Early development destructive brain lesions and their relationship to epilepsy and hippocampal damage

Delayed Formation of Neonatal Reflexes and of Locomotor Skills Is Associated with Poor Maternal Behavior in OXYS Rats Prone to Alzheimer's Disease-like Pathology

Postnatal brain development is characterized by high plasticity with critical windows of opportunity where any intervention may positively or adversely influence postnatal growth and lead to long-lasting consequences later in life. Poor maternal care is among these interventions. Here, we found that senescence-accelerated OXYS rats prone to an Alzheimer's disease-like pathology are characterized by more passive maternal behavior and insufficient care for pups as compared to control (Wistar) rats. OXYS pups demonstrated a delay in physical development (of auricle detachment, of emergence of pelage and incisors, of eye opening, and of vaginal opening in females) and late manifestation of reflexes and locomotor skills. All observed behavioral abnormalities are connected either with poor coordination of limbs' movements or with a decrease in motivation and development of depression-like behavior. It is possible that their manifestations can be promoted by the features of maternal behavior of OXYS rats. Overall, these early-life events may have long-lasting consequences and contribute to neurodegeneration and development of the Alzheimer's disease-like pathology later in life.

Neuroimaging of epilepsy

Imaging is pivotal in the evaluation and management of patients with seizure disorders. Elegant structural neuroimaging with magnetic resonance imaging (MRI) may assist in determining the etiology of focal epilepsy and demonstrating the anatomical changes associated with seizure activity. The high diagnostic yield of MRI to identify the common pathological findings in individuals with focal seizures including mesial temporal sclerosis, vascular anomalies, low-grade glial neoplasms and malformations of cortical development has been demonstrated. Positron emission tomography (PET) is the most commonly performed interictal functional neuroimaging technique that may reveal a focal hypometabolic region concordant with seizure onset. Single photon emission computed tomography (SPECT) studies may assist performance of ictal neuroimaging in patients with pharmacoresistant focal epilepsy being considered for neurosurgical treatment. This chapter highlights neuroimaging developments and innovations, and provides a comprehensive overview of the imaging strategies used to improve the care and management of people with epilepsy.

Bilateral perisylvian ulegyria: Clinicopathological study of patients presenting with pseudobulbar palsy and epilepsy

Structural abnormalities related with pseudobulbar palsy have been gaining attention because of their characteristic symptoms and unique pathogenesis. We present five cases of bilateral perisylvian ulegyria (BPU) presenting epilepsy and pseudobulbar palsy with pathogenesis different from previously reported syndromes. All patients showed medically intractable seizures, complex partial seizures with secondary generalization and clinical symptoms of pseudobulbar palsy, including dysarthria, limitation of tongue movement and drooling. MRI revealed BPU in all patients, and BPU associated with hippocampal sclerosis in four patients. Intracranial EEG recording with subdural grip and stripe was helpful for localizing the area of ictal generation. Resective surgeries, including the temporal lobe, central area and parietal lobe, were performed depending on the localizing information. The surgical outcome was favorable after 9.8 years of follow-up. Characteristic features of ulegyria were confirmed on pathological examination. Ulegyria is considered to be another important perinatal or postnatal structural abnormality which can explain the etiological heterogeneity for pseudobulbar palsy, which results from bilateral perisylvian lesions. Awareness of this disorder can provide a useful strategy for evaluation and treatment which differs from that in perisylvian polymicrogyria.

A Hippocampal Lesion Detected by High-Field 3 Tesla Magnetic Resonance Imaging in a Patient with Temporal Lobe Epilepsy

Nearly 80% of patients with temporal lobe epilepsy have some types of lesion identified by conventional 1.5 tesla (T) magnetic resonance imaging (MRI). We performed high-field 3 T MRI in a 5-year-old patient with recurrent complex partial seizures who was diagnosed as having right temporal lobe epilepsy based on the results of single photon emission computed tomography and ictal video-electroencephalogram monitoring, because 1.5 T MRI failed to detect any abnormalities in the suspected region. High-field 3 T MRI revealed a small high-intensity lesion on fast spin-echo short inversion time inversion-recovery images of the hippocampus, possibly responsible for the seizures. This is the first report detecting a hippocampal lesion by 3 T MRI, which could not be found by conventional 1.5 T MRI.

Lesion lateralization in patients with epilepsy and precocious destructive insults

Destructive brain lesions that occur early in development are often unilateral or asymmetric. We analyzed the lateralization of lesions among a previously reported series of 51 patients with three kinds of destructive lesions based on their topography: specific arterial territory (AT), arterial borderzone territory (Bdz), hemispheric (H). Five patients (all from group Bdz) had bilateral nonlateralizing lesions. The distributions of left- and right-sided lesions were distinct among the groups (P=0.014): in group H, all patients except one presented with right-sided lesions (89%); in group Bdz, left-sided lesions (53%) were more frequent than right-sided lesions (17.7%); in group AT, left- and right-sided lesions were more equally distributed (56 and 44%). Our study suggests that there is a trend toward lesion lateralization among patients with different patterns of precocious destructive lesions. Differences in cerebral maturation and vulnerability between the hemispheres is a possible factor explaining lesion lateralization in early life insults.

Epilepsy and destructive brain insults in early life: a topographical classification on the basis of MRI findings

Destructive insults of early development can lead to a wide variety of lesional patterns and are a well known cause of epilepsy. The aim of this study is to present a topographic magnetic resonance imaging (MRI) classification of these lesions in adult patients with epilepsy. Thirty-three consecutive patients were divided in three groups according to the topographic distribution of their lesion on MRI: hemispheric (H, n = 7); main arterial territory (AT, n = 18); arterial borderzone (Bdz, n = 8). We analyzed clinical, MRI and magnetic resonance angiography (MRA) data. Status epilepticus (SE) during childhood was more common in group H (7/7) than in the groups AT (1/18) and Bdz (0/8) (P < 0.001). MRA pattern of impaired flow signal in the distal segments of all three major arteries in the affected hemisphere was present in 85.7% of group H patients, and was exclusive to this group. 88.8% (16/18) of patients from group AT presented congenital motor deficit, in contrast to 37.5% (3/8) of group Bdz, and in none of group H (P < 0.001). All patients with Bdz lesions had antecedent of fetal distress, in contrast to 1/7 from group H and 5/18 of group AT (P = 0.001). The MRAs of patients with Bdz lesions were often normal except in those with larger lesions. Our data suggest that in adult patients with epilepsy due to precocious destructive brain insults, a MRI topographical classification distributes them in relatively homogenous clinical groups.