[Meningoencephalitis caused by listeria monocytogenes].

This case report illustrates the difficulties that can arise when diagnosing a CNS infection. Following an episode of gastroenteritis, our patient developed dizziness, a fever up to 39 °C, photophobia, double vision, multiple cranial nerve deficits, and a resting nystagmus with alternating directions, and presented to the emergency department. Blood inflammatory markers were unremarkable, and a contrast-enhanced head CT scan revealed no abnormalities. The patient was discharged home with a provisional diagnosis of Meniere's disease. Two days later, the patient developed increasing lethargy and was transferred by his wife to the central hospital. Clinical evidence of multiple cranial nerve deficits and a central oculomotor disorder, accompanied by impaired consciousness and tetraataxia, were found; neurocranial MRI revealed rhombencephalitis and cervical myelitis, whilst cerebrospinal fluid analysis showed an inflammatory-infectious profile with Listeria monocytogenes cultured from the sample. Magnetic resonance imaging is the examination of choice for the diagnostic imaging of Listeria meningoencephalitis. Identifying the pathogen in the cerebrospinal fluid in cases of neurolisteriosis can be difficult. A relatively normal cerebrospinal fluid glucose level, moderate lymphocytic pleocytosis and a moderately elevated cerebrospinal fluid protein level may be erroneously attributed to a viral or mycobacterial infection. Cerebrospinal fluid cultures are positive in 33-43 % of cases of brainstem encephalitis and in 90 % of cases of meningitis. Listeria monocytogenes causes a neurological infection and usually presents as meningoencephalitis. Around 10 % of patients with bacterial meningitis have cranial nerve involvement, and hearing loss usually resulting from purulent labyrinthitis is observed in approximately 10-20 % of patients.