Mild encephalopathy/encephalitis with a reversible splenial lesion (MERS): A report of five neonatal cases

Abstract

Mild encephalopathy/encephalitis with a reversible splenial (MERS) lesion is a clinic-radiological entity. The clinical features of MERS in neonates are still not systemically reported. This paper presents five cases of MERS, and the up-to-date reviews of previously reported cases were collected and analyzed in the literature. Here we describe five cases clinically diagnosed with MERS. All of them were neonates and the average age was about 4 days. They were admitted for the common neurological symptoms such as hyperspasmia, poor reactivity and delirium. Auxiliary examinations during hospitalization also exhibited features in common. In this report, we reached following conclusions. Firstly, magnetic resonance imaging revealed solitary or comprehensive lesions in the splenium of corpus callosum, some of them extending to almost the whole corpus callosum. The lesions showed low intensity signal on T1-weighted images, homogeneously hyperintense signal on T2-weighted images, fluid-attenuated inversion recovery and diffusion-weighted images, and exhibited an obvious reduced diffusion on apparent diffusion coefficient map. Moreover, the lesions in the magnetic resonance imaging disappeared very quickly even prior to the clinical recovery. Secondly, all the cases depicted here suffered electrolyte disturbances especially hyponatremia which could be easily corrected. Lastly, all of the cases recovered quickly over one week to one month and majority of them exhibited signs of infections and normal electroencephalography.

Keywords

mild encephalopathy/encephalitis with a reversible splenial lesion / neonate / magnetic resonance imaging

References

[1] Garcia-Monco JC, Cortina IE, Ferreira E, et al. Reversible splenial lesion syndrome (RESLES): What’s in a name? J Neuroimaging, 2011,21(2):e1-14

[2] KashiwagiM, TanabeT, ShimakawaS, et al. . Clinico-radiological spectrum of reversible splenial lesions in children. J Brain Dev, 2014, 36(4): 330-336

[3] TadaH, TakanashiJ, BarkoviehAJ, et al. . Clinically mild encephalitis/encephalopathy with a reversible splenial lesion. Neurology, 2004, 63(10): 1854-1858 PMID: 15557501

[4] TakanashiJ. Two newly proposed infectious encephalitis/ encephalopathy syndromes. Brain Dev, 2009, 31(7): 521-528 PMID: 19339128

[5] ZhangY, ChenWA, YongBI, et al. . Clinical study of 107 patients with clinically mildly encephalitis/encephalopathy accompanied by a reversible splenium lesion of corpus callosum. Zhongguo Quanke Yixue (Chinese), 2014, 12(6): 875-878

[6] KashiwagiM, TanabeT, ShimakawaS, et al. . Clinico-radiological spectrum of reversible splenial lesions in children. J Brain Dev, 2014, 36(4): 330-336

[7] ZhaoL, WuY, GuoM, et al. . Clinically mild encephalitis/ encephalopathy with a reversible splenial lesion of corpus callosum in a child and literature review. Zhong Hua Er Ke Za Zhi (Chinese), 2014, 52(3): 218-222

[8] HuangZJ, ZhouMH, WangB, et al. . Analysis on the clinical features of three patients with reversible lesions of the corpus callosum syndrome. Zhongguo Shenjing Mianyixue He Shenjingbingxue Zazhi, 2014, 21(1): 16-19

[9] TakanashiJ, AtsushiI, FumioH, et al. . Differences in the time course of splenial and white matter lesions in clinically mild encephalitis/encephalopathy with a reversible splenial lesion. J Neurol Sci, 2010, 292(2): 24-27 PMID: 20236662

[10] HashimotoY, TakanashiJ, KaihoK, et al. . A splenial lesion with transiently reduced diffusion in clinically mild encephalitis is not always reversible: A case report. J Brain Dev, 2009, 31(9): 710-712

[11] SatoT, UshirodaY, OyamaT, et al. . Kawasaki disease-associated MERS: pathological insights from SPECT findings. J Brain Dev, 2012, 34(7): 605-608

[12] MiyataR, TanumaN, HayashiM, et al. . Oxidative stress in patients with clinically mild encephalitis/encephalopathy with a reversible splenial lesions (MERS). J Brain Dev, 2012, 34(2): 124-127