Magnetic resonance imaging, electroencephalogram, and selected neuropsychological testing in staged corpus callosotomy.

A 21-year-old man with medically intractable secondarily generalized atonic seizures underwent a corpus callosotomy on Nov 5, 1981. Though improved, the falling seizures persisted. In January 1984, magnetic resonance imaging (MRI) documented that the anterior quarter of the corpus callosum remained intact. In March, the patient underwent a completion of the callosotomy, at which time the MRI findings were corroborated. Since the second surgery, a further improvement in seizure control has been observed. Use of MRI can document both noninvasively and in vivo the extent of corpus callosotomy. The implications of selected neurophysiologic and neuropsychological findings are also discussed.