Clinical Comparative Study Of Children With Typical And Atypical Absence Seizures

Objective: To compare the clinical features of the children with typicaland atypical absence seizures, and improve our understanding oftypical/atypical absence seizures.Methods: Twenty children with typical absence seizures (the typicalabsence group) and21children with atypical absence seizures (the atypicalabsence group) were compared in terms of the clinical features, who werecollected from the ward and outpatient of the first hospital of Jilin University,from December2010to February2014.Results: There were20patients in the typical group,13females and7males, and21patients in the atypical group,13females and8males，and therewas significant difference in the age of onset (7.31±2.87years vs3.20±2.11years) between the two groups (p＜0.05). The was no significantdifference in the age of medical treatment in the two groups [0.73±0.75years vs1.18±1.69years](p＞0.05)。Typical vs atypical group, change in facial expression/blank stare（60.0vs28.6%）,decreased speed or pause in motor activity（50.0vs19.0%）, clonic（35.0vs9.5%），atonic（15.0vs71.4%）has statistically significant differencein the two groups（P＜0.05），tonic（20.0vs38.1%）has no statistically significant difference（P＞0.05），4children with automatisms were all in thetypical absence group（2were presented with lip snacking，2were presentedwith grope）.There were statistically more tonic seizures in the atypical absencegroup than in the typical absence group（P＜0.05）.An MRI/CT was performed in all children of both groups and was normalin20of the typical absence group and19of the atypical absence, in2patientsof the atypical group an abnormality was found（1had ventricular enlargement,corpus callosum thinning and the other had bilateral occipital limitation atrophy,and abnormal signal of bilateral occipital lobe）.There was statistically significant difference in the normal EEGbackground of typical and atypical group(100.0vs47.6%，P＜0.05).There wereno significant difference in focal and multiply discharges in the two groups(20.0vs42.9%，P＞0.05) and the occipital intermittent rhythmic delta activity(OIRDA) were observed only in the typical absence group.There were18patients in the typical group who underwenthyperventilation, and typical absence seizures can be induced in all of them,while there were10patients in the atypical absence group who underwenthyperventilation, and atypical absence seizures could be induced only in two ofthem.The outcome following3months,6moths,12moths has statisticallysignificant difference between the two groups (P＜0.05), but the outcomefollowing6moths,12moths have no statistically significant difference in the both groups (P＞0.05).The cognition at the initial,following6month,12monthhas statistically significant difference between the two groups (P＜0.05), butthe treatment in both groups at the following6month,12month have nostatistically significant difference (P＞0.05).Conclusion:1.There are more females than males in both typical andatypical absence groups and the age of the onset of the atypical group is earlierthan typical seizure.2. The change in facial expression/blank stare, decreasedspeed or pause in motor activity, clonic, atonic is more common in the typicalgroup.3. The children with atypical seizure often have abnormal EEGbackground, abnormal neuroimaging and cognitive dysfunction.4. The inducingrate of the hyperventilation in the typical absence group is higher.5. Atypicalabsence seizures are often seen in intractable epilepsy syndrome, and havepoorer outcome.