[Neurological pathology associated with vitamin B group deficiency: thiamine, folate and cobalamin]

The "fragility" of the nervous system, especially concerning to its nutrition and metabolism, explains why vitamin deficits are an important cause of neurological pathology. Some deficiency diseases, which can be very severe and irreversible, are still present in our environment; diagnosis, which must be early so as not to delay treatment, can be difficult if we do not have them in mind. In this review we address the most relevant neurological diseases associated with thiamine, folate and cobalamin deficiency, and we focus especially combined subacute degeneration and Wernicke-Korsakoff syndrome.