria
 Subcutaneous nodules
 Soft tissue or intracranial calcifications on plain X‐rays
 Clinical manifestations suggestive of NCC
 Disappearance of intracranial lesions after a trial of anticysticercal   drugs
Epidemiological criteria
 Living or coming from endemic areas with cysticercosis
 Frequent travel to areas endemic in cysticercosis
 Household contact with Taenia solium infection
  • These criteria provide two degrees of diagnostic certainty: definitive diagnosis, in patients who have one absolute criterion or in those who have two major plus one minor and one epidemiological criteria, and probable diagnosis, in patients who have one major plus two minor criteria, in those who have one major plus one minor and one epidemiological criteria, and in those who have three minor plus one epidemiological criteria. CT = computed tomography; MRI = magnetic resonance imaging; NCC = neurocysticercosis.


Management of NCC begins with prophylactic antiepileptic medications, cerebral edema control measures, and antiparasitic treatment. Antiparasitic treatment is controversial and varies by location and medication accessibility. Standard therapy includes praziquantel 50 mg/kg/d for 2 weeks or albendazole 15 mg/kg/d for 1 to 4 weeks. 11 Albendazole has better cysticidal activity and brain tissue penetration in comparison to praziquantel. 12 Although there exists good pharmacotherapy for cysticercosis, antiparasitic drugs often result in transient worsening of neurological symptoms secondary to the inflammation caused by the death of the larvae. These symptoms include seizures, headaches, and even death from severe inflammation, cerebral edema, and cerebral herniation. 10 This acute, potentially fatal, cerebral inflammation is a cause of much controversy over the necessity to treat NCC. Some argue that occasional cases of parenchymal NCC can be benign, treated with prophylactic antiepileptics, and will naturally resolve without antiparasitics. 12 On the other hand, one double‐blind, placebo‐controlled trial evaluated albendazole with corticosteroid therapy versus no treatment and concluded that antiparasitic therapy decreased the number of parasites, reduced the frequency of seizures, and helped the cysts to resolve faster than observed in the placebo group. 13 All patients to be treated with antiparasitic drugs are pretreated with a short course of corticosteroids to offset the inflammation caused by the destruction of the cysts.

The current consensus is to individualize treatment based on the number of parasites, their viability, and the number and location of cystic lesions (Table 3; guidelines for the use of anticysticercal treatment in NCC). 11 Other factors to consider are the degree of associated cerebral inflammation and the severity of symptoms that result. In cases of increased intracranial pressure, the goal of therapy is to reduce the pressure, not antiparasitic treatment. 12 In massive infections (greater than 100 cysts), 4 there is no consensus as to whether to use antiparasitics. 14 Such patients, as the one presented in this case, have a high risk of severe and even fatal adverse effects due to the inflammatory response triggered by antiparasitic agents. There is agreement in the literature that pharmacologic treatment should not be used indiscriminately. Our patient was given antiepileptics and steroids for symptom relief. Due to the large burden of cysticerci, antiparasitic treatment was withheld, and unfortunately, 2 weeks later, the patient passed away secondary to the mass effect, resulting in brain stem herniation.

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Table 3

Guidelines for the use of antiparasitic agents in the treatment of NCC 4

Type of NCCInfection burdenOptions/recommendations
Viable (live cysts) NCCMild (1–5 cysts)Antiparasitic treatment with steroids/antiparasitic treatment,  with the use of steroids only if side effects related to therapy  appear/no antiparasitic treatment, only follow‐up
Moderate (more than 5 cysts)Antiparasitic treatment with steroids
Massive/heavy  (more than 100 cysts)Antiparasitic treatment with high‐dose steroids/chronic steroid  treatment with neuroimaging follow‐up
Enhancing lesions  (degenerating cysts)Mild to moderateNo antiparasitic treatment just follow‐up/antiparasitic treatment  with steroids
Massive/heavyNo antiparasitic treatment, high‐dose steroids, and osmotic  diuretics
Calcified cysticerciAny numberNo antiparasitic treatment
Ventricular cysticercosisNeuroendoscopic removal/cerebrospinal fluid diversion followed  by steroids and antiparasitic drugs/open surgery
Subarachnoid cysts, including giant  cysts or racemose cystsAntiparasitic treatment with steroids with ventricular shunt if  there is hydrocephalus
Hydrocephalus with no visible cystsVentricular shunt, no antiparasitic treatment
  • NCC = neurocysticercosis.

There exists no specific guidelines on the screening and routine treatment of travelers who are either exposed to T solium or who have been found to have adult tapeworms in their stools. Niclosamide (2 mg orally in a single dose) and praziquantel (5 mg/kg orally in a single dose) have been found to be effective against the adult tapeworm. 4 There have been some concerns expressed that praziquantel, when administered in doses that can achieve high enough serum levels to affect brain cysts, can precipitate an inflammatory reaction causing headaches and seizures if the patient has coexistent NCC, but these remain unsubstantiated. It is important to note that this potential adverse effect is very uncommon at doses of praziquantel that are less than 10 mg/kg. Among available drugs, niclosamide is not absorbed from the gastrointestinal tract and appears to be the safest option. 15 Many experts also believe in prescribing a purgative 1 to 2 hours after treatment to expel the worm, so as to avoid the potential risk of having proglottids or eggs returned to the stomach, digested, resulting in an internal autoinfection; however, this recommendation again is not backed with good evidence.

Declaration of interests

The authors state that they have no conflicts of interest.


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