[Dementia in hypothyroidism].

Hypothyroidism is one of the most frequent causes of potentially reversible dementia. According to present knowledge, symptoms of mental impairment begin insidiously and show a slow progression. They may precede the typical somatic manifestations of thyroid dysfunction. Almost complete remission of dementia may be expected from hormone substitution when the diagnosis is established early. The pathogenetic mechanisms which may have important implications for other forms of dementia are still imperfectly understood.