Clinically mild encephalitis/encephalopathy with a reversible splenial lesion

Abstract

The clinical features among the affected patients were nearly identical, consisting of relatively mild CNS manifestations and complete recovery within 1 month.

Isolated Reversible Splenial Lesion in Adult Meningitis: A Case Report and Review of the Literature

“…Recently, similar MRI findings have been reported in some patients with mild encephalitis and encephalopathy (5)(6)(7)(8)(9)(10)(11)(12)(13) (Fig. 1).…”

Encephalopathy with Isolated Reversible Splenial Lesion of the Corpus Callosum

“…Resolution of splenial abnormalities was usually noted within one week on follow-up MR studies, and a complete recovery was obtained within one month. The associated pathogens were varied, including O-157 Escherichia coli (8), measles virus (9), rotavirus (10), Salmonella enteritidis (11), influenza virus (7,12), Legionella pneumophila (13), adenovirus, mumps virus, varicella-zoster virus and an unknown pathogen, however the pathogen was not clarified in 10 of 15 patients (7). It is unknown why the splenium is involved as an isolated site.…”

“…It is unknown why the splenium is involved as an isolated site. The pathogenesis is speculated to involve pathogens or antibodies induced by them that directly damage axons or the myelin sheath in the splenium of the corpus callosum (7,8,10), and the participation of elevated inflammatory cytokines such as interleukin-6 is also postulated in the pathogenesis (7,12). However, these hypotheses remain controversial.…”

Mild Encephalitis/Encephalopathy With a Reversible Splenial Lesion: Evaluation by Diffusion Tensor Imaging -Three Case Reports-

“…3,5,8,[10][11][12][13] MERS is defined as a radiologically reversible lesion in the corpus callosum involving at least the splenium. Patients with MERS have reversible symptoms such as impermanent conscious disturbance and seizures, and generally recover completely within a week.…”

“…3,5,8,10,12,13) The findings in the early phase disappear mostly within a few days with the resolution of symptoms. 3,5,8,10,12,13) MERS has been increasingly reported, but only one case of MERS has involved decrease in size of the splenial lesion over 5 months in T 2 -weighted imaging. 2) In contrast, most hyperintense lesions on diffusion-weighted imaging with decreased ADC values, including cerebral infarction and contusional lesions due to trauma, are irreversible.…”