Dementia, amyotrophy, and periodic complexes on the electroencephalogram -A diagnostic challenge

Background: The clinical diagnosis of neuroclegenerative diseases is a chal lenge to the neurologist. In many cases the diagnosis becomes neuropatholog ical only after the autopsy. Several consensus criteria have been defined f or the clinical diagnosis of different neurodegenerative diseases, among th em the various types of dementia as well as prion-induced diseases. When co mpared with neuropathological findings, these criteria have proved to be re asonably accurate for regular practice, research, and epidemiological studi es. The problem arises when a combination of complementary and clinical dat a are obtained that do not easily match these diagnostic criteria. Case Description: We describe a patient with dementia and periodic complexe s on an electroencephalogram, suggesting a diagnosis of sporadic Creutzfeld t-jakob disease. Results: When the condition progressed, signs and symptoms of a motoneuron disease appeared. Thus, 2 different diagnoses were proposed: (1) an amyotro phic variant of a prion-induced disease; or (2) an ELA dementia syndrome wi th periodic complexes on the electroencephalogram, a finding that previousl y has not been described.