Metabolic and degenerative disorders

Epileptic seizures are frequent in metabolic and degenerative disorders, and may be the presenting or prominent symptoms in a proportion of patients. In a restricted number of diseases the characteristics of epilepsy and associated symptoms are specific enough to constitute a definite syndrome that guides the diagnostic workup: this is the case in progressive myoclonic epilepsies and, to a lesser extent, in neuronal ceroid lipofuscinosis and Alpers syndrome. In most cases, conversely, diagnostic suggestion comes from the recognition of selected - although nonspecific - electroclinical features properly integrated with clinical electrophysiological and imaging findings. In this chapter we summarize the more common electroclinical features that lead to suspicion of a progressive disease and discuss epilepsies with a well-defined syndromic picture. We will also summarize the metabolic diseases frequently associated with epilepsy, underscoring, when present, the peculiar epileptic characteristics. Finally, we will highlight the features of metabolic diseases amenable to specific treatment.