Epilepsia partialis continua and generalized nonconvulsive status epilepticus during the course of argininemia: a report on two cases.

Argininemia is a rare inherited disorder of the urea cycle because of a deficiency of the enzyme arginase I causing an increase of arginine and guanidino compounds in the blood, urine, and cerebrospinal fluid. The clinical picture is characterized by a mild cognitive dysfunction, progressive asymmetrical paraparesis, and seizures. Here, we describe two cases of argininemia where either epilepsia partialis continua (EPC) or nonconvulsive status epilepticus (NCSE) were the presenting manifestations of epilepsy. This is the first report of EPC in an urea cycle disorder. In both the cases, status epilepticus resolved with anticonvulsive drugs. EPC was successfully treated with levetiracetam, and NCSE with valproic acid. No side effects were observed. Because hyperammonemia and NCSE may have the same features of stupor, a neurophysiological approach might prove useful in differentiating these two conditions. Overall, our results strongly indicate that a correct NCSE diagnosis is mandatory to prevent further deterioration in these patients.