Prospective assessment of ictal behavior using the revised Responsiveness in Epilepsy Scale (RES-II)

Abstract

Impaired consciousness in epilepsy has a significant negative impact on patient quality of life, yet is difficult to study objectively. Here we develop an improved prospective Responsiveness in Epilepsy Scale (RES-II) and report initial results compared to the earlier version of the scale (RES). RES-II is simpler to administer and includes both verbal and nonverbal test items. We evaluated 75 seizures (24 patients) with RES and 34 seizures (11 patients) with RES-II based on video-EEG review. The error rate per seizure by test administrators improved markedly from a mean of 2.01±0.04 with RES to 0.24±0.11 with RES-II. Performance during focal seizures showed a bimodal distribution, corresponding to the traditional complex partial vs. simple partial seizure classification. We conclude that RES-II has improved accuracy and testing efficiency compared to the original RES. Prospective objective testing will ultimately lead to a better understanding of the mechanisms of impaired consciousness in epilepsy.

Impaired consciousness in partial seizures is bimodally distributed

“…Of note, the current cohort included 60 seizures from 26 patients that were previously analyzed through similar but distinct methods. [17][18][19] Patients with structural brain abnormalities were included in the seizure cohort, including 8 patients with hippocampal atrophy or increased signal, 7 with cortical gliosis or poststroke encephalomalacia, 5 malformations of cortical development, 4 previous resections, and 1 brain tumor (table e-1).…”

“…The RES is a standardized prospective battery used to assess responsiveness during epileptic seizures. 17,18 Test items evaluate orientation, receptive and expressive language, visual processing, and sensorimotor function (table e-2). RES test items were derived from the JFK CRS-R, a comprehensive, validated tool for the evaluation of patients with chronic disorders of consciousness.…”

“…17,18 CRS-R items were also administered by a trained examiner, and patients with TBI were similarly allowed up to 10 seconds to respond to each item. In both RES and JFK CRS-R, subject responses are graded and assigned a score based on level of responsiveness.…”

“…The original RES 18 was used during the period from June 2009 to September 2011; RES-II 17 was used from September 2011 to September 2012. The 2 versions are generally similar, including many of the same test items, but are administered in a different order to improve efficiency of testing and minimize administration errors.…”

“…The 2 versions are generally similar, including many of the same test items, but are administered in a different order to improve efficiency of testing and minimize administration errors. 17 The most recent RES version used from September 2012 through November 2012 contains only minor further revisions consisting of an alternate version of the "Ear" command and interchange of the order of the "Mirror" and "Ball" items in the battery (table e-2). Data analysis.…”