Surgical outcomes for medically refractory epilepsy secondary to posterior cortex ulegyria as sequelae of perinatal insults.

BACKGROUND: To study surgical outcomes in pharmaco-resistant epilepsy associated with posterior cortex ulegyria secondary to perinatal insults. METHODS: A cohort was analysed for clinico-radiological charectaristics, surgical interventions and seizure outcomes. OBSERVATIONS: A total of 38 patients underwent surgery, divided as group A - curative surgeries (n = 20) and group B - palliative surgeries (n = 18). Mean age of onset of epilepsy in group A was 5.2 ± 3.4 years against 2.7 ± 2.4 years in group B (p < 0.01). Electroclinical Lennox Gastaut Syndrome was encountered in 9/20 patients in group A, against all 18 patients in group B. Disabling reflex epilepsy was seen in 10 (26 %) patients. Interictal electrophysiology localized in the posterior cortex in all patients in group A, but ictal onsets contributed in only 7/20 patients. Nine patients from group A had unilateral parieto-occipital ulegyria while bilateral in 11/20 patients, and 16/18 from group B. Group A patients underwent parieto-occipital resection (n = 10) and temporo-parieto-occipital disconnection (n = 10) while group B underwent complete corpus callosotomy (n = 18). In group A, Engel Ia outcome was achieved in 15/20 patients (75 %) at mean follow up of 23.5 ± 7.9 months. Group B patients experienced cessation of head drops in all 18 patients, with two-third reduction in seizure frequency at 29.2± 12.4 months of mean follow up. Reflex seizures responded completely in both groups. CONCLUSIONS: Epilepsy surgeries for posterior cortex ulegyria results in excellent seizure outcomes. Corpus callosotomy appears highly effective as a palliation for head drop as well as disabling reflex seizures in a well selected cohort.

Failed Hemispherotomy: Insights from Our Early Experience in 40 Patients.

OBJECTIVE: To study the factors responsible for failure of hemispherotomy and outcomes of revision surgery. The effect of the surgeon's learning curve on failures was also analyzed. METHODS: Forty consecutive patients, who underwent functional hemispherotomy through a 4-year period, from the inception of the single-surgeon epilepsy surgery program, were analyzed. RESULTS: A total of 47 functional hemispherotomies were performed in the study period in 40 patients (7 revision surgeries on 6 patients). Mean age of the cohort was 9.45 ± 14.84 years and it included 7 infants (<2 years). Of the 9 patients (23.5%) who failed the first procedure, 6 qualified for revision surgery, all of whom belonged to the cohort of the first 15 patients treated during the first 2 years of the program. Hemimegalencephaly was the most common disease (n = 4). Ipsilateral temporal stem (n = 3), frontobasal connections (n = 2), splenium of corpus callosum (n = 2), and posterior insula (n = 2) were residual undisconnected substrates identified for revision on imaging. The substrates for failure were obvious in 5/6 patients and resulted from incomplete disconnection, implying surgical inadequacy. At the mean follow-up of 30 ± 13.17 months (range, 13-55 months), 35 of 40 patients (87.5%) remained seizure free (Engel class Ia), including 4/6 patients who underwent redo surgery. Revision did not benefit the remaining 2 patients (Engel class III). There was no mortality. CONCLUSIONS: Surgical revision is more common in hemimegalencephaly and in the early days of a surgical program. Affirmative neuroimaging improves the outcomes of subsequent revision surgery.

Heterogeneity of receptor function in colon carcinoma cells determined by cross-talk between type I insulin-like growth factor receptor and epidermal growth factor receptor.

This study identifies a novel cross-talk paradigm between the type I insulin-like growth factor receptor (IGF1R) and epidermal growth factor receptor (EGFR) in colon cancer cells. IGF1R activation by ligand exposure in growth factor-deprived cells induces Akt activation in the FET, CBS, and GEO colon cancer cell lines. Investigation of IGF1R-mediated signaling pathways using small interfering RNA approaches indicated that, as expected, phosphatidylinositol 3'-kinase (PI3K) was activated by IGF1R. Mitogen-activated protein kinase (MAPK) activity as reflected by phospho-extracellular signal-regulated kinase (ERK) induction was not significantly activated until later times following release of these cells from growth factor deprivation stress. The appearance of phospho-ERK was proximal to EGFR activation. Treatment of cells with the PI3K inhibitor LY294002 before release from stress resulted in a concentration-dependent loss of EGFR activation, whereas treatment with the MAPK inhibitor PD98059 did not block EGFR activation, indicating that EGFR activation was downstream of the IGF1R/PI3K pathway. PD98059 inhibition of MAPK was associated with a concentration-dependent reduction in EGFR-mediated phospho-ERK. EGFR inhibitor blocked induction of phospho-ERK, showing that MAPK activity was a consequence of EGFR-mediated signaling. On the other hand, a small-molecule IGF1R inhibitor, PQIP, blocked Akt phosphorylation. The divergent signaling functions of IGF1R and EGFR suggested the potential for synergism by a combination of therapy directed at the two receptors. Combination treatment with PQIP and EGFR inhibitor Tarceva resulted in synergistic effects as indicated by combination index analysis in all three cell lines tested.