Cystic and alveolar echinococcosis.

Echinococcosis of the CNS is very rare. Cystic (CE) and alveolar echininococcosis (AE) vary in their clinical manifestations, course of disease, and prognosis, to the extent that clinicians should look at these two parasitic infections as distinctly different entities. CE causes displacement and pressure atrophy, while AE expands by infiltrative growth. Due to the embolic nature of CE and AE, CNS lesions are most commonly localized supratentorially in the middle cerebral artery. Symptoms and clinical signs are those of space-occupying lesions. Diagnosis is primarily based on imaging (MRI, CT); serology can help to confirm the diagnosis, but is unreliable. In vivo MRS techniques for immobile intracranial CE lesions have become feasible and will assist in diagnosing such lesions in the future. Patients with cerebral CE and AE need an individual therapeutic approach and should generally be managed by a multidisciplinary team of clinicians experienced in the management of CE and neurosurgeons. A minimum follow-up of 5 years, but ideally 10 years, is necessary. Treatment is difficult in advanced disease, in particular in AE, when curative surgery is not possible. AE and CE are among the most neglected infectious diseases and urgently need more attention to improve early detection in exposed populations, diagnosis, and treatment.