Utility of MRI in patients presenting with first time seizure. (P6.290)

OBJECTIVE: To investigate if MRI after first seizure provided additional etiological information compared to CT scan in patients with a normal neurological examination. BACKGROUND: New clinical definition of epilepsy suggests that a patient may be diagnosed with epilepsy even after one unprovoked seizure if the risk of recurrence is high (>60[percnt]). Brain imaging is an important part of this evaluation. The AAN in 2007 recommended imaging with a brain CT or MRI after a first seizure but found that “future research should address the use of brain MRI in this clinical setting”. Our study compared the utility of MRI over CT scan in the setting of a first seizure. DESIGN/METHODS: After IRB approval, we reviewed charts of patients who had both a brain MRI and CT scan between 01/01/2012 -12/31/2013 after first time seizure/ seizure cluster within 24 hours. Questionable paroxysmal event were excluded. Data regarding patient’s demographics, possible provoking factors, neurological examination, CT and MRI reports was collected and analyzed using descriptive statistical tools. RESULTS: A total of 59 patients were analyzed. MRI found a structural lesion that may be causative in 18 (30.5[percnt]) patients. Preliminary CT scan showed a structural causative abnormality seizure in 17 patients (16 confirmed on MRI). Neurological exam showed focal findings in 18 patients (8 had MRI lesion). Only 2 patients with a normal neurological exam and CT scan had positive findings on MRI scan (negative predictive value = 93.9[percnt]). The likelihood of starting antiepileptic drug (AED) was not correlated to positive MRI findings (OR= 1.41; 95[percnt] CI = 0.46 - 3.29, p = 0.58).CONCLUSIONS:The likelihood of finding a causative structural abnormality on MRI in patients with normal neurological exam and CT scan is quite low. In our study, there was no correlation of the MRI findings and AED trial in first time seizure patients.Study Supported by:None Disclosure: Dr. Punia has nothing to disclose. Dr. Dagar has nothing to disclose. Dr. Marks has nothing to disclose.