The effect of electrophysiological and neuroimaging findings on the prognosis of juvenile myoclonic epilepsy proband.

Background: Juvenile myoclonic epilepsy (JME) is a well-defined idiopathic generalized epileptic syndrome, and diagnostic criteria for JME are to have a normal brain imaging and clinical evidence of typical epileptic seizures. The aim of this study is to evaluate electrophysiological and neuroimaging findings of JME and determine their relationship with prognosis.

Methods: Thirty-two patients (23 women and nine men) with a mean age of 22 (16-37) years were included in this study. Interictal electroencephalography (EEG), magnetic resonance imaging (MRI) and single photon emission computed tomography (SPECT) were carried out in all patients.

Results: Analysis of premedication EEGs revealed primary generalized pattern activity in 75% (n=24) and focal abnormalities in 18.75% (n=6). MRI was abnormal in seven (21.88%) patients (two with arachnoid cyst, two with mild cerebral atrophy, two with ventricular enlargement and one with single gliotic lesion), and SPECT imaging detected hypoperfusion in 15 (47%) patients. Hypoperfusion was mostly found on the parietal lobe.

Conclusion: We found that, after medication, only 6.25% of EEGs had primary generalized pattern activity (p<0.0001); nevertheless, the prognosis was good in patients who had typical EEG findings (p=0.106). The prognosis of patients with MRI abnormalities was grave (p=0.023). Twenty percent of the patients who had SPECT abnormalities were seizure free, and 80% of them had been partially controlled (p=0.059). There were no correlations between MRI abnormalities, EEG and SPECT findings.