High Resolution Magnetic Resonance Imaging And Prognostic Factors Of Intractable Epilepsy Associated With Focal Cortical Dysplasia

Objective:To analyze the high-resolution magnetic resonance imaging characteristics of focal cortical dysplasia(FCD)-related refractory epilepsy,and evaluate the application value of high-resolution magnetic resonance imaging in the diagnosis of FCD.To investigate the effects of preoperative imaging evaluation,pathological types,and clinical factors on the prognosis of focal cortical dysplasia(FCD)-related refractory epilepsy.Materials and methods:The imaging and clinical data of 63 patients with FCD-related refractory epilepsy who were diagnosed by postoperative pathology at the brain hospital of Hunan province from April 2018 to September 2020were collected.The postoperative epilepsy control was followed up for 6to 36 months.The prognosis was graded according to the Engel grading system.EngelⅠwas defined as a good prognosis,and EngelⅡ-Ⅳwere defined as a poor prognosis.All patients underwent routine and high-resolution MR examinations,summarized and analyzed the FCD imaging manifestations.The SPSS22.0 software was used to statistical analysis,the χ~2 test was used to analyze the imaging,pathological types and clinical factors,and the multivariate Logisitic regression was used to analyze the independent risk factors of prognosis.Result:The study included 63 FCD patients,including 19 FCD type Ⅰ(5 type Ⅰa,10 type Ⅰb,4 type Ⅰc),17 FCD type Ⅱ(8 type Ⅱa,9 type Ⅱb),and 27 FCD type Ⅲ(9 type Ⅲa,5 type Ⅲb,9 type Ⅲc,4 type Ⅲd).MR positive 42 cases(66.67%,FCDⅠpositive 4 cases,FCD Ⅱ13 cases,FCDⅢ25 cases),MR negative 21 cases(33.33%,FCDⅠ15 cases,FCDⅡ4 cases,FCDⅢ2 cases),MR Negative cases were mainly FCD type Ⅰ.FCD usually occurred in the temporal lobe.Ⅰn this group,41 cases(65.08%)were located in the temporal lobe,22 cases(34.92%)were located outside the temporal lobe,18 cases were located in the frontal lobe,2 cases were located in the parieto-occipital lobe,and1 case was located in the temporo-parietal lobe,1 case was located in the parietal lobe.The high-resolution MR showed the lesions more clearly,and 6 cases were only positive for high-resolution MR(FCD typeⅠ,2cases,FCDⅡ type,2 cases,FCD typeⅢ,2 cases).FCD typeⅠMR manifestations:single brain lobe or local brain atrophy changes,local cortex thickening,blurred brain gray and white matter boundaries,3D-T2FLAIR cortical hyperintensity.FCD type Ⅱ MR manifestations:blurred boundaries of brain gray and white matter,cortex thickening,cortical and subcortical T2FLAIR high signal,transmantle sign,local brain sulcus widening,abnormal sulcus walking,hippocampal sclerosis(HS).FCD type Ⅲ images showed typical changes of the corresponding combined lesions(HS,neoplasms,vascular malformations and residual lesions of early brain injury).The χ~2 test univariate analysis showed that MR positive,whether the video electroencephalogram(VEEG)and MR positioning were consistent,the course of disease,and the surgical method of extended resection were the prognostic factors(P<0.05),and the pathological type,gender,Age,type of antiepileptic drugs taken,and location of the lesion had no significant effect on the prognosis(P>0.05).The results of multivariate Logisitic regression analysis showed that the course of disease and whether the location of VEEG and MR were consistent were independent risk factors for the prognosis of patients with FCD-related refractory epilepsy.The probability of a poor prognosis in patients with a course of more than 10 years was 4.591 times that of patients with a course of less than 10 years(OR=4.591,95%CⅠ 1.179～17.877),the probability of poor prognosis in patients with inconsistent VEEG and MR positioning was 6.587 times that of patients with consistent VEEG and MR positioning(OR=6.587,95%CⅠ 1.231～35.261).Conclusion:The high-resolution MR manifestations of FCD typeⅠand typeⅡ,FCD typeⅡand typeⅢoverlap.FCDⅠimaging manifestations are often subtle,the negative rate of MR is the highest,and the diagnosis is difficult.Although FCDⅡhas characteristic imging sign,the probability of appearance is not high.FCD type Ⅲ has the highest MR positive rate due to other lesions,but FCD lesions themselves are difficult to distinguish.High-resolution MR has great value in the detection of FCD lesions and preoperative and postoperative evaluation.The duration of disease,the consistency of VEEG and MR location are independent risk factors for the prognosis of patients with refractory epilepsy associated with FCD.The longer the course of FCD-related refractory epilepsy is not conducive to the prognosis of the patient,and the location of the epileptic foci before surgery is particularly important.For patients with inconsistent VEEG and MR positioning,additional examinations are needed to identify the location of the epileptic foci and must be treated it with caution.