Troubles neuropsychiatriques chez un jeune adulte : penser au parasite !

Abstract

Taenia solium (pork tapeworm) infection is a well-known intestinal infection following ingestion of raw or undercooked meat from cystercotic pigs. But humans can also act as intermediate hosts when they ingest Taenia solium eggs present in contaminated food or water, conducing to cysticercosis. Neurocysticercosis is due to an encystment into the human brain system of Taenia solium larvae. This is a major cause of neuropsychiatric disorders in developing countries where people live in close proximity to livestock. Thirty-three percent of seizures in endemic countries are related to neurocysticercosis. Nevertheless, the World Health Organisation (WHO) classified neurocysticercosis as a zoonosis with an underestimated impact. This parasite mainly spreads in central and South America, sub-Saharan Africa and India. Only imported cases have been described in Europe, of which seventeen percent were found in France, making it one of the most affected countries in the continent. This can be explained by its vast Malagasy community: in Madagascar, the seroprevalence of cysticercosis is high, close to twenty percent. The diagnosis can be very complicated because of the wide array of symptoms (mobility, cognitive, or mental impairments, epilepsy…); neurocysticercosis is also called “the Great Imitator”. This complexity is reinforced furthermore by the poor efficiency of paraclinical exams. The main paraclinic exam is the brain imaging (CT-scan or MRI) showing non-specific calcified lesions of cysts. Electroencephalogram (EEG), lumbar puncture, biology, serology and the fundus of the eye are helpful but not flawless for the diagnosis. For example, the increase of eosinophilia is not found in the chronic form of the disease. As a result of the increasing mobility of people all around the world, parasitic diseases are an emergent problem in our region. Doctors in these non-endemic zones can be challenged by these unfamiliar illnesses. Psychiatrists are often on the front line facing these pathologies that can manifest themselves entirely through psychiatric disorders such as depression, psychotic disorders, etc. The main treatment of neurocysticercosis is albendazole and symptomatic treatment when the parasite reaches calcification. Below, we present the case of a 30-year-old Madagascan, without medical history, who displayed retrograde amnesia after being found wandering in the streets of Paris, claiming he was robbed. A peri traumatic dissociation was initially evoked. But the association of a clouding of consciousness (as presented in this case) with the retrograde amnesia is uncommon for a peritraumatic dissociation. This case clearly shows the difficulty of diagnosing neurocysticercosis. Only after carefully re-reading the CT-scan and relating it to the patient's origin, the disease was finally suggested. Del Brutto criterions are helpful to make the diagnosis of neurocysticercosis. In this case, the patient had one major, one minor and one epidemiological criterion making the diagnosis likely. One month later, the patient made a spontaneous full recovery. This case highlights the complexity of diagnosing neurocysticercosis. Indeed, in non-endemic zones, the symptoms of our patient could be explained by many other diagnostics: partial onset seizures, strokes, cranial trauma, drugs or alcohol abuse, hypoglycemia, other infections with brain calcifications, peritraumatic dissociation, etc. Retrospective or prospective studies could be helpful to improve its screening, diagnosis, and treatment. On the other hand, to improve our knowledge of-, and database for this disease, it could be suitable to class it as a notifiable disease.