Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “AMOBARBITAL”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 181 records · Page 10Linked to original sources
PubMed1994

Nursing implications of the intracarotid amobarbital procedure.

The intracarotid amobarbital procedure, by inactivation of each hemisphere, provides the opportunity to evaluate language and memory function of the individual considering epilepsy surgery. Careful explanation of this procedure, and its importance to the proposed surgery are vital to the patient's cooperation and performance during this examination. The neuroscience nurse has a significant role in the success of this procedure. Nursing interventions include patient education, monitoring for potential complications, providing comfort measures, and assisting in the management of any life-threatening complications which do develop. A relatively little-known procedure outside of comprehensive epilepsy centers, the IAP offers opportunities for nursing research. These queries include investigation of emotional reactions in relation to gender differences, cultural and educational factors which may effect stimulus selection (eg, bilingual patients) and patient performance.

Amobarbital↗
PubMed2005

Removing eye-movement artifacts from the EEG during the intracarotid amobarbital procedure.

PURPOSE: The EEG is often recorded during the intracarotid amobarbital procedure (IAP) to help in the assessment of the spatial extent and the duration of the effect of the drug. In scalp recordings, the EEG is always heavily contaminated with eye movement artifacts as the patient actively performs visual tasks. METHODS: Independent component analysis (ICA) is a new technique for blind source separation. In this study, we separated the EEG data recorded during the IAP into independent components using ICA. The EEG signal was reconstructed by excluding the components related to eye movement and eye blinks. RESULTS: EEGs from 10 IAP tests were analyzed. The experimental results indicate that ICA is very efficient at subtracting eye-movement artifacts, while retaining the EEG slow waves and making their interpretation easier. CONCLUSIONS: ICA appears to be a generally applicable and effective method for removing ocular artifacts from EEG recordings during IAP, although slow waves and ocular artifacts share similar frequency distributions.

Algorithms↗
PubMed1975

Differential effects of chlorpromazine, imipramine, nitrazepam and amobarbital on REM sleep and REM density in man.

The effect of chlorpromazine (CPZ), imipramine (IMP), nitrazepam (NZP) and amobarbital sodium (AMOB) on the REM period of sleep (REMP) was investigated on four subjects by means of all-night sleep polygraphy with the schedule PPPDDDPP where P is placebo and D active drug. CPZ 25 mg resulted in a slight increase in %REMP, and no significant change in REM density (1 second fraction method) and total REM activity during the drug and withdrawal nights. IMP 25 mg produced moderate decrease in %REMP in the three drug nights, whereas REM density decreased only in the first drug night. NZP 5 mg resulted in a slight parallel suppression of %REMP, REM density and total REM activity during the drug nights. AMOB 200 mg produced a slight decrease in %REMP and marked decrease in REM density during the drug nights. Rebound increase of %REMP and a tendency of carry over decrease of REM density were observed in the withdrawal nights. Decrease in the REM density was more marked in AMOB than in NZP drug night. The importance of the simultaneous analysis of %REMP and REM density for the study of effects of psychotrophic drugs on sleep was emphasized.

Adult↗
PubMed1976

Role of the intracarotid amobarbital-pentylenetetrazol EEG test in the diagnosis and surgical treatment of patients with complex seizure problems.

The results of surgical treatment of intractable epilepsy seizures in a group of patients investigated with the intracarotid amobarbital-pentylenetetrazol EEG test were analyzed. This diagnostic test, originally designed to distinguish a mechanism of primary from that of secondary bilateral synchrony in the EEG was also used in a small group of patients with independent bilateral temporal epileptiform spiking. The test has been carried out in 99 patients of which 34 were operated on. Not all the operated patients fulfilled the test criteria for secondary bilateral synchrony.

Adolescent↗
PubMedDate not supplied

Intracarotid amobarbital procedure: I. Prediction of decreased modality-specific memory scores after temporal lobectomy.

To assess predictive value of the intracarotid amobarbital procedure (IAP) for decreased postoperative modality-specific memory, we studied 37 temporal lobectomy patients with intractable partial epilepsy who were selected for operation independent of preoperative IAP findings. When ipsilateral IAP failure was defined by an absolute method as a retention score less than 67%, the results were not associated with decreased modality-specific memory after operation. When ipsilateral IAP failure was defined by a comparative method as a retention score at least 20% lower after ipsilateral than contralateral injection, the results showed greater differences between groups, but differences still did not achieve statistical significance. Four left-resection patients who failed the ipsilateral IAP had a median postoperative change in the Wechsler Memory Scale-Revised (WMS-R) Verbal Memory Index score of -14%, whereas 16 left-resection patients who passed the ipsilateral IAP had a mean postoperative change in the WMS-R Verbal Memory Index score of -7.5% (p = 0.12). These results suggested that the IAP interpreted comparatively may be a helpful adjunctive test in assessment of relative risk for modality-specific memory dysfunction after temporal lobectomy, but larger series of operated patients are needed to confirm this possibility. In this series, complete amnesia was not noted after ipsilateral injection, even in patients with postoperative modality-specific memory decline.

Adolescent↗
PubMedDate not supplied

Intracarotid amobarbital procedure: II. Lateralizing value in evaluation for temporal lobectomy.

The intracarotid amobarbital procedure (IAP) was assessed for lateralizing value in 37 patients who later had temporal lobectomy for intractable epilepsy. Among patients who failed IAP memory testing on one side (defined as a retention score for test items at least 20% lower on one side than the other), significantly more patients failed the injection contralateral (16 of 20, 80%) than ipsilateral (4 of 20, 20%) to the side of later resection (p = 0.008). In addition, preoperative EEG evidence of bilateral temporal epileptogenicity was significantly more frequent among patients who failed the ipsilateral IAP injection (2 of 4, 50%) than among patients who passed the ipsilateral IAP injection (2 of 33, 6%) (p = 0.050). Finally, failure of the contralateral IAP injection involved significantly more severe amnesia for test items (median retention score 25%) than did failure of the ipsilateral injection (median retention score 59%) (p = 0.047). Profoundly low retention scores less than 33% occurred only with contralateral injection. These findings suggest that the IAP has some adjunctive lateralizing value for the epileptogenic hemisphere in patients with temporal lobe epilepsy, especially when the retention score with one injection is profoundly low.

Adolescent↗
PubMedDate not supplied

Comparison of the intracarotid amobarbital procedure and interictal cerebral 18-fluorodeoxyglucose positron emission tomography scans in refractory temporal lobe epilepsy.

The relationship between interictal focal hypometabolism determined by 18-fluorodeoxyglucose positron emission tomography (FDG-PET) scans and memory function with the intracarotid amobarbital procedure (IAP) was evaluated in 23 patients with temporal lobe epilepsy. All patients underwent prolonged EEG/video monitoring. The epileptogenic focus was defined by interictal epileptiform discharges and ictal onsets. All 23 patients had recorded seizures arising exclusively from one temporal lobe. PET showed temporal lobe hypometabolism ipsilateral to the epileptogenic focus in 86% (20 of 23) of patients; IAP showed impaired memory of the hemisphere of seizure onset in 65% (15 of 23). Sixty-five percent (13 of 20) of patients with focal hypometabolism had ipsilateral memory impairment. Memory impairment contralateral to the hypometabolic zone was not observed. Ninety-five percent (22 of 23) of patients demonstrated functional impairment by either PET or IAP (or both) on the epileptogenic side.

Adult↗
PubMed1995

Intracarotid amobarbital procedure as a predictor of material-specific memory change after anterior temporal lobectomy.

Memory testing during the intracarotid amobarbital procedure (IAP) is used extensively to identify temporal lobe surgery candidates "at risk" for developing severe postoperative anterograde amnesia. However, the utility of the IAP in predicting commonly observed material-specific memory deficits has not been thoroughly investigated. We examined the utility of contralateral IAP memory testing, as an index of the functional capacity of the surgical temporal lobe, to predict postoperative material-specific memory changes on the Wechsler Memory Scale-Revised (WMS-R) in patients with left hemisphere speech dominance undergoing left (n = 32) and right (n = 31) temporal lobectomy (TL). Left TL patients who "passed" contralateral IAP memory testing (> or = 68% recognition of memory items) had significantly greater verbal memory decrements than those who "failed" the IAP, presumably as a result of removal of functional tissue. A similar relationship between contralateral IAP performance and visual memory performance was not observed among right TL patients. Thus, the functional adequacy of the tissue to be resected appears to be inversely related to postoperative verbal memory decrement, at least among left TL patients. This relationship is consistent with results of recent studies demonstrating an inverse relationship between verbal memory decrements after left TL and preoperative neuropsychological verbal memory performance, magnetic resonance imaging (MRI) hippocampal volumes, and degree of mesiotemporal sclerosis (MTS).

Adolescent↗
PubMed1996

Intracartotid amobarbital procedure memory performance and age at first risk for seizures distinguish between lateral neocortical and mesial temporal lobe epilepsy.

PURPOSE: To determine whether intracarotid amobarbital procedure (IAP) memory-performance asymmetries and early risk factors for epilepsy distinguish between lateral neocortical temporal lobe epilepsy (LNTLE) and mesiobasal temporal lobe epilepsy (MBTLE). METHODS: We studied 10 patients with LNTLE and 22 with MBTLE. All LNTLE patients showed (a) presence of temporal neocortical lesion or lateral seizure onset by intracranial recording, and (b) absence of mesial temporal sclerosis (MTS) by histopathologic analysis. All patients with MBTLE showed (a) video-scalp EEG seizures consistent with mesial TLE, and (b) presence of unilateral MTS by histopathologic analysis. All patients had good surgical outcomes (Engel I or II). Unilateral IAP memory performance was defined as percentage of memory items presented during hemispheric anesthesia that was recognized after recovery. IAP asymmetry scores were the differences in memory performance after right and left injections. RESULTS: Mean memory-asymmetry scores were significantly lower in the LNTLE than in the MBTLE group. An IAP memory asymmetry of < 25% correctly classified seven of 10 patients with LNTLE, and an asymmetry of > or = 25% correctly classified 18 of 22 patients with MBTLE. Age at first risk for epilepsy was significantly younger in those with MBTLE than in those with nonlesional LNTLE. Results suggest that both IAP memory performance and age at first risk can help distinguish between MBTLE and LNTLE.

Adult↗
PubMed1997

The relation between quantitative MRI measures of hippocampal structure and the intracarotid amobarbital test.

PURPOSE: The increasing sophistication of quantitative magnetic resonance imaging (MRI) techniques has generated hopes that they may eventually supersede the intracarotid amobarbital procedure (IAP) in the presurgical screening for bilateral abnormalities in prospective candidates for temporal lobe epilepsy surgery. As the first step toward this aim, the purpose of this study was to examine the relationship between these measures of structural and functional integrity. METHODS: We examined the relation between memory performance and pass/fail rates on the IAP and two MRI measures of hippocampal integrity: hippocampal volumes, adjusted for intracranial volume (HCvol) and hippocampal T2 relaxometry (HCT2), in 48 patients with medically intractable temporal lobe epilepsy, who underwent the IAP as part of their presurgical evaluation for temporal lobectomy. RESULTS: The unilateral memory scores from the IAP were not significantly correlated with the corresponding HCvol or HCT2 measures in the right- and left-temporal-lobe groups. However, the MRI measures of hippocampal asymmetry (right minus left HCvol, right minus left HCT2) were significantly correlated with our measure of functional asymmetry, the right minus left hemisphere memory score from the IAP, supporting the role of the IAP in lateralising temporal lobe dysfunction. Forty-six patients with unilateral hippocampal sclerosis and concordant EEG studies passed the IAP. Two patients failed the memory component of the IAP. In both cases, other presurgical investigations suggested bilateral abnormalities. CONCLUSIONS: We conclude that patients with unilateral hippocampal sclerosis, established by a rigorous quantitative MRI protocol, and concordant ictal and interictal EEG findings may not be at risk for postoperative amnesia, despite baseline neuropsychological deficits suggestive of bilateral disturbance.

Adult↗
PubMed1999

Criterion-based validity of an intracarotid amobarbital recognition-memory protocol.

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 yes/no 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 near-perfect memory scores. Amnesia had no impact on the speech protocol. Pass/Fail 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.

Adolescent↗
PubMed1999

Effects of incorporating memory confidence ratings and language handicap modifications on intracarotid amobarbital procedure (Wada test) memory asymmetry scores.

PURPOSE: Intracarotid amobarbital procedure (IAP) memory asymmetry scores are often considered in determining lateralization of temporal lobe seizure foci. Additionally, these scores sometimes influence treatment plans for epilepsy surgery candidates. We examined the effects of two scoring modifications on IAP asymmetry scores: incorporating memory confidence ratings (MC), and use of a language handicap (LH) (i.e., adding a point to the memory score with anesthetization of the language-dominant hemisphere), both of which could be applied to most IAP protocols despite variations in testing methods among epilepsy surgery programs. METHODS: Sixty-nine consecutive unilateral temporal lobe epilepsy (TLE) patients with subsequent good surgical outcomes (Engel I or II) underwent bilateral IAP testing. Confidence ratings were obtained for all memory responses. The incorporation of confidence ratings and the application of a language handicap for dominant-hemisphere injections were applied to memory asymmetry scores in all combinations, resulting in four scoring methods. Results of the four methods were compared with respect to the proportion of patients lateralized accurately by each method. RESULTS: No patients were falsely lateralized with any method. Percentage of patients correctly lateralized with each scoring method is shown in Table 2. The results obtained with MC and with MC + LH (67% and 64% of patients accurately lateralized, respectively) were significantly better than results obtained with LH (55%, p<0.05). No other differences were significant. CONCLUSIONS: Although not statistically superior to standard methods, these results suggest that incorporating memory confidence ratings into IAP protocols may increase the likelihood of obtaining asymmetry scores that accurately lateralize to the hemisphere of seizure onset. In contrast, inclusion of a language handicap for scores obtained with the language-dominant ICA injection were not helpful and may even decrease the probability of obtaining clinically useful lateralizing data. These scoring modifications can be applied to most IAP protocols.

Adult↗
PubMed2000

The role of the intracarotid amobarbital procedure in evaluation of patients for epilepsy surgery.

PURPOSE: To examine the role of the intracarotid amobarbital procedure (IAP) in the presurgical evaluation of patients with medically refractory localization-related epilepsy. METHODS: We retrospectively studied 111 patients who underwent cortical resective surgery at our center between 1991 and 1996. In patients with mesial temporal lobe epilepsy (mTLE), a presurgical determination of the epileptogenic zone was compared with localization based on IAP memory asymmetry scores, and with ultimate localization after resective surgery. In patients with neocortical or mesial frontal epilepsy, the IAP was evaluated for evidence of unilateral or bilateral poor memory performance. RESULTS: Of 68 patients with mTLE localized by noninvasive tests, 60 had concordant lateralized memory deficits on IAP. Eight patients had lateralized memory deficits on IAP that were discordant with noninvasive tests and with localization as determined by surgical outcome. All 11 mTLE patients requiring invasive EEG monitoring were correctly lateralized by IAP, including one patient in whom the noninvasive evaluation otherwise provided false lateralization. Of 32 patients with neocortical or mesial frontal lobe epilepsy, 21 displayed memory deficits on IAP. Of 10 patients with bilateral deficits, five had mesial frontal lobe epilepsy. In 13 patients with lateralized memory deficits, seven underwent electrode implantation in the mesial temporal lobe, and four ultimately underwent resection of an epileptogenic mesial temporal lobe in addition to a neocortical resection. CONCLUSIONS: In patients with mTLE, lateralized memory deficits on IAP usually confirm localization provided by noninvasive tests. However, in mTLE not well lateralized by the noninvasive evaluation, and in neocortical or mesial frontal epilepsy, the IAP may provide information regarding localization that ultimately alters surgical management.

Adolescent↗
PubMed2000

Intracarotid amobarbital procedure and prediction of postoperative memory in patients with left temporal lobe epilepsy and hippocampal sclerosis.

PURPOSE: Although temporal lobe epilepsy (TLE) patients with dominant hemisphere hippocampal sclerosis generally have good cognitive outcome after anterior temporal lobectomy (ATL), a minority of patients experience at least mild post-ATL decline on one or more standardized measures of episodic and semantic memory. The goal of this investigation was to determine whether memory outcome in this group could be predicted from preoperative intracarotid amobarbital procedure (IAP) recognition memory scores. METHODS: Data from 22 left TLE patients were studied retrospectively. All were left hemisphere language dominant and had IAP scores for each hemisphere, a significant degree of pathology-confirmed left hippocampal sclerosis (HS+), and no positive MRI findings other than atrophy. Cognitive outcome status was represented by the number of pre- to post-ATL declines across three tests, as defined by 90th percentile Reliable Change Index (RCI) criteria. RESULTS: Only 14% of the sample exhibited decline on more than one memory test. Low right IAP (left hemisphere injection) scores and relatively high preoperative cognitive ability and age at surgery predicted a greater risk of post-ATL memory decline. CONCLUSIONS: A minority of left TLE HS+ patients experience at least a mild degree of RCI-defined decline in episodic or semantic memory after ATL. The right hemisphere IAP memory score, which reflects the functional reserve of the contralateral hemisphere, can help predict the risk of postoperative memory decline for TLE patients in whom HS+ is likely based on the presence of hippocampal atrophy on MRI or early age of seizure onset.

Adult↗
PubMed2000

Does the intracarotid amobarbital procedure predict global amnesia after temporal lobectomy?

PURPOSE: The intracarotid amobarbital procedure (IAP) is widely used to help predict who might be at risk for postoperative amnesia after unilateral temporal lobectomy for intractable seizures. We describe the memory outcome in 10 patients who underwent standard temporal lobectomy, including mesial temporal structures, despite failing the memory portion of the IAP after injections both ipsilateral and contralateral to the resected seizure focus. METHODS: Data for seven of the study subjects were obtained through a retrospective review of patients assessed on a surgical epilepsy unit during a 15-year period who failed the Montreal Neurological Institute IAP memory protocol after both ipsilateral and contralateral injections and subsequently underwent unilateral temporal lobectomy. More recently, we have studied temporal lobectomy patients who failed the Medical College of Georgia memory protocol after both ipsilateral and contralateral injections (n = 3). Preoperative and postoperative memory test scores were compared, and data regarding seizure outcome and self-perception of postoperative memory were collected. RESULTS: At follow-up, none of the patients presented with a pattern indicative of a global amnesia, and 80% demonstrated >90% improvement in their seizure disorder or were seizure-free. CONCLUSIONS: These findings indicate that bilateral memory failure on the IAP does not preclude the removal of an epileptogenic temporal lobe or a successful surgical outcome. In addition, the findings raise questions regarding the validity of the IAP and the possibility that memory may be reorganized in patients with a long history of temporal lobe epilepsy.

Adult↗
PubMedDate not supplied

Intracarotid amobarbital (Wada) test for language dominance: correlation with results of cortical stimulation.

Eighty-eight patients had bilateral intracarotid amobarbital (Wada) testing to determine hemispheric dominance for language in preparation for epilepsy surgery, as well as unilateral extraoperative cortical electrical stimulation using subdural electrode arrays. In none of the patients with left dominance by Wada testing were language areas found with right-sided stimulation, but two patients with right dominance by Wada testing had language areas mapped on the left side. These findings suggest that left dominance by Wada testing is strong evidence for exclusive lateralization of language function in the left hemisphere, but there is concern about the ability of the Wada test to exclude the possibility of some left-sided language function despite apparent right-sided dominance. Patients with left dominance on Wada testing do not need cortical stimulation before extensive right temporal lobectomy, but we believe that patients with right or bilateral dominance on Wada testing should have cortical stimulation for localization of language areas if extensive left or right temporal or frontal resection is planned.

Amobarbital↗
PubMed2005

Unilateral intracarotid amobarbital procedure for language lateralization.

PURPOSE: The determination of language dominance as part of the presurgical workup of patients with pharmacoresistant epilepsies has experienced fundamental changes. With the introduction of noninvasive functional magnetic resonance imaging (fMRI), the number of patients receiving intracarotid amobarbital procedures (IAPs) for assessment of language dominance has decreased considerably. However, recent studies show that because of methodologic limitations of fMRI, IAP remains an important tool for language lateralization. The current study examines whether unilateral instead of bilateral IAP is an adequate way to apply IAP with reduced invasiveness. METHODS: We retrospectively examine the predictive value of unilateral IAP for the results of bilateral IAP based on a sample of 75 patients with various types of language dominance. Target parameters are the prediction of the language-dominant hemisphere and the identification of patients with atypical language dominance. For language assessment based on unilateral IAP, we introduce the measure hemispheric language capacity (HLC). RESULTS: Unilateral IAP performed on the side of intended surgery quantifies language capacity contralateral to the intended surgery. It detects atypical (bilateral or right) language dominance in the majority of patients. Experience with a separate series of 107 patients requiring presurgical language lateralization shows that in >80%, bilateral IAPs are redundant. CONCLUSIONS: Unilateral IAP is principally sufficient for language lateralization in the presurgical evaluation of patients with pharmacoresistant epilepsies. Necessity of bilateral IAP is restricted to few indications (e.g., callosotomy). In times of noninvasive language lateralization, we propose unilateral IAP as the method of choice for the verification of doubtful (bilateral) fMRI activation patterns.

Adolescent↗
PubMed2002

Carotid artery dissection after the intracarotid amobarbital test.

A retrospective chart review of 435 consecutive intracarotid amobarbital tests (IAT) was performed to determine the frequency of carotid artery dissection (CAD) associated with IAT. Three patients with a CAD were found (0.7%). Mean age of patients with dissection (51.3 years) was higher than the average age of 432 patients without dissection (31.7 years) (p < 0.05). All patients had clinical symptoms including face or neck pain. Patients undergoing the IAT are at risk of CAD. Age may be a risk factor.

Adolescent↗