[Abstract] Intracranial EEG analysis in tumor-related epilepsy: Evidence of distant epileptic abnormalities – Clinical Neurophysiology

Highlights

• In most patients with TRE, at least part of SOSz lies distant from the tumor.
• Resection of the brain tumor plus SOSz results in excellent seizure outcome.
• On iEEG, interictal spikes are most abundant and sharpest in the peritumoral region.

Abstract

Objective: In patients with tumor-related epilepsy (TRE), surgery traditionally focuses on tumor resection; but identification and removal of associated epileptogenic zone may improve seizure outcome. Here, we study spatial relationship of tumor and seizure onset and early spread zone (SOSz). We also perform quantitative analysis of interictal epileptiform activities in patients with both TRE and non-lesional epilepsy in order to better understand the electrophysiological basis of epileptogenesis.

Methods: Twenty-five patients (11 with TRE and 14 with non-lesional epilepsy) underwent staged surgery using intracranial electrodes. Tumors were outlined on MRI and images were coregistered with post-implantation CT images. For each electrode, distance to the nearest tumor margin was measured. Electrodes were categorized based on distance from tumor and involvement in seizure. Quantitative EEG analysis studying frequency, amplitude, power, duration and slope of interictal spikes was performed.

Results: At least part of the SOSz was located beyond 1.5 cm from the tumor margin in 10/11 patients. Interictally, spike frequency and power were higher in the SOSz and spikes near tumor were smaller and less sharp. Interestingly, peritumoral electrodes had the highest spike frequencies and sharpest spikes, indicating greatest degree of epileptic synchrony. A complete resection of the SOSz resulted in excellent seizure outcome.

Conclusions: Seizure onset and early spread often involves brain areas distant from the tumor.

Significance: Utilization of epilepsy surgery approach for TRE may provide better seizure outcome and study of the intracranial EEG may provide insight into pathophysiology of TRE.

Source: Intracranial EEG analysis in tumor-related epilepsy: Evidence of distant epileptic abnormalities – Clinical Neurophysiology

[ARTICLE] The case for medical marijuana in epilepsy – Full Text HTML/PDF

Summary

Charlotte, a little girl with SCN1A-confirmed Dravet syndrome, was recently featured in a special that aired on CNN. Through exhaustive personal research and assistance from a Colorado-based medical marijuana group (Realm of Caring), Charlotte’s mother started adjunctive therapy with a high concentration cannabidiol/Δ9-tetrahydrocannabinol (CBD:THC) strain of cannabis, now known as Charlotte’s Web. This extract, slowly titrated over weeks and given in conjunction with her existing antiepileptic drug regimen, reduced Charlotte’s seizure frequency from nearly 50 convulsive seizures per day to now 2–3 nocturnal convulsions per month. This effect has persisted for the last 20 months, and Charlotte has been successfully weaned from her other antiepileptic drugs. We briefly review some of the history, preclinical and clinical data, and controversies surrounding the use of medical marijuana for the treatment of epilepsy, and make a case that the desire to isolate and treat with pharmaceutical grade compounds from cannabis (specifically CBD) may be inferior to therapy with whole plant extracts. Much more needs to be learned about the mechanisms of antiepileptic activity of the phytocannabinoids and other constituents of Cannabis sativa.

Continue HTML —>  The case for medical marijuana in epilepsy – Maa – 2014 – Epilepsia – Wiley Online Library

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