PMC6327704_01
Initial magnetic resonance imaging of brain. Axial fluid-attenuated inversion recovery image (a) through the basal ganglia shows symmetric hyperintensity in the thalamus and basal ganglia (arrows). Axial fluid-attenuated inversion recovery image (b) through the posterior fossa shows symmetric hyperintensity in the dorsal pons (arrowhead) and in the cerebellar peduncles (arrows). The axial diffusion-weighted image (c) and the apparent diffusion coefficient map (d) show areas of diffusion restriction in the cerebellar peduncles and pons. The diffusion-weighted images also showed restriction in bilateral basal ganglia (Images not provided)
AIAN-22-111-g001.jpg
PMC6327704_01_AIAN-22-111-g001.jpg
F1
March 2015, in the setting of low-grade fever and sore throat, he had acute unresponsiveness and extensor posturing. Magnetic resonance imaging (MRI) brain revealed prominent and fairly symmetrical T2/fluid-attenuated inversion recovery signal abnormalities in the cerebellar peduncles, thalamus, midbrain and pons, and to a lesser extent in the left caudate [Figure 1].
A 2-month follow-up computed tomography and magnetic resonance imaging studies. Axial noncontrast computed tomography image (a) shows diffuse cerebral parenchymal volume loss and areas of calcification in the posterior aspects of the putamen (arrows). (b) Diffusion-weighted sequence shows normalization of the signal abnormalities in the basal ganglia. Axial fluid-attenuated inversion recovery images (c and d) show residual hyperintensity in the basal ganglia and the middle cerebelar peduncles (arrows)
AIAN-22-111-g002.jpg
PMC6327704_01_AIAN-22-111-g002.jpg
F2
Repeat brain MRI after 2 months showed resolution of restricted diffusion and enhancement, but areas of calcification were seen in the posterior aspects of the putamen [Figure 2].
Repeat magnetic resonance imaging. Axial fluid-attenuated inversion recovery image (a) through the basal ganglia shows extensive hyperintensity in the thalamus, basal ganglia, central and deep white matter, and the corpus callosum. The axial diffusion-weighted images (b) show corresponding areas of diffusion restriction (arrows). (c) The magnetic resonance spectroscopy shows elevated lactate doublet (arrow) and dampening of the NAA (curved arrow) metabolite peaks. (d) Axial postcontrast T1-weighted image shows areas of amorphous enhancement corresponding areas of fluid-attenuated inversion recovery signal abnormality. Notice the posterior putaminal T1 hyperintensity corresponding to the areas of calcification seen on the prior computed tomography scan (image a, Figure 2)
AIAN-22-111-g003.jpg
PMC6327704_01_AIAN-22-111-g003.jpg
F3
Brain MRI showed extensive areas of signal abnormality similar to, but more extensive than, his previous scans in March 2015 during his presumed influenza encephalopathy diagnosis [Figure 3]. Repeat MRI brain with spectroscopy and spinal cord [Figures 3 and 4] revealed extensive spinal cord swelling with hyperintensity of the central gray matter as well as elevated lactate doublet in the spectroscopy.
Sag T2-weighted through the cervical spine (a) and axial T2-weighted through the conus medullaris (b) show spinal cord swelling and hyperintensity of the central cord matter. Postcontrast T1-weighted of the cervical spine (c) and lumbar spine (d) show focal areas of intramedullary enhancement
AIAN-22-111-g004.jpg
PMC6327704_01_AIAN-22-111-g004.jpg
F4
Repeat MRI brain with spectroscopy and spinal cord [Figures 3 and 4] revealed extensive spinal cord swelling with hyperintensity of the central gray matter as well as elevated lactate doublet in the spectroscopy.