RESUMO
<p><b>OBJECTIVE</b>To investigate whether mammalian target of rapamycin (mTOR) kinase was abnormally activated in maldeveloped balloon cells and dysmorphic neurons of focal cortical dysplasia (FCD) with refractory epilepsy.</p><p><b>METHODS</b>A total of 12 archival cases of FCD typeIIwith medically intractable epilepsy treated between 2008 and 2010 were retrieved. Perilesional brain tissue was used as control specimens (n = 8). The expression of phosphorylated p-AKT (Ser473), p-mTOR (Ser2448) and p-P70S6K (Thr389) was investigated by imunocytochemistry.</p><p><b>RESULTS</b>The expression of p-AKT (Ser473), p-mTOR (Ser2448) and p-P70S6K (Thr389) was found in meldeveloped balloon cells and dysmorphic neurons of FCD. A weak stain in a small amount of pyramid neurons was also found in the control group.</p><p><b>CONCLUSION</b>Abnormal activation of mTOR in maldeveloped balloon cells and dysmorphic neurons of FCD may be a key molecular mechanism underlying the histological changes and repeated seizures.</p>