Acute necrotizing encephalopathy associated with parainfluenza virus in a Caucasian child.

Acute necrotizing encephalopathy is a severe parainfectious disorder with a clear racial predilection for Oriental children living in the Far East. The prognosis was originally reported as grave; however, a mild form of the disease has recently been described. A case of parainfluenza virus-associated acute necrotizing encephalopathy in a Caucasian child with a mild clinical course and excellent prognosis is presented. In this patient, the initial clinical picture was not very impressive, and the diagnosis was delayed until the third week of the illness, when neuroimaging was performed. Two months later, clinical and neuroimaging findings had almost completely resolved. Suggested criteria for a benign prognosis, such as normal liver function and cerebrospinal fluid protein levels, asymmetric thalamic lesions, and no brainstem involvement, were relevant in the present case. An extended diagnostic work-up for metabolic, vascular, coagulation, and infectious diseases was negative apart from a seroconversion for parainfluenza virus. To our knowledge, this is the first reported case of acute necrotizing encephalopathy associated with parainfluenza virus infection. Acute necrotizing encephalopathy, especially in the mild form, might not be fully recognized and could be underdiagnosed in Europe, where the reported incidence of the syndrome is very low.