title: A novel technique of detecting MRI-negative lesion in focal symptomatic epilepsy: intraoperative ShearWave elastography.
abstract: Focal symptomatic epilepsy is the most common form of epilepsy that can often be cured with surgery. A small proportion of patients with focal symptomatic epilepsy do not have identifiable lesions on magnetic resonance imaging (MRI). The most common pathology in this group is type II focal cortical dysplasia (FCD), which is a subtype of malformative brain lesion associated with medication-resistant epilepsy. We present a patient with MRI-negative focal symptomatic epilepsy who underwent invasive electrode recordings. At the time of surgery, a novel ultrasound-based technique called ShearWave Elastography (SWE) was performed. A 0.5 cc lesion was demonstrated on SWE but was absent on B-mode ultrasound and 3-T MRI. Electroencephalography (EEG), positron emission tomography (PET), and magnetoencephalography (MEG) scans demonstrated an abnormality in the right frontal region. On the basis of this finding, a depth electrode was implanted into the lesion. Surgical resection and histology confirmed the lesion to be type IIb FCD. A PowerPoint slide summarizing this article is available for download in the Supporting Information section here.
authors.affiliation: Department of Neurosurgery, The National Hospital for Neurology and Neurosurgery, London, United Kingdom; Joint Department of Physics, Institute of Cancer Research, Sutton, Surrey, United Kingdom.
authors.forename: Huan Wee
authors.initials: HW
authors.lastname: Chan
authors.forename: Ronit
authors.initials: R
authors.lastname: Pressler
authors.forename: Christopher
authors.initials: C
authors.lastname: Uff
authors.forename: Roxanna
authors.initials: R
authors.lastname: Gunny
authors.forename: Kelly
authors.initials: K
authors.lastname: St Piers
authors.forename: Helen
authors.initials: H
authors.lastname: Cross
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Bamber
authors.forename: Neil
authors.initials: N
authors.lastname: Dorward
authors.forename: William
authors.initials: W
authors.lastname: Harkness
authors.forename: Aabir
authors.initials: A
authors.lastname: Chakraborty
mesh_terms: D002648:Child; D054459:Elasticity Imaging Techniques / Q000379:methods*; D004828:Epilepsies, Partial / Q000175:diagnosis* / Q000601:surgery; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D016343:Monitoring, Intraoperative / Q000379:methods*
keywords: Cortical dysplasia; Elastography; Focal epilepsy; Intraoperative ultrasound; Shear wave