Recent advances in imaging epilepsy

Abstract

Around 30 000 people are diagnosed with epilepsy every year in the UK. While many of these respond well to antiepileptic drugs, 20-30% have seizures that are resistant to best medical treatment. For these patients it is important to identify any structural abnormalities responsible for generating seizure activity that may be amenable to surgical resection. There are many imaging modalities available to investigate epilepsy including computed tomography (CT), nuclear medicine and magnetic resonance imaging (MRI). Additional techniques are available in specific circumstances including single positron emission CT, diffusion imaging, MR spectroscopy, perfusion imaging and functional MRI. Clearly with so many options, a targeted approach is required to reach a diagnosis efficiently. In this article, each modality is discussed along with the imaging options for the common causes of focal seizure activity.

Value of clinical features to differentiate refractory epilepsy from mimics: a prospective longitudinal cohort study

“…A diagnostic model including age at onset and brain MRI also had a very high (96%) accuracy in discriminating patients with syncope from those with rE, which was similar to the same model in discriminating patients with syncope from those with rE or PNES (94%). In fact, MRI studies using epilepsy‐specific sequences have shown that patients with rE frequently have imaging abnormalities . Conversely, the standard EEG recording did not distinguish between groups.…”

Lesions masquerading as acute stroke

“…There are many conditions that can cause seizure, including cortical dysplasia, tumors, vascular malformations, etc. (79), but this is outside the scope of this article, which only reviews imaging findings that are the consequence of an epileptic activity, which is also referred to as the ''periictal period.'' It should be noted that the postictal imaging findings can be quite variable and may in some cases show no abnormality on conventional CT and MR imaging (2)(3)(4)(5)(6)(7)(8)77,78,80,81).…”

Cancer and bioethics: Caring and consensus

“…There are many conditions that can cause seizure, including cortical dysplasia, tumors, vascular malformations, etc. (79), but this is outside the scope of this article, which only reviews imaging findings that are the consequence of an epileptic activity, which is also referred to as the “periictal period.” It should be noted that the postictal imaging findings can be quite variable and may in some cases show no abnormality on conventional CT and MR imaging (2–8, 77, 78, 80, 81). Factors influencing the imaging findings include: seizure type and location as well as duration and severity of ictal discharge.…”

“…However, there are now several newer imaging modalities, other than conventional MRI and CT, for example, DWI/DTI, PWI, and positron emission tomography (PET), that have improved sensitivity. Many studies have reported normal findings on conventional MRI and CT of postictal seizure where abnormalities were detected on DWI, PWI, or PET imaging (77–90).…”