Eight-and-a-half syndrome as manifestation of acute disseminated adenovirus encephalomyelitis.

Acute disseminated encephalomyelitis is an immune mediated inflammatory-demyelinizing disease that usually manifests after infection or vaccination in school-age children. It typically presents a prodromal phase with flu-like symptoms, followed by a phase with varied clinical symptoms, neuro-ophthalmological alterations such as ophthalmoplegia or optic neuritis may occur. The differential diagnosis includes tumor, vascular, infectious, inflammatory and demyelinating diseases. Diagnosis is based on the clinical history and the characteristics of brain magnetic resonance imaging, the gold standard test. The study of the cerebrospinal fluid can help to guide the clinical picture. The prognosis is favorable, with an excellent response to corticosteroids and immunoglobulins, with minimal long-term sequelae in most cases. We report the case of an 8-year-old male with acute demyelinating disease due to adenovirus whose manifestation was an eight-and-a-half syndrome.