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MRI findings in eastern equine encephalitis: the "parenthesis" sign
Joshua P Nickerson1, Suma Kannabiran1, Heather N Burbank1
1Department of Radiology, University of Vermont Medical Center, 111 Colchester Avenue, Burlington VT 05401, USA.
Clinical Imaging
|March 21, 2016
Summary
Eastern Equine Encephalitis (EEE) brain imaging may show a distinct "( ) parentheses sign" on T2 or FLAIR scans. This unique finding in the external and internal capsules could help differentiate EEE from other neurological conditions.
Area of Science:
- Neurology
- Infectious Diseases
- Radiology
Background:
- Eastern Equine Encephalitis (EEE) is a rare but severe arboviral infection affecting the central nervous system.
- Diagnostic imaging in EEE cases often reveals nonspecific abnormalities, complicating early identification.
Observation:
- Two patients with EEE presented with characteristic T2/FLAIR hyperintensities on brain MRI.
- These hyperintensities were notably observed in the external and internal capsules, with sparing of the lentiform nuclei.
Findings:
- The study identified a unique imaging pattern described as a "( ) parentheses sign" on T2 or FLAIR sequences.
- This specific radiological sign, characterized by linear hyperintensities in the capsules, is proposed as a potential distinguishing feature for EEE.
Implications:
- The proposed "( ) parentheses sign" may serve as a valuable imaging biomarker for the diagnosis of Eastern Equine Encephalitis.
- This finding could aid radiologists and clinicians in differentiating EEE from other encephalitides, potentially leading to earlier treatment and improved patient outcomes.
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