Authors :
Presenting Author: BOSTON Moschopoulos, MD – Boston Children's Hospital
Patrick Davis, MD – Resident, Neurology, Boston Children's Hospital; Jurriaan Peters, MD – Neurology – Boston Children's Hospital; Masanori Takeoka, MD – Neurology – Boston Children's Hospital; Scellig Stone, MD – Neurosurgery – Boston Children's Hospital; Phillip Pearl, MD – Neurology – Boston Children's Hospital
Rationale:
Posterior cingulate epilepsy (PCE) is rare, underrecognized, and has not yet been well described in the pediatric population. The generator is located in an anatomically deep brain region, and scalp EEG findings are nonspecific. Intracranial EEG evaluation is required to delineate the epileptogenic zone. We present sEEG analysis of two children with medically refractory PCE and identify a common network as described in adults.
1 Methods:
Right hemisphere sEEG implantations were obtained on a seven year old girl with a history of perinatal right thalamic hemorrhage with intraventricular extension complicated by hydrocephalus, ventriculoperitoneal shunting (VP) and right mesial temporal sclerosis (MTS) and a five year old girl with a right posterior cingulate-mesial temporal focal cortical dysplasia.
Results:
Both sEEG recorded electrographic and typical electroclinical asymmetric tonic seizures arising from the right posterior cingulate cortical electrodes. The seizure spread zone involved the orbitofrontal cortex, lateral premotor area, mesial frontal (SMA and paracentral lobule), precuneus, inferior parietal lobule, mesial temporal lobe, anterior cingulate, and other posterior cingulate contacts within two seconds. Stimulation of the posterior-cingulate cortex resulted in robust cortico-cortical evoked potentials (CCEP), which were used to estimate effective connectivity. Strong connectivity was observed between the posterior cingulate and orbitofrontal cortex, lateral premotor area, paracentral lobule, precuneus, inferior parietal lobule, mesial temporal lobe, anterior, middle, and posterior cingulate. Strong connectivity was also observed between sites within the putative seizure onset zone. The first patient had laser ablation of the right posterior cingulate and inferior precuneus and remained seizure-free for five months, followed by one episode suspicious for a seizure, compared to one cluster of seizures every two months preoperatively. The second patient had laser ablation of the right posterior cingulate and mesial temporal lobe. She had one cluster of seizures at four weeks within thirteen weeks of post-operative follow-up, compared to one cluster of seizures every two weeks preoperatively.
Conclusions:
This study displays the semiology and network of PCE in two young children, similar to descriptions in adults.
1 Hyperconnectivity of this network was demonstrated using CCEPs. Asymmetric tonic seizures and the seizure spread zone are characteristic of this challenging focal epilepsy and are related to the extensive connectivity of this region. PCE manifests through the network despite otherwise being a relatively clinically silent area.
Reference
1 Enatsu R, Bulacio J, Nair DR, Bingaman W, Najm I, Gonzalez-Martinez J. Posterior cingulate epilepsy: Clinical and neurophysiological analysis. J Neurol Neurosurg Psychiatry. 2014;85(1). doi:10.1136/jnnp-2013-305604
Funding: None