Epilepsy and porphyria: new perspectives.

Porphyria is a group of disorders caused by alterations in the enzymatic pathway involved in haem biosynthesis. The clinical picture consists of extraneurological and neurological manifestations, seizures being an important feature. The pathogenesis of seizures is probably related to metabolic imbalance such as hyponatremia and to the intrinsic epileptogenic role of some porphyrins. Many studies report that neural damage can follow a porphyric attack, suggesting that these lesions can be epileptogenic. Several reports also pointed out that porphyria can be precipitated by some antiepileptic drugs (AEDs). More recent AEDs appeared and need assessment in relation to porphyria. An educational program including a registry of patients with porphyria, an intensive study of family history and the genetic background may be useful to obtain better epidemiological data and a clearer understanding of pathogenesis. Application of neuroimaging may detect epileptogenic foci, helping to define the specific risk of seizures for each patient.