Electrophysiological target localization is not required for the treatment of functional disorders.

A total of 117 patients underwent 124 functional stereotactic procedures with the Leksell Gamma Knife to treat trigeminal neuralgia, movement disorders and chronic pain. Target identification was performed with stereotactic magnetic resonance imaging alone without electrophysiologic localization. Clinical observation of these patients over 1-41 months indicates that the efficacy of the procedure is comparable with that seen with open stereotactic procedures where electrophysiological localization is used. Using current techniques, the complications of functional neurosurgery with the Gamma Knife are nearly nonexistent. We believe that functional neurosurgery can be performed effectively and safely without electrophysiological localization, using the Leksell Gamma Knife.