Rabies encephalomyelitis vs. ADEM: Usefulness of MR imaging in differential diagnosis

Area of Science:

• Neurology
• Infectious Diseases
• Radiology

Background:

• Rabies is a fatal viral disease preventable by vaccination.
• Encephalomyelitis presents with neurological symptoms and can be challenging to diagnose.
• Differentiating rabies from other encephalitides like ADEM is critical for patient management.

Observation:

• A 12-year-old boy developed rabies encephalomyelitis despite receiving post-exposure anti-rabies vaccination.
• Magnetic resonance (MR) imaging was performed to evaluate the neurological condition.
• The imaging findings were compared with the typical patterns of acute disseminated encephalomyelitis (ADEM).

Findings:

• MR imaging demonstrated a clear predilection for grey matter involvement in rabies.
• Rabies showed specific involvement of midline grey matter regions.
• ADEM typically exhibits predominant white matter lesions, distinguishing it from rabies on MRI.

Implications:

• This case underscores the utility of MRI in diagnosing rabies encephalomyelitis, even in vaccinated individuals.
• MRI findings can help differentiate rabies from ADEM, guiding appropriate clinical decisions.
• Early and accurate diagnosis through advanced imaging is vital for managing post-vaccination neurological complications.