Parry-Romberg is a rare syndrome of unknown origin, characterized by hemiatrophy of the face including subcutaneous tissue, skeletal muscle, and bones, along with various ocular and central nervous system abnormalities. Some investigators consider that injury to the sympathetic fibers of the trigeminal nerve is a cause for evolution of this syndrome. Various central nervous system symptoms have been reported in correlation with the syndrome, including epilepsy and hemiparesis. These symptoms were related to ipsilateral (or, less frequently, contralateral) facial lesions, and in a few case reports were consistent with Rasmussen's encephalitis-like lesions. Many clinical features overlap between facial linear scleroderma and en coup de sabre syndrome, which is characterized by localized inflammation leading to atrophy of the skin and subcutaneous tissues mainly on one side of the face; such overlap can lead to confusion in diagnosis. Furthermore, central nervous system involvement has been reported in en coup de sabre syndrome, leading to further misdiagnosis. The distinction between these two disorders is much disputed. Detailed here is the case of a child who had been diagnosed with en coup de sabre syndrome presenting with severe status migrainosus. Subsequent pathologic clinical, and neuroimaging findings led to a diagnosis of Parry-Romberg syndrome. This diagnosis is set in the context of the similarities, contradictions, and growing confusion between the two syndromes.