Mild Encephalopathy/Encephalitis With Reversible Splenial Lesion Associated With Meningitis Related to Mumps Disease: An Unusual Presentation in a Male Adult
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Updated: Jul 5, 2026

Induction and Clinical Scoring of Chronic-Relapsing Experimental Autoimmune Encephalomyelitis
Published on: July 4, 2007
Aziz Ahizoune1, Yassine El-Adraoui1, Ahmed Bourazza1
1Department of Neurology and Neurophysiology, Mohamed V Military Teaching Hospital, Mohamed V University, Rabat, MAR.
Abstract:
Mild encephalitis/encephalopathy with reversible splenial lesion (MERS) is characterized by mild neurological manifestations associated with spontaneously reversible lesions of the splenium of the corpus callosum. While various conditions and diseases can trigger MERS, infectious causes predominate, with mumps being notably linked to MERS in the pediatric population. Although rare in adults, there are sporadic case reports associating mumps with MERS. Here we report a 23-year-old male patient with a typical presentation of mumps who presented with meningeal syndrome, dizziness, seizures, and right orchitis. Brain MRI showed classic findings of MERS syndrome while cerebrospinal fluid analysis demonstrated lymphocytic pleocytosis. Our patient had a confirmed diagnosis of mumps disease with multiple complications, including MERS, meningitis, and orchitis, and was managed with symptomatic medications and antiviral therapy. Subsequently, there was a gradual resolution of these manifestations and the outcome was favorable, with no residual sequelae.
Insights
Mumps infection can cause Mild Encephalitis/Encephalopathy with Reversible Splenial Lesion (MERS) in adults, a rare but treatable condition. This case highlights favorable outcomes with symptomatic and antiviral treatments.
Area of Science:
- Neurology
- Infectious Diseases
- Radiology
Background:
- Mild Encephalitis/Encephalopathy with Reversible Splenial Lesion (MERS) is a neurological condition characterized by reversible brain lesions.
- Infectious etiologies are common triggers for MERS, particularly mumps in children.
- MERS is infrequently reported in adults, with limited case documentation.
Observation:
- A 23-year-old male presented with mumps, exhibiting symptoms of meningeal syndrome, dizziness, seizures, and orchitis.
- Brain MRI revealed characteristic MERS lesions in the splenium of the corpus callosum.
- Cerebrospinal fluid analysis indicated lymphocytic pleocytosis, consistent with viral meningitis.
Findings:
- The patient was diagnosed with mumps complicated by MERS, meningitis, and orchitis.
- Treatment involved symptomatic management and antiviral therapy.
- Neurological and clinical manifestations showed gradual resolution without sequelae.
Implications:
- This case expands the understanding of mumps as a potential cause of MERS in adults.
- It underscores the importance of considering MERS in adults presenting with neurological symptoms and mumps.
- The favorable outcome emphasizes the effectiveness of timely and appropriate medical intervention.
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