The diversity of neurocysticercosis clinical manifestations in Bali, Indonesia: a case series

Neurocysticercosis (NCC) is a parasitic disease of the nervous system caused by the larval form of Taenia solium which is started to be neglected despite its high prevalence in poor and developing countries. Neurocysticercosis has various clinical manifestations and radiological findings ranging from parenchymal to extra parenchymal location, thus can make it difficult to diagnose. We report four cases of NCC with varying manifestations, including epilepsy, chronic headache, space-occupying lesions with increased intracranial pressure, and asymptomatic case. NCC diagnosis requires imaging studies with either a head CT-scan or head MRI. Management of NCC is based on the clinical manifestations extended from antiepileptic drugs, analgetics, and antiedema to surgery besides anti-parasitic albendazole. This case series describes the clinical manifestations of NCC and the radiologic findings and treatment specifically related to parenchymal and extra-parenchymal lesions.


Introduction
Neurocysticercosis (NCC) is the most common parasitic infectious disease of the central nervous system (CNS) caused by the larval form of the Taenia solium (T.solium).Clinical manifestations of this zoonotic and food-borne disease is pleomorphic from asymptomatic, mild to severe symptoms that may extend from different degrees of disability up to death [1][2][3].T. solium larvae in the CNS can be found in the brain parenchymal or extraparenchymal areas (intraventricular, subarachnoid, and spinal cord) causing various neurological manifestations including epilepsy, chronic headache, hydrocephalus, high intracranial pressure (ICP), stroke, and cognitive impairment [1,4,5].

Case presentations
We report four cases of NCC with pleomorphic clinical manifestations and provided the results from serology and imaging studies.The summary of our case presentations is depicted in Table 1.Head CT scan in this case report used GE revolution, type XR C203J, 16 slices, manufactured from France.We used Siemen brand, Magnetom Skyra type, 3 Tesla from Germany for the MRI examination.Serological examination was carried out by Enzyme-Linked Immunosorbent Assay (ELISA) from serum samples using the Multiskan Go spectrophotometer, Thermo Fisher Scientific produced by Finland at the Department of Parasitology, Faculty of Medicine, Udayana University, Bali.-Sodium diclofenac 50 mg q.12.h per oral -Albendazole 400 mg q.12.h per oral for 2 weeks Pain improvement

Discussion
Four cases above describe the various symptoms and radiological findings on parenchymal (epilepsy, chronic headache, and asymptomatic) and extraparenchymal (cerebellar syndrome with high-pressure obstructive hydrocephalus) NCC.Diagnosing neurocysticercosis requires absolute criteria (based on histopathology, the presence of subretinal cysticercosis or scolex on neuroimaging), neuroimaging criteria (major, confirmatory, and minor), and clinical/exposure criteria (major and minor), leading to definitive or probable NCC [2].All cases were definitive NCC: Patients A and D met 1 major neuroimaging criteria (calcifications in brain parenchyma) and 2 clinical criteria (epilepsy in endemic areas, positive serology in patient A and intramuscular cysticercosis in patient D originating from regional endemic), while patients B and C met only 1 absolute criteria (scolex on neuroimaging).Ventriculo-peritoneal (VP) shunt was performed on patient C. All patients received albendazole and symptomatic medications with good adherence and showed improvements in their signs and symptoms including headache, seizure, and focal neurological deficits.Patients were from Bali and Timor Island which are endemic areas of NCC, where pig farming and raw/undercooked pork consumption are common [2,3].Active T. solium transmission in Bali is limited to the slopes of Mount Agung with poor environment and sanitation, [3,[6][7][8] and a lot of the community seek work in the downtown area, increasing the risk as a taeniasis carrier and transmission of NCC [3,9].
Neurocysticercosis clinical manifestations vary from asymptomatic to severe critical symptoms [5,10,11] associated with larval size, number, stage, location, and host immune response [4,5,12].The highest predilection of NCC is in the brain parenchyma particularly in the grey and white matter junction [5,11], causing adult-onset epilepsy in endemic areas.Headache is reported in one-third of cases and becomes the second most common presentation after epilepsy [13,14].Chronic tension-or migraine-like headache may appear as an isolated symptom or part of the high ICP syndrome [12,13], or related to the cyst degeneration causing inflammation and pain sensation [14].Asymptomatic neurocysticercosis with calcification accounts for 5-25% [4], whereas at autopsy, it is estimated to occur in 50% of NCC cases [11][12][13].Neuroimaging studies found more than one-third of asymptomatic NCC cases [12].
Extraparenchymal neurocysticercosis is a malignant form of NCC found in the intraventricular, cistern/subarachnoid, spinal, and ocular areas [15,16] with worse symptoms and prognosis.Common clinical manifestations of extraparenchymal neurocysticercosis are obstructive hydrocephalus by larvae blocking the ventricular system or communicating hydrocephalus due to basal subarachnoid space inflammation [11,11,17,18].The oncosphere from the larvae penetrates the intraventricular/subarachnoid area through the choroid plexus causing inflammation or space-occupying lesions in the area, especially in the fourth ventricle, which may cause brainstem syndrome [15].
Neuroimaging with head CT-scan is more commonly being conducted than MRI in our setting.The calcifications of parenchymal of NCC can be best visualized using the head CT-scan compared to head MRI.On the other hand, the diagnosis of extra parenchymal NCC, especially in the intraventricular and cistern areas, is very difficult to establish using a head CT scan, since it appears isodense with cerebrospinal fluid (CSF), hence the head MRI is an option in the diagnosis of extra parenchymal NCC with the most common vesicular stage [17].
Management of parenchymal NCC consists of symptomatic therapy utilizing antiepileptic drugs (AED), antiinflammatory, analgesics, and antiparasites [4,11,13].Headache management is tailored according to the type and the underlying cause [13].Corticosteroids in NCC counter the inflammatory process of natural cyst degeneration or the result of antiparasitic drug administration [13,18].Antiparasitic drugs (albendazole, praziquantel) destroy active or degenerating cysts.Combination with steroids is recommended for active cysts.The VP shunt procedure treats high-pressure hydrocephalus due to obstruction in the ventricular area, although in some cases brain cyst removal is required [5,11,13].
There are some strengths and limitations to this case report.These case series provide a wide range of clinical manifestations of NCC, from asymptomatic to neuroemergency cases.The endemicity areas of NCC are shown not only from Bali Island but also from Timor Island.Besides, we also displayed complete aspects of Del Brutto's criteria to diagnose NCC from this case series including the absolute, neuroimaging, clinical, and exposure criteria.Unfortunately, no data are available on longterm follow-up of clinical and radiological outcomes, since patients were referred to their primary care.

Conclusion
Neurocysticercosis is known as "the great imitator" due to various neurological manifestations; therefore, clinicians are required to consider neurocysticercosis in diagnosing patients with seizure, headache, and spaceoccupying lesion with high ICP in the endemic area.
scan: multiple calcifications in the right frontal area Genu X-ray AP/lateral: cigarshaped multiple oval lesions suggesting intramuscular cysticercosis (Fig.5)

Fig. 1 Fig. 2 Fig. 3
Fig. 1 Imaging of patient A; contrast-head CT scan showed multiple calcifications on both hemispheres

Fig. 4 Fig. 5
Fig. 4 Imaging of patient C; Head MRI with T1 contrast on a sagittal view (A) and T2 FLAIR on axial view (B) showed cystic mass around the 4th ventricle area with eccentric hyperintense nodule as scolex (red arrow)

Table 1
Summary of case series M male, F femaleNo Patient M/