Asymmetries in the Effect of Side of Seizure Onset on Recognition Memory Following Intracarotid Amobarbital Injection

Breier, Joshua I.; Thomas, A. B.; Plenger, Patrick; Wheless, James W.; Brookshire, Bonnie L.; Papanicolaou, Andrew C.; Willmore, L. James

doi:10.1111/j.1528-1157.1997.tb01218.x

Cited by 9 publications

(7 citation statements)

References 28 publications

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“…To assess laterality for language during this procedure, patients were given tests of reading, naming, repetition, and comprehension (in the form of a modified token test) after intracarotid amobarbital injection. [1] Performance on each of these tests was rated on a four-point scale (unimpaired, mildly impaired, moderately impaired, and severely impaired). Language representation in the hemisphere ipsilateral to the side of injection was inferred if performance was at least mildly impaired on two tests with performance on another at least moderately impaired.…”

Section: Methodsmentioning

confidence: 99%

Magnetoencephalographic mapping of the language-specific cortex

Papanicolaou¹,

Simos²,

Breier³

et al. 1998

FOC

148

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Object In this paper the authors introduce a novel use of magnetoencephalography (MEG) for noninvasive mapping of language-specific cortex in individual patients and in healthy volunteers. Methods The authors describe a series of six experiments in which normative MEG data were collected and the reliability, validity, and topographical accuracy of the data were assessed in patients who had also undergone the Wada procedure or language mapping through intraoperative cortical stimulation. Conclusions Findings include: 1) receptive language-specific areas can be reliably activated by simple language tasks and this activation can be readily recorded in short MEG sessions; 2) MEG-derived maps of each individual are reliable because they remain stable over time and are independent of whether auditory or visual stimuli are used to activate the brain; and 3) these maps are also valid because they concur with results of the Wada procedure in assessing hemispheric dominance for language and with the results of cortical stimulation in identifying the precise topography of receptive language regions within the dominant hemisphere. Although the MEG mapping technique should be further refined, it has been shown to be efficacious by correctly identifying the language-dominant hemisphere and specific language-related regions within this hemisphere. Further development of the technique may render it a valuable adjunct for routine presurgical planning in many patients who harbor tumors or have epilepsy.

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Section: Methodsmentioning

confidence: 99%

Magnetoencephalographic mapping of the language-specific cortex

Papanicolaou¹,

Simos²,

Breier³

et al. 1998

FOC

148

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“…Other factors must still be considered in the interpretation of nonlateralizing IAP memory results. Among them is the effect of seizure focus side (left vs. right TLE), which is a frequent source of confusion in clinical practice (13,23). IAP memory scores tend to be lower after a dominant hemisphere injection than after a nondominant hemisphere anesthesia ( I 1,24), probably because of the deleterious effect on language function and consciousness (25).…”

Section: Discussionmentioning

confidence: 99%

“…Thus we can theoretically assume that the temporal lobe showing a poorer IAP memory result is the focus of a patient's TLE. Previous studies on the lateralizing value of IAP, however, have reported that IAP memory tests were frequently nonlateralizing (9)(10)(11)(12)(13). Wyllie et al (10) reported that the IAP correctly lateralized seizure focus in only 43% of TLE patients, and in 46%, the IAP memory test was indeterminate.…”

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confidence: 97%

Interpretation of Wada Memory Test for Lateralization of Seizure Focus by Use of ^99mTechnetium‐HMPAO SPECT

et al. 2000

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Summary:Purpose: Although the intracarotid amobarbital procedure (IAP) or Wada test is useful in lateralizing seizure focus in patients with temporal lobe epilepsy (TLE), the results of the IAP memory test are frequently nonlateralizing. An insufficient suppression of the medial temporal region contralatera1 to the seizure focus may contribute to the failure of lateralization. We tried to correlate IAP memory results with the functional changes in the contralateral medial temporal region as measured by single photon emission computed tomography (SPECT) during IAP.Methods: We performed a """technetium-(Tc) hexamethylene-propylene-amine-oxime (HMPAO) brain SPECT in 19 medial TLE patients during a contralateral IAP (sodium amobarbital injected contralateral to the seizure focus). Regional cerebral blood flow (rCBF) was measured in the contralateral medial temporal region. The amount of decrease in the rCBF was calculated by subtracting the previous measurement from the one obtained with the interictal SPECT.Results: Ten (53%) patients passed and nine (47%) failed the contralateral IAP. The mean percentage decrease in rCBF was 5.3 5 5.3%. There was a significant negative correlation between a decrease in the rCBF and the IAP memory-retention score by Spearman correlation (p = -0.53; p <0.021). Patients with smaller decreases in rCBF (<5%) more frequently passed the contralateral IAP memory test than did those with larger decreases (80 vs. 22%; p < 0.023). Conclusions:We suggest that an insufficient suppression of the contralateral medial temporal function is partly responsible for nonlateralizing IAP memory tests. An IAP-SPECT may be useful in interpreting IAP memory tests for the lateralization of seizure focus in TLE patients. Key Words: Intracarotid amobarbital procedure-SPECT-TLE-Lateralimtion-Medial temporal region.Since the Wada test or intracarotid amobarbital procedure (IAP) was introduced to determine the hemispheric dominance for language (1 ), its clinical application has widely expanded. It was soon modified by Milner et al. ( 2 ) to determine the hemispheric dominance for memory as well. In most epilepsy centers, the IAP memory test has been used as a predictor of postoperative memory deficits in patients with temporal lobe epilepsy (TLE) (3-6). It has been known to be useful in predicting patients' surgical outcome after a unilateral temporal lobectomy (7-9) and to provide a lateralizing value in the evaluation of seizure focus (9-1 1).Because chronic and repetitive seizures produce dysAccepted June 8, 1999. Address correspondence and reprint requests to Dr. S. K. Lee at Department of Neurology, College of Medicine, Seoul National University Hospital, 28, Yunkeun-Dong, Chongno-Ku, Seoul, 110-744, Korea. E-mail: sangunlee@medicine.snu.ac.kr function in the epileptic temporal lobe, a better memory performance is anticipated when the temporal lobe ipsilateral to the seizure focus is anesthetized than when the opposite side is. Thus we can theoretically assume that the temporal lobe showing a poorer IAP ...

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“…Milner et al expanded the use of the Wada test to measure unilateral memory function in epilepsy surgery candidates in order to predict postoperative amnesia 12 . Since then, the contributions of the Wada test have been widely extended and include: (i) lateralisation of seizure focus [25][26][27][28][29][30][31][32] ; (ii) prediction of seizure control outcome 29,[33][34][35] ; and (iii) prediction of neuropsychological outcome [36][37][38][39][40][41] . On the other hand, its value to preclude postoperative amnesic syndromes still remains open to question 42,43 .…”

Section: The Wada Testmentioning

confidence: 99%

Presurgical assessment of memory-related brain structures: the Wada test and functional neuroimaging

Akanuma

Koutroumanidis

Adachi³

et al. 2003

Seizure

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Medial temporal lobe structures are known to play a major role in memory processing. Recent work has revealed that extratemporal structures (e.g. the frontal lobe and thalamus) may also be important in memory function. In candidates for epilepsy surgery, particularly in those with temporal lobe seizures, presurgical evaluation of memory function is essential, since seizures may originate in the neural substrate that is critical for memory. In this article, we review the tools used for presurgical evaluation and their contribution to the understanding of memory function, focusing on the Wada test, [18F]fluorodeoxy-glucose positron emission tomography ([18F]FDG-PET) and functional magnetic resonance imaging (fMRI). We also explore perspectives on future studies that may elucidate the role of the temporal and extratemporal structures in memory function and the mechanisms of cerebral plasticity.

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Asymmetries in the Effect of Side of Seizure Onset on Recognition Memory Following Intracarotid Amobarbital Injection

Cited by 9 publications

References 28 publications

Magnetoencephalographic mapping of the language-specific cortex

Magnetoencephalographic mapping of the language-specific cortex

Interpretation of Wada Memory Test for Lateralization of Seizure Focus by Use of ^99mTechnetium‐HMPAO SPECT

Presurgical assessment of memory-related brain structures: the Wada test and functional neuroimaging

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Asymmetries in the Effect of Side of Seizure Onset on Recognition Memory Following Intracarotid Amobarbital Injection

Cited by 9 publications

References 28 publications

Magnetoencephalographic mapping of the language-specific cortex

Magnetoencephalographic mapping of the language-specific cortex

Interpretation of Wada Memory Test for Lateralization of Seizure Focus by Use of 99mTechnetium‐HMPAO SPECT

Presurgical assessment of memory-related brain structures: the Wada test and functional neuroimaging

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Interpretation of Wada Memory Test for Lateralization of Seizure Focus by Use of ^99mTechnetium‐HMPAO SPECT