Trevor Resnick

Magnetic resonance imaging evidence of hippocampal sclerosis in progression: a case report.

Summary: A 32‐month‐old child presented in status epilepticus (SE) involving the left side of the body. Fast spin‐echo magnetic resonance imaging (FSE‐MRI) with hippocampal volumetry performed ≤24 h after the seizure showed increased T2 signal of the right hippocampus, but no atrophy. Complex partial seizures (CPS) appeared at age 33 months, and three more episodes of SE occurred between 33 and 37 months of age. Follow‐up FSE‐MRI at 34 and at 45 months of age demonstrated progressive hippocampal atrophy with resolution of the increased T2 signal. Her CPS became intractable and, at age 51 months, she underwent right temporal lobectomy. In the ensuing 5 months, she has had only one major motor seizure. This case demonstrates that acute increased hippocampal T2 signal intensity can occur soon after SE and hippocampal sclerosis (HS) may become evident within months in the setting of recurrent early childhood SE. This observation may support the hypothesis that early childhood SE can lead to HS. Furthermore, this case suggests that years of temporal lobe CPS may not be necessary for development of HS.

A Safe and Effective Paradigm to Functionally Map the Cortex in Childhood

Conventional cortical stimulation based on pulses of fixed duration briefer than the chronaxie rarely elicit responses in infants and young children. We developed a stimulation paradigm that relies on increments in both stimulus intensity and pulse duration. This approach ensures that stimulation parameters converge to the chronaxie by mathematically minimizing the energy required to elicit a response. In six patients, this paradigm successfully elicited clinical responses and/or afterdischarges at thresholds 5-8 mA below the standard paradigm and at up to 64% lower energy levels. Furthermore, three patients under age 5 years who did not respond to maximal fixed duration stimulation demonstrated afterdischarges and clinical responses when longer pulse durations were utilized. These findings indicate that a paradigm based on dual increments is effective for cortical mapping in children. Furthermore, by ensuring responses at lower energy levels, it may be more efficient for mapping the cortex at all ages.

Localization of seizure foci: pitfalls and caveats.

The pitfalls and difficulties in accurately localizing seizure foci are reviewed. Basic issues regarding modeling, volume conduction, inhomogeneities, and corticocortical propagation are discussed, and the limitations of scalp and intracranial recordings are outlined. The ambiguities in interpreting patterns and their significance are highlighted with a concluding commentary on pitfalls in defining the epileptogenic region.

Subdural monitoring in the evaluation of children for epilepsy surgery.

Noninvasive assessment of children with chronic epilepsy is often imprecise and localization of seizure foci requires intracranial electroencephalographic monitoring. Subdural electrodes provide coverage of large areas of neocortex and are ideally suited for evaluating children with intractable epilepsy and to functionally map critical cortex. This report discusses the role of subdural electroencephalography in the evaluation of childhood epilepsy. (J Child Neurol 1994; 9(Suppl):2S61-2S66).

EEG and brain death determination in children

In a retrospective study involving several medical centers we identified 52 patients under age 5 years who met the adult clinical criteria for brain death and had at least one EEG with electrocerebral silence. Of the 52 patients, 31 died spontaneously and 21 were disconnected from the respirator. Repeat EEGs were obtained in 28 patients, and in all electrocerebral silence persisted. The study suggests that clinical criteria similar to those used for adults in the determination of brain death can also be applied to children above age 3 months and that a single EEG with electrocerebral silence is sufficient to confirm brain death in this age group.

Surgery for Epilepsy Due to Cortical Malformations: Ten‐year Follow‐up

Summary:  Children with malformations of cortical development represent a significant proportion of pediatric epilepsy surgery candidates. From a cohort of 40 children operated on between 1980 and 1992 with malformation of cortical development, 38 were alive and had data 10 years after surgery. Age at surgery ranged from 6 months to 18 years (mean, 9.6 years). Thirty‐six had partial seizures, and two had infantile spasms; 20 were nonlesional. Pathologic diagnoses were cortical dysplasia (n = 31) and developmental tumor (n = 7). At 10‐year follow‐up, 15 (40%) were seizure free, 10 (26%) had >90% seizure reduction, and 13 (34%) were improved or unchanged. Children seizure free at two‐year follow‐up were likely to remain seizure free. Ten‐year seizure freedom was 72% in children with developmental tumors and 32% in the cortical dysplasia group. Complete resection was statistically significant for favorable outcome, and no patient with an incomplete resection was seizure free.

The use of stereotactic radiosurgery to treat intractable childhood partial epilepsy.

Summary:  Purpose: Although conventional surgery is presently used to treat seizures of temporolimbic and neocortical origin, deep‐seated lesions are often associated with morbidity. Stereotactic radiosurgery is a noninvasive procedure that effectively treats patients with vascular malformations and brain tumors, but its efficacy for epileptogenic foci is limited, especially in children.

Medical intractability in children evaluated for epilepsy surgery

We assessed the value of therapeutic reevaluation and additional pharmacotherapy in medically intractable children referred for epilepsy surgery. In 21 children with antiepileptic drug treatment omissions, correcting the omission was ineffective in 19 (90%). Two children (10%), both of whom had structural lesions, achieved significant seizure control with high-dose carbamazepine monotherapy. Therapeutic reevaluation is indicated in all medically intractable children prior to epilepsy surgery.

Surgery for medically intractable temporal lobe epilepsy during early life

Purpose: Temporal lobe epilepsy (TLE) in early life is often a catastrophic disorder with pharmacoresistant seizures and secondary neurological deterioration. There is little data available regarding epilepsy surgery performed in infants and young children and no prior study has focused on TLE.

Ictal head deviation Lateralizing significance of the pattern of head movement

To resolve the controversy surrounding the lateralizing value of ictal head deviation, we analyzed head-turning movements in relation to the actions of the two divisions of the sternocleidomastoid muscle. In 12 (75%) of 16 patients with surgically confirmed lateralized seizure foci, the face rotated upward and contraversive to the hemisphere of seizure origin, consistent with activation of the ipsilateral sternomastoid muscle. One patient showed a sustained, downward ipsiversive head tilt consistent with the action of the ipsilateral cleidomastoid muscle, and three patients had a combined ipsiversive head tilt and contraversive face rotation. No patient exhibited ipsiversive upward face rotation or contraversive head tilting, as would be expected if the contralateral sternocleidomastoid were activated. Our findings indicate that hemispheric seizure foci activate one or both divisions of the ipsilateral sternocleidomastoid muscle. Accurate lateralization of the seizure focus is possible only when ictal head deviation is assessed in the context of the different actions of the sternomastoid and cleidomastoid muscle divisions.To resolve the controversy surrounding the lateralizing value of ictal head deviation, we analyzed head-turning movements in relation to the actions of the two divisions of the sternocleidomastoid muscle. In 12 (75%) of 16 patients with surgically confirmed lateralized seizure foci, the face rotated upward and contraversive to the hemisphere of seizure origin, consistent with activation of the ipsilateral sternomastoid muscle. One patient showed a sustained, downward ipsiversive head tilt consistent with the action of the ipsilateral cleidomastoid muscle, and three patients had a combined ipsiversive head tilt and contraversive face rotation. No patient exhibited ipsiversive upward face rotation or contraversive head tilting, as would be expected if the contralateral sternocleidomastoid were activated. Our findings indicate that hemispheric seizure foci activate one or both divisions of the ipsilateral sternocleidomastoid muscle. Accurate lateralization of the seizure focus is possible only when ictal head deviation is assessed in the context of the different actions of the sternomastoid and cleidomastoid muscle divisions.