Magnetic resonance imaging in herpes simplex encephalitis

Area of Science:

• Neurology
• Radiology
• Infectious Diseases

Background:

• Herpes Simplex Encephalitis (HSE) is a severe neurological condition.
• Accurate early diagnosis is crucial for effective treatment and improved outcomes.
• Conventional imaging techniques like CT may underestimate disease extent.

Purpose of the Study:

• To evaluate the sensitivity of Magnetic Resonance Imaging (MRI) in detecting temporal lobe abnormalities in patients with proven Herpes Simplex Encephalitis (HSE).
• To compare MRI findings with Computed Tomography (CT) scans in HSE diagnosis.
• To assess the utility of MRI in evaluating the extent and nature of HSE lesions.

Main Methods:

• Retrospective analysis of four patients with clinically and serologically confirmed HSE.
• Comparison of MRI findings with prior CT scans.
• Detailed examination of temporal lobe abnormalities, lesion extent, and presence of hemorrhage on MRI.
• Follow-up MRI in one patient to assess long-term changes.

Main Results:

• MRI demonstrated higher sensitivity than CT in detecting temporal lobe abnormalities in HSE.
• MRI revealed lesions to be more extensive than initially suspected on CT.
• Findings were consistent with an acute inflammatory process, with hemorrhage noted in only one patient.
• A previously described CT finding of sharp transition to normal at the lentiform nucleus was found to be less specific for HSE.

Conclusions:

• MRI is a more sensitive imaging modality than CT for the early diagnosis of Herpes Simplex Encephalitis (HSE).
• MRI provides a more accurate assessment of lesion extent and characteristics, aiding in diagnosis and management.
• Persistent MRI signal abnormalities may indicate residual effects of HSE, useful for evaluating long-term disabilities.