Histopathology of Listeria Meningitis.

Listeria monocytogenes meningitis is the third most common cause of bacterial meningitis in adults and has high mortality and morbidity rates. We describe the clinical course and score brain pathology of 5 patients who died of listeria meningitis. All patients were immunocompromised and ages ranged between 48 and 76 years. Three cases were confirmed by cerebrospinal fluid culture; one was confirmed by brain culture; and one diagnosis was based on a positive blood culture and neuropathological findings. Mild inflammation of meningeal arteries was found in 3 of 5 cases (60%). Moderate/severe ventriculitis was seen in 4 of 4 cases (100%), abscesses in 3 of 4 cases (75%), mild vascular inflammation in 4 of 5 cases (80%), mild/moderate hemorrhage in 2 of 4 cases (50%), mild/moderate thrombosis of meningeal artery in 3 of 5 cases (60%), and 1 case (25%) showed a moderate infarct. The inflammatory cells present in the meninges were characterized by a mix of monocytes, macrophages, and neutrophils and removal of apoptotic inflammatory cells by macrophages (efferocytosis). Gram stain showed intra- and extracellular presence of rod-shaped bacteria in 3 cases. Pathological examination was characterized by moderate to severe ventriculitis, abscesses and abundant efferocytosis which has been suggested to be exploited by L. monocytogenes for cell-to-cell spread.

Early trigeminal nerve involvement in Listeria monocytogenes rhombencephalitis: case series and systematic review.

Listeria monocytogenes is associated with rhombencephalitis. However, the exact mechanisms of brainstem invasion remains poorly understood. Here, we demonstrate clinical and radiological data suggesting that Listeria may invade the brainstem via the trigeminal nerve. Three females (41, 64 and 70 years) with culture proven L. monocytogenes bacteremia and rhombencephalitis were investigated in the period of 2014-16. T2-weighted and contrast-enhanced T1-weighted MRI revealed a cerebellopontine abscess in all three patients, including the involvement of the trigeminal nerve root. In two patients, MRI also revealed selective contrast enhancement of the sensory trigeminal tract in the pons and medulla oblongata. Prior to any other neurological symptoms, two patients complained of hypoesthesia and a tingling sensation in the ipsilateral half of the face, consistent with sensory trigeminal nerve dysfunction on that side. In addition, we identified another 120 cases of Listeria rhombencephalitis following a systematic review. Cranial nerves VII, V, IX, and X, respectively, medulla oblongata, cerebellum and pons, were the most frequently involved brain structures. The present clinical and radiological findings corroborate earlier data from animal experiments, indicating that L. monocytogenes may be capable of retrograde intra-axonal migration along the cranial nerves. We suggest that in a subset of patients with rhombencephalitis L. monocytogenes enters the cerebellopontine angle through the trigeminal nerve, invading the brainstem via the sensory trigeminal nuclei.

Transcranial Color-Coded Duplex in Acute Encephalitis: Current Status and Future Prospects.

BACKGROUP AND PURPOSE: There are limited data regarding the diagnostic yield of transcranial color-coded Doppler (TCCD) in acute encephalitis. We present our preliminary observations of consecutive ultrasound evaluations in 2 patients with acute encephalitis and we review the possible diagnostic role of TCCD in such cases. METHODS: We describe two cases of acute encephalitis that presented with aphasia and confusion and underwent repeat TCCD evaluation at baseline and after 48 hours in both patients. We also critically review the current literature regarding potential TCCD applications in acute central nervous system infections. RESULTS: Serial TCCD evaluations revealed the following triad of abnormal findings in both patients: (i) elevated pulsatility index (PI) in the left middle cerebral artery (M1 MCA) at baseline (>1.2), (ii) increased PI in left M1 MCA by >25% in comparison to right M1 MCA, and (iii) decrease in PI in left M1 MCA by >25% at the follow-up evaluation at 48 hours. The decrease in PI in left M1 MCA coincided with symptom improvement in both patients. DISCUSSION: The focal transient increase in left M1 MCA PI may be attributed to focally increased intracranial pressure or peripheral vasospasm of distal left MCA branches. Since there are limited reports in the literature concerning TCCD evaluation of patients with central nervous system infections, our preliminary findings require independent confirmation in a larger series of patients.

[Solitary listerial abscess of the brain stem. Cure with antibiotic treatment]. / Abcès listerien solitaire du tronc cérébral. Guérison sous traitement antibiotique.

A healthy 26-year-old man, without initially presenting fever, rapidly developed a focal right pontomedullary deficit associated with an aseptic lymphocytic meningitis. The diagnosis of Listeria infection was confirmed by blood cultures. CT and MRI demonstrated an abscess extending from the superior cerebellar peduncle to the lateral portion of the medulla. Immunological controls gave no indication of deficiency. With ampicillin therapy, started on the 5th day, clinical recovery was almost complete, but a soft palate right paresis persisted as the unique sequel. Antibiotic therapy was maintained for 5 months up to normal CSF and CT. One year after the onset, MRI was also normal. The rare nature of listerial abscess in the brainstem is discussed with regard to rhombencephalitides.

Computed tomography in bacterial meningitis of childhood.

The hospital records of 85 children with bacterial meningitis were reviewed and a subset of 25 children who underwent computed tomography of the head were identified. The major stated indications for computed tomography were fever (8 patients), seizures (4 patients), signs of increased intracranial pressure (4 patients), focal neurologic dysfunction (3 patients) and recurrent meningitis (2 patients). Abnormal findings were demonstrated by computed tomography in 20 of 25 patients but in 8 patients consisted solely of nonspecific dilatation of spaces containing cerebrospinal fluid or of basilar enhancement. The yield of information that was useful either diagnostically or therapeutically was low; positive findings of obvious clinical relevance were present in only 2 cases. Computed tomography provides an accurate means of diagnosing intracranial complications of bacterial meningitis. It must be used conservatively, however, to limit expense and radiation exposure and enhance the yield of potentially relevant information. Computed tomography is indicated for children with persistent neurologic dysfunction, persistently positive cerebrospinal fluid cultures or recurrent meningitis, whereas it is of little value for children with prolonged fever alone.

Computed tomographic scanning in Listeria monocytogenes meningitis.

Seven adults with Listeria monocytogenes infection of the central nervous system had computed X-ray tomography of the head performed. One patient had a normal scan, three had hydrocephalus; cerebral edema, an arachnoid cyst and hyperemia were each noted in one patient. Atrophy of the vermis of the cerebellum was demonstrated on follow-up scans in two patients. Further studies are necessary to determine whether such atrophy is a frequent sequelae of L. monocytogenes central nervous system infection.