Appearance of EEG abnormalities in two patients during long-term treatment with B vitamins

Two female patients, one treated for epilepsy by phenobarbital (PB) and carbamazepine (CBZ), the other suffering from neurosis and free of any drug therapy, were given group B vitamins (riboflavin and nicotinic acid respectively) and showed during the long-term administration of these vitamins 2-3 Hz generalized electro-encephalographic (EEG) abnormalities. These EEG changes were detected incidentally and were not associated with any clinical manifestation; they disappeared progressively within several weeks after discontinuation of vitamin therapy. In our opinion, it is likely that the treatment with B vitamins was entirely responsible for the EEG changes, as one of the patients did not receive any other drug, while the other did not show any significant change of PB and CBZ plasma levels during vitamin therapy. However, other cases reported will be necessary to confirm our impressions.