Jump to comment:

• Do we really need a new antihelminthic drug for neurocysticercosis?
  Amit Prasad
  Published on: 3 July 2008

• Published on: 3 July 2008

  Do we really need a new antihelminthic drug for neurocysticercosis?

  • Amit Prasad, Senior Research Fellow
  • Other Contributors:
    • Rakesh K Gupta, Avantika Verma, Kashi N Prasad

  Dear Editor,

  First of all, we would like to congratulate Carpio et al., (2008) for their paper entitled “The effects of albendazole treatment on neurocysticercosis: a randomized controlled trial”. However, we are not in agreement with the authors urge for a new antihelminthic drug for the treatment of neurocysticercosis (NCC). Therapy for NCC aims at clearance of cysts in the brain and reduced risk of seizure in futu...

  Show More

  Dear Editor,

  First of all, we would like to congratulate Carpio et al., (2008) for their paper entitled “The effects of albendazole treatment on neurocysticercosis: a randomized controlled trial”. However, we are not in agreement with the authors urge for a new antihelminthic drug for the treatment of neurocysticercosis (NCC). Therapy for NCC aims at clearance of cysts in the brain and reduced risk of seizure in future. The authors (Carpio et al., 2008) in the present study had found significant reduction in the number of active cysts in treatment group compared to placebo group (37.7% vs. 20.0%; p=0.048) at the end of 12 months follow up; however the difference in the occurrence of symptoms was not significant. Earlier studies from different parts of the world had also reported more or less same findings (Garcia et al, 2004). However these studies had over looked two most important questions: (1) why few cysts do not respond to antihelminthic drug (AHD) treatment, and (2) whether the asymptomatic NCC cases be given AHD prophylactically.

  It is evident from the population based studies, few cysts respond to anti-parasitic drug therapy (degenerate and may get clear on neuroimaging); while others do not respond. The penetrating power of albendazole (ABZ) in brain parenchyma may be considered as one of the reason for different outcome, but this will stand true only for cysts at different locations; however few cysts do not respond to ABZ in close vicinity of responding cysts in same patient, or at the same locations in different patients. That indicates that the reason might be different from the penetrating power of ABZ, and drag our attention towards the immunological environment of that non responding cyst and genetic make up of host-parasite. The immunological changes associated with the natural course and following anti-parasitic treatment with and without steroid largely remain unknown. Very few immuno-histochemical studies have been done due to limited specimen tissue (Flisser et al., 1990, Restrepo et al., 1998). It has been reported that genetic differences in cysticerci may affect their infectivity and pathogenicity, and may also contribute to the severity of the disease (Vega et al., 2003). Studies related to immune interaction and genetic make up of host-parasite as risk for seizures may clarify the relation between NCC and epilepsy in future. It would be worthwhile to know what are the immunological parameters associated with these non-responding cysts. Prospective study on large animal model of NCC(swine) to evaluate the immune profile following ABZ therapy with and without steroid and comparing the immune response with responder and non- responder will help better understanding of the disease immunopathogenesis and to develop management strategy for patients suffering from NCC, instead of looking for newer AHD.

  Many studies had shown, a large number of the people harboring different stages of NCC remain asymptomatic in the otherwise normal individuals (Prasad et al., 2008; Montano et al., 2005). We had earlier reported a large number of these asymptomatic individuals carry vesicular cysts (22.6%; Prasad et al., 2008). The presence of degenerating NCC in the asymptomatic group questions the need of prophylactic treatment with anti-epileptic and anti-parasitic drugs for such individuals. The option to follow up such individuals with imaging and to treat them only if they become symptomatic needs to be explored.

  Competing interest: None

  References:

  1.Flisser A, Gnzalez D, Skhurovich M. Parziquantel treatment of porcine brain and muscle Taenia solium cysticercosis: radiological, physiological and histopathological studies. Parasitol Res 1990; 76: 263-269.

  2.Restrepo BI, Liaguno P, Sandoval MA, Enciso JA, Teale JM. Analysis of immune lesions in neurocysticercosis patients: central nervous system response to helminth appears Th-1 like instead of Th-2. J. Neuroimmunol 1998; 89: 64-72

  3.Montano SM, Villaran MV, Ylquimiche L et al. Neurocysticercosis: association between seizures, serology, and brain CT in rural Peru. Neurology 2005; 65: 229-33.

  4.Prasad A, Gupta RK, Pradhan S et al. “What triggers seizures in neurocysticercosis?- A MRI based Study in Pig Farming Community from a District of North India”. Parasitol Int 2008; 55: 166-171.

  5.Vega R, Pinero D, Ramanankandrasana B et al. Population genetic structure of Taenia solium from Madagascar and Mexico: implications for clinical profile diversity and immunological technology. Int. J Parasitol 2003; 33: 1479-85.

  Show Less

  Conflict of Interest:
  None declared.

  • Back to top