Interictal brain SPECT in patients with medically refractory temporal lobe epilepsy

THESES

INTERICTAL BRAIN SPECT IN PATIENTS WITH MEDICALLY REFRACTORY TEMPORAL LOBE EPILEPSY (ABSTRACT)^*. THESIS. RIO DE JANEIRO, 2000.

MARIA EMILIA COSENZA ANDRAUS ^**

INTRODUCTION: The brain single photon emission computed tomography (SPECT) is a functional neuroimaging method that can detect localized changes in cerebral blood flow. Temporal lobe epilepsy (TLE) is the most common epileptic syndrome in adults, and more than 50% are medically refractory. The SPECT can contribute to investigation of epileptogenic focus and is one of pre-surgical evaluation methods of these patients.

OBJECTIVES:To evaluate the utility of interictal SPECT in localization of the epileptogenic focus in a population of patients from the Epilepsy Clinic of Neurology Service of Hospital Universitário Clementino Fraga Filho, Universidade Federal do Rio de Janeiro (HUCFF/UFRJ), with refractory TLE and normal brain computed tomography (CT) scans, studying the correlation between SPECT, electroencephalogram (EEG) and, in some cases, brain magnetic resonance imaging (MRI); to compare the results to some literature series; to contribute with data that will justify the implementation of an Epilepsy Program in the HUCFF/UFRJ.

METHOD:Transverse, prospective study, including 23 outpatients with medically refractory TLE, classified according to the International League Against Epilepsy (ILAE) criteria. Eleven (47.8%) were females, and the mean age at the moment of inclusion in this study was 30.34 + 8.91 (18-49). The mean age of the illness onset was 12.21 + 10.29 (1-35) and the time of illness was 18.13 + 9.73 years (3-35). All of patients presented normal brain CT scans and scalp EEG with temporal epileptiform changes, when submitted to interictal etilendicistein dietil ester (ECD-^99mTc) brain SPECT. Eleven patients had also performed brain MRI. The results were compared to the other six literature series, with similar sample population, after submitted to the same statistical treatment. Data are presented as middle + standard error (maximum-minimum). The statistical analysis was based on Fuzzy logics.

RESULTS: Twelve (52.2%) of 23 patients had abnormal SPECT. Among these, five (41.6% of abnormal SPECTs) presented unilateral SPECT changes at the same side of the EEG (hypoperfusion in four and hyperperfusion in one), three (25%) presented bilateral hypoperfusion associated with bilateral EEG changes, and four (33.3%) presented unilateral hypoperfusion associated with bilateral EEG changes. Among the 11 patients who had performed MRI, 3 (27.2%) presented temporal lobe abnormality correspondent to the SPECT. The correlation index between SPECT x EEG (Pearson correlation = 0.998; p <0.0005), SPECT x MRI (Pearson correlation = 0.998; p <0.0005) and SPECT x EEG x MRI (Pearson correlation = 0.998; p <0.0005) were highly significant, with significance levels at 0.01 and trust interval at 99% in all correlations.

CONCLUSIONS:The interictal brain SPECT was useful for the similarity of the EEG and MRI results. The correlation studies presented results comparable to the other literature series, with no significant deviations. Even so, the results of the SPECT indicate the necessity of to accomplish other complementary methods in the continue of the investigation, considering that results added up are associated with the diagnostic optimization to localize the epileptogenic focus and better therapeutic strategies.

KEY WORDS: temporal lobe epilepsy, diagnosis, single photon emission computed tomography, Fuzzy logics.

** Address: Rua Djalma Ulrich 201 / 1201, 22071-020 Rio de Janeiro RJ, Brasil.

*

SPECT cerebral interictal em pacientes com epilepsia do lobo temporal de difícil controle (Resumo). Tese de Mestrado, Universidade Federal do Rio de Janeiro (Área: Clínica Médica/Neurologia). Orientadora: Soniza Vieira Alves Leon.

Publication Dates

• Publication in this collection
  06 Dec 2000
• Date of issue
  Sept 2000