Transient hypothyroidism associated with viral Human Parechovirus encephalitis in a newborn.

Human Parechovirus type 3 (HPeV-3) is a neurotropic virus which can cause neonatal encephalitis, presenting as encephalopathy with seizures and diffuse white matter lesions on brain imaging. Neurodevelopmental outcome is linked to the extent of white matter abnormalities. We report on a neonate with clinical and biochemical findings of transient central hypothyroidism associated with HPeV-3 encephalitis. The co-occurrence of transient hypothyroidism and viral encephalitis has not been reported in newborns before. Transient suppression of the hypothalamo-pituitary-thyroidal axis is described in critically ill babies as the nonthyroidal-illness syndrome. Assessment of thyroid function in neonatal cases of HPeV-3 infection is required to conclude whether a transient hypothyroidism as in nonthyroidal-illness syndrome may be triggered by viral meningo-encephalitis and if treatment may influence neurodevelopmental outcome.