Our patient is a 36-year-old female with a history of adult onset seizures. She was born and raised in Mexico and emigrated to the United States at the age of 8. Since arriving to the United States, she had never returned to Mexico. She had her first seizure about 10 years before presentation, at which point she was placed on anti-epileptic medications that were subsequently weaned off without any further seizure activity in the past several years. No prior imaging was available for our review, but the patient denied report of any intracranial lesions that could be identified as the culprit of the adult onset seizures.
She initially presented to an outside institution with progressively worsening bilateral headaches over the past year that were associated with vertigo and intermittent nausea. The headaches were worse at night and on waking up in the morning, and they improved throughout the day. A computerized tomography (CT) scan demonstrated ventriculomegaly and transependymal flow, with evidence of obstruction at the level of the fourth ventricle. She was referred to our clinic by our neurology colleagues, where she was found to have no neurologic deficits on examination. Outpatient magnetic resonance imaging (MRI) demonstrated obstructed hydrocephalus secondary to a lobulated cystic mass within the fourth ventricle, with a streak of internal linear enhancement most consistent with racemose NCC. A worm was easily identified within the cyst on the MRI [Figure 1].
Given the chronic nature of the lesion and her benign clinical examination, she was scheduled for elective surgery a few weeks later. She underwent right frontal burr hole for endoscopic third ventriculostomy and placement of external ventricular drain (EVD), then she was positioned prone and underwent suboccipital craniotomy for resection of the fourth ventricular cystic mass followed by duraplasty. The cyst was removed as a single en bloc specimen, although during the process of removal, a small portion of the cyst ruptured into the ventricle - this was quickly suctioned and extensively irrigated. Gross examination [Figure 2] and pathology [Figure 3] demonstrated a mature T. solium plerocercoid larvae measuring 1.2 x 0.5 x 0.2 cm encased in a tan, gelatinous, cystic membrane.
Postoperatively, she had no neurologic deficits. Her EVD was quickly weaned with minimal drainage and low intracranial pressure, so it was removed on postoperative day 2. She underwent ophthalmologic examination, demonstrating no evidence of an active ocular infection or involvement of NCC, but concern for a chronic, inactive choroidal inflammatory process. Our infectious disease colleagues were consulted and found no other risk factors for NCC aside from living in Mexico until the age of 8, and she was negative for tuberculosis infection. Given her longstanding history of seizures, but recent presentation with an active lesion, it was felt that she may have been auto-infecting. She underwent a 21-day course of albendazole with a 14-day dexamethasone taper for protection against aseptic meningitis. She was also prescribed a single dose of praziquantel at the end of her therapy given concerns for possible auto-infection from her gastrointestinal system. On discharge, her headaches, vertigo, and nausea had completely resolved.