Abstracts

Rationale: This research consists of a study focused on epilepsy patients in which we are trying to associate abnormal MRI findings with drug-resistant epilepsy. Until this research is an ongoing study, then we are just showing some preview results.Background:Epilepsy is the most prevalent neurologic disorder in our practice. We know that 30% of epilepsy patients will be resistant to medical treatment.¹Neuroimaging techniques can provide information about structural abnormalities, hence information about the likely underlying etiology of epilepsy, which in turn will suggest a possible focus; in addition to functional abnormalities (cerebral flow or metabolic problem) and consequently a probable focus of epilepsy. The advantages of these tests are non-invasiveness, the possibility to choose patients candidates for surgery and be able to give a better prognosis after surgery.²The leading causes of demonstrable epilepsy by imaging, in children and adults, correspond to mesial temporal sclerosis (hippocampal sclerosis), malformations of cortical development (MCD), brain tumors and cysticercosis. Methods: Objective:To determinate if there is an association between drug-resistant epilepsy and structural brain lesions on MRI.Methods:Patients have recruited during epilepsy consult at the Hospital Central San Luis Potosi Neurology department. We formed two groups of patients, group A confirmed by drug-resistant epilepsy patients, and group B is the control patients with drug-controlled epilepsy. We made the drug-resistant epilepsy diagnosis based on the current ILAE definition. All the MRI studies were revised twice, firstly by the neuroimaging specialist and then by two neurologists.Inclusion criteria: Patients must fulfill epilepsy diagnosis, be more than 15 years old and they must have at least one cerebral MRI study. Results: Results:We have recruited so far 86 patients, 52 % men (45/86) 48 % women (41/86), mean age 34 years old. Group A drug-resistant epilepsy 44% (38), Group B Drug controlled epilepsy 56% (48).In group A drug-resistant epilepsy 87 % have an abnormal MRI study, being temporal lobe sclerosis(TLS) the main etiology (39.5%) followed by MCD (15.8%). While in group B just 52% had an abnormal MRI, being TLS only 6.3%.  Conclusions: Discussion.In a study of 525 patients over a 13-year period, 27% classified as idiopathic epilepsy, 29% secondary to structural injury and 45% as cryptogenic. Crisis control achieved in 63% of patients. 43% of patients with structural epilepsy secondary to injury continued to have seizures despite treatment, compared to 26% of patients with idiopathic epilepsy.³Another study with 550 patients with focal type epilepsy, showed that those with mesial temporal sclerosis were less likely to achieve therapeutic control compared with other types of lesions. Only 43% of patients with mesial temporal sclerosis achieved crisis control compared to 78% with arteriovenous malformation, 67% cerebral infarction, 63% primary tumor, 57% cortical gliosis, 55% cerebral atrophy and 57% with cortical dysplasia.⁴Finally, we know that the prognosis and success of treatment with AED depend on the cause of epilepsy. Patients without an identifiable structural lesion have a better prognosis to remain crisis free of 50%. In comparison, with patients with MDC of 25% and unilateral hippocampal sclerosis of 11%.^5,6Our results are similar, but it is notorious that cysticercosis has low prevalence (5%) in the current investigation contrary to some national reports. We will report a higher number of cases in the meeting because the study is on going. Funding: No funding was received for this research.