Parenchymal neurocysticercosis: follow-up and staging by MRI

Abstract

We describe the evolution of parenchymal cerebral cysticerci on MRI, to assess signs of early cyst degeneration. We studied 15 lesions in four treated and one untreated patient. MRI was performed before therapy and repeated in the 1st month after each course of anticysticercus drugs, every 4 months during the 1st year and then annually; the follow-up period was 8-48 months. Lesions were classified according to changes in four features: cyst content and capsule signal, gadolinium enhancement and oedema signal. We were able to recognise each of the pathological phases; five MRI stages were identified. Stage 1 showed oedema and/or nodular gadolinium enhancement in the tissue invasion phase; stage 2 was cerebrospinal fluid-like signal within a cyst in the vesicular phase; stage 3 showed a thick capsule with an impure liquid content signal and surrounding oedema, in the cystic phase; stage 4 showed the disappearance of the cyst fluid content signal in the degenerative phase; stage 5 showed a calcified lesion in the residual phase. Stage 1 lesions disappeared after therapy; the other progressed from one stage to another. Stage 4 indicated the end of viability of the parasite and determined the point after which treatment was useless. On T2-weighted images changes in the cyst content differed according to the history of the lesion; nodular low intensity followed the natural degeneration of the parasite and a mixed fluid signal with punctate low signal seemed to represent the specific result of therapy. MRI staging can help in the evaluation of indications for treatment and facilitate clinical therapeutic trials.

Neurocysticercosis in a preschool-age child: case report

“…Neuroimaging studies [15][16][17] constitute a rather effective tool in patients suspected to have NC. Byrd et al 15 described the head CT findings in 30 adults and 15 children (age range, 6-17 years) with NC, who were classified in four groups according to cyst location: parenchymatous (11 children), ventricular-cisternal (1 child), ependymal-meningeal (1 child), and mixed (2 children).…”

“…Dumas et al 16 reported on the radiological progression of 15 NC lesions that were followed with serial MRI studies, and were able to define five stages of neuroradiologic evolution, according to cysticercus content signal-intensity compared with CSF, presence and degree of surrounding edema, and contrast enhancement. Lesions in stage 1 resolved without progression to subsequent stages in response to specific treatment, while stage 4 lesions involuted even without treatment.…”

Taenia antigens detection in the cerebrospinal fluid of patients with neurocysticercosis and its relationship with clinical activity of the disease

“…In a recent consensus proposing diagnostic criteria for NC, several images were emphasized and classified as absolute, major and minor criteria 19 . Neuroimaging is strongly applied in the diagnosis for NC, permitting visualization of the parasite in its different stages [20][21][22] . Examination of cerebrospinal fluid (CSF) may be a valuable diagnostic tool, providing sensitive information about the inflammatory process and activity of NC [23][24][25][26][27] .…”

Reactivation of neurocysticercosis: case report.

“…At this stage the inflammation and edema associated with the degenerating lesion are markedly decreased. 4,5 With time, the involuted lesion undergoes complete calcification or resorption. At this stage, the infection is no longer considered to be active.…”