Abstracts

Proponents of tissue-sparing selective temporal resections for patients with mesial temporal sclerosis and intractable epilepsy begrudgingly acknowledge the lack of neuropsychological data demonstrating any related savings with these procedures. Seizure outcome in well-selected patients appears to be equivalent between the more [ldquo]selective[rdquo] and larger traditional temporal lobectomies. One interpretation of why no obvious savings follows from selective resection is that the tissue is somehow rendered dysfunctional by the operation. Alternatively, it may be that we are not adequately probing the function of the spared temporal tissue., Ten consecutive patients who underwent transcortical (second temporal gyrus) transventricular selective amygdalohippocampectomy for mesial temporal sclerosis and intractable epilepsy were examined post-operatively with formal visual field testing. Each patient also had post-operative MRI to demonstrate the extent of resection and exclude complications. These patients were compared to a reference case of intractable non-lesional temporal lobe epilepsy operated by the same surgeon. This patient underwent a more radical traditional temporal corticoamygdalohippocampectomy. Pre and post operative visual fields and MRI are available for this patient also., The patient who underwent traditional temporal lobectomy demonstrated the expected homonymous superior quadrantopsia. Patients who underwent the selective procedure demonstrated some evidence of visual field loss, albeit to a lesser extent than that of the reference case., This finding has several important implications the most of salient of which suggests that the selective procedure results in the sparing of viable and functionally important brain tissue. Additionally, these data support the notion from recent studies of MR tractography, that the fibers of Meyer[apos]s Loop course further anterior in the temporal lobe than is generally acknowledged., (Supported by Department of Neurology and Neurosurgery McGill University.)