Memory and temporal lobe surgery: a review

Morphological features of the neonatal brain support development of subsequent cognitive, language, and motor abilities

Knowledge of the role of brain maturation in the development of cognitive abilities derives primarily from studies of school-age children to adults. Little is known about the morphological features of the neonatal brain that support the subsequent development of abilities in early childhood, when maturation of the brain and these abilities are the most dynamic. The goal of our study was to determine whether brain morphology during the neonatal period supports early cognitive development through 2 years of age. We correlated morphological features of the cerebral surface assessed using deformation-based measures (surface distances) of high-resolution MRI scans for 33 healthy neonates, scanned between the first to sixth week of postmenstrual life, with subsequent measures of their motor, language, and cognitive abilities at ages 6, 12, 18, and 24 months. We found that morphological features of the cerebral surface of the frontal, mesial prefrontal, temporal, and occipital regions correlated with subsequent motor scores, posterior parietal regions correlated with subsequent language scores, and temporal and occipital regions correlated with subsequent cognitive scores. Measures of the anterior and middle portions of the cingulate gyrus correlated with scores across all three domains of ability. Most of the significant findings were inverse correlations located bilaterally in the brain. The inverse correlations may suggest either that a more protracted morphological maturation or smaller local volumes of neonatal brain tissue supports better performance on measures of subsequent motor, language, and cognitive abilities throughout the first 2 years of postnatal life. The correlations of morphological measures of the cingulate with measures of performance across all domains of ability suggest that the cingulate supports a broad range of skills in infancy and early childhood, similar to its functions in older children and adults.

Recent advances in epilepsy surgery: temporal lobectomy and multiple subpial transections

THIS ARTICLE REVIEWS four major advances in epilepsy surgery, especially the most frequently performed surgery, temporal lobectomy, as follows: 1) the ability to preoperatively identify (using magnetic resonance imaging) the pathological condition of hippocampal sclerosis (a key component to the syndrome of mesial temporal lobe epilepsy, 2) the ability to identify preoperatively which temporal lobe candidates are at risk for postoperative memory problems, 3) the standardization of temporal lobectomy with respect to how much hippocampus should be resected, 4) a validation of the novel surgical technique of multiple subpial transections. This technique allows surgeons to attack foci within nondispensible cortex and therefore enlarges the applicability of surgical treatment to otherwise inoperable patients and potentially improves outcome.

Verbal and visual memory impairment in children with epilepsy

Verbal and visual memory performances were evaluated in 60 epileptic children and 60 normal control subjects with Signoret's Memory Battery scale. Eighteen patients had idiopathic generalized epilepsy and 42 had partial epilepsy, mostly of the temporal (n = 28) and frontal (n = 10) lobes. Memory scores were statistically lower in epileptics than in controls and significant differences were found within each group: (1) children with idiopathic generalized epilepsy had a slight depression of visual memory; (2) memory disorder was more severe in partial epilepsy; and (3) children with left and right temporal lobe epilepsy had marked memory deficits related to hemispheric specialization.