The Evolution of Subclinical Seizures in Children With Tuberous Sclerosis Complex

Background:Subclinical seizures are electrographic seizures that present without subjective or objective clinical symptoms. In tuberous sclerosis complex, it is not known whether subclinical seizures occur alone, forewarn, or coexist with clinical seizures. To address this knowledge gap, we studied the prevalence and evolution of subclinical seizures in tuberous sclerosis complex.Methods:We retrospectively reviewed electroencephalography (EEG) data from our tuberous sclerosis complex clinic with subclinical seizures and clinical seizures in a blinded fashion. Based on EEG location and ictal pattern, subclinical seizures were classified as having a clinical counterpart from the same epileptogenic region (match) or not (no match).Results:Of 208 children with tuberous sclerosis complex, 138 had epilepsy and available EEG data. Subclinical seizures were detected in 26 of 138 (19%) children. Twenty-four children had both subclinical seizures and clinical seizures captured on EEG. In 13 of 24, subclinical seizures were detected as a novel, not previously recorded seizure type. In these children, subclinical seizures preceded matching clinical seizures in 4 (31%) within a median time of 4.5 months (range 2-14), whereas 9 (69%) never had any matching clinical seizure. In 11 of 24 children, subclinical seizures were not novel and could be matched to a previously recorded clinical seizure. Matching seizure types were focal (n = 10, 67%), tonic (n = 2), epileptic spasms (n = 2), and status epilepticus (n = 1).Conclusions:Subclinical seizures occur in one-fifth of children with tuberous sclerosis complex and epilepsy, and match with clinical seizures in a small majority. In a third of patients presenting with a novel subclinical seizure, matching clinical seizures follow.

Association between Familial Deficiency of Mannose-Binding Lectin and Mutations in the Corresponding Gene and Promoter Region

ABSTRACT In a recent report, our group presented clinical research data supporting the role of mannose-binding lectin (MBL) deficiency in susceptibility to meningococcal disease (W. A. Bax, O. J. J. Cluysenaer, A. K. M. Bartelink, P. C. Aerts, R. A. B. Ezekowitz, and H. van Dijk, Lancet 354:1094-1095, 1999). This association was reported earlier by Hibberd et al. (M. L. Hibberd, M. Sumiya, J. A. Summerfield, R. Booy, M. Levin, and the Meningococcal Research Group, Lancet 353:1049-1053, 1999) but was not based on family data. Our study included three members of one family who had acquired meningococcal meningitis in early adulthood. The objective of the present study was to investigate whether the genotypes of the MBL gene in this family, analyzed by PCR, correlate with MBL concentrations. We found that genotype variants in the MBL gene and promoter region match the low functional MBL levels (<0.25 μg of equivalents/ml) in the sera of the three patients in this family and that a significant correlation between genotype MBL deficiency and meningococcal disease existed.