What is the rare neurological disorder associated with the measles virus, typically developing in children or adolescents, characterized by progressive dementia and seizures?

The condition associated with the measles virus that develops in children or adolescents, featuring progressive dementia and seizures, is recognized as subacute sclerosing panencephalitis (SSPE). This rare neurological disorder typically manifests several years following a measles infection, even after the individual appears to have fully recovered from the measles itself.

In SSPE, the virus causes a gradual deterioration of neurological function, leading to symptoms such as personality changes, cognitive decline, seizures, and ultimately, severe neurological impairment. The underlying mechanism involves a persistent infection of the central nervous system by the measles virus, which causes inflammation and damage over time.

This distinguishing characteristic of being a post-infectious complication of measles, along with its specific symptom profile, clearly identifies SSPE as the correct choice compared to other disorders in the list. Other conditions, like amyotrophic lateral sclerosis, Huntington's disease, and Creutzfeldt-Jakob disease, have different etiologies and clinical presentations that do not involve a direct link to the measles virus or exhibit the same pattern of cognitive and neurological decline following a viral infection.