ABSTRACT
PURPOSE: The success of epilepsy surgery lies in identifying the ictal onset zone accurately. The significance of auras has little been explored on surgical outcome in drug-resistant epilepsy. This study focuses on the clinicopathological correlation of aura(s) and its role in predicting surgical outcome in drug-resistant temporal lobe epilepsy (TLE). We compared surgical outcome in TLE between patients with and without aura and identified the clinico-pathological, radiological and surgical differences between the two groups. METHODS: Consecutive patients who underwent presurgical evaluation from January 2009 to December 2014 for drug-resistant TLE who underwent anterior temporal lobectomy (ATL) were included. Patients were followed up at 3months, 12 months and then annually. RESULTS: Among 456 patients, 344(75%) had aura. Multivariate logistic regression showed that prototype EEG pattern at ictal onset (OR 2.12, 95% CI 1.18-3.06, p = 0.012) and right sided epileptogenic zone (OR 1.82 95% CI 1.18-3.78, p = 0.007) were significantly associated with presence of aura. There was no difference in surgical outcome between those with and without aura. But patients with auditory aura (OR 7.28, CI 2.80-18.95, p = 0.0002) and vertiginous aura (OR 3.01, CI 1.55-7.85, p = 0.028) had a poor surgical outcome. Bivariate analysis showed that normal MRI (p = 0.028) and normal/indeterminate pathology (p = 0.001) were significantly more common with auditory/vertiginous auras. CONCLUSIONS: Mere presence of aura does not affect outcome after TLE surgery. However, auditory and vertiginous auras are predictors of poor surgical outcome. These patients require more extensive screening for an ictal onset zone beyond standard limits of ATL before surgery.
Subject(s)
Anterior Temporal Lobectomy/methods , Epilepsy, Temporal Lobe/surgery , Treatment Outcome , Adult , Cohort Studies , Drug Resistant Epilepsy/surgery , Electroencephalography , Epilepsy, Temporal Lobe/diagnostic imaging , Epilepsy, Temporal Lobe/physiopathology , Female , Humans , Logistic Models , Magnetic Resonance Imaging , Male , Predictive Value of Tests , Statistics, Nonparametric , Young AdultABSTRACT
Accurate identification of the epileptogenic zone is an important prerequisite in presurgical evaluation of refractory epilepsy since it affects seizure-free outcomes. Apart from structural magnetic resonance imaging (sMRI), delineation has been traditionally done with electroencephalography and nuclear imaging modalities. Arterial spin labelling (ASL) sequence is a non-contrast magnetic resonance perfusion technique capable of providing similar information. Similar to single-photon emission computed tomography, its utility in epilepsy is based on alterations in perfusion linked to seizure activity by neurovascular coupling. In this article, we discuss complementary value that ASL can provide in the evaluation and characterization of some basic substrates underlying epilepsy. We also discuss the role that ASL may play in sMRI negative epilepsy and acute scenarios such as status epilepticus.
Subject(s)
Electroencephalography , Epilepsy , Magnetic Resonance Imaging , Neuroimaging , Neurovascular Coupling , Perfusion , Seizures , Status Epilepticus , Tomography, Emission-ComputedABSTRACT
BACKGROUND: Rasmussen encephalitis (RE) is a rare devastating disease of childhood causing progressive neurological deficits and intractable seizures, typically affecting one hemisphere. Characteristic MRI features include progressive unihemispheric focal cortical atrophy and grey- or white-matter high-signal changes and basal ganglion involvement, particularly of the caudate nucleus. OBJECTIVE: To analyse the pattern of involvement of different brain structures in a series of patients with RE and to attempt clinical correlation. MATERIALS AND METHODS: We reviewed the medical records and neuroimaging data of 12 patients diagnosed with RE satisfying the European Consensus Statement diagnostic criteria. RESULTS: The disease manifested as seizures in all patients and was refractory; epilepsia partialis continua was a notable feature (nine patients). Hemiparesis of varying grades was noted in all but one patient; none had extrapyramidal signs. Neuroimaging showed cortical involvement in the insular/periinsular regions in 11 patients. Caudate atrophy was noted in ten patients. Putaminal atrophy was seen in nine patients, six of whom had additional hyperintense signal changes. CONCLUSIONS: Our study highlights frequent putaminal atrophy and signal changes in RE, which suggests a more extensive basal ganglion involvement than emphasized previously. Recognition of putaminal changes may be a useful additional tool in the radiological diagnosis of RE.
