Post-COVID-19 myelopathy
General description
The coronavirus disease 2019 (COVID-19) pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is primarily recognized as a respiratory illness. However, a substantial body of evidence has established its capacity to affect multiple organ systems, including the central and peripheral nervous systems. Neurological manifestations are observed in a significant proportion of patients, ranging from common symptoms such as anosmia and headache to severe, life-altering syndromes including stroke, encephalopathy, and acute disseminated encephalomyelitis (ADEM).
Among these neurological sequelae, myelopathy—an inflammatory disorder of the spinal cord—has emerged as a relatively rare but often severe complication. Post-COVID-19 myelopathy typically presents as acute inflammatory myelopathy (AIM) or acute transverse myelitis (ATM), an immune-mediated condition affecting motor, sensory, and autonomic pathways of the spinal cord.
References
- Okumura, Motohiro, et al. "‘Grasshopper sign’: the novel imaging of post-COVID-19 myelopathy with delayed longitudinal white matter abnormalities." BMJ Neurology Open 6.1 (2024): e000730.
Grasshopper sign (Antennae)
On coronal images of the brain, the sign manifests as bilateral hyperintense signals on T2 and FLAIR imaging along the corticospinal tracts. These lesions extend from the posterior limb of the internal capsules up into the corona radiata, resembling a grasshopper's antennae.
Grasshopper sign (Face)
On axial T2-weighted images of the spinal cord, the sign is characterized by bilateral, symmetric hyperintensity in the dorsal (posterior) and lateral white matter columns. This pattern gives the appearance of a grasshopper's face.