Epileptic encephalopathy in children with risk factors for brain damage.

In the study of 887 new born infants with prenatal and perinatal risk factors for brain damage, 11 children with West syndrome that progressed into Lennox-Gastaut syndrome and another 4 children with Lennox-Gastaut syndrome that had not been preceded by West syndrome were found. In this study we present the main findings of these 15 subjects. In all infants multifactor antecedents were detected. The most frequent risk factors were prematurity and severe asphyxia; however placenta disorders, sepsis, and hyperbilirubinemia were also frequent. In all infants MRI direct or secondary features of periventricular leukomalacia were observed. Followup of all infants showed moderate to severe neurodevelopmental delay as well as cerebral palsy. It is concluded that prenatal and perinatal risk factors for brain damage are very important antecedents that should be taken into account to follow up those infants from an early age in order to detect and treat as early as possible an epileptic encephalopathy.

Magnesium valproate in learning disabled children with interictal paroxysmal EEG patterns: Preliminary report.

Previous studies have investigated whether routine use of antiepileptic drugs is adequate to improve cognitive abilities in children who are learning disabled not otherwise specified (LD NOS) and who display interictal paroxysmal patterns in the electroencephalogram (EEG) but do not have epilepsy, and the findings of these studies have been controversial. In the current study, 112 LD children without epilepsy were assessed; however, only 18 met the strict inclusion/exclusion criteria in order to obtain a homogeneous sample. These children showed interictal paroxysmal patterns in the EEG, and a randomized, double-blind trial was carried out on them. The children were treated with either magnesium valproate (MgV; 20mg/kg/day) or a placebo for six months, and differences in WISC subtests, in a computerized reading skills battery (BTL) and EEG recordings were evaluated between groups before and after the treatment period. Performance IQ score and several items of the BTL (rhymes and ordering of words) improved in children who received MgV, whereas no changes were observed in the placebo group. No changes in the number of interictal paroxysmal patterns were observed in any group; however increased EEG currents at 10.92 and 12.87Hz (alpha band) in posterior regions and decreased currents in frequencies within the theta band (3.90, 4.29 and 5.07Hz) in frontal regions and at 4.68 and 5.46Hz in the parietal cortex were observed, suggesting an improvement in EEG maturation.

Analysis of auditory function using brainstem auditory evoked potentials and auditory steady state responses in infants with perinatal brain injury.

Approximately 2-4 % of newborns with perinatal risk factors present hearing loss. The aim of this study was to analyse the auditory function in infants with perinatal brain injury (PBI). Brainstem auditory evoked potentials (BAEPs), auditory steady state responses (ASSRs), and tympanometry studies were carried out in 294 infants with PBI (586 ears, two infants had unilateral microtia-atresia). BAEPs were abnormal in 158 (27%) ears, ASSRs in 227 (39%), and tympanometry anomalies were present in 131 (22%) ears. When ASSR thresholds were compared with BAEPs, the assessment yielded 92% sensitivity and 68% specificity. When ASSR thresholds were compared with tympanometry results as an indicator of middle-ear pathology, the assessment gave 96% sensitivity and 77% specificity. When BAEP thresholds were compared with tympanometry results, sensitivity was 35% and specificity 95%. In conclusion, BAEPs are useful test for neonatal auditory screening; they identify with more accuracy sensorineural hearing losses. ASSRs are more pertinent for identifying conductive hearing loss associated with middle-ear pathology. The consistency and accuracy of these results could be considered in additional studies.

Habituation of visual evoked potentials in healthy infants and in infants with periventricular leukomalacia.

OBJECTIVE: To investigate whether habituation of flash visual evoked potentials is already present during the first 3 months of life, and to explore differences between healthy infants, term infants with periventricular leukomalacia (PVL), and preterm infants with PVL. METHODS: Referential recordings to stimuli consisting of photic stimulation presented in blocks were obtained. A total of 25 blocks, 15-stimuli each, were presented. Intrablock and interblock habituation effects were analyzed. RESULTS: In healthy infants of 42-50 and 51-58 weeks of post-conceptional age (PCA), a negative central component (NCC) showed a significant decrease in amplitude due to stimulus repetition. NCC habituation was also observed in term infants with PVL at 51-58 weeks of PCA, but not in term infants with PVL at 42-50 weeks of PCA. NCC habituation was not apparent in preterm infants with PVL. CONCLUSIONS: These results suggest that the neural mechanisms of visual habituation are normally present during the first month of life, but the presence of PVL delays the emergence of these mechanisms, particularly in preterm infants. SIGNIFICANCE: The habituation of flash visual evoked potentials may be developed into a reliable tool to examine normal and abnormal development of early neural processes.

Repetitive transcranial magnetic stimulation decreases the number of seizures in patients with focal neocortical epilepsy.

PURPOSE: To evaluate the number of seizures and interictal epileptiform discharges (IEDs) in patients with focal neocortical epilepsy before, during and after rTMS. METHODS: Twelve patients (seven men and five women, mean age 29.3+/-15.8 years) were studied. An open-label study with baseline (4 weeks), intervention (2 weeks) and follow-up (8 weeks) periods was carried out. Repetitive transcranial magnetic stimulation (rTMS) with 900 pulses, intensity of 120% motor resting threshold and 0.5Hz frequency was used. A 120 channel EEG was recorded; an electrical source analysis of IEDs with Variable Resolution Electromagnetic Tomography (VARETA) was performed. The number of seizures per week and IEDs per minute were measured and compared in the three periods. RESULTS: During the basal period the mean seizure frequency was 2.25 per week; in the intervention period it decreased to 0.66 per week (F=2.825; p=0.0036) which corresponds to a 71% reduction. In the follow-up period the mean frequency was 1.14 seizures per week, that is, a 50% reduction in the number of seizures. In the visual EEG analysis, the baseline IED frequency was 11.9+/-8.3events/min; it decreased to 9.3+/-7.9 during 2 weeks of rTMS with a further reduction to 8.2+/-6.6 in the follow-up period. These differences however were not significant (p=0.190). CONCLUSION: We conclude that 2 weeks of rTMS at 0.5Hz with a figure-of-eight coil placed over the epileptic focus, determined with VARETA, decreases the number of seizures in patients with focal epilepsy, without reduction in IEDs.

Auditory steady-state responses in infants with perinatal brain injury.

Infants with perinatal brain injury present impairments in motor, visual, auditory, and cognitive functions. The most useful methods for detecting auditory alterations are auditory brainstem responses and otoacoustic emissions. Auditory steady-state responses have been reported as a reliable and objective technique for evaluating the hearing threshold. Auditory brainstem responses and auditory steady-state responses were carried out in 53 infants with perinatal brain injury and abnormal neurologic findings. With auditory brainstem responses, 33 (62.26%) infants presented normal and 20 abnormal results; 8 (15.09%) exhibited mild alterations, 8 (15.09%) moderate, and 4 (7.54%) severe alterations. With auditory steady-state responses, 17 (32.0%) infants were normal and 36 (67.9%) had abnormal results. When auditory steady-state responses were compared with auditory brainstem responses gold standard, the assessment gave 100% sensitivity, 51.51% specificity, 55.55% positive predictive value, and 100% negative predictive value. Abnormalities were mild in 21 (39.6%) infants, moderate in 10 (18.9%), and 5 (9.4%) exhibited severe hearing loss. We conclude that hearing loss is a frequent abnormality in infants with perinatal brain injury, and auditory steady-state responses have a high sensitivity for detecting hearing impairment, which is more evident in mild hearing loss for specific frequencies.