[Hypothyroidism and cognition in the elderly].

The consequences of hypothyroidism on cognition are long known since the description of dementia associated with hypothyroidism. Additional data from experimental studies support the impact of thyroid hormones on the central nervous system and cognition. Cognitive impairment in relation with hypothyroidism (even sub clinical hypothyroidism) in elderly subjects involves memory, attention, and executive functions. Hypothyroidism may be associated with somatic, neurologic, psychiatric, social and environmental data. Cross-sectional and longitudinal studies are frequently heterogeneous but suggest a complex relationship between hypothyroidism and cognition.