Neurocysticercosis in Radiographically Imaged Seizure Patients in U.S. Emergency Departments

Samuel Ong, David A. Talan, Gregory J. Moran, William Mower, Michael Newdow, Victor C.W. Tsang, Robert W. Pinner, and the EMERGEncy ID NET Study Group


Emerging Infectious Diseases. 2002;8(6) 

In This Article


A total of 1,801 eligible patients with 1,833 emergency department visits were enrolled during the 2-year study period. Twenty-eight patients had multiple visits; four patients underwent evaluation on three separate occasions ( Table 1 ). A diverse group of seizure patients were enrolled in the study ( Table 2 ).

From the entire study population, 2.1% (38) patients met the case definition for neurocysticercosis ( Table 3 ). Of patients who underwent both CT scanning and serologic testing, 2.9% met the case definition. Thirty-four patients satisfied the case definition based on classic CT scan findings, and four satisfied the case definition based on a positive serologic test coupled with CT scan findings consistent with neurocysticercosis. Neurocysticercosis was identified at 9 of the 11 study sites; 6 sites enrolled more than one patient ( Table 3 ). Patients with this disease tended to be younger than patients who did not meet the case definition ( Table 4 ). Patients were also more likely to be Hispanic, have been born outside the United States, have visited or lived in an endemic region, be uninsured, and have a reported history of neurocysticercosis. Overall, approximately 9% of patients with Hispanic ethnicity who came to an emergency room with a seizure met the case definition for neurocysticercosis. The prevalence of the disease in the Hispanic patients with seizures ranged from 9% to 13.5% in the highest risk sites.

Patients meeting the case definition for neurocysticercosis were not more likely to have a new-onset seizure (versus having an established history of seizures; RR 1.1; CI 0.56 to 2.01). Neurocysticercosis patients were, however, more likely to have focal motor or partial complex seizures than those without neurocysticercosis (RR 2.6; CI 1.3 to 5.5) ( Table 4 ).

Serologic testing was performed on 49.4% (890) of the 1,801 patients enrolled, and results were positive in 2% (18) cases. No significant differences were detected in age, seizure history, seizure type, prior history of neurocysticercosis, immigrant status, or exposure to an endemic region between the patients who underwent serologic testing and those who did not. Nine of the seropositive patients had CT scan findings consistent with neurocysticercosis; nine did not. Compared with the seronegative patients, seropositive patients were more likely to be Hispanic (RR 8.7; CI 3.1 to 24.1), have visited or lived in a neurocysticercosis-endemic region (RR 6.8; CI 2.2 to 20.5), and have an abnormal CT scan (RR 1.7; CI 1.2 to 2.3). Seropositivity was not significantly associated with either new-onset seizures or prior seizure history. Serology was positive in 27% of the patients who had neuroimaging findings characteristic of neurocysticercosis, 5.3% of those with consistent neuroimaging findings, and 1.1% of those with neuroimaging findings inconsistent with neurocysticercosis.

Seven patients reported a history of neurocysticercosis. Four (57%) of these patients had neuroimaging findings typical of or consistent with neurocysticercosis. Serologic testing was performed on two of the seven patients with one negative and one positive result.

The use of our case definition identified two patients who were not diagnosed with neurocysticercosis by the emergency department physician but who were later clinically diagnosed with neurocysticercosis. One was a child born in the United States to Laotian parents whose travel history was unknown; the other was a man of Hispanic ethnicity whose travel history and immigration status were not available. On the other hand, half of the patients diagnosed with neurocysticercosis by their treating physician did not satisfy our case definition. No confirmed cases of domestically acquired neurocysticercosis were identified during the study period.


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