A Comparison of Neuropsychological Outcomes following Responsive Neurostimulation and Anterior Temporal Lobectomy in Drug-Resistant Epilepsy

Neuropsychological outcomes following temporal lobe resection for drug-resistant epilepsy (DRE) are well established. For instance, left anterior temporal lobectomy (LATL) is associated with a greater risk for cognitive morbidity compared to right (RATL). However, the impact of neuromodulatory devices, specifically responsive neurostimulation (RNS), remains an area of active interest. There are currently no head-to-head comparisons of neuropsychological outcomes after surgical resection and neuromodulation. This study reports on a cohort of 21 DRE patients with the RNS System who received comprehensive pre- and post-implantation neuropsychological testing. We compared both cognitive and seizure outcomes in the RNS group to those of 307 DRE patients who underwent LATL (n = 138) or RATL (n = 169). RNS patients had higher seizure rates pre-intervention. While fewer in the RNS group achieved Class I Engel outcomes compared to the ATL cohorts, RNS patients also showed seizure frequency declines from pre- to post-intervention that were similar to those who underwent resective surgery. Moreover, the RNS and RATL groups were similar in their neuropsychological outcomes, showing no significant cognitive decline post-intervention. In contrast, the LATL group notably declined in object naming and verbal list learning. Direct comparisons like this study may be used to guide clinicians in shared decision making to tailor management plans for patients' overall treatment goals.

Application of the International Classification of Cognitive Disorders in Epilepsy (IC-CoDE) to frontal lobe epilepsy using multicenter data

RATIONALE

The International Classification of Cognitive Disorders in Epilepsy (IC-CoDE) was recently introduced as a consensus-based, empirically-driven taxonomy of cognitive disorders in epilepsy and has been effectively applied to patients with temporal lobe epilepsy (TLE). The purpose of this study was to apply the IC-CoDE to patients with frontal lobe epilepsy (FLE) using national multicenter data.

METHODS

Neuropsychological data of 455 patients with FLE aged 16 years or older were available across four US-based sites. First, we examined test-specific impairment rates across sites using two impairment thresholds (1.0 and 1.5 standard deviations below the normative mean). Following the proposed IC-CoDE guidelines, patterns of domain impairment were determined based on commonly used tests within five cognitive domains (language, memory, executive functioning, attention/processing speed, and visuospatial ability) to construct phenotypes. Impairment rates and distributions across phenotypes were then compared with those found in patients with TLE for which the IC-CoDE classification was initially validated.

RESULTS

The highest rates of impairment were found among tests of naming, verbal fluency, speeded sequencing and set-shifting, and complex figure copy. The following IC-CoDE phenotype distributions were observed using the two different threshold cutoffs: 23-40% cognitively intact, 24-29% single domain impairment, 13-20% bi-domain impairment, and 18-33% generalized impairment. Language was the most common single domain impairment (68% for both thresholds) followed by attention and processing speed (15-18%). Overall, patients with FLE reported higher rates of cognitive impairment compared with patients with TLE.

CONCLUSIONS

These results demonstrate the applicability of the IC-CoDE to epilepsy syndromes outside of TLE. Findings indicated generally stable and reproducible phenotypes across multiple epilepsy centers in the U.S. with diverse sample characteristics and varied neuropsychological test batteries. Findings also highlight opportunities for further refinement of the IC-CoDE guidelines as the application expands.

Responsive Neurostimulation of the Anterior Thalamic Nuclei in Refractory Genetic Generalized Epilepsy: A Case Series

Genetic generalized epilepsies (GGEs) are thought to represent disorders of thalamocortical networks. There are currently no well-established non-pharmacologic treatment options for patients with drug-resistant GGE. NeuroPace's Responsive Neurostimulation (RNS) System was approved by the United States Food and Drug Administration to treat focal seizures with up to two ictal foci. We report on three adults with drug-resistant GGE who were treated with thalamic RNS. Given the severity of their epilepsies and the potential ictogenic role of the thalamus in the pathophysiology of GGE, the RNS System was palliatively implanted with leads in the bilateral anterior thalamic nuclei (ANT) of these patients. The ANT was selected because it was demonstrated to be a safe target. We retrospectively evaluated metrics including seizure frequency over 18-32 months. One patient required explantation due to infection. The other two patients were clinical responders. By the end of the observation period reported here, one patient was seizure-free for over 9 months. All three self-reported an improved quality of life. The clinical response observed in these patients provides 'proof-of-principle' that GGE may be treatable with responsive thalamic stimulation. Our results support proceeding to a larger study investigating the efficacy and safety of thalamic RNS in drug-resistant GGE.

Reliable change on the selective reminding test in a series of left-hemisphere language dominant patients with right temporal lobe epilepsy

The Selective Reminding Test (SRT) is widely used in pre-surgical evaluations for people with epilepsy; however, important characteristics such as reliability and stability over time within an epilepsy-specific control cohort are unclear. In this study, we document test-retest reliabilities, practice effects, and Reliable Change Indices (RCI) for this test in a sample of right temporal lobe epilepsy patients who are left hemisphere dominant for language and underwent surgical resection on the right temporal lobe. A sample of 101 adults with a right temporal lobe seizure focus (mean age = 38.5) was administered the SRT pre- and post-right temporal lobe surgery. Test-retest reliabilities were modest (r = 0.44-0.59). Practice effects were minimal (0.25-2.04). Reliable Change Indices were calculated and ranged from 4 to 26 depending on the SRT index. The RCI's indicate that relatively moderate to large changes on the SRT are needed for a change score to be considered a significant change in an individual's performance. The RCIs can be used to detect a reliable change in patients undergoing left temporal lobe epilepsy surgery who are at significant risk for verbal memory decline.

Cognitive decline and quality of life after resective epilepsy surgery

OBJECTIVES

The objectives of this study were to examine the association between cognitive decline and quality of life (QoL) change in a large sample of individuals with drug-resistant epilepsy who underwent resective surgery and to examine whether the association between cognitive decline and QoL is differentially affected by seizure classification outcome (Engel Class 1 vs. 2-4) or side of surgery (left vs. right hemisphere).

MATERIALS AND METHODS

The sample comprised 224 adults (ages ≥ 18) with drug-resistant focal epilepsy treated with resective surgery who underwent comprehensive pre-operative and post-operative evaluations including neuropsychological testing and the Quality of Life in Epilepsy Inventory - 31 between 1991 and 2020. Linear mixed-effects models were fit to examine subject-specific trajectories and assess the effects of time (pre- to post-operative), cognitive decline (number of measures that meaningfully declined), and the interaction between time and cognitive decline on pre- to post-operative change in QoL.

RESULTS

Increases in QoL following resection were observed (B = -10.72 [SE = 1.22], p < .001; mean difference between time point 1 and time point 2 QoL rating = 8.11). There was also a main effect of cognitive decline on QoL (B = -.85 [SE = .27], p = .002). Follow-up analyses showed that the number of cognitive measures that declined was significantly associated with post-surgical QoL, (r = -.20 p = .003), but not pre-surgical QoL, (r = -.04 p = .594), and with pre-to post-surgery raw change in QoL score, (r = -.18 p = .009). A cognitive decline by time point interaction was observed, such that those who had greater cognitive decline had less improvement in overall QoL following resection (B = .72 [SE = .27], p = .009). Similar results were observed within the Engel Class 1 outcome subgroup. However, within the Engel Class 2-4 outcome subgroup, QoL improved following resection, but there was no main effect of cognitive decline or interaction between cognitive decline and time point on QoL change. There was no main effect of resection hemisphere on overall QoL, nor were there interactions with hemisphere by time, hemisphere by cognitive decline, or hemisphere by time by cognitive decline.

CONCLUSIONS

Quality of life improves following epilepsy surgery. Participants who had cognitive decline across a greater number of measures experienced less improvement in QoL post-operatively overall, but there was no clear pattern of domain-specific cognitive decline associated with change in QoL. Our results indicate that cognitive decline in a diffuse set of cognitive domains negatively influences post-operative QoL, particularly for those who experience good seizure outcomes (i.e., seizure freedom), regardless of the site or side of resection.

Prediction of Naming Outcome With fMRI Language Lateralization in Left Temporal Epilepsy Surgery

BACKGROUND AND OBJECTIVES

Naming decline after left temporal lobe epilepsy (TLE) surgery is common and difficult to predict. Preoperative language fMRI may predict naming decline, but this application is still lacking evidence. We performed a large multicenter cohort study of the effectiveness of fMRI in predicting naming deficits after left TLE surgery.

METHODS

At 10 US epilepsy centers, 81 patients with left TLE were prospectively recruited and given the Boston Naming Test (BNT) before and ≈7 months after anterior temporal lobectomy. An fMRI language laterality index (LI) was measured with an auditory semantic decision-tone decision task contrast. Correlations and a multiple regression model were built with a priori chosen predictors.

RESULTS

Naming decline occurred in 56% of patients and correlated with fMRI LI (r = -0.41, p < 0.001), age at epilepsy onset (r = -0.30, p = 0.006), age at surgery (r = -0.23, p = 0.039), and years of education (r = 0.24, p = 0.032). Preoperative BNT score and duration of epilepsy were not correlated with naming decline. The regression model explained 31% of the variance, with fMRI contributing 14%, with a 96% sensitivity and 44% specificity for predicting meaningful naming decline. Cross-validation resulted in an average prediction error of 6 points.

DISCUSSION

An fMRI-based regression model predicted naming outcome after left TLE surgery in a large, prospective multicenter sample, with fMRI as the strongest predictor. These results provide evidence supporting the use of preoperative language fMRI to predict language outcome in patients undergoing left TLE surgery.

CLASSIFICATION OF EVIDENCE

This study provides Class I evidence that fMRI language lateralization can help in predicting naming decline after left TLE surgery.

Cognitive and functional outcomes following a traumatic brain injury sustained 22 years after epilepsy surgery: A case report

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Long-term outcomes were presented for a patient status post epilepsy surgery and TBI.

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Cognitive stability was documented over a 22-year follow-up period.

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Good cognitive and functional outcomes were demonstrated in late life.

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Protective factors include seizure outcome, cognitive reserve, and medical status.

Anterior temporal lobectomy (ATL) is an effective treatment for drug-resistant epilepsy, and risk for post-surgical naming and verbal memory decline after dominant hemisphere ATL is well-established. However, less is known about later life cognitive and functional outcomes following ATL performed in early or mid-life, as there are few studies that report very long-term outcomes, and the intersection of epilepsy and the aging process is not well-understood. Factors that may promote healthy cognitive aging or confer increased risk for cognitive decline in late life for those with seizure onset in early or mid-life have yet to be determined. This case report describes an individual with drug-resistant epilepsy who was treated with left ATL in mid-life, and then subsequently sustained a moderate traumatic brain injury 22 years later. The excellent recovery and remarkable stability of cognitive performance over time may be associated with several protective factors such as favorable seizure outcome, high cognitive reserve, and the absence of co-occurring medical conditions. This case also highlights the clinical utility of serial neuropsychological testing at multiple timepoints across the lifespan for those with epilepsy, and the importance of considering the clinical significance, or functional impact, of cognitive deficits in this population.

Temporal lobe regions essential for preserved picture naming after left temporal epilepsy surgery

OBJECTIVE

To define left temporal lobe regions where surgical resection produces a persistent postoperative decline in naming visual objects.

METHODS

Pre- and postoperative brain magnetic resonance imaging data and picture naming (Boston Naming Test) scores were obtained prospectively from 59 people with drug-resistant left temporal lobe epilepsy. All patients had left hemisphere language dominance at baseline and underwent surgical resection or ablation in the left temporal lobe. Postoperative naming assessment occurred approximately 7 months after surgery. Surgical lesions were mapped to a standard template, and the relationship between presence or absence of a lesion and the degree of naming decline was tested at each template voxel while controlling for effects of overall lesion size.

RESULTS

Patients declined by an average of 15% in their naming score, with wide variation across individuals. Decline was significantly related to damage in a cluster of voxels in the ventral temporal lobe, located mainly in the fusiform gyrus approximately 4-6 cm posterior to the temporal tip. Extent of damage to this region explained roughly 50% of the variance in outcome. Picture naming decline was not related to hippocampal or temporal pole damage.

SIGNIFICANCE

The results provide the first statistical map relating lesion location in left temporal lobe epilepsy surgery to picture naming decline, and they support previous observations of transient naming deficits from electrical stimulation in the basal temporal cortex. The critical lesion is relatively posterior and could be avoided in many patients undergoing left temporal lobe surgery for intractable epilepsy.

Changes in description naming for common and proper nouns after left anterior temporal lobectomy

Numerous studies have shown that surgical resection of the left anterior temporal lobe (ATL) is associated with a decline in object naming ability (Hermann et al., 1999). In contrast, few studies have examined the effects of left ATL surgery on auditory description naming (ADN) or category-specific naming. Compared with object naming, which loads heavily on visual recognition processes, ADN provides a more specific measure of concept retrieval. The present study examined ADN declines in a large group of patients who were tested before and after left ATL surgery, using a 2 × 2 × 2 factorial manipulation of uniqueness (common vs. proper nouns), taxonomic category (living vs. nonliving things), and time (pre- vs. postsurgery). Significant declines occurred across all categories but were substantially larger for proper living (PL) concepts, i.e., famous individuals. The disproportionate decline in PL noun naming relative to other conditions is consistent with the notion that the left ATL is specialized not only for retrieval of unique entity concepts, but also plays a role in processing social concepts and person-specific features.

Temporal lobe epilepsy is associated with distinct cognitive phenotypes

Neuropsychological assessment is critical for understanding the impact of seizures on cognition and informing treatment decisions. While focus is often placed on examining groups based on seizure type/epilepsy syndrome, an alternate approach emphasizes empirically derived groups based solely on cognitive performance. This approach has been used to identify cognitive phenotypes in temporal lobe epilepsy (TLE). The current study sought to replicate prior work by Hermann and colleagues (2007) and identify cognitive phenotypes in a separate, larger cohort of 185 patients with TLE (92 left TLE, 93 right TLE). Cluster analysis revealed 3- and 4-cluster solutions, with clusters differentiated primarily by overall level of performance in the 3-cluster solution (Low, Middle, and High performance) and by more varying cognitive phenotypes in the 4-cluster solution (Globally Low, Low Executive Functioning/Speed, Low Language/Memory, and Globally High). Differences in cognitive performance as well as demographic and clinical seizure variables are presented. A greater proportion of the patients with left TLE were captured by Cluster 3 (Low Language/Memory) than by the other 3 clusters, though this cluster captured only approximately one-third of the overall group with left TLE. Consistent with prior findings, executive functioning and speed emerged as additional domains of interest in this sample of patients with TLE. The current results extend prior work examining cognitive phenotypes in TLE and highlight the importance of identifying the comprehensive range of potential cognitive profiles in TLE.

MEG language lateralization in partial epilepsy using dSPM of auditory event-related fields

OBJECTIVE

Methods employed to determine hemispheric language dominance using magnetoencephalography (MEG) have differed significantly across studies in the choice of language-task, the nature of the physiological response studied, recording hardware, and source modeling methods. Our goal was to determine whether an analysis based on distributed source modeling can replicate the results of prior studies that have used dipole-modeling of event-related fields (ERFs) generated by an auditory word-recognition task to determine language dominance in patients with epilepsy.

METHODS

We analyzed data from 45 adult patients with drug-resistant partial epilepsy who performed an auditory word-recognition task during MEG recording and also completed a language fMRI study as part of their evaluation for epilepsy surgery. Source imaging of auditory ERFs was performed using dynamic statistical parametric mapping (dSPM). Language laterality indices (LIs) were calculated for four regions of interest (ROIs) by counting above-threshold activations within a 300-600ms time window after stimulus onset. Language laterality (LL) classifications based on these LIs were compared to the results from fMRI.

RESULTS

The most lateralized MEG responses to language stimuli were observed in a parietal region that included the angular and supramarginal gyri (AngSmg). In this region, using a half-maximal threshold, source activations were left dominant in 32 (71%) patients, right dominant in 8 (18%), and symmetric in 5 patients (11%). The best agreement between MEG and fMRI on the ternary classification of regional language dominance into left, right, or symmetric groups was also found at the AngSmg ROI (69%). This was followed by the whole-hemisphere and temporal ROIs (both 62%). The frontal ROI showed the least agreement with fMRI (51%). Gross discordances between MEG and FMRI findings were disproportionately of the type where MEG favored atypical right-hemispheric language in a patient with right-hemispheric seizure origin (p<0.05 at three of the four ROIs).

SIGNIFICANCE

In a parietal region that includes the angular and supramarginal gyri, language laterality estimates based on dSPM of ERFs during auditory word-recognition shows a degree of MEG-fMRI concordance that is comparable to previously published estimates for MEG-Wada concordance using dipole counting methods and the same task. Our data also suggest that MEG language laterality estimates based on this task may be influenced by the laterality of epileptic networks in some patients. This has not been reported previously and deserves further study.

Practice guideline summary: Use of fMRI in the presurgical evaluation of patients with epilepsy: Report of the Guideline Development, Dissemination, and Implementation Subcommittee of the American Academy of Neurology

OBJECTIVE

To assess the diagnostic accuracy and prognostic value of functional MRI (fMRI) in determining lateralization and predicting postsurgical language and memory outcomes.

METHODS

An 11-member panel evaluated and rated available evidence according to the 2004 American Academy of Neurology process. At least 2 panelists reviewed the full text of 172 articles and selected 37 for data extraction. Case reports, reports with <15 cases, meta-analyses, and editorials were excluded.

RESULTS AND RECOMMENDATIONS

The use of fMRI may be considered an option for lateralizing language functions in place of intracarotid amobarbital procedure (IAP) in patients with medial temporal lobe epilepsy (MTLE; Level C), temporal epilepsy in general (Level C), or extratemporal epilepsy (Level C). For patients with temporal neocortical epilepsy or temporal tumors, the evidence is insufficient (Level U). fMRI may be considered to predict postsurgical language deficits after anterior temporal lobe resection (Level C). The use of fMRI may be considered for lateralizing memory functions in place of IAP in patients with MTLE (Level C) but is of unclear utility in other epilepsy types (Level U). fMRI of verbal memory or language encoding should be considered for predicting verbal memory outcome (Level B). fMRI using nonverbal memory encoding may be considered for predicting visuospatial memory outcomes (Level C). Presurgical fMRI could be an adequate alternative to IAP memory testing for predicting verbal memory outcome (Level C). Clinicians should carefully advise patients of the risks and benefits of fMRI vs IAP during discussions concerning choice of specific modality in each case.

Should we continue to drain the pylorus in patients undergoing an esophagectomy?

A systematic review of the literature was performed to assess the necessity of a pyloric drainage procedure during an esophagectomy with gastric conduit reconstruction. Earlier data recommend performing a pyloric drainage procedure for all esophagectomies; however, recent studies have questioned this. A thorough literature search (January 2001-November 2011) was performed using the terms esophagectomy, pyloroplasty, pyloromyotomy, botulinum toxin, and pyloric drainage. Only studies that compared patient outcome after undergoing an esophagectomy with a pyloric drainage procedure with those undergoing an esophagectomy without a pyloric drainage procedure were selected. Only four studies, comprising 668 patients in total, were identified that compared patient outcome after undergoing an esophagectomy with or without a pyloric drainage procedure, and two additional meta-analyses were identified and selected for discussion. All studies were retrospective, and because of the heterogeneity of studies, patient demographics, reporting, and statistical analysis of patient outcome, pooling of data and meta-analysis could not be performed. Careful analysis demonstrated that pyloric drainage procedure was associated with a non-significant trend for delayed gastric emptying and biliary reflux, while not affecting the incidence of dumping. No correlation was determined between a pyloric drainage procedure and anastomotic leaks, postoperative pulmonary complications, length of hospital stay, and overall perioperative morbidity. While there are risks associated with a pyloric drainage procedure and data exist supporting its omission during an esophagectomy, no good conclusion can be drawn from the current literature. Larger multi-institutional, prospective studies are required to definitively answer this question.

Predictors of language lateralization in temporal lobe epilepsy

Among patients with epilepsy, atypical (rightward) language lateralization has been associated with left-handedness, a left seizure focus, an early age at seizure onset, and familial sinistrality, although these associations are not consistently observed. No study has examined all of these factors in relation to language lateralization in the same epilepsy sample, let alone in a sample comprised only of patients with temporal lobe epilepsy. Moreover, little consideration has been given in previous studies to how language lateralization might be influenced by the interplay between different factors, or how much unique variance in language lateralization is explained by each factor. The primary aim of this study was to examine the combined influences of handedness, side of seizure focus, age at seizure onset, and familial sinistrality on language lateralization in temporal lobe epilepsy patients. A secondary aim was to determine which factors uniquely contribute to the prediction of language lateralization. 162 patients with intractable temporal lobe epilepsy underwent functional MRI language mapping, from which language lateralization indexes were derived. Degree of handedness was measured via the Edinburgh Handedness Inventory. Main and 2-way interaction effects on language lateralization indexes were examined via linear regressions and Fisher exact tests. Significant effects were next examined in multiple regressions to identify unique predictors of language lateralization indexes. When examined in isolation in regressions, only left-handedness and a left seizure focus predicted atypical (rightward) language lateralization. These results, however, were qualified by interaction effects demonstrating that stronger left hand preference was associated with greater atypical language lateralization only among patients with a left seizure focus, an early or intermediate age at seizure onset, or no familial sinistrality. In follow-up multiple regressions, the interaction terms accounted for a significant amount of variance in language lateralization indexes above and beyond main effects. Additionally, side of seizure focus and its interaction with handedness uniquely predicted language lateralization indexes. Results indicate that degree of left-handedness is a marker of greater atypical (rightward) language lateralization in temporal lobe epilepsy but only in the context of seizure characteristics that have the potential to drive joint reorganization of language and hand preference (i.e., left seizure focus, or early or intermediate age at seizure onset) or in the absence of a genetic predisposition for left-handedness (i.e., no familial sinistrality). This study advances existing knowledge by illustrating how different factors combine to jointly affect language lateralization, and by identifying side of seizure focus and its interaction with handedness as unique predictors of language lateralization in temporal lobe epilepsy.

Naming outcome after left or right temporal lobectomy in patients with bilateral language representation by Wada testing

OBJECTIVE

This study aimed to examine language outcome after left or right anterior temporal lobectomy (ATL) in patients with epilepsy with bilateral language representation on intracarotid sodium amobarbital (Wada) testing.

METHODS

Twenty-two patients with epilepsy with bilateral language (Wada laterality index between -50 and 50) underwent right ATL (RATL, n=10) or left ATL (LATL, n=12). All the patients were administered the Boston Naming Test preoperatively and six months postoperatively.

RESULTS

Left anterior temporal lobectomy patients showed greater postoperative naming decline than RATL patients. Group differences were also observed on subtests of the Wada test. Performance on the Wada naming and comprehension subtests was better in the nonsurgical hemisphere than in the surgical hemisphere in the RATL group, but there was no difference between the nonsurgical and the surgical hemisphere naming and comprehension performance in the LATL group.

CONCLUSIONS

Left anterior temporal lobectomy patients with bilateral language are at greater risk for naming decline than RATL patients with bilateral language. This difference may be due to relatively better naming and comprehension abilities in the nonsurgical hemisphere in the RATL group.

Naming outcome prediction in patients with discordant Wada and fMRI language lateralization

OBJECTIVE

Investigations of the validity of fMRI as an alternative to Wada language testing have yielded Wada/fMRI discordance rates of approximately 15%, but almost nothing is known regarding the relative accuracy of Wada and fMRI in discordant cases. The objective of this study was to determine which of the two (the Wada test or the language fMRI) is more predictive of postoperative naming outcome following left anterior temporal lobectomy in discordant cases.

METHODS

Among 229 patients with epilepsy who prospectively underwent Wada and fMRI language testing, ten had discordant language lateralization results, underwent left anterior temporal lobectomy, and returned for postoperative language testing. The relative accuracy of Wada and fMRI for predicting language outcome was examined in these cases.

RESULTS

Functional magnetic resonance imaging provided a more accurate prediction of language outcome in seven patients, Wada was more accurate in two patients, and the two tests were equally accurate in one patient.

CONCLUSIONS

In cases of discordance, fMRI predicted postsurgical naming outcome with relatively better accuracy compared to the Wada test.

Language lateralization by fMRI and Wada testing in 229 patients with epilepsy: rates and predictors of discordance

PURPOSE

To more definitively characterize Wada/functional magnetic resonance imaging (fMRI) language dominance discordance rates with the largest sample of patients with epilepsy to date, and to examine demographic, clinical, and methodologic predictors of discordance.

METHODS

Two hundred twenty-nine patients with epilepsy underwent both a standardized Wada test and a semantic decision fMRI language protocol in a prospective research study. Language laterality indices were computed for each test using automated and double-blind methods, and Wada/fMRI discordance rates were calculated using objective criteria for discordance. Regression analyses were used to explore a range of variables that might predict discordance, including subject variables, Wada quality indices, and fMRI quality indices.

KEY FINDINGS

Discordant results were observed in 14% of patients. Discordance was highest among those categorized by either test as having bilateral language. In a multivariate model, the only factor that predicted discordance was the degree of atypical language dominance on fMRI.

SIGNIFICANCE

fMRI language lateralization is generally concordant with Wada testing. The degree of rightward shift of language dominance on fMRI testing is strongly correlated with Wada/fMRI discordance, suggesting that fMRI may be more sensitive than Wada to right hemisphere language processing, although the clinical significance of this increased sensitivity is unknown. The relative accuracy of fMRI versus Wada testing for predicting postsurgical language outcome in discordant cases remains a topic for future research.

Extent of lymph node resection does not increase perioperative morbidity and mortality after surgery for stage I lung cancer in the elderly

BACKGROUND & OBJECTIVES

Pathologic evaluation of > 10 lymph nodes (LNs) is considered necessary for accurate lung cancer staging. However, physicians have concerns about increased risk in perioperative mortality (POM) and morbidity with more extensive LN sampling, particularly in the elderly. In this study, we compared the outcomes in elderly patients with stage I non-small cell lung cancer (NSCLC) undergoing extensive (> 10 nodes) and limited (≤ 10 nodes) LN resections.

METHODS

Using data from the Surveillance, Epidemiology and End Results registry linked to Medicare records, we identified 4975 patients ≥ 65 years of age with stage I NSCLC who underwent a lobectomy between 1992 and 2002. Risk of perioperative morbidity and POM after the evaluation of ≤ 10 vs. >10 LNs was compared among patients after adjusting for propensity scores.

RESULTS

Multiple regression analysis showed similar POM between the two groups (OR, 1,01; 95% CI, 0,71-1,44). Other postoperative complications were similar across groups except for thromboembolic events, which were more common among patients undergoing resection of > 10 LNs (OR, 1,72; 95% CI, 1,12-2,63).

CONCLUSIONS

These data suggest that evaluation of > 10 LNs, which allows for more accurate staging, appears to be safe in the elderly patients undergoing lobectomy for stage I NSCLC without compromising postoperative recovery.

The contribution of neuropsychology to diagnostic assessment in epilepsy

Neuropsychology plays a vital role in the treatment of epilepsy, providing information on the effects of seizures on higher cortical functions through the measurement of behavioral abilities and disabilities. This is accomplished through the design, administration and interpretation of neuropsychological tests, including those used in functional neuroimaging or cortical mapping and in intracarotid anesthetic procedures. The objective of this paper is to define and summarize in some detail the role and methods of neuropsychologists in specialized epilepsy centers. Included are information and recommendations regarding basic ingredients of a thorough neuropsychological assessment in the epilepsy setting, as well as suggestions for an abbreviated alternative exam when needed, with emphasis on functions associated with specific brain regions. The paper is intended for novice and experienced neuropsychologists to enable them to develop or evaluate their current practices, and also for other clinicians, who seek a better understanding of the methodology underlying the neuropsychological input to their work.

A comparison of two fMRI methods for predicting verbal memory decline after left temporal lobectomy: language lateralization versus hippocampal activation asymmetry

PURPOSE

Language lateralization measured by preoperative functional magnetic resonance imaging (fMRI) was shown recently to be predictive of verbal memory outcome in patients undergoing left anterior temporal lobe (L-ATL) resection. The aim of this study was to determine whether language lateralization or functional lateralization in the hippocampus is a better predictor of outcome in this setting.

METHODS

Thirty L-ATL patients underwent preoperative language fMRI, preoperative hippocampal fMRI using a scene encoding task, and pre- and postoperative neuropsychological testing. A group of 37 right ATL (R-ATL) surgery patients was included for comparison.

RESULTS

Verbal memory decline occurred in roughly half of the L-ATL patients. Preoperative language lateralization was correlated with postoperative verbal memory change. Hippocampal activation asymmetry was strongly related to side of seizure focus and to Wada memory asymmetry but was unrelated to verbal memory outcome.

DISCUSSION

Preoperative hippocampal activation asymmetry elicited by a scene encoding task is not predictive of verbal memory outcome. Risk of verbal memory decline is likely to be related to lateralization of material-specific verbal memory networks, which are more closely correlated with language lateralization than with overall asymmetry of episodic memory processes.

Influence of race on kidney transplantation in the Department of Defense healthcare system

BACKGROUND

We report the influence of race on transplant outcomes in the Department of Defense (DOD) system.

METHODS

Retrospective cohort analysis of all kidney transplants performed at WRAMC from 1996 to 2005. Kaplan-Meier analysis was used to assess for differences in graft survival, and Cox regression was used to calculate adjusted hazard ratios for graft loss. For our analyses, we used the cutoff of 6 years (year 2000) when we introduced thymoglobulin induction; maintenance immunosuppression consisted of mycophenolate mofetil and tacrolimus, and rapid steroid taper (completed withdrawal at 6 weeks) was used for all patients.

RESULTS

There were 220 transplants (91 Blacks, 107 Caucasians and 22 Asians). Because the curve for graft survival for Blacks over time violated the proportional hazards assumption (at 6 years post-transplant), analysis was segregated into two segments. Through 6 years of follow-up, graft survival was 77% for Blacks and 81% for non-Blacks (p = 0.74 by log rank). Through 9 potential years of follow-up, graft survival for Blacks was 56% and 78% for Whites (p = 0.005). In Cox regression analysis, Black race, compared with non-Black race, was not significantly associated with graft loss at 6 years, but was significantly associated with graft loss occurring after 6 years.

CONCLUSIONS

In the DOD health system, no significant differences were seen in graft survival among recipients of different races at 6 years. Black recipients who received a kidney transplant before the year 2000 showed decreased graft survival compared to non-Blacks. This was consistent with change in immunosuppressive regimen in our institution with the introduction of thymoglobulin induction and maintenance therapy with tacrolimus, mycophenolate mofetil and withdrawal of prednisone at 6 weeks.

A comparison of five fMRI protocols for mapping speech comprehension systems

AIMS

Many fMRI protocols for localizing speech comprehension have been described, but there has been little quantitative comparison of these methods. We compared five such protocols in terms of areas activated, extent of activation, and lateralization.

METHODS

fMRI BOLD signals were measured in 26 healthy adults during passive listening and active tasks using words and tones. Contrasts were designed to identify speech perception and semantic processing systems. Activation extent and lateralization were quantified by counting activated voxels in each hemisphere for each participant.

RESULTS

Passive listening to words produced bilateral superior temporal activation. After controlling for prelinguistic auditory processing, only a small area in the left superior temporal sulcus responded selectively to speech. Active tasks engaged an extensive, bilateral attention, and executive processing network. Optimal results (consistent activation and strongly lateralized pattern) were obtained by contrasting an active semantic decision task with a tone decision task. There was striking similarity between the network of brain regions activated by the semantic task and the network of brain regions that showed task-induced deactivation, suggesting that semantic processing occurs during the resting state.

CONCLUSIONS

fMRI protocols for mapping speech comprehension systems differ dramatically in pattern, extent, and lateralization of activation. Brain regions involved in semantic processing were identified only when an active, nonlinguistic task was used as a baseline, supporting the notion that semantic processing occurs whenever attentional resources are not controlled. Identification of these lexical-semantic regions is particularly important for predicting language outcome in patients undergoing temporal lobe surgery.

Functional MRI and Wada studies in patients with interhemispheric dissociation of language functions

Rare patients with chronic epilepsy show interhemispheric dissociation of language functions on intracarotid amobarbital (Wada) testing. We encountered four patients with interhemispheric dissociation in 490 consecutive Wada language tests. In all cases, performance on overt speech production tasks was supported by the hemisphere contralateral to the seizure focus, whereas performance on comprehension tasks was served by the hemisphere with the seizure focus. These data suggest that speech production capacity is more likely to shift hemispheres than is language comprehension. Wada and fMRI language lateralization scores were discordant in three of the four patients. However, the two methods aligned more closely when Wada measures loading on comprehension were used to calculate lateralization scores. Thus, interhemispheric dissociation of language functions could explain some cases of discordance on Wada/fMRI language comparisons, particularly when the fMRI measure used is not sensitive to speech production processes.

Use of preoperative functional MRI to predict verbal memory decline after temporal lobe epilepsy surgery

PURPOSE

Verbal memory decline is a frequent complication of left anterior temporal lobectomy (L-ATL). The goal of this study was to determine whether preoperative language mapping using functional magnetic resonance imaging (fMRI) is useful for predicting which patients are likely to experience verbal memory decline after L-ATL.

METHODS

Sixty L-ATL patients underwent preoperative language mapping with fMRI, preoperative intracarotid amobarbital (Wada) testing for language and memory lateralization, and pre- and postoperative neuropsychological testing. Demographic, historical, neuropsychological, and imaging variables were examined for their ability to predict pre- to postoperative memory change.

RESULTS

Verbal memory decline occurred in over 30% of patients. Good preoperative performance, late age at onset of epilepsy, left dominance on fMRI, and left dominance on the Wada test were each predictive of memory decline. Preoperative performance and age at onset together accounted for roughly 50% of the variance in memory outcome (p < 0.001), and fMRI explained an additional 10% of this variance (p <or= 0.003). Neither Wada memory asymmetry nor Wada language asymmetry added additional predictive power beyond these noninvasive measures.

DISCUSSION

Preoperative fMRI is useful for identifying patients at high risk for verbal memory decline prior to L-ATL surgery. Lateralization of language is correlated with lateralization of verbal memory, whereas Wada memory testing is either insufficiently reliable or insufficiently material-specific to accurately localize verbal memory processes.

Functional magnetic resonance imaging of language in epilepsy

Functional magnetic resonance imaging (fMRI) has revolutionized our understanding of functional networks and cerebral organization in both normal and pathological brains. In the present review, we describe the use of fMRI for mapping language in epilepsy patients prior to surgical intervention including a discussion of methodological issues and task design, comparisons between fMRI and the intracarotid sodium amobarbital test, fMRI studies of language reorganization, and the use of fMRI laterality indexes to predict outcome after anterior temporal lobectomy.

Predictors of naming decline after dominant temporal lobectomy: age at onset of epilepsy and age of word acquisition

This study examined factors affecting object naming decline in patients who have undergone anterior temporal lobectomy (ATL) and the correlation between age of word acquisition and loss of specific object names postoperatively. The Boston Naming Test (BNT) was used to assess changes in object-naming performance in patients who underwent ATL. Correlation analyses were performed by group (dominant or nondominant ATL) on individual items from the BNT to determine if age of acquisition of object names had an effect on postoperative word loss. The influence of age at onset of seizures on naming decline was examined in the dominant ATL group. Only patients who had undergone dominant ATL experienced significant clinical and statistical declines after surgery. Among the patients who underwent dominant ATL, those with late age at onset of seizures declined significantly more than those with early-onset seizures. When individual object names were examined, age of acquisition of words predicted whether words were lost or gained after surgery.

Acute renal allograft rejection following pegylated IFN-alpha treatment for chronic HCV in a repeat allograft recipient on hemodialysis: a case report

Interferon alpha (IFN-alpha) can be effective therapy for patients with chronic kidney disease who have chronic hepatitis C (HCV). However, acute allograft rejection has been reported in association with IFN-alpha following kidney transplantation, and therefore IFN therapy is recommended prior to, rather than after, kidney transplantation whenever feasible. The special case of repeat allograft recipients who contract HCV after the first transplantation presents special difficulties. This report features the case of a repeat allograft recipient who presented with neutropenic fevers after 5 months of pegylated IFN-alpha therapy, initiated 6 months following the functional loss of his third graft and the reinitiation of hemodialysis (HD). Physical exam, radiographic and laboratory findings led to allograft nephrectomy. The pathologic findings supported a diagnosis of acute-on-chronic rejection. This represents a rare case of IFN-alpha induced rejection following allograft failure and return to HD in a repeat allograft recipient. It also calls attention to the need for a high index of suspicion for the development of allograft rejection, which may require allograft nephrectomy even after allograft 'failure'.

Characterization of an immune response

The characterization of any detected antibodies provides detailed information that can be critical to understanding the significance of an immune response. The BIAcore immunoassay provides a straightforward means of characterizing many aspects of the immune response including antibody concentration, specificity, binding affinity, and the presence of isotypes. One important aspect of the immune response is determination of neutralizing capability, which requires a biological assay. The ultimate clinical significance of an immune response can only be fully understood when data from antibody characterization are coupled with clinical data from the patient. Some of the factors that can contribute to the clinical significance of an immune response are: (i) magnitude of the immune response (concentration of antibodies detected); (ii) duration of the immune response (continuous antibody production or sporadic and not sustained); (iii) correlation with any adverse events; (iv) correlation with a change in pharmacokinetics (either mediating sustained circulation or enhanced clearance of the drug); (v) biological neutralization of the drug; (vi) biological neutralization of an endogenous protein. Full characterization of the immune response requires the incorporation of antibody assays, pharmacokinetic assays, and clinical data.

New technologies for the detection of antibodies to therapeutic proteins

The determination of antibody formation in response to a therapeutic product requires that a variety of data be evaluated. In addition to examining immuno-assay and bioassay results, it is important to determine any clinical relevance. By also examining pharmacokinetic data as well as other clinical results, an evaluation can be made as to whether any clinically relevant antibodies were generated. To help in this evaluation, it is important to fully characterize the antibodies that are generated. Both the BIAcore and IGEN platforms are powerful tools for determining if antibodies have been produced in a subject The BIAcore is also able to characterize these antibodies as to isotype, relative concentration, and relative affinity. The bioassay result can identify serum samples that contain an agent capable of inhibiting a biological effect of a drug. When combined with the results of an immuno-assay, it is possible to determine if the antibodies are capable of neutralizing the drug.

Use of preoperative functional neuroimaging to predict language deficits from epilepsy surgery

BACKGROUND

Left anterior temporal lobectomy (L-ATL) may be complicated by confrontation naming deficits.

OBJECTIVE

To determine whether preoperative fMRI predicts such deficits in patients with epilepsy undergoing L-ATL.

METHODS

Twenty-four patients with L-ATL underwent preoperative language mapping with fMRI, preoperative intracarotid amobarbital (Wada) testing for language dominance, and pre- and postoperative neuropsychological testing. fMRI laterality indexes (LIs), reflecting the interhemispheric difference between activated volumes in left and right homologous regions of interest, were calculated for each patient. Relationships between the fMRI LI, Wada language dominance, and naming outcome were examined.

RESULTS

Both the fMRI LI (p < 0.001) and the Wada test (p < 0.05) were predictive of naming outcome. fMRI showed 100% sensitivity and 73% specificity in predicting significant naming decline. Both fMRI and the Wada test were more predictive than age at seizure onset or preoperative naming performance.

CONCLUSIONS

Preoperative fMRI predicted naming decline in patients undergoing left anterior temporal lobectomy surgery.

Use of biosensors to monitor the immune response

Biosensor instruments, such as the BIACORE, are gaining popularity for analysing serum samples for the presence of antibodies. These instruments offer several advantages in the detection and subsequent characterization of clinically relevant antibodies generated in response to administration of therapeutic proteins. Much like other common immunoassay platforms, immobilized ligand is used to capture antibodies. Unlike conventional approaches, the ligand is immobilized to the surface of a biosensor chip, with detection based upon surface plasmon resonance. This assay platform, therefore, does not require reporter molecules such as enzymes, fluorochromes or radioisotopes that are common to conventional immunoassay methodologies. Additional desirable features of the biosensor platform include real-time detection of the binding of antibody to ligand (for kinetic measurements) as well as straightforward characterization of antibody isotype, specificity and relative concentration. This is all performed with minimum serum requirements (typically 10 microlitres per sample analysed) in a fully automated environment. The unique features of the biosensor instrument warrant that these assays are referred to as biosensor immunoassays to clearly distinguish them from more conventional immunoassay methodologies, such as ELISA.

Spatial variation of plasma flow in the oxazolone-stimulated microcirculation

INTRODUCTION

In cutaneous lymphocytic inflammation, enhanced regional blood flow is suggested by persistent erythema and warmth. Direct assessment of the microcirculation, however, has been limited by tissue edema and skin thickness.

METHODS

To assess the microcirculatory adaptations to the epicutaneous antigen oxazolone, we studied the first pass kinetics and microvascular topography of the inflammatory skin microcirculation using a specially adapted epi-illumination intravital microscopy system. The fluorescence intravital videomicroscopy and streaming image acquisition of fluorescein-labeled dextran (approximately 500,000 MW) injections were used to assess changes in plasma flow.

RESULTS

Direct plasma tracer injections of both the oxazolone-stimulated and control microcirculation demonstrated comparable transit times (leading edge and intensity-weighted peak times) from the carotid artery to the superficial vascular plexus (p > 0.05). In contrast to transit times, continuous infusion of the plasma tracer demonstrated a significant increase in the delivery of the fluorescein-labeled dextran to the oxazolone-stimulated microcirculation. Quantitative morphometry of intravital microscopic images demonstrated a 2.2-fold increase in the mean diameter of vessels in the superficial vascular plexus (p < 0.01). Further, fluorescence intensity mapping indicated that the increase was associated with increased perfusion of focal regions of the superficial vascular plexus (p < 0.001).

CONCLUSIONS

These results indicate that the oxazolone-stimulated adaptations of the inflammatory microcirculation include both microvascular dilatation and the redistribution of plasma flow.

Esophagectomy for esophageal cancer

This review considers the esophagectomy techniques in the treatment of esophageal cancer and provides the guidelines for optimizing the patients' chances at cure, minimizing the risk of mediastinal enteric leak (which carries a mortality rate as high as 50%) and minimizing associated pulmonary insufficiency and infection. The 4 most commonly used routes for resection and replacement include a transhiatal, transthoracic (Ivor-Lewis), tri-incisional (right chest then simultaneous abdominal and left neck), and left chest (distal tumors). Each of these techniques will be described as will the use of colon and jejunum for esophageal replacement. The healthy stomach is the preferred conduit for esophageal replacement. The stomach is well vascularized, easily reaches to the neck, and requires only a single anastomosis for re-establishing intestinal continuity. When the stomach is not available (usually because of prior surgery or disease) the choice of conduits include colon and jejunum. With respect to minimally invasive esophagectomy for esophageal cancer, several groups have significant experience with this and report excellent results. This is an evolving technique but holds much promise for improving the quality of life of patients with cancer without compromising their survival. In locally advanced middle third tumors, thoracotomy and dissection under direct vision's desirable and improves the safety of the operation. The same may apply to tumors receiving neoadjuvant therapy. For tumors of the distal esophagus, transhiatal, tri-incisional, and Ivor-Lewis resection are probably equally as safe, and appear to result in equivalent long-term survival. An intrathoracic anastomotic leak is disastrous, carrying a mortality rate of up to 50%. Any surgeon who performs esophagectomy with an intrathoracic anastomosis must do so with a low incidence of leakage, certainly under 5%. Consideration should be given to a cervical placement if there are factors increasing the risk such as the use of induction therapy.

Impact of HIV seropositivity on graft and patient survival after cadaveric renal transplantation in the United States in the pre highly active antiretroviral therapy (HAART) era: an historical cohort analysis of the United States Renal Data System

BACKGROUND

National statistics are presented for patient survival and graft survival in patients seropositive for the human immunodeficiency virus (HIV+) at the time of renal transplantation in the era prior to highly active antiretroviral therapy (HAART).

METHODS

Historical cohort analysis of 63, 210 cadaveric solitary renal transplant recipients with valid HIV serology entries in the United States Renal Data System (USRDS) from 1 January 1987 to 30 June 1997. The medical evidence form was also used for additional variables but, because of fewer available values, was analyzed in a separate model. Outcomes were patient characteristics and survival associated with HIV+ status.

RESULTS

Thirty-two patients (0.05%) in the study period were HIV+ at transplant. HIV+ patients were comparable to the national renal transplant population in terms of gender and ethnic distribution but were younger and had younger donors and better HLA matching than the USRDS population. Patient and graft three-year survival were significantly reduced in HIV+ recipients (53% graft, 83% patient survival) relative to the USRDS population (73% and 88%, respectively). In multivariate analysis, HIV+ status was independently associated with patient mortality and decreased graft survival in recipients of cadaveric kidney transplants.

CONCLUSIONS

This analysis was retrospective and may underestimate the number of HIV+ patients transplanted in the United States. Although the clinical details of patient selection for transplant were unknown, these results show HIV+ patients can have successful outcomes after cadaveric renal transplantation, although outcomes are significantly different from HIV- recipients.

Hepatitis C virus seropositivity at the time of renal transplantation in the United States: associated factors and patient survival

National statistics for patient characteristics and survival of renal transplant recipients positive for hepatitis C virus (HCV+) at the time of renal transplant are presented. A historical cohort analysis of 33479 renal transplant recipients in the United States Renal Data System from 1 July, 1994 to 30 June, 1997 has been carried out. The medical evidence form was also used for additional variables, but because of fewer available values, this was analyzed in a separate model. Outcomes were patient characteristics and survival associated with HCV+. Of 28692 recipients with valid HCV serologies, 1624 were HCV+ at transplant (5.7% prevalence). In logistic regression analysis, HCV+ was associated with African-American race, male gender, cadaveric donor type, increased duration of pre-transplant dialysis, previous transplant, donor HCV+, recipient (but not donor) age, serum albumin, alcohol use, and increased all-cause hospitalizations. Diabetes and IgA nephropathy were less associated with HCV+. Total all-cause, unadjusted mortality was 13.1% in HCV+ vs. 8.5% in HCV- patients (p <0.01 by log rank test). In Cox regression, mortality was higher for HCV+ (adjusted hazard ratio = 1.23, 95% confidence interval = 1.01-1.49, p = 0.04). HCV+ recipients were more likely to be African-American, male, older, and to have received repeat transplants and donor HCV+ transplants. HCV+ recipients also had substantially longer waiting times for transplant. In contrast to recent studies, diabetes did not have an increased association with HCV+, perhaps due to limitations of the database. HCV+ recipients had increased mortality and hospitalization rates compared with other transplant recipients.

Chemotherapy for a patient with advanced non-small-cell lung cancer during pregnancy: a case report and a review of chemotherapy treatment during pregnancy

BACKGROUND

Lung cancer is the most common cause of cancer death in women in the USA. Lung cancer arising during pregnancy is rare and has been reported only 15 times since the 1950s. However, the use of chemotherapy for lung cancer during pregnancy has not previously been reported.

METHODS

The history, treatment and outcome of a patient with stage IV non-small-cell lung carcinoma (NSCLC) diagnosed during pregnancy is presented. Previous published reports on lung cancer were retrieved by a literature search of Medline and Cancerlit.

RESULTS

A 31-year-old woman was diagnosed as having stage IV NSCLC with bilateral pulmonary involvement when 26 weeks pregnant. Her shortness of breath progressed to dyspnea at rest on 100% inspired oxygen. Therefore, she was treated with systemic chemotherapy using cisplatin and vinorelbine. Despite this treatment, her oxygenation declined further over the next 4 days and thus the baby was delivered via cesarean section after 27 weeks of gestation. Four cycles of vinorelbine and cisplatin have now been administered. Following this treatment, the patient has experienced a significant clinical improvement and no longer requires supplemental oxygen. No chemotherapy-related adverse effects have been noted in the baby. In the 15 previously reported patients with concurrent lung cancer and pregnancy, chemotherapy administration during pregnancy has not been described.

CONCLUSIONS

Treatment of lung cancer with chemotherapy during pregnancy should be considered on an individual basis with regard to the stage of the cancer and the maturity of the fetus. To our knowledge, the case presented here is the first report of a woman receiving chemotherapy for lung cancer while pregnant.

Transthoracic esophagectomy with radical mediastinal and abdominal lymph node dissection and cervical esophagogastrostomy for esophageal carcinoma

BACKGROUND

Several techniques for esophageal resection have been reported. This study examines the morbidity, mortality, and early survival of patients after transthoracic esophagectomy for esophageal carcinoma using current staging techniques and neoadjuvant therapy. The technique includes right thoracotomy, laparotomy, and cervical esophagogastrostomy (total thoracic esophagectomy) with radical mediastinal and abdominal lymph node dissection.

METHODS

Three hundred forty-two patients had surgery for esophageal carcinoma between 1989 and 2000 at our institution. Two hundred fifty consecutive patients had esophagectomy using this technique. Kaplan-Meier curves and univariate and multivariate analyses were performed by postsurgical pathologic stage.

RESULTS

Median age was 62.7 years (31 to 86 years). Fifty-nine were female. Eighty-one percent (202) had induction chemotherapy (all patients with clinical T3/4 or N1). Early postoperative complications included recurrent laryngeal nerve injury (14% [35]), chylothorax (9%, [22]), and leak (8%, [19]). Median length of stay was 13 days (5 to 330 days). In-hospital or 30-day mortality was 3.6% (9). Overall survival at 3 years was 44%; median survival was 25 months, and 3-year survival by posttreatment pathologic stage was: stage 0 (complete response) (n = 60), 56%; stage I (n = 32), 65%; stage IIA (n = 67), 41%; stage IIB (n = 30), 46%; and stage III (n = 49), 17%. Mean follow-up was 24 months (SEM 1.6, 0 to 138 months). Five patients with tumor in situ, 6 patients with stage IV disease, and 1 patient who could not be staged (12 pts) were excluded from survival and multivariate calculations. In univariate and different models of multivariate analysis, age more than 65 years, posttreatment T3, and nodal involvement were predictive of poor survival. For univariate analysis, p = 0.002, p = 0.004, p = 0.02, respectively; for multivariate analysis, p = 0.001, p = 0.003, p = 0.02, respectively.

CONCLUSIONS

Total thoracic esophagectomy with node dissection for esophageal cancer appears to have acceptable morbidity and mortality with encouraging survival results in the setting of neoadjuvant therapy. Patients who show complete response after induction chemoradiotherapy appear to have improved long-term survival.

Memory outcome after left anterior temporal lobectomy in patients with expected and reversed Wada memory asymmetry scores

PURPOSE

The ideal candidate for anterior temporal lobectomy surgery shows a Wada memory asymmetry (WMA) score characterized by better memory performance in the hemisphere contralateral to the seizure focus relative to the ipsilateral (surgical) hemisphere. However, some surgical candidates show a reversed WMA or better Wada memory performance in the hemisphere of surgical interest relative to the hemisphere contralateral to the seizure focus. To date, no data are available contrasting memory and seizure outcome for these two Wada groups. The present study compared memory and seizure outcome after left anterior temporal lobectomy (L-ATL) in patients showing expected and reversed WMA scores, and also examined the relationship of the individual hemisphere Wada memory scores for predicting verbal memory outcome after L-ATL.

METHODS

We compared 6-month postoperative verbal memory change scores and seizure outcome in L-ATL patients with either an expected (n=12) or reversed WMA (n=9) pattern on Wada memory testing.

RESULTS

L-ATL patients showing a reversed WMA score had a poorer verbal memory outcome and poorer seizure control after surgery compared with patients showing a WMA score in the expected direction.

CONCLUSIONS

L-ATL patients with a reversed WMA score have a greater risk for memory morbidity and poorer seizure outcome than do patients with a WMA score in the expected direction. The WMA score was the best predictor of memory outcome after L-ATL. When the WMA score is not considered, both individual Wada hemisphere scores (contralateral and ipsilateral) provided significant and independent contribution to predicting postoperative verbal memory functioning. These findings are discussed in the context of the functional reserve and hippocampal adequacy models of memory change after temporal lobectomy.

Combined antegrade and retrograde dilation: a new endoscopic technique in the management of complex esophageal obstruction

BACKGROUND

Esophageal strictures that cause complete obstruction are often difficult to dilate with standard bougienage techniques.

METHODS

A new technique was developed and applied, combined antegrade and retrograde dilation, for dilatation of complex esophageal strictures. The stomach is accessed and an endoscope (9.8 mm diameter) is directed under fluoroscopy in a retrograde fashion into the distal esophagus. A guidewire with a hydrophilic coating is advanced through the stricture and then pulled through the mouth with a simultaneously placed proximal endoscope. The guidewire is then used as a guide for antegrade esophageal dilatation.

RESULTS

Ten patients with complex esophageal strictures (with and without fistulas) were treated with this technique. Three required a second combined antegrade and retrograde dilation procedure. All strictures were dilated and no perforations occurred.

CONCLUSIONS

Combined antegrade and retrograde dilation is a safe and effective technique for dilation of complex obstructing esophageal lesions.

Biphasic response of the regional lymphatics in the normal lymphocyte transfer reaction

BACKGROUND

Initially developed for histocompatibility testing, the normal lymphocyte transfer (NLT) reaction involves the intradermal injection of allogeneic lymphocytes from one individual to another. Because of the unique kinetics of the immunological response to allogeneic lymphocytes, the NLT reaction has been considered an informative system for the analysis of transplant immunity.

METHODS

In this study, we used bilateral efferent lymph duct cannulations in sheep to examine the regional lymphatic response to the NLT reaction. Our studies used monoclonal antibodies to define lymphocyte population dynamics and DNA flow cytometry to reflect lymphocyte proliferative responses.

RESULTS

The results confirmed a biphasic NLT reaction. An unexpected finding was the marked differences between the early and late NLT responses. The early response was characterized by T-lymphocyte proliferation, as reflected by S-phase DNA, which was comparable in both the NLT-stimulated and contralateral control efferent lymphocytes. This bilateral proliferative response was observed in both CD4+ and CD8+ lymphocytes. In contrast, the late response was restricted to the efferent lymph from the NLT-stimulated lymph node. Dual-parameter flow cytometry demonstrated that the dominant component of this unilateral NLT response was CD8+ lymphocytes.

CONCLUSIONS

These results suggest important functional distinctions between systemic and regional lymphatic responses to intradermal alloantigens.

Bronchoscopic volume reduction: a safe and effective alternative to surgical therapy for emphysema

Lung volume reduction surgery (LVRS), the removal of damaged, hyperexpanded lung, has been shown to improve respiratory function in many patients with end-stage emphysema. We report the results of an animal study using a new transbronchoscopic alternative to LVRS in which a washout solution and fibrin-based glue are used to collapse, seal, and scar target regions of abnormal lung. Twelve sheep had static and dynamic lung functions measured at baseline. Emphysema was produced by inhaled papain (7,000 U/wk x 4 wk), resulting in a significant increase of lung volumes, compliance, and airway resistance. The animals were then divided into three treatment groups of four animals, and underwent surgical volume reduction (SVR), bronchoscopic volume reduction (BVR), or bronchoscopy alone (Sham-BVR). Response to each intervention was assessed 8 to 12 wk after treatment by measuring lung function and examining lung tissue. BVR and SVR groups responded with significant and similar decreases in TLC and residual volume (RV). Tissue examination demonstrated that BVR caused collapse of the lung with focal scarring in 11 of 20 target territories (55% success rate). Three of the 11 target zones developed sterile abscesses. Postprocedure complications were less frequent with BVR than with SVR. This pilot study suggests that lung volume reduction can be achieved in animals without surgery using a bronchoscopic approach and a novel fibrin-based glue system. BVR has the potential for simplifying volume reduction, extending indications, and reducing morbidity, mortality, and costs in humans.

Magnetic resonance analysis of postsurgical temporal lobectomy

BACKGROUND AND PURPOSE

The effect of temporal lobe transection area, volume of postoperative gliosis, and surgical technique on patients' seizure-free outcome is unknown. The authors studied the effects of these variables on patients' seizure-free outcome.

METHODS

A retrospective review of magnetic resonance imaging examinations acquired 3 to 18 months after temporal lobe resection was carried out for 18 patients with intractable temporal lobe seizures and known postsurgical outcomes for more than 2 years. The total volume of radiologically probable gliosis evident on axial proton-density-weighted images was calculated for each patient using software on an independent console. The total area of temporal lobe surface transected by the scalpel was calculated as well, using sagittal T1-weighted images. The total volume of gliosis, the total area of transected temporal lobe, and the specific type of surgery (sparing vs no sparing of the superior temporal gyrus) were then correlated with the postsurgical outcome of the patients. An examiner with no prior knowledge of the patients' postsurgical outcomes carried out the above calculations and measurements. The patients' postoperative outcome was defined using Engel classifications, and patients were divided into 2 groups: group A with Engel class 1 (n = 9) and group B with Engel classes 2-4 (n = 9).

RESULTS

The mean volumes of postoperative gliosis were not significantly different between group A (3592.3 mm3) and group B (4270 mm3). The mean area of transected temporal lobe was also similar between group A (1865.2 mm2) and group B (1930 mm2). With regard to surgical technique, there were 5 patients who had the superior temporal gyrus resected and 13 who did not. Eighty percent of patients with the superior temporal gyrus resected were Engel class 1 or 2, whereas only 20% were of Engel class 3 or 4.

CONCLUSIONS

The authors found no clear association between postoperative outcome and residual temporal lobe gliosis, the surgical technique, or the total area of temporal lobe transected by the scalpel.

Cell adhesion molecule expression in the sheep thymus

Cell adhesion molecules are potential regulating factors in both prethymic and intrathymic T cell development. An experimental challenge has been the development of a large animal model that facilitates in vivo studies of both intrathymic development and lymphocyte migration. To extend earlier studies of thymic development, we have developed a panel of monoclonal antibodies (mAb) to a variety of sheep cell adhesion molecules. Immunohistochemistry was used to define mAb reactivity and flow cytometry was used to quantify expression of cell adhesion molecules within the thymus. To facilitate flow cytometry definition of cortical thymocytes, mAbs were developed to the sheep CD1 antigen. Dual parameter flow cytometry provided a phenotypic characterization of cell adhesion molecule expression on both CD1(+) and CD1(-) sheep thymocyte populations. These studies demonstrated significantly enhanced cortical thymocyte expression of three cell adhesion molecules: beta1 integrin (CD29), ICAM-2 and LFA-3. The beta1 integrin cell adhesion molecule was also expressed at higher levels on CD1(+) thymocytes in post-natal lambs as compared to adult sheep. These studies of thymocyte membrane molecule expression should facilitate future investigations of sheep intrathymic development and T lymphocyte immigration.

Changing trends in partial nephrectomy at Walter Reed Army Medical Center

PURPOSE

To evaluate the change in indications, frequency, complications, and outcome in patients undergoing partial nephrectomy at a single institution during a 25-year period.

MATERIALS AND METHODS

A retrospective chart review was performed for patients who underwent partial nephrectomy at Walter Reed Army Medical Center from 1970 to 1995. A total of 309 patient records were reviewed for patient age, sex, and primary diagnosis. A more detailed analysis was performed on 47 records of patients who underwent partial nephrectomy from 1986 to 1996.

RESULTS

The number of partial nephrectomies declined from the 1970s to the 1990s, demonstrating the trend away from nephron-sparing surgery for benign disease. Partial nephrectomies for renal cell carcinoma increased during the same period. Fifty-seven percent (12 of 21) of patients from 1986 to 1996 underwent partial nephrectomy for incidentally discovered renal tumors. Complications occurred in 25% (11 of 44) of patients, with acute renal insufficiency occurring in 4.5% (2 of 44). Twenty-two of 25 patients who underwent partial nephrectomy for renal cell carcinoma were followed for a mean of 45.6 months. The cancer-specific 5-year survival rate for partial nephrectomy was 88.1%.

CONCLUSION

Trends in nephron-sparing surgery showed a movement away from performing ablating surgery for benign disease and toward nephron-sparing surgery for renal masses. Despite a higher complication rate, the curative ability of partial nephrectomy is similar to that of radical nephrectomy.

Sequential thoracic metastasectomy prolongs survival by re-establishing local control within the chest

OBJECTIVE

The value of sequential thoracic metastasectomies is unknown. We evaluate repeat metastasectomy for limited recurrences within the thorax.

METHODS

From July 1988 to September 1998, 54 patients underwent 2 to 6 separate sequential procedures to excise metastases after recurrence isolated to the thorax. Kaplan-Meier survival and Cox modeling determined prognostic variables.

RESULTS

Thirty-three men and 21 women, 22 to 76 years underwent 2 (100%, n = 54), 3 (50%), 4 (22%), or 5 to 6 (11%) metastasectomies. Fifty-four percent of patients had carcinoma, 35% sarcoma, 9% germ cell, and 2% melanoma. There were no operative deaths; all late deaths occurred from cancer. Median follow-up was 48 months. Cumulative 5-year survival from the second procedure was 57%. After the second, third, fourth, and fifth procedures, respectively, permanent control was achieved in 15 (27%) of 54 patients, 5 (19%) of 27, 1 (8%) of 12, and 0 of 7. Recurrence amenable to additional surgery occurred in 27 (50%) of 54, 12 (44%) of 27, 6 (50%) of 12, and 1 (17%) of 6. Mean hazard for the development of unresectable recurrence increased from 0.21 after the second procedure to 0.91 after the fifth procedure. The 5-year survival for the 27 patients undergoing only 2 metastasectomies was 60% (median not yet reached), 33% for the 15 patients undergoing only 3 metastasectomies (median 34.7 months), and 38% for the 12 patients undergoing 4 or more (median 45.6 months). From the time a recurrence was declared unresectable, patients had a 19% 2-year survival (median 8 months).

CONCLUSIONS

Multiple attempts to re-establish intrathoracic control of metastatic disease is justified in carefully selected patients, but the magnitude of benefit decays with each subsequent attempt.

Aldehyde fixation of thiol-reactive fluorescent cytoplasmic probes for tracking cell migration

Tracking of cell migration plays an important role in the study of morphogenesis, inflammation, and metastasis. The recent development of probes that exist as intracellular peptide-fluorescence dye adducts has offered the possibility of aldehyde fixation of these dyes for detailed anatomic studies of lymphocyte trafficking. To define the conditions for fixation of these cytoplasmic fluorescent probes, we compared fixation conditions containing formaldehyde, glutaraldehyde, paraformaldehyde, zinc formaldehyde, and glyoxylate, as well as fixation by quick-freezing in liquid nitrogen-cooled methylbutane. The efficacy of aldehyde fixation of the cell fluorescence was assessed by quantitative tissue cytometry and flow cytometry. We studied cytoplasmic fluorescent dyes with discrete emissions in the green [5-chloromethylfluorescein diacetate (CMFDA); 492 ex, 516 em] and orange [5-(and-6)-(4-chloromethyl(benzoyl)amino) tetramethylrhodamine (CMTMR); 540 ex, 566 em] spectra. The results demonstrated that aldehyde fixation preserved cell fluorescence for more than 6 months. The primary difference between the aldehyde fixatives was variability in the difference between the yield of the cell fluorescence and the relevant background fluorescence. Formaldehyde and paraformaldehyde were superior to the other fixatives in preserving cell fluorescence while limiting background fluorescence. With these fixatives, both the CMFDA and CMTMR fluorescent dyes permitted sufficient anatomic resolution for reliable localization in long-term cell tracking studies.