EEG and granular osmiophilic elements in early-onset Alzheimer's disease

Early-onset Alzheimer's disease (EOAD) is a rare genetic disorder mainly attributable to a mutation in the presenilin 1 (PSEN1) gene. Clinical profile and instrumental findings share common features with adult neuronal ceroid lipofuscinosis. We documented the clinical course in EOAD patients bearing mutations in PSEN1. Genetic screening for dementia, EEG acquisition and determination of granular osmiophilic elements (GRODs) from skin biopsy were performed in a patient suffering from a severe cognitive decline and visual hallucinations. The pathogenic M146I mutation in PSEN1, and instrumental findings common to adult neuronal ceroid lipofuscinosis were found in the same patient. Posterior low pseudoperiodic sequences at EEG and GRODS elements at skin biopsy might constitute a signature in EOAD.