Related Experiment Videos
Temporal lobe epilepsy due to hippocampal sclerosis in pediatric candidates for epilepsy surgery
A Mohamed1, E Wyllie, P Ruggieri
1Department of Neurology, The Cleveland Clinic Foundation, OH 44195, USA.
Insights
Pediatric temporal lobe epilepsy (TLE) with hippocampal sclerosis (HS) shows similar features and seizure outcomes to adults. Dual pathology, common in children, does not negatively impact surgical results.
Area of Science:
- Pediatric Neurology
- Epileptology
- Neuroimaging
- Surgical Neurology
Background:
- Temporal lobe epilepsy (TLE) with hippocampal sclerosis (HS) is a common cause of intractable seizures in children and adolescents.
- Understanding the specific clinical, imaging, and histopathological features of pediatric TLE-HS is crucial for surgical planning and predicting outcomes.
- Previous studies have primarily focused on adult populations, leaving a gap in knowledge regarding pediatric TLE-HS characteristics.
Purpose of the Study:
- To comprehensively characterize the clinical, electroencephalography (EEG), magnetic resonance imaging (MRI), and histopathologic features of pediatric TLE caused by HS.
- To explore the seizure outcomes following epilepsy surgery in this specific pediatric population.
- To compare findings in children and adolescents with TLE-HS.
Main Methods:
- Retrospective study of 17 children (4-12 years) and 17 adolescents (13-20 years) who underwent anteromesial temporal resection between 1990 and 1998.
- Analysis included clinical seizure semiology, EEG findings (interictal spikes), MRI (hippocampal sclerosis, temporal neocortical abnormalities), and histopathology.
- Seizure outcome was assessed at a mean follow-up of 2.6 years.
Main Results:
- Seizures were characterized by decreased awareness and responsiveness, with varying automatisms between age groups.
- MRI confirmed HS in all patients; subtle temporal neocortical abnormalities were frequent, especially in children.
- Dual pathology (HS with cortical dysplasia) was found in 79% of patients, higher than expected, but did not predict poor surgical outcome.
- Seventy-eight percent of patients achieved seizure freedom post-surgery, comparable to adult series.
Conclusions:
- Pediatric TLE-HS presents with features similar to adults, occurring in children as young as 4 years.
- Focal hippocampal atrophy may not always be evident in total hippocampal volumetry on MRI.
- Children exhibit a high incidence of dual pathology, often predicted by MRI, but this does not adversely affect seizure control.
- Epilepsy surgery for TLE-HS in pediatric patients yields outcomes comparable to those reported in adult studies.
Objective:
To characterize the clinical, EEG, MRI, and histopathologic features and explore seizure outcome in pediatric candidates for epilepsy surgery who have temporal lobe epilepsy (TLE) caused by hippocampal sclerosis (HS).
Methods:
The authors studied 17 children (4 to 12 years of age) and 17 adolescents (13 to 20 years of age) who had anteromesial temporal resection between 1990 and 1998.
Results:
All patients had seizures characterized by decreased awareness and responsiveness. Automatisms were typically mild to moderate in children and moderate to marked in adolescents. Among adolescents, interictal spikes were almost exclusively unilateral anterior temporal, as opposed to children in whom anterior temporal spikes were associated with mid/posterior temporal, bilateral temporal, extratemporal, or generalized spikes in 60% of cases. MRI showed hippocampal sclerosis on the side of EEG seizure onset in all patients. Fifty-four percent of children and 56% of adolescents had significant asymmetry of total hippocampal volumes, whereas the remaining patients had only focal atrophy of the hippocampal head or body. Subtle MRI abnormalities of ipsilateral temporal neocortex were seen in all children and 60% of adolescents studied with FLAIR images. On histopathology, there was an unexpectedly high frequency of dual pathology with mild to moderate cortical dysplasia as well as HS, seen in 79% of children and adolescents. Seventy-eight percent of patients were free of seizures at follow-up (mean, 2.6 years). A tendency for lower seizure-free outcome was observed in patients with bilateral temporal interictal sharp waves or bilateral HS on MRI. The presence of dual pathology did not portend poor postsurgical outcome.
Conclusions:
TLE caused by HS similar to those in adults were seen in children as young as 4 years of age. Focal hippocampal atrophy seen on MRI often was not reflected in total hippocampal volumetry. Children may have an especially high frequency of dual pathology, with mild to moderate cortical dysplasia as well as HS, and MRI usually, but not always, predicts this finding. Postsurgical seizure outcome is similar to that in adult series.