Commentary on Yagi

Review of the preand post-marketing studies of zonisamide in Japan provides valuable insight into the optimal use of this drug; in particular, its efficacy in specific seizure subtypes. After reviewing the data, Dr. Yagi has teased out some important distinctions regarding epilepsy and seizure subtypes. In particular, clinical trial results for patients who have temporal versus non-temporal lobe epilepsy are not usually separated out, as was done in Dr. Yagi’s report. In animals, hippocampal and non-hippocampal areas differ in seizure-kindling threshold and density of receptors; both of which serve as sites of action for many antiepilepsy drugs (AEDs). In clinical trials, patients tend to be lumped together for analysis, and distinctions are not drawn about whether the agent being studied is more effective in one type of seizure over another. For this reason it is not clear whether some AEDs are more effective in some types of partial seizures. Dr. Yagi’s analysis provides some useful direction for future reporting of clinical trial results. The most remarkable findings in these studies of zonisamide are among patients with secondarily generalized epilepsy. Patients with atypical absence seizures appeared to do extremely well on zonisamide. Those with atonic