CASE 13128 Published on 01.11.2015

An aetiology of late-onset epilepsy

Section

Neuroradiology

Case Type

Clinical Cases

Authors

R.CHIBLI,A.M.FILIP

CHU Avicenne 10000 Rabat, Morocco; Email:chibli.radia@gmail.com
Patient

38 years, female

Categories
Area of Interest Neuroradiology brain ; Imaging Technique MR, CT
Clinical History
A 38-year-old African woman, who recently had a first seizure and presented at emergency with another generalized tonic-clonic seizure. She was born in Cabo Verde.
No focal neurological deficit and she had no complaints in the past. Laboratory findings depicted normal blood and cerebrospinal fluid. A CT and then a brain MR were performed.
Imaging Findings
CT showed a solitary low-density lesion measuring 11 mm, well-circumscribed, containing a small high-density eccentric nodule and surrounding oedema located in the right parietal lobe. The lesion has a ring-like enhancing after contrast administration (Fig. 1).
On MR imaging, the lesion has hypo-intense signal on T1W and FLAIR and hyper-intense on T2WI. Gadolinium-enhanced MR revealed a peripheral rim enhancement of the lesion. Surrounding oedema (Fig. 2).
On MRI Imaging control, 5 months after treatment, there was regression of the size and contrast enhancement of the right parietal lesion (Fig. 3).
Discussion
Cysticercosis is the most common parasitic infection of the central nervous system in immuno-competent patients. The infection is caused by the larval form of Taenia solium, the porcine tapeworm, for which the human is the only definitive host. The parasite is acquired by humans ingesting poorly cooked, infected pork or by accidental ingestion of contaminated food or water. The disease burden is spreading to non-endemic areas because of increasing migration [1]. It affects males slightly more frequently than females, mainly in young and middle-aged adults [3].
The central nervous system is involved in 60-90% of patients with cysticercosis [2].
NCC is a chronic, slowly-progressing, frequently asymptomatic disease.
The clinical presentation is nonspecific and highly variable. The two most common clinical manifestations are epilepsy and intracranial hypertension.
There is a spectrum of common imaging findings on CT or on MRI, often characteristic, depending on the stage of the disease: four stages are recognised. [4]

The first stage, known as the vesicular stage, corresponds to a cystic lesion: living larval cysts with identifiable scolex as an eccentric nodule, with no contrast enhancement of the wall and no surrounding oedema. The cysts measure 5-20 mm and have a thin, smooth wall. The signal intensity of the cysts will be similar to that of CSF on T1W and T2W images. There is no immune response by the host at this stage, and the disease is clinically asymptomatic.

In the second stage, known as the colloidal stage, the parasite begins to degenerate. The cyst develops a thicker capsule with contrast enhancement, with an intense inflammatory reaction in the adjacent brain parenchyma, that may result in prominent oedema and mass effect. The scolex may not be visible, and oedema increases from mild to moderate.
The third stage: granular nodular (pathological stage), at which most patients become symptomatic, is represented by a shrunken cyst, which has mineralised content and a thickened capsule, with nodular enhancement, with or without oedema.
The granulomatous lesion becomes a calcified nodule or focal area of gliosis, in the final nodular calcified stage. Surrounding oedema is usually not present and a minimal residual contrast enhancement may be seen.
In general, the diagnosis is based on neuroimaging and serologic analysis.
The treatment is complex and individualised. It includes antiepileptic drugs, cysticidal agents, immunosuppressive agents, and sometimes, a surgical excision is required.
In our case, after treatment with Albendazole and antiepileptic, a 5 month follow-up MRI confirmed decreased size and contrast enhancement of the right parietal lesion.
Differential Diagnosis List
Adult onset seizures in a patient with neurocysticercosis.
Metastasis
Abscess
Glioma (high grade)
Final Diagnosis
Adult onset seizures in a patient with neurocysticercosis.
Case information
URL: https://www.eurorad.org/case/13128
DOI: 10.1594/EURORAD/CASE.13128
ISSN: 1563-4086
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