Abstracts

Rationale: Focal Cortical Dysplasia (FCD) is a common malformation of cortical development and one of the most common etiologies of intractable epilepsy in pediatric and adult population.  As these patients fail multiple AEDs, they often undergo pre-surgical evaluation that includes multiple MRI evaluations. We are reporting interval cystic transformation seen on MRI of two patients with FCD. An extensive review of the literature on FCD did not reveal that such findings were previously reported. Methods: Case review series. Results: The MRI studies of the two patients with intractable epilepsy and FCD were analyzed. After careful review of the imaging, we noted that these patients developed cystic transformation, which were not present on the earlier MRI.   Patient 1.Initial brain MRI from 4/27/2006 (Figure 1 A) showed FCD without evidence of cystic lesions, which were apparent on the follow up MRI from 8/26/16 (Figure 1 B, C.) Patient 2.Initial brain MRI from 2000 (Figure 2 A) showed FCD without evidence of cystic lesions, which were noted on the follow up MRI from 3/1/2017 (Figure 2B, 2C.) Conclusions: Our review of these two cases demonstrates that FCD lesions can go on to develop cystic transformation.  The significance of these changes and their impact on seizure frequency is unknown and needs further investigation. This observation illustrates the need to account for cystic transformation in FCD lesions and raises the question whether resecting the cystic component is vital for achieving a seizure freedom. This question becomes important in cases where cystic changes overly an eloquent cortex as they cannot be fully resected. Funding: None