State of the art in neurocysticercosis

Arturo Carpio， Matthew L. Romo

1Escuela de Medicina， Universidad de Cuenca， Ecuador

2GH Sergievsky Center， College of Physicians and Surgeons， Columbia University， New York， USA

3CUNY School of Public Health， New York， USA

State of the art in neurocysticercosis

Arturo Carpio1，2✉， Matthew L. Romo1，3

1Escuela de Medicina， Universidad de Cuenca， Ecuador

2GH Sergievsky Center， College of Physicians and Surgeons， Columbia University， New York， USA

3CUNY School of Public Health， New York， USA

ARTICLE INFO

Article history：

Received 15 May 2016

Received in revised form 16 June 2016

Accepted 15 July 2016

Available online 20 August 2016

Neurocysticercosis

Cysticercosis

Taenia solium

Diagnosis

Therapeutics

Epidemiology

Diagnosis of neurocysticercosis （NCC） based merely on computed tomography （CT） and magnetic resonance imaging may be doubtful when considering that parenchymal and extraparenchymal NCC are practically distinct clinical and pathophysiological entities. In this letter， we comment on a recent case report by Rizvi et al.

Dear editor，

Accurate diagnosis of neurocysticercosis （NCC） is a challenge. A recent case report published by Rizvi et al reported that the diagnosis of NCC in their patient was based on a multilobulated cystic mass in the posteromedial left temporal/occipital region with surrounding edema seen on computed tomography （CT） and magnetic resonance imaging （MRI） ［1］. This sole diagnostic criterion may be doubtful when considering that parenchymal and extraparenchymal NCC are practically distinct entities from clinical， immunological， and pathophysiological points of view ［2］. Although CT and MRI are useful in diagnosis of NCC， their utility varies depending mainly upon the parasite evolutionary stage （vesicular， colloidal，granular-nodular， and calcified phases）. It has been proposed that visualization of the scolex inside the cysts is a characteristic imageof parenchymal NCC ［3］； however， extraparenchymal NCC is more difficult to detect by imaging because the attenuation and signal intensity of the cyst’s content is similar to that of CSF. The cystic wall is usually not detected， and the cysts frequently lack a scolex. MRI techniques such as fluid-attenuated inversion recovery（FLAIR）， as well as 3D sequences such as Fast Imaging Employing Steady-state Acquisition （FIESTA）， 3D Constructive Interference in SteadyState （3D-CISS）， and 3D SPoiled Gradient Recalled echo sequences （SPGR）， have proven to be useful in evaluating ventricular cysts and permit better detection of the parasites ［4］. We would recommend that the patient case reported by Rizvi et al［1］ be re-evaluated using these new MRI techniques in order to confirm the diagnosis.

Treatment of NCC is complex and should be individualized according to the location and viability of the parasites ［2］. Symptomatic treatment is based upon clinical manifestations：antiepileptic drugs for seizures， mannitol for high intracranialpressure， and analgesics for headache. Steroids are often administered to reduce inflammation； however， optimal dose，duration， and timing of administration and discontinuation remain unknown. Antihelminthic drugs， such praziquantel and albendazole，（separately or combined） are currently used to kill the parasite. Clinical trials of parenchymal NCC treatment using these drugs have shown disappearance of parasites in about half of the patients；while there are no randomized controlled trials providing evidence for treatment of extraparenchymal NCC so far ［2］. Neurosurgical intervention should be considered for hydrocephalus requiring ventriculo-peritoneal shunt or intraventricular excision of a cyst. In the case report by Rizvi et al.［1］， at the very least it is important to know how （and if） the cystic mass responded to antihelminthic treatment on imaging， as this would help to further support a diagnosis of NCC.

NCC is still an important public health issue worldwide and is widely prevalent in many countries with high poverty in sub-Saharan Africa， Asia， and Latin America. Indeed the number of cases in nonendemic countries has also increased due to international travel and relocation［2］. Rizvi et al［1］ include a figure of “the geographic distribution of NCC，” which is incorrect and not applicable to the epidemiology of NCC. The World Health Organization［5］ has recently published an updated map of the approximate distribution of Taenia solium/cysticercosis （Figure 1） infection， showing a more accurate distribution of endemic and suspected endemic areas of this parasitic disease around the world， based on current and reliable epidemiological data.

Figure 1. Endemicity of Taenia solium infection， 2015.

Conflict of interest statement

We declare that we have no conflict of interest.

［1］ Rizvi SA， Saleh AM， Frimpong H， Al Mohiy HM， Ahmed J， Edwards RD，Ahmed SS. Neurocysticercosis： A case report and brief review. Asian Pac J Trop Med 2016；9（1）：100-102.

［2］ Carpio A， Romo ML， Parkhouse RM， Short B， Dua T. Parasitic diseases of the central nervous system： lessons for clinicians and policy makers. Expert Rev Neurother 2016； 4：1-14.

［3］ Zee CS， Go JL， Kim PE， DiGiorgio CM. Imaging of neurocysticercosis. Neuroimag Clin N Am 2000；10：391-407.

［4］ Carrillo Mezo R， Lara García J， Arroyo M， Fleury A. Relevance of 3D magnetic resonance imaging sequences in diagnosing basal subarachnoid neurocysticercosis. Acta Trop 2015；152：60-65.

［5］ World Health Organization. Taeniasis/cysticercosis［Online］. Avaliable at：http：//www.who.int/taeniasis/en/ ［Accessed on March 8th， 2016］.

10.1016/j.apjtm.2016.06.010

✉Corresponding author： Arturo Carpio， Avenida 12 de Abril s/n， Uniuersity of Cuenca， Ecuador

Tel： 593 7 2830127

E-mail： arturocarpio@etapanet.net； arturo.carpio@ucuenca.edu.ec