Contribution of Bilingualism to Cognitive Reserve of an Italian Literature Professor at High Risk for Alzheimer's Disease.

Bilingualism is an independent component of cognitive reserve that permits to delay dementia onset up to 5 years. We describe a case of a bilingual Italian man affected by mild cognitive impairment with high cognitive reserve that, despite the presence of multiple risk factors (ApoE ɛ4/ɛ4 genotype, older age, untreated Obstructive Sleep Apnea Syndrome, AD-like biomarker alterations) did not convert to Alzheimer's disease up to 5 years follow-up. The present case confirms the role of bilingualism as a strong protective factor for dementia, even in the occurrence of multiple risk factors.