Summary:Purpose: The value of scalp recordings to localize and lateralize seizure onset in temporal lobe epilepsy has been assessed by comparing simultaneous scalp and intracranial foramen ovale (FO) recordings during presurgical assessment. The sensitivity of scalp recordings for detecting mesial temporal ictal onset has been compared with a "gold standard" provided by simultaneous deep intracranial FO recordings from the mesial aspect of the temporal lobe. As FO electrodes are introduced via anatomic holes, they provide a unique opportunity to record simultaneously from scalp and mesial temporal structures without disrupting the conducting properties of the brain coverings by burr holes and wounds, which can otherwise make simultaneous scalp and intracranial recordings unrepresentative of the habitual EEG.Methods: Simultaneous FO and scalp recordings from 314 seizures have been studied in 110 patients under telemetric presurgical assessment for temporal lobe epilepsy. Seizure onset was identified on scalp records while blind to recordings from FO electrodes and vice versa.Results: Bilateral onset (symmetric or asymmetric) was more commonly found in scalp than in FO recordings. The contrary was true for unilateral seizure onset. In seizures with bilateral asymmetric onset on the scalp, the topography of largestamplitude scalp changes at onset does not have localizing or lateralizing value. However, 75-76% of seizures showing unilateral scalp onset with largest amplitude at T1/T2 or T3/T4 had mesial temporal onset. This proportion dropped to 42% among all seizures with a unilateral scalp onset at other locations. Of those seizures with unilateral onset on the scalp at T1/T2, 65.2% showed an ipsilateral mesial temporal onset, and 10.9% had scalp onset incorrectly lateralized with respect to the mesial temporal onset seen on FO recordings. In seizures with a unilateral onset on the scalp at electrodes other than T1/T2, the proportions of seizures with correctly and incorrectly lateralized mesial temporal onset were 37.5 and 4.2%, respectively. Thus the ratio between incorrectly and correctly lateralized mesial temporal onsets is largely similar for seizures with unilateral scalp onset at T1/T2 (16.7%) and for seizures with unilateral scalp onset at electrodes other than T1/T2 (11.2%). The onset of scalp changes before the onset of clinical manifestations is not associated with a lower proportion of seizures with bilateral onset on the scalp, or with a higher percentage of mesial temporal seizures or of mesial temporal seizures starting ipsilateral to the side of scalp onset. In contrast, the majority (78.4%) of mesial temporal seizures showed clinical manifestations starting after ictal onset on FO recordings.Conclusions: A bilateral scalp onset (symmetric or asymmetric) is compatible with a mesial temporal onset, and should not deter further surgical assessment. Although a unilateral scalp onset at T1/T2 or T3/T4 is associated with a higher probability of mesial temporal onset, a unilateral onset at other scalp e...

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Introduction: Hydrocephalus is a common central nervous system disorder in children. In spite of its importance, it has not been subjected to sufficient epidemiological studies, particularly in the developing countries. The aim of this study was to provide information from a representative series of newly diagnosed cases of infantile hydrocephalus on the birth prevalence, associated factors and mortality. Methodology: A prospective study was conducted over a 1-year period from April 1996 to March 1997 in the city of Al-Madinah Al-Munawarah, Saudi Arabia. Except for neural tube defects and brain tumors, all cases of hydrocephalus diagnosed within the first 28 days of life were included. A control group of 104 subjects was studied for comparison. Information about antenatal, natal and early postnatal periods were obtained by interviewing the mothers of the newborns. Results: During the study period, 26 cases of infantile hydrocephalus were detected. The birth prevalence was 1.6 per 1,000 live births. There was no sex preponderance as the male to female ratio was 1.2:1. Multiple pregnancies were detected in 21 (81%) cases. Nineteen (73%) cases were the product of consanguineous parent and 4 patients had a positive family history of hydrocephalus. The number of preterm infants was 16 (62%). The number of low birth weights (less than 2,500 g) was 18 (69%). An Apgar score of less than 8 occurred in 18 (69%) cases. The mode of delivery was vaginal in 15 (58%) women. The 6 months mortality rate was 23% (6 infants). Conclusion: The birth prevalence of infantile hydrocephalus in this study was significantly higher than in the developed countries. A positive family history of hydrocephalus, low birth weight, low Apgar score and abdominal delivery were found to be associated factors. The mortality rate in the first 6 months of life was significantly higher in hydrocephalus infants than in controls.