Natural History of Treated Subarachnoid Neurocysticercosis

Abstract

Subarachnoid neurocysticercosis (SUBNCC) is usually caused by an aberrant proliferative form of Taenia solium causing mass effect and arachnoiditis. Thirty of 34 SUBNCC patients were treated with extended cysticidal and anti-inflammatory regimens and followed up a median of 4.2 years posttreatment (range: 15 for ≥ 4 years, 20 ≥ 2 years, 26 > 1 year, and 3 < 1 year). The median ages at the time of first symptom, diagnosis, and enrollment were 29.7, 35.6, and 37.9 years, respectively; 58.8% were male and 82.4% were Hispanic. The median time from immigration to symptoms (minimum incubation) was 10 years and the estimated true incubation period considerably greater. Fifty percent also had other forms of NCC. Common complications were hydrocephalus (56%), shunt placement (41%), infarcts (18%), and symptomatic spinal disease (15%). Thirty patients (88.2%) required prolonged treatment with albendazole (88.2%, median 0.55 year) and/or praziquantel (61.8%; median 0.96 year), corticosteroids (88.2%, median 1.09 years), methotrexate (50%, median 1.37 years), and etanercept (34.2%, median 0.81 year), which led to sustained inactive disease in 29/30 (96.7%) patients. Three were treated successfully for recurrences and one has continuing infection. Normalization of cerebral spinal fluid parameters and cestode antigen levels guided treatment decisions. All 15 patients with undetectable cestode antigen values have sustained inactive disease. There were no deaths and moderate morbidity posttreatment. Corticosteroid-related side effects were common, avascular necrosis of joints being the most serious (8/33, 24.2%). Prolonged cysticidal treatment and effective control of inflammation led to good clinical outcomes and sustained inactive disease which is likely curative.

Figure 1.

Course of disease, NIH enrollment, drug administration and cerebral spinal fluid (CSF) white cell blood count (WBC) counts, and cestode antigen levels over time. Small arrows above the x axis indicate the extent of time before or after labeled dates.

Figure 2.

(A) Axial T2-weighted images at the levels of the pons, midbrain, and lateral ventricles. Cystic masses are seen in the perimesencephalic cistern (white hollow arrows) with secondary distortion of adjacent brain stem structures. Hydrocephalus is noted with transependymal cerebrospinal fluid seepage. A left lateral ventricular cyst can also be seen (black arrow). (B) Pre- and postcontrast T1-weighted images showing abnormal enhancement along the courses of the middle cerebral arteries (MCAs) and anterior cerebral arteries (ACAs) and extending into the interpeduncular cistern (white arrows). (C) Sagittal postcontrast T1-weighted images showing suprasellar rim enhancing cyst anteriorly displacing the pituitary stalk (white arrow). (D) Axial T2-weighted images obtained on March 5, 2018, showing resolution of cystic masses and mass effect on the brain stem structures. The ventricular cyst has markedly decreased in size (black arrow). (E) Pre- and postcontrast T1-weighted images show significant improvement of the perivascular and meningeal enhancing lesions (white arrows). (F) Sagittal postcontrast T1-weighted images show resolution of the suprasellar cyst.

Figure 3.

(A) Postcontrast T1-weighted images showing abnormal enhancement along the courses of the MCAs and ACAs bilaterally with associated cystic changes (white arrows). (B) Axial T2, axial apparent diffusion coefficient (ADC) maps, and axial postcontrast T1-weighted images showing subacute infarcts in the left basal ganglia and centrum semiovale (black arrows). (C) Abnormal enhancement in the right side of the perimesencephalic cistern (white arrows) along the course of the right posterior cerebral artery (PCA). (D) Axial T2, axial ADC maps, and axial postcontrast T1-weighted images showing acute infarction in the right medial occipito-parietal region (white hollow arrows).

Figure 4.

(A) Axial CT scan image (July 20, 2017) in bone windows, showing right basal ganglia calcific lesion with typical outline of a cyst with scolex. (B) Scout view of the CT scan showing the cyst with scolex (white arrow). (C) Magnified view of the cyst on CT. (D) Soft tissue windows of the brain showing multiple other calcific lesions, mainly in the left perimesencephalic cistern (white arrow) and left Sylvian fissure (double white arrows). Smaller calcifications are seen in the anterior interhemispheric fissure and in the left lateral ventricle.