Antiepileptic Drugs and Their Impact On Balance

Antiepileptic drugs (AEDs) are being used with increasing frequency, not only to manage epilepsy, but also in the treatment of other conditions including neuropathic pain, migraine headaches and psychiatric conditions requiring mood stabilization. Although AEDs as a class are commonly prescribed in older patients and those with a predisposition to imbalance, the effect these drugs exert on gait and equilibrium has received very little study. Data from controlled efficacy and safety trials suggests that some AEDs are more apt to affect balance than others, even at therapeutic doses. In particular, phenytoin, primidone and phenobarbital produce more dizziness than some of the newer AEDs such as lamotrigine, levetiracetam and oxcarbazepine. For some of the other new AEDs, the data are simply not sufficient to estimate their effect on balance. This article reviews the current evidence that may guide the clinician in choosing a medication likely to have a low impact on gait and balance. Considering the risks and morbidity associated with imbalance and falls, particularly in the elderly, the direct effects of AEDs on balance should be examined further.