A PET scan in a child with Rasmussen's encephalitis typically shows what kind of metabolic activity?

In Rasmussen's encephalitis, a chronic inflammatory neurological condition that typically affects one hemisphere of the brain, the PET scan commonly reveals widespread hemispheric hypometabolism. This decreased metabolic activity reflects the overall dysfunction due to the inflammatory process and neuronal damage associated with the disease.

As the condition progresses, one hemisphere often becomes significantly impaired, leading to hypometabolism due to reduced neuronal activity in that region. This finding is consistent with the clinical manifestations of the disorder, which include seizures, cognitive decline, and motor deficits. Therefore, the identification of widespread hypometabolism on a PET scan can help in diagnosing Rasmussen's encephalitis and understanding its impact on brain function.