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High-Resolution 3D Imaging of Rabies Virus Infection in Solvent-Cleared Brain Tissue
Published on: April 30, 2019
MR imaging in human rabies
Jiraporn Laothamatas1, Thiravat Hemachudha, Erawady Mitrabhakdi
1Department of Radiology, Ramathibodi Hospital, Bangkok 10400, Thailand.
Background And Purpose:
Whether human rabies of different forms, encephalitic (furious) and paralytic (dumb), share similar MR imaging patterns is unknown. We assessed the diagnostic value of MR imaging in both forms of the disease and compared the clinical and neuroimaging findings.
Methods:
Three patients with paralytic and two with encephalitic rabies were examined during preserved or deteriorated levels of consciousness. Six MR examinations of the brain, three of the spinal cord, and one of the brachial plexus were performed with a 1.5-T superconducting magnet.
Results:
No difference was noted between the MR findings in both clinical forms of human rabies. Nonenhancing, ill-defined, mild hyperintensity changes in the brain stem, hippocampi, hypothalami, deep and subcortical white matter, and deep and cortical gray matter were demonstrated on T2-weighted images in the noncomatose patients with rabies. Enhancement along the brachial plexus of the bitten arm was noted in one patient with encephalitic rabies who at that time had only local neuropathic pain symptoms. Enhancement with gadolinium-based contrast material was seen at the hypothalami, brain stem nuclei, spinal cord gray matter, and intradural cervical nerve roots only when the patients became comatose.
Conclusion:
Both forms of human rabies share a similar MR imaging pattern. Such pattern and the lack of enhancement in a noncomatose patient with suspected encephalitis may differentiate rabies from other viral encephalitides.
Insights
Human rabies, both encephalitic and paralytic forms, show similar MR imaging patterns. This pattern, especially the lack of enhancement in noncomatose patients, can help differentiate rabies from other viral encephalitides.
Area of Science:
- Neurology
- Radiology
- Infectious Diseases
Background:
- Human rabies presents in encephalitic (furious) and paralytic (dumb) forms.
- The similarities and differences in MR imaging patterns between these forms are not well understood.
- Assessing MR imaging's diagnostic value in both forms is crucial.
Purpose of the Study:
- To determine if encephalitic and paralytic rabies share similar MR imaging patterns.
- To evaluate the diagnostic utility of MR imaging in human rabies.
- To compare clinical and neuroimaging findings in different rabies forms.
Main Methods:
- MR imaging of the brain, spinal cord, and brachial plexus was performed on five patients (two encephalitic, three paralytic).
- Examinations were conducted using a 1.5-T superconducting magnet.
- Patients' levels of consciousness were assessed during imaging.
Main Results:
- No significant differences in MR imaging findings were observed between encephalitic and paralytic rabies.
- Noncomatose patients showed nonenhancing, ill-defined hyperintensities in various brain regions (brain stem, hippocampi, white/gray matter).
- Contrast enhancement in the brain, spinal cord, and nerve roots was observed only in comatose patients.
Conclusions:
- Encephalitic and paralytic rabies exhibit similar MR imaging characteristics.
- The observed MR imaging pattern, particularly the absence of enhancement in noncomatose patients, may help distinguish rabies from other viral encephalitides.
