Diffusion-Weighted Magnetic Resonance Imaging in Rhombencephalitis due to Listeria

Transcription

1 cta Radiologica ISSN: (Print) (Online) Journal homepage: Diffusion-Weighted Magnetic Resonance Imaging in Rhombencephalitis due to Listeria monocytogenes H. G. Hatipoglu, M. Onbasioglu Gurbuz,. Sakman & E. Yuksel To cite this article: H. G. Hatipoglu, M. Onbasioglu Gurbuz,. Sakman & E. Yuksel (2007) Diffusion-Weighted Magnetic Resonance Imaging in Rhombencephalitis due to Listeria monocytogenes, cta Radiologica, 48:4, To link to this article: Published online: 04 ug Submit your article to this journal rticle views: 363 Full Terms & Conditions of access and use can be found at

2 CSE REPORT CT RDIOLOGIC Diffusion-Weighted Magnetic Resonance Imaging in Rhombencephalitis due to Listeria monocytogenes H. G. HTIPOGLU, M.ONSIOGLU GURUZ,.SKMN &E.YUKSEL Department of Radiology, nkara Numune Education and Research Hospital, nkara, Turkey Hatipoglu HG, Onbasioglu Gurbuz M, Sakman, Yuksel E. Diffusion-weighted magnetic resonance imaging in rhombencephalitis due to listeria monocytogenes. cta Radiol 2007;48: We present diffusion-weighted imaging findings of a case of rhombencephalitis due to Listeria monocytogenes. It is a rare, life-threatening disorder. The diagnosis is difficult by clinical findings only. In this report, we aim to draw attention to the role of conventional and diffusion-weighted magnetic resonance imaging findings. To our knowledge, this is the first case report in the literature with apparent diffusion coefficient values of diseased brain parenchyma. Key words: dults; brain/brain stem; CNS; infection; MR diffusion/perfusion Hatice Gul Hatipoglu, Maresal Fevzi Cakmak cad, 64/, esevler, nkara, Turkey (tel , fax , . gulhatip@yahoo.com) Listeria monocytogenes constitutes 1 2% of all bacterial meningitis cases (6). The mortality rate is 19 50% (2). Early diagnosis can decrease the morbidity and mortality of this pathogen (1). Central nervous system listeriosis is a diagnostic and therapeutic challenge to the clinician. In this report, we aim to draw attention to the role of conventional and diffusion-weighted magnetic resonance imaging (MRI) findings. To our knowledge, this is the first case report in the literature with apparent diffusion coefficient values of the diseased brain parenchyma. Case report 19-year-old man presented to the emergency room with vertigo, diplopia, nausea, vomiting, and fever. His complaints began after an upper respiratory tract infection a week previous. His medical history was unremarkable. The neurological examination revealed effacement of the right nasolabial sulcus, hypoesthesia on the right side of the face, ataxia, and nystagmus. Computerized tomography (CT) of the head was normal on admission. fter a couple of days, his neurological condition deteriorated to a comatose state. MRI images were obtained with a 1.5T machine (Excite; GE Medical Systems, Milwaukee, Wisc., US). The diffusion-weighted imaging (DWI) sequence was echo planar single-shot spin echo. The images were obtained by using two different b values (0 and 1000 s/mm 2 ). The apparent diffusion coefficient (DC) values were measured automatically. There were signal changes in the medulla oblongata, pons, cerebellar pedincules, medial longitudinal fasciculus, and cerebellar hemisphere on the right side, which was hypointense on T1- weighted images (Fig. 1 and ) and hyperintense on T2-weighted and FLIR images (Fig. 2 and ). fter contrast administration, there was patchy enhancement (Fig. 3 and ). The lesions, which were hyperintense on DWI (Fig. 4), were hypointense on DC map (Fig. 4). The average DC value was s/mm 2, with a standard deviation of The average diffusion signal intensity was , with a standard deviation of The average DC and diffusion signal intensity values for normal parenchyma on the contralateral side were s/mm 2 and , respectively. These measurements, both for DC and diffusion signal intensity, were calculated by one operator with a 24 mm 2 region of interest. The neuroradiological diagnosis was Listeria rhombencephalitis. The CSF culture confirmed the diagnosis. Treatment was rearranged with appropriate antibiotics. His condition improved significantly. He has since been on a physical therapy program for the neurological sequela. DOI / # 2007 Taylor & Francis

3 Diffusion-Weighted MRI in Rhombencephalitis due to Listeria monocytogenes 465 Fig. 1.,. T1-weighted axial images demonstrate hypointense regions in the medulla oblongata, medial longitudinal fasciculus, pons, and cerebellar pedincules on the right side, with some extension to the cerebellum (arrows). Note the arachnoid cyst in the left anterior temporal region. Discussion Listeria monocytogenes is a rare form of rhombencephalitis (6). It is a life-threatening disease (2). Early diagnosis is crucial for treatment (1). Listeria rhombencephalitis is not only seen in immunocompromised but also healthy individuals. The disease is more common in neonates, the elderly, and the debilitated. It is less commonly seen in young adults who have been exposed to farm animals and contaminated food (9). Listeria infection has a biphasic course. It is often misdiagnosed initially because the prodromal symptoms are nonspecific. The prodromal symptoms include fever, headache, and vomiting. In a week, brainstem findings predominate (6, 9). Gram stain and culture of the Fig. 2. T2-weighted () and FLIR () images demonstrate hyperintense regions in the pons and cerebellar pedincules on the right side (arrows). cta Radiol 2007 (4)

4 466 H. G. Hatipoglu et al. Fig. 3. Note the patchy contrast enhancement in the brainstem on the axial () and sagittal () post-contrast T1-weighted images (arrows). cerebrospinal fluid are negative in most cases, which may lead to a delay in diagnosis and treatment (9). CT findings are usually normal (1, 10). eamhardening artifacts limit visualization of the brain stem. In one study, CT findings of six out of 13 patients were normal in spite of brainstem involvement (10). MRI findings were first reported by JUST et al. in 1987 (6). In reported cases, lesions have been hypointense on T1- and hyperintense on T2- weighted images (1, 6, 9, 10). We noted similar signal changes. The lesions are usually confined to the brainstem and cerebellum (1, 2, 5 10). The temporal and frontal lobes are rarely involved. This might lead to misdiagnosis as herpes encephalitis (8). In this report, the lesions were solely located in the brainstem and cerebellum. The differential diagnosis is broad, including viral encephalitis, lymphoma, vasculitic diseases, neurosarcoidosis, tuberculosis, and brain tumors (1, 8). Lesions might be confused with multiple sclerosis plaques (5). Fig. 4. Diffusion weighted image () and DC map () demonstrate a nodular lesion with diffusion restriction in the brain stem (arrows). cta Radiol 2007 (4)

5 Diffusion-Weighted MRI in Rhombencephalitis due to Listeria monocytogenes 467 Spinal cord involvement has been also reported (7). ENITO-LEON et al. (3) first reported the DWI findings of Listeria rhombencephalitis. We noted several nodular lesions in the brainstem with significantly restricted diffusion. These lesions were markedly hyperintense on DWI images and hypointense on DC map. The DC values were lower than in the normal corresponding brain parenchyma and were consistent with a necrotic process, probably an abscess. The brain abscess was reported to be hyperintense on DWI (4). This might be an important finding to differentiate the lesions from tumoral processes in selected cases. The regions with diffusion restriction were surrounded by hyperintense signal intensity on DWI, DC map, and T2- weighted images, which most likely denotes edema consistent with T2 shine through. In conclusion, central nervous system listeriosis is a rare disease with a high mortality rate. Therefore, early magnetic resonance imaging may be warranted to avoid delay in diagnosis and treatment. Diffusion-weighted imaging findings might be useful for early detection of necrotic foci. References 1. lper G, Kneppel L, Kanal E. MR findings in listerial rhombencephalitis. m J Neuroradiol 1995;17: rmstrong RW, Fung PC. rainstem encephalitis (rhombencephalitis) due to Listeria monocytogenes: case report and review. Clin Infect Dis 1993;16: enito-leon J, lvarez-linera J, Jimenez L, Varela M. Diagnostic usefulness of diffusion-weighted magnetic resonance imaging in listerial rhombencephalitis. Eur J Neurol 2002;9: Castillo M. Imaging brain abscesses with diffusionweighted and other sequences. m J Neuroradiol 1999;20: Falini, Kesavadas C, Pontesilli S, Rovaris M, Scotti G. Differential diagnosis of posterior fossa multiple sclerosis lesions neuroradiological aspects. Neurol Sci 2001;Suppl 22: Just M, Kramer G, Higer HP, Thomke F, Pfannenstiel P. MRI of Listeria rhombencephalitis. Neuroradiology 1987;29: King SJ, Jeffree M. MRI of an abscess of the cervical spinal cord in a case of Listeria meningoencephalomyelitis. Neuroradiology 1993;35: Protopsaltis J, Kokkoris S, restas PS, Chrysos G, Salvanos L, Samara C, et al. Neurolisteriosis mimicking herpes simplex encephalitis in an immunocompromized patient. Scand J Infect Dis 2006;38: Salgado MJ, Damani NN, Llewellyn CG, Maloney WJ, Vandorpe R, Sangalang VE. Magnetic resonance imaging of the brain stem and cerebellum complicating Listeria monocytogenes rhombencephalitis. Can ssoc Radiol J 1996;47: Uldry P, Kuntzer T, ogousslavsky J, Regli F, Miklossy J, ille J, et al. Early symptoms and outcome of Listeria monocytogenes rhombencephalitis: 14 adult cases. J Neurol 1993;240: cta Radiol 2007 (4)