Seizures and encephalopathy.

There is a complex relationship between seizures and encephalopathy. Seizures alone without any underlying neurologic or medical illness can be the sole cause of encephalopathy. Often these patients have a history of epilepsy, in which case accurate diagnosis is straightforward. Acute neurologic conditions often contribute to encephalopathy, but also increase the risk of seizures--many of which are subclinical. In these scenarios, it can be difficult to determine whether the encephalopathy is caused by seizures, the underlying neurologic disorder, or both. In addition, systemic diseases are commonly associated with encephalopathy; they may also increase the risk of seizures, although less commonly than acute neurologic conditions, and therefore may go unrecognized. This review will examine common and uncommon causes of seizures in encephalopathic patients, typical clinical presentations as well as diagnosis and treatment.