Developmental Assessment-Based Surgical Intervention for Intractable Epilepsies in Infants and Young Children

Abstract

Summary: Purpose: To define the most appropriate time for surgery for medically intractable epilepsies in infants and young children. Methods: First we examined retrospectively the changes in developmental quotients (DQs) during the clinical course and the clinical factors affecting the DQ in 39 consecutive patients younger than 15 years, who underwent surgical treatment for intractable epilepsy. Second, we examined prospectively five new patients for early detection of developmental arrest or regression by periodic developmental assessments and whether this could lead to early surgical intervention, eventually resulting in minimal developmental defects. Results: Retrospective studies revealed that the DQ progressively decreased with age and that the reduction of DQ was related to continuing frequent seizures in many patients. The prospective studies demonstrated that periodic developmental assessments could detect the reduction of DQ at 5 months or later after onset of frequent seizures in three patients. In two other patients, operations were performed before reduction of DQs, and their postoperative DQ levels were normal. The postoperative recovery of DQ was complete in one patient whose operation was performed 3 months after reduction of DQ, whereas it was incomplete in two others whose operations were carried out at 12 and 14 months after reduction, respectively. Furthermore, three patients with normal developmental outcome had shorter periods between the onset of frequent seizures and the operation (≤7 months) than those of two patients with developmental delay (≥17 months). Conclusions: To minimize the developmental defects, periodic developmental assessments should be initiated when frequent seizures have occurred, and surgery should be considered as soon as possible when DQ reduction is recognized.

Changing the paradigm of 1-stage total callosotomy for the treatment of pediatric generalized epilepsy

“…Therefore, early surgical intervention is very important because developmental defects can be minimized if the seizures are surgically controlled. 3,22,23 The cerebral hemispheres connect with 6 midline commissural structures: the anterior commissure, posterior commissure, corpus callosum, hippocampal commissure, the massa intermedia of the thalamus, and the fornix. More than 60% of the 300 million fibers that make up the corpus callosum are fast-conduction myelinated fibers.…”

Interictal spikes in developing rats cause long-standing cognitive deficits

“…The key concept of the epileptic encephalopathies is that the slowing or regression of development is primarily due to seizures, abnormal interictal spikes (IIS), or cortical dysrhythmia as reflected in the electroencephalogram (EEG), and not solely due to the underlying cause of the seizures (Nabbout and Dulac, 2003). While it can be reasonably argued that all of the epilepsy syndromes have an underlying etiology that could lead to the cognitive impairment, the observation that children with epileptic encephalopathies who are successfully treated with medications or surgery can regain normal cognitive function is a demonstration that it is the seizures or abnormal EEG, or both, that are responsible for the cognitive impairment (Asarnow et al, 1997; Matsuzaka et al, 2001; Zupanc, 2003; Besag, 2004). …”

Increase in cognitive function is seen in many single-operated pediatric patients after epilepsy surgery

“…Drug-resistant epilepsy (DRE) leads to a debilitating life with gross impact on quality of life [1]. Recurrent seizures are known to cause permanent and progressive changes in brain structure and function, leading to impaired brain development and a loss in cognitive functioning [2][3][4]. Cognitive development may slow or cease after the onset of seizures 2,3,5 -8].…”