• 1.

    Fleury A, Carpio A, Romo ML, San-Juan D, Sander JW, 2017. Reproducibility of diagnostic criteria for ventricular neurocysticercosis. Am J Trop Med Hyg 97: 1952.

    • Search Google Scholar
    • Export Citation
  • 2.

    Bustos JA, Garcia HH, Del Brutto OH, 2017. Reliability of diagnostic criteria for neurocysticercosis for patients with ventricular cystic lesions or granulomas: a systematic review. Am J Trop Med Hyg 97: 653657.

    • Search Google Scholar
    • Export Citation
  • 3.

    Del Brutto OH, Nash TE, White AC Jr, Rajsherkhar V, Wilkins PP, Sing G, Vasquez CM, Salgado P, Gilman RH, Garcia HH, 2017. Revised diagnostic criteria for neurocysticercosis. J Neurol Sci 372: 202210.

    • Search Google Scholar
    • Export Citation
  • 4.

    Carpio A 2016. New diagnostic criteria for neurocysticercosis: reliability and validity. Ann Neurol 80: 434442.

  • 5.

    Gilman RH, 2016. Diagnostic criteria for neurocysticercosis – a difficult update. Nat Rev Neurol 12: 560561.

 

 

 

 

Reproducibility of Diagnostic Criteria for Ventricular Neurocysticercosis

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  • 1 Center for Global Health – Tumbes, Universidad Peruana Cayetano Heredia, Cysticercosis Unit, Instituto Nacional de Ciencias Neurológicas, Lima, PeruDepartment of Microbiology, Universidad Peruana Cayetano Heredia, Cysticercosis Unit, Instituto Nacional de Ciencias Neurológicas, Lima, PeruE-mails: javier.bustos@jhu.edu and hgarcia1@jhu.edu
  • 2 School of Medicine, Universidad Espíritu Santo – Ecuador, Guayaquil, EcuadorE-mail: oscardelbrutto@hotmail.com

Dear Sir,

In the letter “Reproducibility of Diagnostic Criteria for Ventricular Neurocysticercosis,”1 the authors manifest their unhappiness with the results of the systematic review we conducted to assess reliability of the revised Del Brutto’s set of diagnostic criteria for ventricular neurocysticercosis (NCC), mainly concerning specificity.2

Specificity is the ability of a test to appropriately detect as negative a condition that does not exist in a given patient. According to the revised Del Brutto’s set of diagnostic criteria for NCC,3 only four of the 41 reviewed patients with other ventricular infections would be erroneously diagnosed as definitive NCC.2 These four false-positive diagnoses resulted from the presence of two major neuroimaging findings (ventricular cystic lesion plus additional parenchymal lesions) together with clinical/exposure criteria.3 None of the 41 cases had any absolute criteria for NCC, nor any confirmative neuroimaging criteria, and as such no other definitive diagnoses of NCC would be made using our criteria. This means that for this set we found a specificity of 90.2% (95% confidence interval [CI]: 75.9–96.8%), as detailed in our systematic review.2 We don’t understand how specificity was calculated as 31.7% or 55% by Fleury et al. Perhaps they included “probable” cases as positively diagnosed.

According to the modified set of criteria for NCC used to determine the specificity for our set, a definitive diagnosis of extraparenchymal NCC is established in patients presenting with subarachnoid or intraventricular cysts without scolex, associated with at least two of the following: 1) hydrocephalus, 2) inflammatory cerebrospinal fluid (CSF), 3) positive CSF immunological tests (enzyme-linked immunosorbent assay (ELISA) or enzyme-linked immunotransfer blot (EITB), and 4) presence of single or multiple calcifications or parenchymal vesicular or degenerating cysts.4 The poor specificity of this categorization is obvious because any patient with an intraventricular cyst associated with hydrocephalus and an inflammatory CSF would be characterized as definitive NCC. Both hydrocephalus and inflammatory abnormalities in the CSF are unspecific, and many patients with other infections requiring different management might be misdiagnosed as NCC.5 Indeed, 25 of the 41 cases with proven non-cysticercotic ventricular lesions that we analyzed in our systematic review had either ventricular cystic or granulomatous lesions (with a cystic component) without scolex associated with hydrocephalus and inflammatory CSF or with concomitant parenchymal lesions.4 These 25 false-positive cases thus lower the specificity to 39% (95% CI: 24.6–55.5%). It is difficult to understand how specificity, as calculated by Fleury et al, was 78.1% or 82.5% in spite of the categorization of these 25 cases. Again, one possibility is that their case review was not blind, and perhaps they did not categorize lesions with cystic contents as cysts. Relevant information on the 25 false-positive cases is summarized in Table 1.

Table 1

Cases with non-cysticercotic–related ventricular cystic lesions or granulomas, where the diagnosis is definitive cysticercosis based on the modified set of diagnostic criteria proposed by Carpio et al.4

ReferenceVentricular cystic lesion or granuloma*Other imaging findingsHydrocephalusCSF analysisDefinitive diagnosis
Acta Neurochir 2004;146:1151YesYesInflammatoryTuberculoma
AJNR 1996;17:110YesYesInflammatoryCryptococcosis
AJNR 2002;23:273YesParenchymal cyst no scolexYesInflammatoryCryptococcosis
BMJ Case Rep 2014;bcr2014-203837YesYesInflammatoryTuberculoma
Br J Radiol 2010;83-e14YesYesInflammatoryCryptococcosis
Case Rep Clin Med 2013;2:81YesYesInflammatoryTuberculoma
Case Rep Neurol 2015;7:156YesYesInflammatoryPyogenic abscess
Clin Infect Dis 1993;16:435YesYesInflammatoryPyogenic abscess
Indian J Pathol Microbiol 2008;51:553YesParenchymal cyst no scolexInflammatoryCryptococcosis
Indian J Tuberc 2014;61:166YesYesInflammatoryTuberculoma
Indian Pediatr 2011;48:161YesYesInflammatoryTuberculoma
J Comput Assist Tomogr 1993;17:547 (case 1)YesYesInflammatoryCryptococcosis
J Comput Assist Tomogr 1993;17:547 (case 2)YesYesInflammatoryCryptococcosis
J Craniofacial Surg 2010;21:1291YesYesInflammatoryAspergillosis
J Neuroradiol 2008;35:63YesYesInflammatoryTuberculoma
Mayo Clin Proc 1999;74:803YesYesInflammatoryHistoplasmosis
Med Mycol Case Rep 2015;10:18YesYesInflammatoryRhizopus abscess
Neurol India 1999;47:327YesYesInflammatoryTuberculoma
Neurol India 2014;62:73YesParenchymal cyst no scolexYesTuberculoma
Neurol Med Chir (Tokyo) 2002;42:501YesYesInflammatoryTuberculoma
Neuropathology 2014;34:210YesYesInflammatoryCryptococcosis
Neuroradiology 1993;35:149YesParenchymal cyst no scolexYesHydatid disease
Neuroradiology 2003;45:908YesYesInflammatoryPyogenic abscess
Pediatr Neurosurg 2017;52:93YesYesInflammatoryTuberculoma
Surg Neurol 2007;67:647YesYesInflammatoryCryptococcosis

Granuloma with cystic component.

REFERENCES

  • 1.

    Fleury A, Carpio A, Romo ML, San-Juan D, Sander JW, 2017. Reproducibility of diagnostic criteria for ventricular neurocysticercosis. Am J Trop Med Hyg 97: 1952.

    • Search Google Scholar
    • Export Citation
  • 2.

    Bustos JA, Garcia HH, Del Brutto OH, 2017. Reliability of diagnostic criteria for neurocysticercosis for patients with ventricular cystic lesions or granulomas: a systematic review. Am J Trop Med Hyg 97: 653657.

    • Search Google Scholar
    • Export Citation
  • 3.

    Del Brutto OH, Nash TE, White AC Jr, Rajsherkhar V, Wilkins PP, Sing G, Vasquez CM, Salgado P, Gilman RH, Garcia HH, 2017. Revised diagnostic criteria for neurocysticercosis. J Neurol Sci 372: 202210.

    • Search Google Scholar
    • Export Citation
  • 4.

    Carpio A 2016. New diagnostic criteria for neurocysticercosis: reliability and validity. Ann Neurol 80: 434442.

  • 5.

    Gilman RH, 2016. Diagnostic criteria for neurocysticercosis – a difficult update. Nat Rev Neurol 12: 560561.

Author Notes

Financial support: J. A. B. is partially supported by FIC-NIH grant TW001140, and O.H.D. is supported by Universidad Espíritu Santo – Ecuador.

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