Table 3.
Case summaries of children with Influenza-associated encephalitis (IAE) in Sydney, 2017.
| Case | Age (years) sex (M/F) | Clinical syndrome | Flu type | MRI findings | CSF white cell count (×106/L) | Influenza positive on CSF. | Neuronal/inflammatory antibody testing | ICU | Treatment given | Neopterin (nmol/L) | mRS (Baseline; discharge) |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 14y, F | Encephalitis, Previous cerebellitis aged 7 years, full recovery. |
B | T2 hyperintensity involving the margins of the lateral ventricles, clastrum, mammillary bodies, and caudate nucleus [Fig. 1G and H] | 1 | Not performed. | NMDAR, VGKC, NMO, TPO antibodies – negative. | Yes | 3rd generation cephalosporin Oseltamivir Aciclovir IVIG Corticosteroid Plasmapheresis |
174 | 0; 6 (Death) |
| 2 | 13y, F | ANE Previous ADEM aged 4y, full recovery. |
A | Multiple symmetrical foci of diffusion restriction & T2 hyperintensity in the cerebellum pons, cerebral white matter and basal ganglia. Left thalamic haemorrhage. [Fig. 1E] | 0 | Not performed. | Not performed. | Yes | 3rd generation cephalosporin Oseltamivir Aciclovir IVIG Corticosteroid |
none | 0; 3 |
| 3 | 10y, M | Hyperkinetic movement disorder. Mild cerebral palsy. GMFCS 1. |
B | Normal. | 3.3 | Negative. | NMDAR, VGKC antibodies – negative. TPO & thyroglobulin antibodies positive. | No | 3rd generation cephalosporin IVIG Corticosteroid |
77.3 | 0; 2 |
| 4 | 9y, M | Encephalitis with focal status epilepticus. Previously well. |
A | Normal. | 3.9 | Positive. Influenza A |
NMDAR, VGKC antibodies – negative. TPO and thyroglobulin antibodies positive. | No | 3rd generation cephalosporin Aciclovir IVIG Corticosteroid |
203 | 0; 1 |
| 5 | 7y M | Encephalitis with possible PRES Previously well. |
B | Initial scan normal. Repeat 5 days later: Cortical and subcortical vasogenic oedema in posterior and anterior watershed areas with a few non-specific foci of restricted diffusion.[Fig. 1D] | 10 | Not performed. | Not performed. | Yes | 3rd generation cephalosporin Oseltamivir Aciclovir |
74 | 0; 2 |
| 6 | 6y F | Cerebellitis Previously well. |
A | T2 and FLAIR hyperintensities in both cerebellar hemispheres. Enhancement of the cerebellar folia with gadolinium. [Fig. 1F] | 242 | Negative | NMDAR, VGKC, GAD, PCA1, PCA2, Hu, Ri, Ma 1&2, amphiphysin antibodies, MOG - negative | Yes | 3rd generation cephalosporin Oseltamivir Aciclovir IVIG Corticosteroid |
16 | 0; 4 |
| 7 | 4y F | AESD, Reye like syndrome 2 previous episode of status epilepticus, known epilepsy. |
A (H3) | Multiple foci of T2/FLAIR hyperintensity and diffusion restriction in the subcortical white matter of the left frontal and deep white matter of parietal lobes. Reduction in volume of right temporal lobe with hyper intense signal in right hippocampus.[Fig. 1A] | 0 | Negative | NMDAR, VGKC antibodies – negative. | Yes | 3rd generation cephalosporin Corticosteroid |
201 | 2; 5 |
| 8 | 4y F | Encephalitis Mosaic tetrasomy X, cerebral palsy, developmental delay. |
A (H109) | Stable appearance from previous scans. Moderate atrophy of the superior vermis of the cerebellum. Non-specific T2 hyperintensiites in the subcortical white matter. | 2.7 | Not performed. | Not performed. | Yes | 3rd generation cephalosporin Oseltamivir |
34 | 4; 4 |
| 9 | 2y M | AESD Previously well. History of simple febrile seizures. |
A | Bilateral restricted diffusion in the peri-rolandic and posterior white matter with sparing of the basal ganglia [Fig. 1B] | 0 | Not performed. | Not performed. | Yes | 3rd generation cephalosporin Oseltamivir Aciclovir Corticosteroid |
317 | 0; 3 |
| 10 | 1.3y F | HHS Previously well. |
A (H109) | T2/FLAIR hyper- intensity and mild diffusion restriction of the left temporal and left occipital lobes. Lacate peak on MRS on the left side. [Fig. 1C] | 4.1 | Negative | NMDAR, VGKC, TPO antibodies - negative | Yes | 3rd generation cephalosporin Oseltamivir Aciclovir IVIG Corticosteroid |
669 | 0; 3 |
| 11 | 1.2y M | Subcortical myoclonus Previously well. This child was found to have a mutation in the POLG gene. |
A | Initial scan: non-specific left thalamic T2 hyperintensity. Repeat 3 weeks later: Diffusion restriction lateral part of left thalamus. [Fig. 1I] |
6 | Not performed. | Not performed | Yes | 3rd generation cephalosporin Aciclovir IVIG Corticosteroid |
28 | 0; 4 |
ANE, acute necrotizing encephalopathy; AESD, acute encephalopathy with biphasic seizure disorder and late diffusion restriction; ADEM, acute disseminated encephalomyelitis; HHS, hemconvulsion hemiplegic syndrome; ICU, intensive care unit, POLG, polymerase gamma, PRES, posterior reversible encephalopathy syndrome. MOG, myelin oligodendrocyte glycoprotein; NMDAR, N-methyl-d-aspartate antibody; VGKC, voltage gated potassium channel antibody; GAD, glutamic acid decarboxylase antibody; TPO, thyroperoxidase antibody; NMO, neuromyelitis optica antibody; PCA1, purkinje cell cytoplasmic antibody 1; PCA2, purkinje cell cytoplasmic antibody 2.