Rhombencephalitis caused by Listeria monocytogenes with striking involvement of trigeminal nerve on MR imaging

Abstract

The listeria rhombencephalitis is an uncommon and severe infection of the brainstem, usually occurring in healthy adults with a typical biphasic picture 1 . A prodrome of fever, headache, nausea and vomiting followed by abrupt neurological symptoms 2 . A stiff neck is present in half of the cases and positive culture in cerebrospinal fluid (CSF) in about 40% of the cases. Mortality is high and serious sequelae are common 2 . We report a case of a patient with involvement of the brainstem and a favorable outcome. CASEA 65-year-old man presented with pain in right jaw, nuchal pain and right facial palsy, following gastroenteritis. The neurological exam revealed a palsy of VI and VII right cranial nerves, right hemifacial hypoesthesia, strength grade 3, hyperreflexia, Babinski sign bilaterally, neck stiffness and axial ataxia. The CSF showed: 100 cells/mm 3 (95% lymphocytes); protein 63 mg/dL; glucose 95 mg/dL; negative cultures for bacteria, fungi and acidfast bacilli. Magnetic resonance imaging (MRI) showed bilateral and asymmetric lesions involving the brainstem with a striking enhancement along the right trigeminal nerve and ipsilateral spinal trigeminal nucleus (Figure).With the diagnostic suspicion of herpes zoster encephalitis, the patient was treated with acyclovir and was transferred to an intensive care unit due to respiratory failure 24 hours later.Blood cultures showed the presence of Listeria monocytogenes later. Acyclovir was interrupted and intravenous ampicillin plus dexamethasone were initiated. The infection improved but the patient remained with severe neurological sequelae. The second MRI showed multiple hemorrhagic foci in the cerebellar hemispheres, brainstem, basal ganglia nuclei and capsular region. Mild signal abnormalities remained in the brainstem and cerebellar peduncles.At four months he began walking and making sounds that were gradually replaced by full speech. DISCUSSIONListeria monocytogenes is a Gram-positive organism transmitted by consumption of contaminated food. The diagnosis can be delayed if no meningeal signs are presented in the beginning of the disease 4 as in our patient. Cultures of CSF and blood are positive in 41% and 61% of cases, respectively 3 . In our case only the blood culture was positive.The CSF typically reveals an increased leukocyte count, with predominance of polymorphonuclear cells, increased protein, and normal glucose levels 5 . Our patient presented only a predominance of lymphomononuclear cells, maybe due to precoceous CSF examination.MRI is important for the early detection of parenchymal lesions, therefore, being crucial for early diagnosis and follow-up

Listerial brainstem encephalitis – treatable, but easily missed

“…Computed tomography (CT) is less sensitive than MRI in LBE; [3][4][5] two of five patients in this study had abnormal findings. Striking cranial nerve enhancement may be seen on MRI, [12] or, less often, on CT, and was present in three of our six patients (two MRI, one CT). Radiological appearances are nonspecific, however, and in a region of high tuberculosis prevalence listerial brainstem abscesses may be radiologically indistinguishable from tuberculomas.…”

Listerial Rhombencephalitis in an Immunocompetent Woman

“…Serology is not useful for diagnosis of acute cases, although listeriolysin O antibodies have been used to identify patients with noninvasive illness. As far as diagnostic imaging is concerned, MR imaging is crucial for detection of parenchymal lesions and early diagnosis of this illness: patchy signal hyperintensity throughout the medulla and cerebellar peduncles on T2 weighted images, always in association with a hypointense dot, and numerous gadolinium-enhanced microabscesses in the rhombencephalon [18, 19]. …”

Neuromelioidosis: Craniospinal MRI Findings in Burkholderia pseudomallei Infection

“…Taken together these findings support the hypothesis for direct cranial nerve spread, thereby bypassing the blood brain barrier by B. pseudomallei to access the CNS. Other neurotropic infections such as members of herpesviridae, Borrelia burgdorferi , and Listeria monocytogenes can also involve the cranial nerves, usually manifesting as cranial nerve thickening and enhancement . However, a distinguishing feature in CNS melioidosis is that cranial nerve disease is much more extensive and shows contiguous intraaxial spread into the brain stem, and thus, resulting in microabscesses.…”