Adam E. Klein, MD - West Virginia State Medical Association

| Scientific Articleabscesses occurred within amonth of diagnosis and while thepatient was taking appropriateantibiotics. 3 Only one patient whodied from a listerial abscess had aneurosurgical procedure, whichlikely points to the importance ofsurgical drainage of these lesions. 3Treatment often includesneurosurgical drainage of lesionsgreater than 2.5 cm in size. 3Antimicrobial therapy mustalso be initiated, with the mosteffective treatment reported in theliterature being ampicillin withgentamycin. 1,2,3,4,5 Relapse in onepatient was attributed to treatmentwith ampicillin alone, although tworeported patients were successfullytreated with this regimen. 1 Secondlineagents include vancomycin andBactrim. 1,2,3 Duration of therapy hasbeen reported from two weeks to14 months. 3 Due to the toxicity ofgentamycin, it was decided to treatour patient with an 8 week course ofampicillin alone. She did well withthis treatment and follow up MRIdemonstrated resolution of the lesion,and her symptoms did not return.The pathology of listerialabscesses has not beenwell‐characterized, howeverseveral studies have examinedthe pathological appearance oflisterial rhombencephalitis in bothhumans and ruminants. 6,7 Listerialrhombencephalitis is thought tooccur through a unique mechanismof infection through injured oralmucosa with retrograde axonaltransport along cranial nerves. 6Pathological studies of these caseshave revealed microglial cells as wellas microabscesses with neutrophilsand macrophages. 6,7 Occasionalnecrotic neurons and neuronophagiawere also present. 6,7 Significant to ourcase, microglial nodules were seen inseveral cases, consisting of microglialcells and T-lymphocytes. 6 Microglialnodules are rare in brain abscessesdue to other infectious etiologies.ConclusionListerial brain abscesses are anunusual neurologic manifestation ofListeria infection. These infectionsmay have a complicated clinical andpathological picture. The propensityto occur in the immunocompromisedhost has been recognized, and inparticular, this infection can occur inthe settings of diabetes mellitus andCOPD, two common predisposingconditions found in West Virginia.References1. Mylonakis E, Hohmann EL, CalderwoodSB. Central nervous system infection withListeria monocytogenes: 33 years’experience at a general hospital and reviewof 776 episodes from the literature.Medicine 1998; 77: 313-36.2. Cone LA, Leung MM, Byrd RG, et al.Multiple cerebral abscesses because ofListeria monocytogenes: Three case reportsand a literature review of supratentoriallisterial brain abscesses. SurgicalNeurology 2003; 59: 320-8.3. Eckburg PB, Montoya JG, Vosti KL. Brainabscess due to Listeria moncytogenes: Fivecases and a review of the literature.”Medicine 2001; 80: 223-35.4. Cone LA, Somero MS, Qureshi FJ, et al.Unusual infections due to Listeriamonocytogenes in the southern Californiadesert. International Journal of InfectiousDiseases 2008; 12: 578-81.5. Soares-Fernandes JP, Beleza P, CerqueiraJJ, et al. Simultaneous supratentorial andbrainstem abscesses due to Listeriamonocytogenes. Journal of Neuroradiology2008; 35: 173-6.6. Antal EA, Loberg EM, Dietrichs E, at al.Neuropathological findings in 9 cases ofListeria monocytogenes brain stemencephalitis. Brain Pathology 2005;15:187-91.7. Oevermann A, Zurbriggen A, VandeveldeM. “Rhombencephalitis caused by Listeriamonocytogenes in humans and ruminants:A zoonosis on the rise? InterdisciplinaryPerspectives on Infectious Disease 2010.1-22.Your Practice.Your Future.Your Agency.In case it’s notthis obvious...1.800.257.4747, ext. 22 » 304.542.0257July/August 2012 | Vol. 108 15