This chapter is intended as an overview of the different antiepileptic drugs (AED) that can also be used to treat movement disorders and of the rationale for their use. There are two main sections: the first reports in alphabetic order AEDs with a well-established use in both fields (epilepsy and movement disorders); the second contains other AEDs that have a less defined use profile in movement disorder treatment, because of their recent introduction or their narrow spectrum of action. The aim is, whenever possible, to highlight the mechanisms of action that can be shared by the drugs in the treatment of both epilepsy and movement disorders.
Acetazolamide (AZM) is a sulfonamide that inhibits carbonic anhydrase, an enzyme responsible for conversion of carbon dioxide and water to bicarbonate (Roblin & Clapp, 1950). Its use in epilepsy has a long history but remains limited (Bergstron et al., 1952; Ramsey & De Toledo, 1997). On the contrary, AZM is highly effective in treating episodic ataxias as serendipitously discovered in a patient misdiagnosed with periodic paralysis (Griggs et al., 1978).
Although several reports have claimed the efficacy of AZM as an AED, most of these studies were performed before the adoption of the International Classification of the Epilepsies (Commission, 1989) and it is therefore difficult to determine clearly what types of epilepsies respond to the drug.
In partial epilepsies, different open studies indicate more than 50% seizure reduction in 25% to 52% of patients, with a minority of them being seizure free.