The intracarotid amytal procedure memory examination and hippocampal pathology

The intracarotid amytal procedure memory examination and hippocampal pathology

210 National Academy of Neuropsychology Sass, K.J., Sass, A., Westerveld, M., Green, A., Silverman, D., Kaalaas, J., Dubow, II. Yale University Sch...

84KB Sizes 0 Downloads 84 Views

210

National Academy

of Neuropsychology

Sass, K.J., Sass, A., Westerveld, M., Green, A., Silverman, D., Kaalaas, J., Dubow, II. Yale University School of Medicine. Correlation of the GAS (Graduated Assessment of Sedation) with Standardized Neuropsychological Examination Instruments.

The GAS (Graduated Assessment of Sedation) was developed to assess the cognitive effects of anesthesia. Its validity in that context was demonstrated in a prior report. This paper examines the correlation of the GAS index with standardized neuropsy~hologic~ examination instruments. One hundred neurologically impaired adults completed the GAS and a comprehensive neuropsychological battery. Correlation coefficients were calculated for the GAS index with the other neuropsychological data. Significant correlations were observed for the GAS with the WAIS-R Verbal (c-.47) and Performance (r--.57) IQ scores. Correlations greater than 3 in magnitude were also observed for the GAS with the Trail Making Test (A and B), Comprehension, Picture Arrangement, Block Design, and Digit Symbol. Modest, but statistically significant correlations (greater than .4) were noted with numerous other neuropsychological measures. These data suggest that the GAS may be used as a general measure of neuropsychologi~~ fun~tion~g for the purpose of screening.

Sass, K.J., Westerveld, W., Novelly, R.A.. Spencer. D.D., Spencer, S.S., Kim, J., Sass, A. Yale University School of Medicine. The Intracarolid Amytal Procedure Memory Examination and Hippocampal Pathology. To prevent a severe amnestic disorder following unilateral hippocampectomy, memory examination is conducted during the intracarotid amytal procedure (IAP). Whiie clinical memory examination has been shown to predict degree of hip~~pa1 pathology, little is known about the ne~pa~oiogicai correlates of IAP memory findings. The hypothesis that IAP memory fmdings wouid vary with the degree of neuronal loss in Cal, Ca3, and the Hilar area of the Dentate was evaluated in patients undergoing hippocampectomy. Fifty left speech dominant, epileptic patients without structural lesions (27 left loci, 23 right foci) were studied. Eighteen of these patients failed to demonstrate memory in the hemisphere which was ultimately operated upon. However, there was no greater cell loss for this group in the CA1 and Hitar fields, when compared to patients who passed the IAP memory exam. Only in Ca3 were neuronal cell counts significantly greater in patients demonstrating memory than those who did not. It has been reported that when memory capabilities of one hemisphere are clearly inferior to those of the contralateral side, the seizure focus is found to be within the hemisphere associated with the memory impairment in virtually all cases. On the basis of our findings, we conclude that the IAP memory examination may be usefuI for IateraIi~tion of seizure foci, but it does not predict the degree of hip~ampa1 pathology as well as cIinicaI measures of memory.