A case of MERS presenting with acute motor aphasia and tetraparesis and literature review

Mild encephalopathy wıth reversible splenial lesions (MERS) are a clinical–radiological diagnosis that can be diagnosed with radiological imaging and can be accompanied by impaired consciousness, aphasia, headache, and paralysis. MERS can be divided into two different types based on radiological findings; Involvement of the splenium is seen in type 1, and involvement of the splenium and deep white matter is seen in type 2. MERS Type 2 is very rare in adults. Here, we describe a patient diagnosed with MERS Type 2 and our therapeutic intervention. A 22-year-old woman presented with slurred speech, weakness in the extremities and headache that started 14 h ago. The patient had sore throat and fever of 37.6 °C for 2 days, and medical history or family history were unremarkable. Neurological examination revealed that she was conscious, cooperative, with no signs of meningeal irritation. Speech comprehension, naming, and repetition were preserved, motor examination revealed 5/5 left upper extremity strength, 4/5 right upper extremity strength, and 2/5 bilateral lower extremity strength. Diffusion-weighted magnetic resonance imaging (MRI-DWI) revealed bilateral deep white matter and splenium symmetrical diffusion restriction. Blood tests showed high C-reactive protein (CRP) and no leukocytosis. No cells were detected in the cerebrospinal fluid (CSF), protein was 151 mg/dl, glucose was within normal limits. The patient, who developed quadriparesis during follow-up, was started on pulse dose steroids. Neurological examination improved to patient’s baseline at the 12th hour of treatment. In the 72nd hour control MRI-DWI, it was seen that the lesions had regressed. Culture/Polymerase chain reaction (PCR) for bacterial/viral infection agents came back negative. After steroids were given for 5 days, patient was discharged at her baseline. MERS is a rare diagnosis in adults and can be radiologically confused with acute toxic leukoencephalopathy. It can be distinguished clinically by the absence of prior infection, fever, and toxic agent exposure. Although there is no consensus in the literature regarding the treatment, the clinical picture improved rapidly after steroid in our case. Despite being rare, it should be considered in the differential diagnosis of patients with deep white matter lesions in adults.