Monisha Goyal

Effect of topiramate on seizures and respiratory dysrhythmia in Rett syndrome

Rett syndrome, a neurodevelopmental disorder, manifests in the first few years of life with developmental arrest, stereotyped behaviors, and respiratory abnormalities. Seizures occur in 70 to 80% of patients. Clinical drug trials have not demonstrated the superiority of any specific antiepilepsy drug. We report our experience with topiramate in eight patients with Rett syndrome. Topiramate was initiated as monotherapy in two patients and as adjunctive therapy in six patients. Seven patients had improved seizure control. Respiratory abnormalities improved by 50 to 75% in two patients and by 20 to 50% in two others. In our cohort, seven of eight patients showed improvement in seizure control and/or respiratory abnormalities on topiramate. Topiramate was well tolerated. The effect of topiramate, a broad-spectrum drug, could be due to its γ-aminobutyric acid (GABA)ergic and glutaminergic effects, both systems thought to be disordered in Rett syndrome. (J Child Neurol 2004;19:588-591).

Loss of cation-chloride cotransporter expression in preterm infants with white matter lesions: implications for the pathogenesis of epilepsy.

Epilepsy associated with preterm birth is often refractory to anticonvulsants. Children who are born preterm are also prone to cognitive delay and behavioral problems. Brains from these children often show diffuse abnormalities in cerebral circuitry that is likely caused by disrupted development during critical stages of cortical formation. To test the hypothesis that prenatal injury impairs the developmental switch of &ggr;-amino butyric acid (GABA)ergic synapses from excitatory to inhibitory, thereby disrupting cortical circuit formation and predisposing to epilepsy, we used immunohistochemistry to compare the expression of cation-chloride transporters that developmentally regulate postsynaptic GABAergic discharges in postmortem cerebral samples from infants born preterm with known white matter injury (n = 11) with that of controls with minimal white matter gliosis (n = 7). Controls showed the expected developmental expression of cation-chloride transporters NKCC1 and KCC2 and ofcalretinin, a marker of a GABAergic neuronal subpopulation. Samples from infants with white matter damage showed a significant loss of expression of both NKCC1 and KCC2 in subplate and white matter. By contrast, there were no significant differences in total cell number or glutamate transporter VGLUT1 expression. Together, these novel findings suggest a molecular mechanism involved in the disruption of a critical stage of cerebral circuit development after brain injury from preterm birth that may predispose to epilepsy.

High-resolution MRI enhances identification of lesions amenable to surgical therapy in children with intractable epilepsy.

Summary:  Purpose: Many children with refractory epilepsy can achieve better seizure control with surgical therapy. An abnormality on magnetic resonance imaging (MRI), along with corroborating localization by other modalities, markedly increases chances of successful surgical outcome. We studied the impact of high‐resolution MRI on the surgical outcome of intractable epilepsy.

Expanding the role of surgery in intractable extratemporal pediatric epilepsy

The aim of epilepsy surgery in children is not only to control seizures but also to curtail future adverse neurological sequelae and improve quality of life. If presurgical evaluation demonstrates discordant or multifocal disease, intracranial surgery may be denied as a viable treatment option. When surgical therapy is offered not just as curative but also as palliative therapy, many children not considered optimal surgical candidates may benefit. From a consecutive series of 57 cases involving children who underwent intracranial epilepsy surgery at Rainbow Babies and Childrens Hospital during 2001-2005, the authors present in detail 3 cases involving children who benefited significantly from such an aggressive approach. Marked improvement occurred not only in seizure control, but also in developmental and social functioning.

Rasmussen syndrome and CNS granulomatous disease with NOD2/CARD15 mutations

Rasmussen syndrome (RS) is a clinical diagnosis characterized by persistent focal seizures in a previously healthy child. Occasionally, the typical features of RS may be followed by another diagnosis. We discuss the course of a 12-year-old girl who presented with RS but was later diagnosed with CNS granulomatous disease and NOD2/CARD15 mutations. Her response to infliximab suggests that it should be included in immune-modulatory therapies used to treat these refractory disorders.