A Case Report of a Boy With Clinically Mild Encephalopathy and a Reversible Splenial Lesion Associated With Severe Acute Respiratory Syndrome-Coronavirus 2 Infection.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is associated with a high frequency of central nervous system abnormalities, particularly acute encephalopathy, in children. We report the case of a nine-year-old boy with SARS-CoV-2-associated clinically mild encephalopathy with a reversible splenial lesion. The patient was admitted to our hospital with fever, vomiting, and poor speech. The patient tested positive for SARS-CoV-2 by polymerase chain reaction of a nasal swab sample. The cerebrospinal fluid cell count was normal. The patient had a low serum sodium level upon admission. Computed tomography of the brain revealed mild cerebral edema. Diffusion-weighted magnetic resonance imaging (MRI) revealed transient abnormally high signal intensity in the splenium of the corpus callosum. Electroencephalography revealed generalized high-voltage slow waves. The patient was clinically diagnosed with mild encephalopathy and a reversible splenial lesion associated with SARS-CoV-2 infection. The patient was discharged without any neurological sequelae. In conclusion, it is useful to perform MRI evaluations in children with SARS-CoV-2 infection and impaired consciousness, poor speech, and behavior, considering the possibility that they may be in the early stages of encephalopathy.