Usefulness of language and memory testing during intracarotid amobarbital testing: observations from an fMRI study.

Full Abstract

BACKGROUND:
Several procedures for testing language lateralization and memory function exist during the intracarotid amobarbital test (IAT). The use of functional magnetic resonance imaging (fMRI) gives the opportunity to assess the validity of some of these procedures, or at least to inspect the neuronal correlates. A comprehensive fMRI protocol was tested, aimed at addressing aspects of lateralization of language, as well as testing memory in relation to activation of mesiotemporal regions. Here we report observations with possible consequences for the current IAT procedures.

MATERIALS AND METHODS:
The protocol consisted of three language tasks (overt naming, semantic decision and silent word generation) and two memory tasks (encoding and retrieving visual scenes). The paradigms used a block-related procedure in nine right-handed normal volunteers. During the procedure dynamic weighted full brain images were acquired which are sensitive to the blood oxygenation activation effect.

RESULTS :
Encoding showed symmetrical bilateral activation in the mesiotemporal regions, specifically the hippocampus, parahippocampal gyrus and fusiform gyrus. With a retrieval task activation of the mesiotemporal areas was restricted to the posterior hippocampal area. Overt object naming showed results, similar to encoding tasks with bilateral activation of hippocampal areas. Silent word generation showed much stronger ability to lateralize than the other two language-related tasks and especially object naming.

CONCLUSION:
Activation revealed by fMRI activation shows that IAT procedures, using active semantic language processing or comprehensive procedures with multiple language tasks have the highest guarantee for individual activation lateralization. Simple object naming does not guarantee a lateralized language fMRI activation pattern. Of the different memory procedures during IAT, the procedures (Interview and the Montreal) demanding encoding processing will be related to larger areas of bilateral hippocampal activation than procedures (Seattle) exclusively requiring retrieval. Moreover, tasks using recognition of previously presented language items (naming objects) are equally effective for assessing hippocampal activation compared with presenting separate memory items.

Learn Faster Today Improve your study skills

Author information

Author/s: Aldenkamp, A P (AP); Boon, P A (PA); Deblaere, K (K); Achten, E (E); Backes, W H (WH); Boon, P (P); Hofman, P (P); Troost, J (J); Vandemaele, P (P); Vermeulen, J (J); Vonck, K (K); Wilmink, J (J);

Affiliation: Epilepsy Centre 'Kempenhaeghe', Ghent University Hospital, Belgium. AdenkampB(-atsign-)Kempenhaeghe.nl

Journal and publication information

Publication Type: Journal Article; Research Support, Non-U.S. Gov't

Journal: Acta neurologica Scandinavica (Acta Neurol Scand), published in Denmark. (Language: eng)

Reference: 2003-Sep; vol 108 (issue 3) : pp 147-52

Dates: Created 2003/08/12; Completed 2003/10/23; Revised 2006/11/15;

PMID: 12911455, status: MEDLINE (last retrieval date: 12/26/2008)

Sourced from the National Library of Medicine. Abstract text and other information may be subject to copyright.

External Links for this article (including full text providers, if available):

Click Electronic Full-text Provider Links to see options for finding the electronic full text links to this article. Note there may be a subscription or fee required for access to the full text. See our FAQ for information on finding FREE full text articles.

This article may also be located in paper journal collections available in many libraries. Use the Journal and Publication Information above to find the full article.

MeSH headings (categories)

This article was linked to the MESH Headings shown below.

Adult
Amobarbital - diagnostic use
Brain Mapping
Carotid Arteries
Female
Functional Laterality
Humans
Hypnotics and Sedatives - diagnostic use

Language
Magnetic Resonance Imaging - methods
Male
Memory
Photic Stimulation
Predictive Value of Tests
Semantics
Temporal Lobe - physiology; physiopathology

Associated Chemicals: Hypnotics and Sedatives (0) ; Amobarbital (57-43-2)

These are the highest related articles currently in the database:

See 100+ related articles.