Summary:Purpose: Numerous studies have demonstrated changes in cognitive, memory, and language functioning in adults and adolescents after temporal lobectomy, yet little information is available regarding neuropsychological outcome in preadolescent children.Methods: We studied pre-and postoperative neuropsychological test results from 14 children who underwent temporal lobe resection for intractable epilepsy at age 7-12 years (mean 9.4 years).Results: Thirteen patients (93%) had no seizures or less than one seizure a year at follow-up 23-48 months (mean 34 months) after operation. Postoperative neuropsychological testing was performed 6-9 months (mean 7 months) after surgery in 13 patients and 36 months after the first operation in 1 patient who underwent two-stage resection of a tumor. Verbal, Performance, and Full Scale IQ were initially in the lowaverage range, with no significant change across the pre-and postoperative evaluations. Immediate verbal memory performance decreased significantly in children who initially performed above the median preoperatively and tended to decrease in children who had left rather than right temporal lobe resection. Significant postoperative decreases in delayed memory scores were independent of preoperative ability or side of resection.Conclusions: Our small study suggests vulnerability to postoperative decline in immediate verbal memory scores in preadolescent children who have higher baseline immediate memory function or undergo left rather than right temporal lobe resection, similar to that observed in adolescents in adults. The entire group exhibited a statistically significant decrease in delayed verbal memory. Study of larger series of patients will be important to clarify further the short-and long-term risks and benefits of temporal lobe resection in childhood.

Early low-grade left frontal and temporal tumors usually did not result in transfer of language dominance to the contralateral hemisphere. Tumors may grow slowly along with the developing brain in young children, with continued left hemisphere language development in regions separate from the neoplasm. Successful tumor resection can be accomplished, but it may require cortical stimulation for localization and sparing of nearby language areas.

Rats prepared with serial visual-cortical ablations can relearn the horizontal-vertical stripes discrimination problem if given interoperative training. However, they fail to discriminate between obliquely oriented stripes. The findings are discussed in relation to the concept that pattern perception is completely dependent upon the integrity of cortically related systems. Furthermore, the criteria for constructing pattern discriminanda are outlined, and reasons are presented for abandoning some of the classical stimuli used to test form perception in striate-extra-striate preparations.It is thoroughly established that if rats are given training on a black-white discrimination problem and then subjected to bilateral ablations of the posterior cortex, they show no postoperative retention of performance of the problem but can nonetheless relearn it. Lashley (1935) believed that relearning of the problem was a function of subcortical systems, and his concept has since been supported by Horel, Bettinger, Royce, and Meyer (1966) and Meyer, Yutzey, Dalby, and Meyer (1968). The latter studies have shown that the problem is relearnable by rats with complete neocortical ablations, regardless of whether the ablations are performed with one-stage or two-stage procedures.More recent research has been directed toward assessments of the variables which govern the rate at which the problem is relearned by rats with posterior ablations . One of the approaches has involved the use of procedures in which the animals are trained on the problem, subjected to unilateral posterior cortical ablations, then given inter operative retraining on the problem, SUbjected to second-stage ablations of the contralateral cortex, and then re-retrained on the problem. When this serial unilateral method is employed, the problem is finally relearned at a rate that is faster than the rate at which the problem is relearned by one-stage bilateral posterior preparations, or by subjects with two-stage posterior ablations which receive no interoperative practice

Most parents report satisfaction with the outcome of their child's corpus callosotomy, but are influenced by improvement in aspects of function and behavior in addition to seizure reduction.

The present investigation involved an examination of susceptibility to visual masking of older adults displaying evidence of Alzheimer's disease and healthy, cognitively intact older adults. Results indicated that the cognitively impaired group was more susceptible to the perceptual interference of a visual mask than was the cognitively intact group. In addition, the impaired group was found to be particularly susceptible to masking by a visual pattern (which had similar figural characteristics to target stimuli) as compared to masking by random noise (which had figural characteristics unrelated to the target). Finally, susceptibility to masking was found to be negatively correlated with performance on the Information subtest of the Wechsler Adult Intelligence Scale-Revised and with rated level of cognitive functioning. It was concluded that this pattern of results represents an acceleration of changes in perceptual processing typically associated with normal human aging.