ABSTRACT
This article primarily represents the contributions of two young investigators to the understanding of the neuropsychological consequences of epilepsy and its treatment. The authors have reviewed two key areas of importance: the complex relationship between cognitive dysfunction and epilepsy and the risks of cognitive dysfunction in children as a consequence of in utero exposure to antiepileptic drug treatment. The work of two young investigators is presented and future research needs are outlined.
Subject(s)
Anticonvulsants/adverse effects , Brain/growth & development , Cognition Disorders/etiology , Epilepsy/drug therapy , Prenatal Exposure Delayed Effects , Brain/drug effects , Brain/embryology , Cognition Disorders/complications , Epilepsy/complications , Female , Fetal Development/drug effects , Humans , Neuropharmacology/methods , Neuropharmacology/trends , PregnancyABSTRACT
The primary aim of this study was to determine whether hippocampal asymmetries in fluorodeoxyglucose (FDG) uptake on preoperative PET scans would predict post-temporal lobectomy verbal memory (VM) decline in patients with left temporal lobe epilepsy. A quantitative asymmetry index (AI) of uptake values within a hippocampal region of interest (ROI) was defined by an automated technique. No statistically significant effect of the hippocampal AI on the outcome measure, the pre- to postsurgical change in Logical Memory Percent Retention, was evident. Post hoc analyses revealed that AIs of the superior and inferior temporal gyri approached significance, however, with relatively greater left-sided preoperative metabolism predicting better VM outcomes. This finding suggests reorganization of function and/or retained function of remaining tissue. Although hippocampal FDG-PET asymmetries did not significantly predict changes in VM, the predictive value of neocortical AIs should be further explored. Automated ROI parcellation provides a feasible tool for use in such investigations.
Subject(s)
Epilepsy, Temporal Lobe/physiopathology , Epilepsy, Temporal Lobe/surgery , Fluorodeoxyglucose F18 , Hippocampus/diagnostic imaging , Memory Disorders/etiology , Psychosurgery , Verbal Learning/physiology , Adult , Brain Mapping , Cohort Studies , Epilepsy, Temporal Lobe/diagnostic imaging , Epilepsy, Temporal Lobe/pathology , Female , Functional Laterality/physiology , Humans , Linear Models , Magnetic Resonance Imaging , Male , Memory Disorders/diagnostic imaging , Middle Aged , Neuropsychological Tests , Positron-Emission Tomography/methods , Psychosurgery/adverse effects , Retrospective Studies , Treatment Outcome , Young AdultABSTRACT
Although anterograde memory deficits are well documented in patients with epilepsy, the extent to which remote memory deficits occur is less clear. This is due in part to a lack of reliable methods for assessment. The present study examined the feasibility of using the Transient News Events Test (TNET) to assess remote memory in subjects status post anterior temporal lobectomy (ATL) for the treatment of refractory seizures. Results indicated significantly poorer performance of the patient group compared to healthy controls. The decrement in performance within the patient group was evident only for items from more recent time periods. Reasons for an apparent stability of the most remote memories with ATL and implications regarding hippocampal function are reviewed. In conclusion, the TNET provides a feasible method for assessment of remote memory function in patients with epilepsy, with decrements in performance noted in comparison to a healthy control group in this retrospective study.
Subject(s)
Kluver-Bucy Syndrome/diagnosis , Memory Disorders/diagnosis , Memory Disorders/etiology , Postoperative Complications/diagnosis , Adult , Age Factors , Analysis of Variance , Education , Epilepsy, Temporal Lobe/diagnosis , Epilepsy, Temporal Lobe/psychology , Female , Functional Laterality/physiology , Humans , Kluver-Bucy Syndrome/epidemiology , Kluver-Bucy Syndrome/psychology , Linear Models , Male , Memory Disorders/psychology , Memory, Short-Term/physiology , Middle Aged , Postoperative Complications/epidemiology , Postoperative Complications/psychology , Psychomotor Performance/physiology , Recognition, Psychology/physiology , Sex FactorsABSTRACT
The purpose of this study was to characterize the epileptogenicity of tubers and surrounding cortex in patients with tuberous sclerosis complex (TSC). Three pediatric patients with TSC and intractable epilepsy underwent surgical resection of tubers associated with epileptogenic foci. In all patients, presurgical imaging revealed a prominent tuber that correlated on electroencephalography (EEG) with frequent interictal epileptiform discharges and electrographic seizures. Intracranial electrocorticography (ECoG) was performed using subdural grids placed over the tuber and surrounding cortex and depth electrodes positioned directly within the tuber. In all three patients, the depth electrode within the tuber was electrographically silent, whereas the surrounding cortical tissue showed significant epileptiform activity. The tuber and the electrically active adjacent cortex were resected. The patients experienced a drastic reduction in seizure frequency postsurgery. Epileptogenicity of cortical tubers may derive not from the lesion itself, but rather from the perturbation or abnormal development of the surrounding cortex.
