[Listeria monocytogenes encephalitis revealed by left progressive hemiparesis].

BACKGROUND

Central nervous system listeriosis is a diagnostic and therapeutic challenge for the clinician.

METHODS

We report the case of a 66-year-old woman who was admitted for a left progressive hemiparesis associated with headaches. She was treated for one year by immunosuppressive drugs for vulgaris pemphigus. At the time of admission, examination revealed left hemiparesis without fever, and a computed tomography brain scan demonstrated a focal lesion in the right frontal lobe. Blood analyses were normal. Two days after, she suddenly developed fever (40 degrees C), and aggravation of her motor deficit followed by partial motor seizures. The cerebrospinal fluid was normal. Treatment with amoxicillin (3g IV q6h), cefotaxim, gentamycin (120mg IV q12h) and aciclovir was started empirically. The brain MRI without gadolinium displayed infiltrative lesions in the right hemisphere and in the mildbrain. The blood culture grew Listeria monocytogenes. The antimicrobial regimen was changed to amoxicillin for seven weeks and gentamicin for the first ten days. Four days after beginning the antimicrobial regimen, the brain MRI with gadolinium displayed several abscesses measuring less than one cm diameter. The clinical and imaging outcome excellent.

CONCLUSIONS

Meningitis is by far the most central nervous system listeriosis. In our patient, the diagnosis of listeria monocytogenes encephalitis was established on the basis of positive blood cultures, as such patients do not have sterile cerebrospinal fluid.