[ABSTRACT] Over a variable period of time of about two years, neurodegenerative pathologies with predominant focal impairment present a selective alteration of a specific cortical function. Symptoms are sporadic in patients of approximately 65 years of age and with the evolution of the disorder some patients continue to experience selective defficiency, while more than half present a dementia-type diffuse disorder within about five years. One of the degenerative focal syndromes that we should ou