A Rat Model of Neurocysticercosis-Induced Hydrocephalus: Chronic Progressive Hydrocephalus with Mild Clinical Impairment.

BACKGROUND: Hydrocephalus is the most common complication of extraparenchymal neurocysticercosis, combining obstructive and inflammatory mechanisms that impair cerebrospinal fluid circulation. METHODS: We studied the long-term progression of neurocysticercosis-induced hydrocephalus in a rat model. We generated an experimental rat model of neurocysticercosis-induced hydrocephalus by cisternal inoculation of cysts or antigens of Taenia crassiceps and compared it with the classic model of kaolin-induced hydrocephalus. We used 52 animals divided into 4 groups: 1) control, 2) neurocysticercosis-induced hydrocephalus by cysts or 3) by antigens, and 4) kaolin-induced hydrocephalus. We studied behavioral, radiologic, and morphologic alterations at 1 and 6 months after inoculation by open field test, magnetic resonance imaging, and immunohistochemical localization of aquaporin-4 (AQP-4). RESULTS: Behavioral changes were observed later in neurocysticercosis-induced than in kaolin-induced hydrocephalic rats (P = 0.023). The ventricular volume of hydrocephalus induced by experimental neurocysticercosis progressively evolved, with the magnetic resonance imaging changes being similar to those observed in humans. Periventricular inflammatory and astrocytic reactions were also observed. AQP-4 expression was higher in the sixth than in the first month after inoculation (P = 0.016) and also occurred in animals that received antigen inoculation but did not develop hydrocephalus, suggesting that AQP-4 may constitute an alternative route of cerebrospinal fluid absorption under inflammatory conditions. CONCLUSIONS: Our neurocysticercosis-induced hydrocephalus model allows for the long-term maintenance of hydrocephalic animals, involving mild clinical performance impairments, including body weight and behavioral changes.

Effect of Albendazole Treatment in an Experimental Model of Neurocysticercosis-Induced Hydrocephalus

Hydrocephalus is a major concern in neurocysticercosis (NCC), and its management is more challenging than that of hydrocephalus caused by other etiologies. Even though albendazole is a well-established drug for the treatment of NCC, the death of the parasites may worsen the clinical symptoms and eventually, deteriorate the course of hydrocephalus. The aim of this study was to analyze the effects of treatment with albendazole on the course of hydrocephalus as well as on animal behavior in a ratmodel of NCC-induced hydrocephalus in order to verify whether the course of hydrocephalus and the animal behavior were changed. Ventricle volumes before and after treatment showed a slight but non-statistically significant difference (168.11 mm3 versus 184.98 mm3, p » 0.45). The distribution and location of the cysts were unaffected. In addition, the behavioral patterns before and after the treatment were not significantly different, as assessed by the open field test. On histologic assessment, mononuclear leukocyte infiltration was present in diverse sites, such as the perivascular and peri-ependymal regions, choroid plexus, and meningeal membranes. A positive correlation was found between the degree of ventricle enlargement and tissue damage. Further studies with long-term comparisons are required.