Criterion‐Based Validity of an Intracarotid Amobarbital Recognition‐Memory Protocol

Abstract

Summary: Purpose: We tested whether the behavioral components of an Intracarotid Amobarbital Protocol (IAP) had criterion validity. It was hypothesized that a recognition-memory test designed for intracarotid injections and used to predict the risk of global amnesia before an elective temporal lobectomy should also identify persons who are severely amnesic due to other neurologic causes. Divergent validity predicts that speech tasks would be unaffected by amnesia. Test-retest reliability also was measured.Methods: Fifteen persons with severe amnesia were administered four alternate forms of a yesho recognition-memory protocol and a speech protocol. No drug injection occurred. Standardized neuropsychological tests were used to divide the amnesic group into those with Global Amnesia (i.e., retain no ongoing memories), Severe Amnesia (i.e., memory impaired), and Amnesia Plus (severe amnesia plus other neuropsychologic deficits).Results: Two persons with Global Amnesia obtained scores at or below chance (i.e., failed) on the memory protocol. Unexpectedly, 12 of 13 severely amnesic persons obtained nearperfect memory scores. Amnesia had no impact on the speech protocol. PassFail outcomes were highly correlated across all four sets.Conclusions: A four-item IAP memory protocol showed good reliability and criterion validity in identifying the rare condition of Global Amnesia, but it was insensitive to other disabling, severe amnesic disorders. This IAP memory protocol might have validity in predicting a postsurgical Global Amnesic disorder, but it did not identify and therefore could not predict other more common severe amnesic disorders. Key Words: IAP-Memory-Validity.The Wada test or intracarotid amobarbital protocol (IAP) has been used clinically for almost 40 years to measure cerebral lateralization of speech (l), and predict severe amnesic syndromes (2-4). More recently clinicians use IAP results to confirm lateralization of a temporal lobe seizure focus ( 5 ) and predict verbal memory loss (6,7). For a more thorough review of how this procedure has evolved, see Rausch and Langfitt (7), Acharya and Dinner (S), and a special issue of Bruin and Cognition (9,lO). The purpose of this article is to review empirically based evidence that IAP memory protocols can reliably and validly measure very severe memory disorders, including global amnesia.Base rates of global amnesia after temporal lobectomy

Selective Posterior Cerebral Artery Wada Better Predicts Good Memory and Naming Outcomes Following Selective Stereotactic Thermal Ablation for Medial Temporal Lobe Epilepsy Than Internal Carotid Artery Wada

“…We used the Medical College of Georgia (MCG) Wada procedure for all patients. 36 This procedure involves exposure to eight novel, three-dimensional objects while under the effects of the barbiturate, followed by a recognition recall of the eight objects presented in a set of foils (24 total objects) after resolution of drug effects. Immediately following barbiturate injection, eight 3-dimensional objects were shown to the patient, with each presented across both visual fields to the patient for approximately 5 seconds.…”

Human neuropsychology in Canada: The 1990s (a review of research by Canadian neuropsychologists conducted over the past decade).

“…Her research has been primarily on persons undergoing temporal lobectomy for treatment of epilepsy and has included investigations of cognitive functioning following temporal lobectomy using subjective reports (McGlone, 1994) and objective measures (Phillips & McGlone, 1995). She has also examined the use of intracarotid sodium amobarbital procedures to study awareness of hemiplegia (Dywan, McGlone, & Fox, 1995) and to predict the risk of amnesia in surgical candidates (McGlone et al., 1999). Other work has included examinations of sex differences in hemispheric asymmetry by studying unilateral strokes (McGlone, Losier, & Black, 1997), and collaboration on an extensive review of cerebral localization research (Young & McGlone, 1992).…”

Selective or Superselective Wada Test for Postoperative Memory Prediction?

“…Therefore, we decided to proceed with a superselective Wada test to exclude a postoperative amnesic syndrome. We chose an easy memory test battery similar to a paradigm proven to distinguish between global amnesia and severe memory impairments [10]. Our test battery consisted of two sets of four verbal items (two short and two longer concrete words) presented simultaneously orally and written and four abstract designs.…”