FDG-PET/MRI coregistration improves detection of cortical dysplasia in patients with epilepsy

Area of Science:

• Neuroimaging
• Epilepsy Surgery
• Medical Diagnostics

Background:

• Cortical dysplasia (CD) presents diagnostic challenges in epilepsy surgery due to often undetectable MRI abnormalities.
• Accurate identification of CD is crucial for successful surgical intervention and patient outcomes.

Purpose of the Study:

• To determine if fluorodeoxyglucose (FDG)-PET/MRI coregistration enhances the recognition of cortical dysplasia (CD) in epilepsy surgery candidates.
• To compare the diagnostic yield of FDG-PET/MRI coregistration with standard presurgical evaluation methods.

Main Methods:

• A comparative study analyzing patients undergoing presurgical evaluation for epilepsy between 2000-2003 (without FDG-PET/MRI) and 2004-2007 (with FDG-PET/MRI).
• Neuroimaging and clinical variables were analyzed, distinguishing between mild (Palmini type I) and severe (Palmini type II) CD.
• Concordance between EEG and neuroimaging findings was assessed.

Main Results:

• The FDG-PET/MRI coregistration cohort (2004-2007) showed increased CD detection, particularly mild type I CD, with fewer requiring invasive intracranial electrodes.
• In the 2004-2007 cohort, 85% of type I CD cases had normal non-UCLA MRI scans; UCLA MRI detected CD in 78% of patients.
• FDG-PET scans were positive in 71% of CD cases, revealing less hypometabolism in type I vs. type II CD. Postoperative seizure freedom was 82%.

Conclusions:

• Integrating FDG-PET/MRI coregistration significantly enhances noninvasive identification of cortical dysplasia (CD) in epilepsy surgery evaluations.
• This technique is particularly beneficial for patients with nonconcordant findings or normal MRI scans, especially in mild type I CD.
• The improved diagnostic accuracy facilitated successful surgical treatment for CD patients.