Monkeypox encephalitis with transverse myelitis in a female patient

Abstract

The 2022 monkeypox outbreak has affected 110 countries worldwide, outside of classic endemic areas (ie, west Africa and central Africa). On July 23, 2022, the outbreak was classified by WHO as a public health emergency of international concern. Clinical presentation varies from mild to life-changing symptoms; neurological complications are relatively uncommon and there are few therapeutic interventions for monkeypox disease. In this Grand Round, we present a case of monkeypox with encephalitis complicated by transverse myelitis in a previously healthy woman aged 35 years who made an almost complete recovery from her neurological symptoms after treatment with tecovirimat, cidofovir, steroids, and plasma exchange. We describe neurological complications associated with orthopoxvirus infections and laboratory diagnosis, the radiological features in this case, and discuss treatment options.

Figure 1

Initial MRI scan (A–B) Axial proton density images showing a supratentorial white matter atypicality (arrow, A) and cortical swelling (dotted arrow, A). Swelling of both thalami was noted (arrows, B). (C–D) T2-weighted images showed further hyperintensities within the supratentorial white matter (arrow, C), middle cerebellar peduncle (arrow, D), and brainstem (dotted arrow, D).

Figure 2

Encephalitis changes on MRI of the head (A–E) Axial 3D-FLAIR images showing atypical hyperintensity within the posterior limb of the left internal capsule (arrow, A), bilateral thalami (B), splenium of the corpus callosum (arrow, C), middle cerebellar peduncle (arrow, D), and left side of the medulla (arrow, E). (F–G) Axial T2 sequence highlighting extensive cortical swelling (arrows, F) and resulting early uncal herniation with brainstem mass effect (arrow, G). (H–K) DWI (H, J) and ADC maps (I, K) show patchy, low ADC signal, suggesting reduced diffusivity within the cerebral cortex (arrows, H–I) and the left brachium pontis lesion (arrows, J–K). ADC=apparent diffusion coefficient. DWI=diffusion-weighted imaging. FLAIR=Fluid Attenuated Inversion Recovery.

Figure 3

Transverse myelitis on MRI of the spine (A–B) Sagittal short-tau inversion recovery sequence showing extensive transverse myelitis of the spinal cord with long segments of T2 hyperintensity and cord swelling in the cervicothoracic (arrow, A) and lumbar (arrow, B) cord. (C–D) Pre-contrast and post-contrast sagittal T1 sequences showing avid enhancement of the cauda equina nerve roots. (E–F) Axial T2 through the upper and mid cervical spine showing signal hyperintensity involving central grey and peripheral white matter (arrows). (G–H) Post-contrast axial T1 imaging through the upper and mid cervical spine showing patchy enhancement within the cervical spine (arrows). (I–J) Axial, post-contrast T1 imaging through the cauda equina nerve roots showing enhancement of the cauda equina nerve roots.