Subdural EEG Patterns in Children with Cortical Dysplastic and Nondysplastic Lesions
Abstract number :
1.191
Submission category :
Year :
2001
Submission ID :
692
Source :
www.aesnet.org
Presentation date :
12/1/2001 12:00:00 AM
Published date :
Dec 1, 2001, 06:00 AM
Authors :
D. Turkdogan, MD, Neuroscience Center, Miami Children[ssquote]s Hospital, Miami, FL; P. Jayakar, PhD, MD, Neuroscience Center, Miami Children[ssquote]s Hospital, Miami, FL; M. Duchowny, MD, Neuroscience Center, Miami Children[ssquote]s Hospital, Miami, FL
RATIONALE: To investigate and compare interictal and ictal patterns recorded with chronic intracranial electrodes in children with focal cortical dysplasia (CD) and non-dysplastic (NCD) lesions (low-grade tumor or gliosis).
METHODS: Interictal epileptiform discharges and ictal onset and propagation patterns were retrospectively analyzed in 10 children (6F,4M) aged 4-14 (mean 7.53) years with CD and in 9 children (4F, 5M) aged 6.3-17 (mean 12.70) years with NCD (tumor-4; gliosis-5). Interictal patterns were classified as single spikes or repetitive epileptiform discharges (REDs) consisting of bursts of spikes/fast activity. Ictal patterns were classified by extent of ictal onset zone (focal, regional or diffuse) and morphology.
RESULTS: [underline]Interictal Patterns[/underline]: Interictal recordings revealed REDs in 10 CD (spikes-8 , fast activity-7) and 9 NCD (tumor-3, gliosis-6) (spikes-5, fast activity-6) patients. Interictal recordings revealed isolated spikes in 4 CD cases and 7 NCD cases.
[underline]Ictal Onset Patterns[/underline]: Fifty seizures in 10 CD patients revealed continuous spikes (n=29), low amplitude fast (n=39), electrodecrement (n=22) and DC shift (n=13). In 42 seizures of 9 NCD patients, there were continuous spikes (n=26), low amplitude fast (n=16), electrodecrement (n=4) and DC shift (n=4). The two groups were not statistically different.
[underline]Ictal Localization[/underline]: Ictal onset was focal in 37/53 (70%) seizures of CD patients and 30/42 (71%) seizures of NCD patients. Ictal onset was regional in 15 CD seizures and 12 NCD seizures. Diffuse onset was recorded in 1 CD seizure. Localization of ictal onset correlated with interictal abnormalities in 47 CD seizures (89%) and 30 NCD seizures (71%). These differences were also not statistically significant. In contrast, the interval between seizure onset and propagation was significantly shorter in CD patients (mean 7.71 sec) compared to NCD patients (mean 30.71 sec; p[lt] 0.03).
CONCLUSIONS: Ictal onset patterns and interictal discharges are similar in childhood seizures due to CD and NCD. REDs assist in localization of the epileptogenic zone but do not always demarcate its extent. However, propagation is significantly more rapid and more extensive in seizures due to CD.