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MR Imaging Patterns and Prognosis in Powassan Virus Encephalitis
1Department of Neurology, Hartford Hospital and University of Connecticut School of Medicine, Hartford, CT.
Background:
Powassan virus (POWV) encephalitis is an arbovirus infection and the only tick-borne encephalitis serogroup which is present in mainland North America. The magnetic resonance (MR) imaging described with POWV encephalitis is varied, nonspecific, and limited in number, and as such, imaging patterns and outcomes with this arbovirus infection are not well appreciated.
Methods:
A case report and literature review of the MR imaging associated with POWV encephalitis and correlate of the MR pattern with outcome is considered.
Results:
The cerebellar dominant MR imaging pattern was identified in 50% of POWV encephalitis cases and was associated with a 60% fatality rate. POWV encephalitis with prominent cerebellar involvement on MR imaging responded to intravenous steroid.
Conclusions:
A cerebellar dominant MR pattern in POWV encephalitis was common, associated with a poor prognosis, and recognition could change management from supportive to life-saving.
Insights
Powassan virus (POWV) encephalitis, a North American tick-borne illness, often shows a cerebellar-dominant pattern on MR imaging. This pattern is linked to poor outcomes but may respond to steroids.
Area of Science:
- Neurology
- Infectious Diseases
- Radiology
Background:
- Powassan virus (POWV) encephalitis is a significant arbovirus infection endemic to North America.
- It is the sole tick-borne encephalitis serogroup found in mainland North America.
- Current understanding of MR imaging patterns and outcomes in POWV encephalitis is limited due to varied and nonspecific findings.
Conclusions:
- A cerebellar-dominant MR imaging pattern is a common finding in Powassan virus encephalitis.
- This pattern indicates a poor prognosis.
- Early recognition of this MR pattern can guide management, potentially shifting from supportive care to life-saving interventions.
