Pyridoxine dependent seizures--a wider clinical spectrum.

We report 4 infants with pyridoxine dependent seizures who had clinical features that led to diagnostic uncertainty. Their clinical course was unusual in 1 or more of the following: later onset of initial seizures; a seizure free period after taking of anticonvulsants, but before taking of pyridoxine; a long remission after withdrawal of pyridoxine; and atypical seizure type. This report illustrates a broader range of clinical features and highlights the need to consider the diagnosis of pyridoxine dependent seizures in any infant with intractable epilepsy, regardless of the pattern of seizures and the response to anticonvulsant medications. In such a case, 100 mg intravenous pyridoxine should be given and, if a definite clinical response is established, oral pyridoxine should be continued indefinitely.