48 Three-dimensional

Tl -weighted images, as well as T2 and fluid attenuated inversion recovery (FLAIR) sequences, need to be performed using appropriate slice thickness and orientation. In TLE, coronal cuts perpendicular to the long axis of the hippocampus are required to correctly assess the presence of hippocampal atrophy and gliosis. Gradient echo sequences can be useful to detect small cavernous angiomas, whereas gadolinium should be used when a tumor is observed or suspected. Recent reports suggest that the use of 3-Tcsla magnets increases the detection rate of subtle epileptogenic lesions, including focal cortical dysplasia.49 Long term video-scalp EEG monitoring Inhibitors,research,lifescience,medical In the majority of surgical candidates, video-EEG monitoring plays an essential, role in the presurgical evaluation, by providing a detailed description of ictal clinical signs and EEG discharge, as well as prolonged interictal recordings. We have previously commented on the value of ictal semiology and interictal Inhibitors,research,lifescience,medical EEG abnormalities. Ictal EEG also provides valuable latcralizing and localizing information with regard to the ictal onset zone.50,51 However, it might be misleading in patients with a deeply located focus (ie, mesial frontal, parietal, occipital, or insular), by either failing to detect a clcarcut epileptic discharge,

or by only showing the seizure spread to distant cortical Inhibitors,research,lifescience,medical areas.52,53 In rare instances, a surgical decision might be taken without a video-EEG recording of seizures. This applies to patients with simple partial seizures that perfectly match with the location of a focal epileptogenic lesion involving the Inhibitors,research,lifescience,medical corresponding primary sensory or motor cortex, a situation where the information provided by the videoscalp EEG recording of seizure is unlikely to influence the surgical strategy. Optional

investigations Three major caveats must be considered when discussing the utility of these presurgical investigations: Inhibitors,research,lifescience,medical None of these diagnostic tools has been properly evaluated through RCTs whose primary end point should be their impact on the proportion Montelukast Sodium of patients successfully operated. In 2006, the Health Technological Assessment (HTA) program of the UK National Health Service (NHS) published a comprehensive “systematic review of the effectiveness and LY335979 cost-effectiveness of neuroimaging assessments used to visualise the seizure focus in people with refractory epilepsy being considered for surgery.”54 Their main conclusion was that “Due to the limitations of the included studies, the results of this review do little to inform clinical, practice, with insufficient evidence regarding effectiveness and cost-effectiveness of imaging techniques in the work-up for epilepsy surgery. ” There is no consensus regarding the optimal gold standard that should be used for assessing the performance of these presurgical investigations.