Neurocysticercosis is caused by the accidental ingestion of eggs from Taenia solium whose larvae lodge in the central nervous system. In this study we found that cysts within the cerebrospinal fluid leaded to high rates of raised intracranial pressure, meningitis, seizures and headache. Imaging studies such as magnetic resonance are useful for diagnosis, identification of the compromised sites of the central nervous system and, then, for treatment guidance. The pattern of lesions identified through magnetic resonance in our paper helps physicians on searching and analyzing some typical findings of extraparenchymal neurocysticercosis.
Neurocysticercosis is the most common parasitic disease of the central nervous system (CNS) worldwide. It is caused by the accidental ingestion of eggs of the tapeworm Taenia solium. After hatching from the eggs, some of the larvae lodge themselves in the CNS, where they induce inflammatory reactions causing various symptoms. Although neurocysticercosis has potential for eradication, it is a neglected disease that remains endemic in Latin America, Sub-Saharan Africa, and Southeast Asia. In addition, migratory flows have reintroduced the disease in Europe and the USA, increasing public health expenditure.
There are two main forms of neurocysticercosis, parenchymal and extraparenchymal. Cyst localization determines the clinical presentation of the patient. Cysts within the brain parenchyma are responsible for seizures that generally respond well to antiepileptic drugs. In such cases, the prognosis is good unless there is a large parasite burden. In contrast, extraparenchymal neurocysticercosis has a very poor course with high rates of mortality and disability.
Cysts in the cerebrospinal fluid (CSF) compartments elicit inflammatory responses that can cause vasculitis, meningitis, CSF circulation imbalance, and elevated intracranial pressure. Consequently, such cysts can cause strokes, hydrocephalus, and death. Cysts in the subarachnoid space over the convexity of the brain develop and progress similarly to parenchymal cysts. It is hypothesized that cysts located extraparenchymally may continuously absorb the CSF and may grow to large sizes, resulting in compression of adjacent structures. This phenomenon is called hydropic degeneration and is implicated in the transformation of the cellulose into the racemose type of cysticerci. Generally, scolices are absent in parasites located in these regions, and the cysts show a characteristic morphology with complex proliferating membranes resembling a cluster of grapes. In the brain ventricles, the cysts can cause ependymitis and direct obstruction of the CSF flow, which in turn results in hydrocephalus and often requires surgical intervention.