Radiculomyelitic rabies: can MR imaging help?

Abstract

Radiculomyelitic (silent) rabies and acute disseminated encephalomyelitis have similar clinical presentations but distinct management and prognostic implications. It is thus important to differentiate between the two antemortem. Because of their distinct pathologic abnormalities, MR imaging may be helpful in distinguishing between the two entities. We report a case in which MR imaging helped us to diagnose silent rabies antemortem, which was subsequently confirmed at autopsy.

Fig 1.

Axial T2-weighted image of the dorsal spine reveals hyperintensity of central gray matter, with sparing of the white matter.

Fig 2.

Images show cranial extension to symmetrically involve bilateral thalami, hippocampi, basal ganglia, and the dorsal aspect of the brainstem. A, T2-weighted MR image of the brain, obtained at the level of basal ganglia, reveals hyperintensity of the caudate head and lentiform nucleus. B, T2-weighted MR image of the brain, obtained at the level of the pons, reveals hyperintensity of the posterior portion of the pons.

Fig 3.

Perivascular lymphocytic infiltrate and microglial hyperplasia in the cervical cord (hematoxylin and eosin, original magnification ×140). Inset shows positive immunostaining using monoclonal anti-rabies antibodies.