Empirical techniques for determining the reliability, magnitude, and pattern of neuropsychological change after epilepsy surgery

Polygenic burden and its association with baseline cognitive function and postoperative cognitive outcome in temporal lobe epilepsy

OBJECTIVE

Demographic and disease factors are associated with cognitive deficits and postoperative cognitive declines in adults with pharmacoresistant temporal lobe epilepsy (TLE), but the role of genetic factors in cognition in TLE is not well understood. Polygenic scores (PGS) for neurological and neuropsychiatric disorders and IQ have been associated with cognition in patient and healthy populations. In this exploratory study, we examined the relationship between PGS for Alzheimer's disease (AD), depression, and IQ and cognitive outcomes in adults with TLE.

METHODS

202 adults with pharmacoresistant TLE had genotyping and completed neuropsychological evaluations as part of a presurgical work-up. A subset (n = 116) underwent temporal lobe resection and returned for postoperative cognitive testing. Logistic regression was used to determine if PGS for AD, depression, and IQ predicted baseline domain-specific cognitive function and cognitive phenotypes as well as postoperative language and memory decline.

RESULTS

No significant findings survived correction for multiple comparisons. Prior to correction, higher PGS for AD and depression (i.e., increased genetic risk for the disorder), but lower PGS for IQ (i.e., decreased genetic likelihood of high IQ) appeared possibly associated with baseline cognitive impairment in TLE. In comparison, higher PGS for AD and IQ appeared as possible risk factors for cognitive decline following temporal lobectomy, while the possible relationship between PGS for depression and post-operative cognitive outcome was mixed.

SIGNIFICANCE

We did not observe any relationships of large effect between PGS and cognitive function or postsurgical outcome; however, results highlight several promising trends in the data that warrant future investigation in larger samples better powered to detect small genetic effects.

Neuropsychological Rehabilitation for Epilepsy in India: Looking Beyond the Basics

BACKGROUND

Neuropsychological Rehabilitation (NR) helps manage cognitive deficits in epilepsy. As internationally developed programs have limited applicability to resource-limited countries, we developed a program to bridge this gap. This 6-week caregiver-assisted, culturally suitable program has components of (1) psychoeducation, (2) compensatory training, and, (3) cognitive retraining and is called EMPOWER (Indigenized Home Based Attention and Memory Rehabilitation Program for Adult Patients with Drug Refractory Epilepsy). Its efficacy needs to be determined.

METHODS

We carried out an open-label parallel randomized controlled trial. Adults aged 18-45 years with Drug Refractory Epilepsy (DRE), fluency in Hindi and or English, with impaired attention or memory (n = 28) were randomized to Intervention Group (IG) and Control Group (CG). The primary outcomes were objective memory (Auditory Verbal Learning Test), patient and caregiver reported everyday memory difficulties (Everyday Memory Questionnaire-Revised), number of memory aids in use, depression (Hamilton Depression Rating Scale), anxiety (Hamilton Anxiety Rating Scale) and quality of life (Quality of Life in Epilepsy-31). Intention to treat was carried out for group analysis. In the absence of norms necessary for computing Reliable Change Indices (RCIs), a cut-off of +1.0 Standard Deviation (SD) was utilized to identify clinically meaningful changes in the individual analysis of objective memory. A cut-off of 11.8 points was used for quality of life. Feedback and program evaluation responses were noted.

RESULTS

The majority of the sample comprised DRE patients with temporal lobe epilepsy who had undergone epilepsy surgery. Group analysis indicated improved learning (p = 0.013), immediate recall (p = 0.001), delayed recall (p < 0.001), long-term retention (p = 0.031), patient-reported everyday memory (p < 0.001), caregiver-reported everyday memory (p < 0.001), anxiety (p = 0.039) and total quality of life (p < 0.001). Individual analysis showed improvement in 50 %, 64 %, 71 %, 57 %, and 64 % of patients on learning, immediate recall, delayed recall, long-term retention, and total quality of life respectively. Despite improvements, themes indicative of a lack of awareness and understanding of cognitive deficits were identified. Overall, the program was rated favorably by patients and caregivers alike.

CONCLUSION

NR shows promise for patients with DRE, however larger studies are warranted. The role of cognition in epilepsy needs to be introduced at the time of diagnosis to help lay the foundation for education and acceptance.

Neuropsychological outcome after frontal surgery for pediatric-onset epilepsy with focal cortical dysplasia in adolescent and young adult

OBJECTIVE

We investigated neuropsychological outcome in patients with pharmacoresistant pediatric-onset epilepsy caused by focal cortical dysplasia (FCD), who underwent frontal lobe resection during adolescence and young adulthood.

METHODS

Twenty-seven patients were studied, comprising 15 patients who underwent language-dominant side resection (LDR) and 12 patients who had languagenondominant side resection (n-LDR). We evaluated intelligence (language function, arithmetic ability, working memory, processing speed, visuo-spatial reasoning), executive function, and memory in these patients before and two years after resection surgery. We analyzed the relationship between neuropsychological outcome and resected regions (side of language dominance and location).

RESULTS

Although 75% of the patients showed improvement or no change in individual neuropsychological tests after surgical intervention, 25% showed decline. The cognitive tests that showed improvement or decline varied between LDR and n-LDR. In patients who had LDR, decline was observed in Vocabulary and Phonemic Fluency (both 5/15 patients), especially after resection of ventrolateral frontal cortex, and improvement was observed in WCST-Category (7/14 patients), Block Design (6/15 patients), Digit Symbol (4/15 patients), and Delayed Recall (3/9 patients). In patients who underwent n-LDR, improvement was observed in Vocabulary (3/12 patients), but decline was observed in Block Design (2/9 patients), and WCST-Category (2/9 patients) after resection of dorsolateral frontal cortex; and Arithmetic (3/10 patients) declined after resection of dorsolateral frontal cortex or ventrolateral frontal cortex. General Memory (3/8 patients), Visual Memory (3/8 patients), Delayed Recall (3/8 patients), Verbal Memory (2/9 patients), and Digit Symbol (3/12 patients) also declined after n-LDR.

CONCLUSION

Postoperative changes in cognitive function varied depending on the location and side of the resection. For precise presurgical prediction of neuropsychological outcome after surgery, further prospective studies are needed to accumulate data of cognitive changes in relation to the resection site.

Case study of invalid to valid shift in cognitive performance following successful treatment of psychogenic nonepileptic seizure events

Patients with psychogenic nonepileptic seizure (PNES) who fail performance validity testing (PVT) may appear to produce non-valid cognitive profiles. Consequently, they may not get referred to treatment and events persist, with worsening disability and high resource utilization. As a result, we report pre- and post-treatment neuropsychological evaluation findings in a 59-year-old woman with a confirmed diagnosis of PNES established using video-EEG monitoring. At pre-treatment baseline neuropsychological evaluation, PNES events occurred weekly to daily. Performance was impaired across PVTs and across multiple cognitive domains. After behavioral intervention specific to PNES, these events substantially reduced in frequency to rare stress-induced flares. Post-treatment neuropsychological evaluation revealed marked improvement of most cognitive and behavioral scores from baseline, and valid PVT scores. We review predisposing, precipitating, and perpetuating factors for PNES and cognitive impairment in this case and discuss the patient's outcome from treatment. Effectively managing PNES events and dissociative tendencies while reducing unnecessary pharmacological interventions appears to have allowed this patient to function closer to her optimal state. This case illustrates the complexity of Functional Neurologic Disorder (FND) clinical presentation and challenges the assumption that suboptimal neuropsychological performance predicts poor treatment engagement and outcome. We showcase the reversibility of PNES and cognitive manifestations of FND using targeted psychotherapeutic interventions, which resulted in reduced disability and associated healthcare costs, as well as re-engagement in life.

Immediate neural impact and incomplete compensation after semantic hub disconnection

The human brain extracts meaning using an extensive neural system for semantic knowledge. Whether broadly distributed systems depend on or can compensate after losing a highly interconnected hub is controversial. We report intracranial recordings from two patients during a speech prediction task, obtained minutes before and after neurosurgical treatment requiring disconnection of the left anterior temporal lobe (ATL), a candidate semantic knowledge hub. Informed by modern diaschisis and predictive coding frameworks, we tested hypotheses ranging from solely neural network disruption to complete compensation by the indirectly affected language-related and speech-processing sites. Immediately after ATL disconnection, we observed neurophysiological alterations in the recorded frontal and auditory sites, providing direct evidence for the importance of the ATL as a semantic hub. We also obtained evidence for rapid, albeit incomplete, attempts at neural network compensation, with neural impact largely in the forms stipulated by the predictive coding framework, in specificity, and the modern diaschisis framework, more generally. The overall results validate these frameworks and reveal an immediate impact and capability of the human brain to adjust after losing a brain hub.

What are we really predicting with fMRI in epilepsy surgery?

While memory and language functional magnetic resonance imaging (fMRI) paradigms are becoming evermore refined, the measures of outcome they predict following epilepsy surgery tend to remain single scores on pencil and paper tests that were developed decades ago and have been repeatedly shown to bear little relation to patients' subjective reports of memory problems in the real world. The growing imbalance between the increasing sophistication of the predictive paradigms on the one hand and the vintage measures of the outcome on the other in the fMRI epilepsy surgery literature threatens the clinical relevance of studies employing these technologies. This paper examines some of the core principles of assessing neuropsychological outcomes following epilepsy surgery and explores how these may be adapted and applied in fMRI study designs to maximize the clinical relevance of these studies.

Characterization and Prediction of Short-term Outcomes in Memory After Temporal Lobe Resection in Children With Epilepsy

BACKGROUND AND OBJECTIVES

The aim of this study was to characterize short-term outcomes in episodic memory, as assessed by the Children's Memory Scale (CMS), after temporal lobe resection in children with epilepsy using empirical methods for assessing cognitive change (i.e., reliable change indices [RCI] and standardized regression-based change scores [SRB]) and develop and internally validate clinically applicable models to predict postoperative memory decline.

METHODS

This retrospective cohort study included children aged 6-16 years who underwent resective epilepsy surgery that included the temporal lobe (temporal only: "temporal" and multilobar: "temporal plus") and who completed preoperative and postoperative neuropsychological assessments including the CMS. Change scores on the CMS delayed memory subtests (Faces, Stories, and Word Pairs) were classified as decline, no change, or improvement using epilepsy-specific RCI and SRB. Logistic regression models for predicting postoperative memory decline were developed and internally validated with bootstrapping.

RESULTS

Of the 126 children included, most of them demonstrated either no significant change (54%-69%) or improvement (8%-14%) in memory performance using RCI on individual measures at a median of 7 months after surgery. A subset of children (23%-33%) showed postoperative declines. Change distributions obtained using RCI and SRB were not statistically significantly different from each other. Preoperative memory test score, surgery side, surgery extent, and preoperative full-scale IQ were predictors of memory decline. Prediction models for memory decline included subsets of these variables with bias-corrected concordance statistics ranging from 0.70 to 0.75. The models were well calibrated although slightly overestimated the probability of verbal memory decline in high-risk patients.

DISCUSSION

This study used empiric methodology to characterize memory outcome in children after temporal lobe resection. Provided online calculator and nomograms may be used by clinicians to estimate the risk of postoperative memory decline for individual patients before surgery.

A phase 1 open-label trial evaluating focused ultrasound unilateral anterior thalamotomy for focal onset epilepsy

OBJECTIVE

Focused ultrasound ablation (FUSA) is an emerging treatment for neurological and psychiatric diseases. We describe the initial experience from a pilot, open-label, single-center clinical trial of unilateral anterior nucleus of the thalamus (ANT) FUSA in patients with treatment-refractory epilepsy.

METHODS

Two adult subjects with treatment-refractory, focal onset epilepsy were recruited. The subjects received ANT FUSA using the Exablate Neuro (Insightec) system. We determined the safety and feasibility (primary outcomes), and changes in seizure frequency (secondary outcome) at 3, 6, and 12 months. Safety was assessed by the absence of side effects, that is, new onset neurological deficits or performance deterioration on neuropsychological testing. Feasibility was defined as the ability to create a lesion within the anterior nucleus. The monthly seizure frequency was compared between baseline and postthalamotomy.

RESULTS

The patients tolerated the procedure well, without neurological deficits or serious adverse events. One patient experienced a decline in verbal fluency, attention/working memory, and immediate verbal memory. Seizure frequency reduced significantly in both patients; one patient was seizure-free at 12 months, and in the second patient, the frequency reduced from 90-100 seizures per month to 3-6 seizures per month.

SIGNIFICANCE

This is the first known clinical trial to assess the safety, feasibility, and preliminary efficacy of ANT FUSA in adult patients with treatment-refractory focal onset epilepsy.

Pre-surgical features of intrinsic brain networks predict single and joint epilepsy surgery outcomes

Despite the effectiveness of surgical interventions for the treatment of intractable focal temporal lobe epilepsy (TLE), the substrates that support good outcomes are poorly understood. While algorithms have been developed for the prediction of either seizure or cognitive/psychiatric outcomes alone, no study has reported on the functional and structural architecture that supports joint outcomes. We measured key aspects of pre-surgical whole brain functional/structural network architecture and evaluated their ability to predict post-operative seizure control in combination with cognitive/psychiatric outcomes. Pre-surgically, we identified the intrinsic connectivity networks (ICNs) unique to each person through independent component analysis (ICA), and computed: (1) the spatial-temporal match between each person's ICA components and established, canonical ICNs, (2) the connectivity strength within each identified person-specific ICN, (3) the gray matter (GM) volume underlying the person-specific ICNs, and (4) the amount of variance not explained by the canonical ICNs for each person. Post-surgical seizure control and reliable change indices of change (for language [naming, phonemic fluency], verbal episodic memory, and depression) served as binary outcome responses in random forest (RF) models. The above functional and structural measures served as input predictors. Our empirically derived ICN-based measures customized to the individual showed that good joint seizure and cognitive/psychiatric outcomes depended upon higher levels of brain reserve (GM volume) in specific networks. In contrast, singular outcomes relied on systematic, idiosyncratic variance in the case of seizure control, and the weakened pre-surgical presence of functional ICNs that encompassed the ictal temporal lobe in the case of cognitive/psychiatric outcomes. Our data made clear that the ICNs differed in their propensity to provide reserve for adaptive outcomes, with some providing structural (brain), and others functional (cognitive) reserve. Our customized methodology demonstrated that when substantial unique, patient-specific ICNs are present prior to surgery there is a reliable association with poor post-surgical seizure control. These ICNs are idiosyncratic in that they did not match the canonical, normative ICNs and, therefore, could not be defined functionally, with their location likely varying by patient. This important finding suggested the level of highly individualized ICN's in the epileptic brain may signal the emergence of epileptogenic activity after surgery.

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.

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.

Neuropsychological outcomes after frontal lobectomy to treat intractable epilepsy

OBJECTIVE

Frontal lobectomy is often used as a surgical treatment for frontal lobe epilepsy, especially when a large epileptogenic zone in the frontal lobe is inferred from preoperative evaluation. The frontal lobe is important for cognitive functions such as executive functions and verbal fluency, but the neuropsychological outcome after a frontal or prefrontal lobectomy that includes both the dorsolateral prefrontal cortex and ventral prefrontal cortex has not been studied thoroughly. In the present study, we evaluated neuropsychological outcomes after patients with frontal lobe epilepsy received a frontal or prefrontal lobectomy.

METHODS

We retrospectively reviewed the data of patients with frontal lobe epilepsy who underwent a frontal or prefrontal lobectomy that includes both the dorsolateral prefrontal cortex and ventral prefrontal cortex at 16 years or older from October 2004 to December 2014, with a minimum postoperative follow-up of 24 months. We analyzed and compared neuropsychological outcomes, including executive functions, verbal fluency, intelligence, and memory, before and after the operation.

RESULTS

Eighteen patients were 16 years or older and underwent pre- and postoperative (2 years after the operation) neuropsychological evaluations. Patients showed significant deterioration only on the Benton Visual Retention Test. Performance on tests of frontal lobe functions, such as executive function and verbal fluency, showed no significant deterioration.

CONCLUSIONS

Overall cognitive performance, including functions widely thought to depend on the frontal lobe, is stable after a frontal or prefrontal lobectomy to treat frontal lobe epilepsy.

Cognitive outcomes following frontal lobe resection for treatment of epilepsy in children and adolescents

OBJECTIVE

To use reliable change indices (RCIs) developed specifically for pediatric patients with epilepsy to examine cognitive outcomes after frontal lobe resection for pharmacoresistant epilepsy.

METHODS

Forty-one pediatric patients (25 male, Mage = 10 years) completed comprehensive neuropsychological evaluations before and an average of 6.5 months after frontal lobe resections for treatment of epilepsy. Evaluations included tests of intelligence, attention/working memory, processing speed, language, visuospatial skills, executive function, and episodic memory. Practice effect-adjusted RCIs were used to determine clinically significant postoperative cognitive change. Demographic, disease, and surgical variables were examined to identify factors associated with postoperative cognitive decline or improvement.

RESULTS

Within each cognitive domain, there was a large proportion of patients (51-84%) who did not exhibit significant cognitive change. In terms of overall cognitive profile, 44% demonstrated improvement in at least one domain and 69% declined in at least one domain. Postoperative cognitive improvement occurred most commonly in the domain of processing speed, whereas postoperative cognitive decline occurred most frequently in the domain of visuospatial skills. Younger age at surgery was associated with cognitive improvement. Older age at seizure onset and higher baseline cognitive performance were associated with cognitive decline.

SIGNIFICANCE

Approximately 6.5 months after frontal lobe resection, only 15% of our sample showed stable performance across all cognitive domains. Seventeen percent of patients showed improvements without declines, 42% showed declines without improvements, and 27% showed a mix of improvements and declines across different cognitive domains. Age and baseline abilities were associated with postoperative cognitive change on multiple measures. With 1 in 8 children demonstrating postoperative decline across three or more domains, further research is needed to identify factors associated with cognitive decline in order to inform clinical decision-making and patient/family counseling.

Nomograms to Predict Verbal Memory Decline After Temporal Lobe Resection in Adults With Epilepsy

OBJECTIVE

To develop and externally validate models to predict the probability of postoperative verbal memory decline in adults after temporal lobe resection (TLR) for epilepsy using easily accessible preoperative clinical predictors.

METHODS

Multivariable models were developed to predict delayed verbal memory outcome on 3 commonly used measures: Rey Auditory Verbal Learning Test (RAVLT) and Logical Memory (LM) and Verbal Paired Associates (VPA) subtests from Wechsler Memory Scale-Third Edition. With the use of the Harrell step-down procedure for variable selection, models were developed in 359 adults who underwent TLR at the Cleveland Clinic and validated in 290 adults at 1 of 5 epilepsy surgery centers in the United States or Canada.

RESULTS

Twenty-nine percent of the development cohort and 26% of the validation cohort demonstrated significant decline on at least 1 verbal memory measure. Initial models had good to excellent predictive accuracy (calibration [c] statistic range 0.77-0.80) in identifying patients with memory decline; however, models slightly underestimated decline in the validation cohort. Model coefficients were updated with data from both cohorts to improve stability. The model for RAVLT included surgery side, baseline memory score, and hippocampal resection. The models for LM and VPA included surgery side, baseline score, and education. Updated model performance was good to excellent (RAVLT c = 0.81, LM c = 0.76, VPA c = 0.78). Model calibration was very good, indicating no systematic overestimation or underestimation of risk.

CONCLUSIONS

Nomograms are provided in 2 easy-to-use formats to assist clinicians in estimating the probability of verbal memory decline in adults considering TLR for treatment of epilepsy.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that multivariable prediction models accurately predict verbal memory decline after TLR for epilepsy in adults.

Stereoelectroencephalographic language mapping of the basal temporal cortex predicts postoperative naming outcome

OBJECTIVE

In drug-resistant temporal lobe epilepsy (TLE) patients, the authors evaluated early and late outcomes for decline in visual object naming after dominant temporal lobe resection (TLR) according to the resection status of the basal temporal language area (BTLA) identified by cortical stimulation during stereoelectroencephalography (SEEG).

METHODS

Twenty patients who underwent SEEG for drug-resistant TLE met the inclusion criteria. During language mapping, a site was considered positive when stimulation of two contiguous contacts elicited at least one naming impairment during two remote sessions. After TLR ipsilateral to their BTLA, patients were classified as BTLA+ when at least one positive language site was resected and as BTLA- when all positive language sites were preserved. Outcomes in naming and verbal fluency tests were assessed using pre- and postoperative (means of 7 and 25 months after surgery) scores at the group level and reliable change indices (RCIs) for clinically meaningful changes at the individual level.

RESULTS

BTLA+ patients (n = 7) had significantly worse naming scores than BTLA- patients (n = 13) within 1 year after surgery but not at the long-term evaluation. No difference in verbal fluency tests was observed. When RCIs were used, 5 of 18 patients (28%) had naming decline within 1 year postoperatively (corresponding to 57% of BTLA+ and 9% of BTLA- patients). A significant correlation was found between BTLA resection and naming decline.

CONCLUSIONS

BTLA resection is associated with a specific and early naming decline. Even if this decline is transient, naming scores in BTLA+ patients tend to remain lower compared to their baseline. SEEG mapping helps to predict postoperative language outcome after dominant TLR.

Methylphenidate treatment for cognitive symptoms associated with ADHD in a pediatric epilepsy patient following resection of a left frontal cortical dysplasia

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ADHD symptoms can emerge or worsen after epilepsy surgery.

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Methylphenidate use improved cognitive symptoms of ADHD in our patient.

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Seizure aggravation did not occur following use of a neurostimulant in our patient.

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Our patient benefitted from a multidisciplinary intervention approach.

We present data on a 10-year-old patient with drug-resistant epilepsy who was treated with methylphenidate for symptoms of attention deficit hyperactivity disorder (ADHD) that developed after she underwent surgical resection of a left frontal cortical dysplasia. . The patient’s parents reported methylphenidate was helpful in improving their child’s reading performance. Based on parents’ report, we examined benefits of methylphenidate on our patient’s cognitive problems in a controlled setting. The patient underwent a neuropsychological evaluation completed in three sessions over a five-day period. Methylphenidate was administered prior to the second testing session only and was associated with improvements in the patient’s attention, executive function, processing speed, and short-term memory performances. In comparison, word-reading performance, a task less susceptible to neurological impairment, was stable over the three sessions. The patient remained seizure-free after surgery and use of methylphenidate did not reduce seizure threshold. These findings support the use of methylphenidate in treating targeted cognitive problems associated with ADHD emerging after epilepsy surgery in children.

Consequences of mesial temporal sparing temporal lobe surgery in medically refractory epilepsy

OBJECTIVE

We compared long-term seizure outcome, neuropsychological outcome, and occupational outcome of anterior temporal lobectomy (ATL) with and without sparing of mesial structures to determine whether mesial sparing temporal lobectomy prevents memory decline and thus disability, with acceptable seizure outcome.

METHODS

We studied patients (n = 21) and controls (n = 21) with no evidence of mesial temporal sclerosis (MTS) on MRI who had surgery to treat drug-resistant epilepsy. Demographic and pre- and postsurgical clinical characteristics were compared. Patients had neuropsychological assessment before and after surgery. Neuropsychological analyses were limited to patients with left-sided surgery and available data (n = 14 in each group) as they were at risk of verbal memory impairment. The California Verbal Learning Test II (CVLT-II) (sum of trials 1-5, delayed free recall) and the Logical Memory subtest of the Wechsler Memory Scale III or IV (WMS-III or WMS-IV) (learning and delayed recall of prose passages) were used to assess verbal episodic learning and memory. Seizure and occupational outcomes were assessed.

RESULTS

The chance of attaining seizure freedom was similar in the two groups, so sparing mesial temporal structures did not lessen the chance of stopping seizures. Sparing mesial temporal structures mitigated the extent of postoperative verbal memory impairment, though some of these individuals suffered decline as a consequence of surgery. Occupational outcome was similar in both groups.

SIGNIFICANCE

Mesial temporal sparing resections provide a similar seizure outcome as ATL, while producing a better memory outcome. Anterior temporal lobectomy including mesial structure resection did not increase the risk of postoperative disability.

Getting Physical: A Specific Boost for Cognition in Epilepsy?

Effect of Combined Physical Training on Cognitive Function in People With Epilepsy: Results From a Randomized Controlled Trial

Feter N, Alt R, Häfele CA, et al. Epilepsia. 2020;61(8):1649-1658. doi:10.1111/epi.16588. PMID: 32602966.

Objective:

To examine the effect of 12-week exercise program on cognitive function in people with epilepsy.

Methods:

Twenty-one physically inactive patients were randomized into 2 groups: the exercise group (EG) or the control group. Exercise group performed 12 weeks of combined physical training. Control group was advised to maintain usual daily activities. Exercise group received a structured, individually supervised exercise program with two 60-minute sessions per week. Each session included warmup (5 minutes), aerobic (15-20 minutes at 14-17 on Borg scale), strength (2-3 sets, 10-15 repetitions), and 5-minute active stretches. Sociodemographic characteristics, clinical information, memory (Digit Span Test [DST]), executive function (Trail Making Test [TMT] A and B), Stroop Color and Word Test, a verbal fluency task, global cognitive function (Montreal Cognitive Assessment [MoCA]), anthropometric measurements (weight, height, and hip and waist circumferences), cardiorespiratory fitness (maximal oxygen consumption [V.o₂max]), and strength (dynamometer) were measured at baseline and after the 12-week intervention.

Results:

Exercise decreased time spent on TMT-A from baseline to postintervention (difference = −7.9 seconds, 95% CI = −14.5 to −1.3, P = .023). Exercise group improved total number of words on the verbal fluency task after intervention (difference = 8.1 words, 95% CI = 3.0-13.2, P = .002). Exercise group also improved the score on MoCA at 1.7 (95% CI = 0.1-3.3, P = .043) points. We observed a 22.4% (95% CI = 13.1-31.6, P = .021) improvement in executive function in EG. No effect of group, time, or group × time was observed on any other cognitive test. Changes in V˙o₂max were negatively associated with changes in performance on DST (r = −0.445, P = .049) and overall memory score (r = −0.544, P = .042).

Significance:

This randomized controlled trial provided the first evidence that combined physical training improves executive function in adults with epilepsy, showing main improvements in attention and language tasks. Physical exercise should be encouraged for people with epilepsy to reduce the burden on cognitive function associated with this disease.

Atypical language representation as a protective factor against verbal memory decline following epilepsy surgery

OBJECTIVE

An important role of neuropsychology in the preoperative evaluation of epilepsy surgery candidates is to assess risk for postoperative memory decline. One factor associated with postoperative verbal memory decline is surgery in the language-dominant temporal lobe (TL). The aim of the study was to determine whether atypical language representation has a protective effect against verbal memory decline following left temporal, frontotemporal, or hippocampal excision.

METHODS

Data from 61 patients with medically refractory epilepsy, Wada testing, and pre- and postsurgical memory assessment from four comprehensive epilepsy surgery centers were gathered and examined for pre- to postsurgical memory change. Wada testing was used to determine language dominance (left vs. atypical [bilateral + right]). Postoperative memory change was examined at both the individual (using nonparametric analyses) and group (using parametric analyses) levels for the two language dominance groups.

RESULTS

Significant postoperative verbal memory decline was observed in the left hemisphere language-dominant group, while the atypical language group showed verbal memory improvement. Individuals with left hemisphere language dominance were more likely to show postoperative declines in verbal memory, whereas individuals with atypical language dominance were significantly less likely to decline. As expected, there were no significant differences between language groups with regard to postoperative visuospatial memory outcome.

CONCLUSION

Patients with atypical language dominance had better verbal memory outcomes following left hemisphere resections than those with left hemisphere language dominance suggesting that typical memory substrates likely reorganized along with language. Thus, atypical cerebral organization of language may be considered a protective factor against verbal memory decline following epilepsy surgery involving the left TL.

Assessing Cognitive Change and Quality of Life 12 Months After Epilepsy Surgery-Development and Application of Reliable Change Indices and Standardized Regression-Based Change Norms for a Neuropsychological Test Battery in the German Language

Objective

The establishment of patient-centered measures capable of empirically determining meaningful cognitive change after surgery can significantly improve the medical care of epilepsy patients. Thus, this study aimed to develop reliable change indices (RCIs) and standardized regression-based (SRB) change norms for a comprehensive neuropsychological test battery in the German language.

Methods

Forty-seven consecutive patients with temporal lobe epilepsy underwent neuropsychological assessments, both before and 12 months after surgery. Practice-effect-adjusted RCIs and SRB change norms for each test score were computed. To assess their usefulness, the presented methods were applied to a clinical sample, and binary logistic regression analyses were conducted to model the odds of achieving improvement in quality of life (QOL) after surgery.

Results

The determined RCIs at 90% confidence intervals and the SRB equations for each test score included in the test battery are provided. Cohen’s kappa analyses revealed a moderate mean agreement between the two measures, varying from slight to almost perfect agreement across test scores. Using these measures, a negative association between improvement in QOL and decline in verbal memory functions after surgery was detected (adjusted odds ratio = 0.09, p = 0.006).

Significance

To the best of our knowledge, this study is the first to develop RCIs and SRB change norms necessary for the objective determination of neuropsychological change in a comprehensive test battery in the German language, facilitating the individual monitoring of improvement and decline in each patients’ cognitive functioning and psychosocial situations after epilepsy surgery. The application of the described measures revealed a strong negative association between improvement in QOL and decline in verbal memory functions after surgery.

Cognitive and behavioral outcome of stereotactic laser amydalohippocampotomy in a pediatric setting

We present neuropsychological and functional outcome data in a teenager undergoing stereotactic laser amygdalohippocampotomy (SLAH) who had drug-resistant mesial temporal lobe epilepsy due to left hippocampal sclerosis. Given strong baseline cognitive performance, there was concern for post-operative declines in language and verbal memory were this patient to undergo open resection. She was evaluated pre- and post-ablation with clinical and experimental neuropsychological measures including semantic memory, category-specific object/face recognition and naming, spatial learning, and socio-emotional processing. The patient became seizure-free following SLAH and experienced significant improvements in school performance and social engagement. She experienced improvement in recognition and naming of multiple object categories, memory functions, and verbal fluency. In contrast, the patient declined significantly in her ability to recognize emotional tone from facial expressions, a socio-emotional process that had been normal prior to surgery. We believe this decline was related to surgical disruption of the limbic system, an area highly involved in emotional processing, and suspect such deficits are an under-assessed and unrecognized risk for all surgeries involving the amygdalohippocampal complex and broader limbic system regions. We hope this positive SLAH outcome will serve as impetus for group level research to establish its safety and efficacy in the pediatric setting.

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Stereotactic laser ablation can be used successfully in pediatric epilepsy.

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At risk cognitive abilities did not decline after focal ablation in this teenager.

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Functional improvement was observed that paralleled gains in seizure status and cognition.

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Deficits still occurred in select areas related to focal structures ablated.

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Socio-emotional deficits can result from surgeries restricted to the amygdalohippocampal complex.

Standardized regression-based clinical change score cutoffs for normal pressure hydrocephalus

Background

Presently, for patients presenting with suspected Normal Pressure Hydrocephalus (NPH) who undergo temporary drainage of cerebrospinal fluid (CSF) there is no defined model to differentiate chance improvement form clinical significance change at the individual patient level. To address this lack of information we computed standard regression based clinical change models for the 10 Meter Walk Test, Timed Up & Go, Dual Timed Up & Go, 6-Minute Walk Test, Mini-Balance Evaluation Systems Test, Montreal Cognitive Assessment, and Symbol Digit Modalities using data from patients with suspected NPH that underwent temporary drainage of CSF. These clinically significant change modes can classify clinically significant improvement following temporary drainage of CSF at the individual patient level. This allows for physicians to differentiate a clinically significant improvement in symptoms from chance improvement.

Methods

Data was collected from 323 patients, over the age of 60, with suspected NPH that underwent temporary drainage of CSF with corresponding gait and cognitive testing. McSweeney Standardized Regression Based Clinical Change Models were computed for standard gait and cognitive measures: Timed Up & Go, Dual Timed Up & Go, 10 Meter Walk Test, MiniBESTest, 6-Minute Walk Test, Montreal Cognitive Assessment, and Symbol Digit Modalities Test. To assess the discriminate validity of the measures we used correlations, Chi², and regression analyses.

Results

The clinical change models explained 69–91.8% of the variability in post-drain performance (p <  0.001). As patient scores became more impaired, the percent change required for improvement to be clinically significant increased for all measures. We found that the measures were not discriminate, the Timed Up & Go was highly related to the 10 Meter Walk Test (r = 0.85, R² = 0.769–0.738, p <  0.001), MiniBESTest (r = − 0.67, R² = 0.589–0.734, p <  0.001), and 6 Minute Walk Test (r = − 0.77, R² = 0.71–0.734, p <  0.001).

Conclusion

Standardized Regression Based Clinically Significant Change Models allow for physicians to use an evidence-based approach to differentiate clinically significant change from chance improvement at the individual patient level. The Timed Up & Go was shown to be predictive of detailed measures of gait velocity, balance, and endurance.

Hemispherectomy in adults and adolescents: Seizure and functional outcomes in 47 patients

OBJECTIVE

To examine longitudinal seizure and functional outcomes after hemispherectomy in adults and adolescents.

METHODS

We reviewed 47 consecutive patients older than 16 years who underwent hemispherectomy between 1996 and 2016 at our center. Clinical, electroencephalographic (EEG), imaging, neuropsychological, surgical, and functional status data were analyzed.

RESULTS

Thirty-six patients were 18 years or older at surgery; 11 were aged between 16 and 18 years. Brain injury leading to hemispheric epilepsy occurred before 10 years of age in 41 (87%) patients. At a mean follow-up of 5.3 postoperative years (median = 2.9 years), 36 (77%) had Engel class I outcome. Longitudinal outcome analysis showed 84% seizure freedom (Engel IA) at 6 months, 76% at 2 years, and 76% at 5 years and beyond, with stable longitudinal outcomes up to 12 years from surgery. Multivariate analysis demonstrated that acute postoperative seizures and contralateral interictal spikes at 6-month follow-up EEG were associated with seizure recurrence. Patients who could walk unaided preoperatively and had no cerebral peduncle atrophy on brain magnetic resonance imaging were more likely to experience worsening of motor function postoperatively. Otherwise, postoperative ambulatory status and hand function were unchanged. Of the 19 patients who completed neuropsychological testing, 17 demonstrated stable or improved postoperative outcomes.

SIGNIFICANCE

Hemispherectomy in adults is a safe and effective procedure, with seizure freedom rates and functional outcome similar to those observed in children.

Regression-based formulas for predicting change in memory test scores in healthy older adults: Comparing use of raw versus standardized scores

INTRODUCTION

Standardized regression based (SRB) methods can be used to determine whether meaningful changes in performance on cognitive assessments occur over time. Both raw and standardized scores have been used in SRB models but it is unclear which score metric is most appropriate for predicting follow-up performance. The aim of the present study was to examine differences in SRB prediction formulas using raw versus standard scores on two memory tests commonly used in assessment of older adults.

METHOD

The sample consisted of 135 healthy older adults who underwent baseline and 1-year follow-up neuropsychological assessment including the Hopkins Verbal Learning Test-Revised and Brief Visuospatial Memory Test-Revised. Regression models were fit to predict Time 2 scores from Time 1 scores and demographic variables. Separate models were fit using raw scores and standardized scores. Akaike's information criterion (AIC) was used to determine whether models using raw or standardized scores resulted in best fit. Pearson correlation and intraclass correlation coefficients were calculated between observed and predicted scores. Mean differences between observed and predicted scores were examined using pairwise t tests. To investigate whether a similar pattern of results would be evident using prediction formulas for nonmemory tests, all analyses were also conducted for nonmemory tests.

RESULTS

All regression models were significant, and R² values for memory test raw score models were larger than those generated by standardized score models. Memory test raw score models were also a better fit based on smaller AIC values. For nonmemory tests, raw score models did not consistently outperform standardized score models. All correlations between observed and predicted Time 2 scores were significant, and none of the predicted scores significantly differed from their respective observed score.

CONCLUSION

For each memory measure, raw score models outperformed standardized score models. For nonmemory tests, neither score metric model consistently outperformed the other.

Longitudinal Standards for Mid-life Cognitive Performance: Identifying Abnormal Within-Person Changes in the Wisconsin Registry for Alzheimer's Prevention

OBJECTIVES

A major challenge in cognitive aging is differentiating preclinical disease-related cognitive decline from changes associated with normal aging. Neuropsychological test authors typically publish single time-point norms, referred to here as unconditional reference values. However, detecting significant change requires longitudinal, or conditional reference values, created by modeling cognition as a function of prior performance. Our objectives were to create, depict, and examine preliminary validity of unconditional and conditional reference values for ages 40-75 years on neuropsychological tests.

METHOD

We used quantile regression to create growth-curve-like models of performance on tests of memory and executive function using participants from the Wisconsin Registry for Alzheimer's Prevention. Unconditional and conditional models accounted for age, sex, education, and verbal ability/literacy; conditional models also included past performance on and number of prior exposures to the test. Models were then used to estimate individuals' unconditional and conditional percentile ranks for each test. We examined how low performance on each test (operationalized as &lt;7th percentile) related to consensus-conference-determined cognitive statuses and subjective impairment.

RESULTS

Participants with low performance were more likely to receive an abnormal cognitive diagnosis at the current visit (but not later visits). Low performance was also linked to subjective and informant reports of worsening memory function.

CONCLUSIONS

The percentile-based methods and single-test results described here show potential for detecting troublesome within-person cognitive change. Development of reference values for additional cognitive measures, investigation of alternative thresholds for abnormality (including multi-test criteria), and validation in samples with more clinical endpoints are needed. (JINS, 2019, 25, 1-14).

Repetitive transcranial magnetic stimulation directed to a seizure focus localized by high-density EEG: A case report

We demonstrate feasibility of using high-density EEG to map a neocortical seizure focus in conjunction with delivery of magnetic therapy. Our patient had refractory seizures affecting the left leg. A five-day course of placebo stimulation followed a month later by active rTMS was directed to the mapped seizure dipole. Active rTMS resulted in reduced EEG spiking, and shortening of seizure duration compared to placebo. Seizure frequency, however, improved similarly in both placebo and active treatment stages. rTMS-evoked EEG potentials demonstrated that a negative peak at 40 ms - believed to represent GABAergic inhibition - was enhanced by stimulation.

Stereotactic EEG-guided laser interstitial thermal therapy for mesial temporal lobe epilepsy

OBJECTIVE

To determine the outcomes of combined stereo-electroencephalography-guided and MRI-guided stereotactic laser interstitial thermal therapy (LITT) in the treatment of patients with drug-resistant mesial temporal lobe epilepsy (mTLE).

METHODS

We prospectively assessed the surgical and neuropsychological outcomes in 21 patients with medically refractory mTLE who underwent LITT at the University of Chicago Medical Center. We further compared the surgical outcomes in patients with and without mesial temporal sclerosis (MTS).

RESULTS

Of the 21 patients, 19 (90%) underwent Invasive EEG study and 11 (52%) achieved freedom from disabling seizures with a mean duration of postoperative follow-up of 24±11 months after LITT. Eight (73%) of 11 patients with MTS achieved freedom from disabling seizures, whereas 3 (30 %) of 10 patients without MTS achieved freedom from disabling seizures. Patients with MTS were significantly more likely to become seizure-free, as compared with those without MTS (P=0.002). There was no significant difference in total ablation volume and the percentage of the ablated amygdalohippocampal complex between seizure-free and non-seizure-free patients. Presurgical and postsurgical neuropsychological assessments were obtained in 10 of 21 patients. While there was no group decline in any neuropsychological assessment, a significant postoperative decline in verbal memory and confrontational naming was observed in individual patients.

CONCLUSIONS

MRI-guided LITT is a safe and effective alternative to selective amygdalohippocampectomy and anterior temporal lobectomy for mTLE with MTS. Nevertheless, its efficacy in those without MTS seems modest. Large multicentre and prospective studies are warranted to further determine the efficacy and safety of LITT.

Time to push the age limit: Epilepsy surgery in patients 60 years or older

Objective

To summarize the existing literature on resective epilepsy surgery (RES) in older adults (≥60 years old) and examine seizure and neuropsychological outcomes in a single‐center large cohort of older adults undergoing RES and their comparison to a consecutive, younger (25‐ to45‐year‐old) adult population who underwent RES in routine clinical practice.

Methods

First, a comprehensive literature review was performed. Then, we identified older adults who underwent RES at our center (2000–2015). Outcome analysis was performed on patients who had ≥1 year of clinical follow‐up. A younger cohort of patients who underwent RES during the same period was selected for comparison. The 2 groups were compared with respect to demographic and disease variables as well as key clinical outcomes.

Results

Seizure outcomes on 58 older patients were reported in existing literature; 72% achieved Engel class I outcome ≥1 year postoperatively. Sixty‐four older adults underwent RES at our center, accounting for 2.8% of all RES during the study period. A total of 51 older adults (M_age = 65) among them had ≥1‐year clinical follow‐up; 80% achieved Engel I outcome after a mean follow‐up of 3.2 years. This was comparable to the 68% Engel class I outcome among 50 consecutive younger adults, despite later age of onset, longer epilepsy duration, and more comorbidities (all p < 0.001) among older adults. The majority (86%) of older adults were referred to our center after years of suffering from drug‐resistant epilepsy. There were no group differences in surgical complications. However, 1 older adult passed away post‐RES. There was no difference in post‐RES neuropsychological outcomes compared to younger adults, except significantly higher number of older adults showed a decline in confrontational naming.

Significance

RES in well‐selected older adults is a safe and effective therapy, and advanced age should not preclude consideration of surgical therapy in older adults with pharmacoresistant epilepsy.

Temporal lobe asymmetry in FDG-PET uptake predicts neuropsychological and seizure outcomes after temporal lobectomy

OBJECTIVE

The objective of this study was to determine whether preoperative [¹⁸F]fludeoxyglucose (FDG)-positron emission tomography (PET) asymmetry in temporal lobe metabolism predicts neuropsychological and seizure outcomes after temporal lobectomy (TL).

METHODS

An archival sample of 47 adults with unilateral temporal lobe epilepsy who underwent TL of their language-dominant (29 left, 1 right) or nondominant (17 right) hemisphere were administered neuropsychological measures pre- and postoperatively. Post-TL seizure outcomes were measured at 1year. Regional FDG uptake values were defined by an automated technique, and a quantitative asymmetry index (AI) was calculated to represent the relative difference in the FDG uptake in the epileptic relative to the nonepileptic temporal lobe for four regions of interest: medial anterior temporal (MAT), lateral anterior temporal (LAT), medial posterior temporal (MPT), and lateral posterior temporal (LPT) cortices.

RESULTS

In language-dominant TL, naming outcomes were predicted by FDG uptake asymmetry in the MAT (r=-0.38) and LPT (r=-0.45) regions. For all patients, visual search and motor speed outcomes were predicted by FDG uptake asymmetry in all temporal regions (MPT, r=0.42; MAT, r=0.34; LPT, r=0.47; LAT, r=0.51). Seizure outcomes were predicted by FDG uptake asymmetry in the MAT (r=0.36) and MPT (r=0.30) regions. In all of these significant associations, greater hypometabolism in regions of the epileptic temporal lobe was associated with better postoperative outcomes.

CONCLUSIONS

Our results support the conclusion that FDG uptake asymmetry is a useful clinical tool in assessing risk for cognitive changes in patients being considered for TL.

Neuropsychological outcomes following stereotactic laser amygdalohippocampectomy

OBJECTIVE

The objective was to analyze neuropsychological testing data from 15 patients before and after stereotactic laser ablation surgery for temporal lobe epilepsy and to describe the seizure outcomes after stereotactic laser ablation surgery.

METHODS

A retrospective review of 15 patients who underwent stereotactic laser ablation and who also underwent neuropsychological testing before and after surgery was performed. Verbal and visual memory was assessed in all 15 patients using California Verbal Learning Test and Wechsler Memory Scale IV. Naming was assessed in 9 of 15 patients using the Boston Naming Test. Statistical analysis was performed to determine clinically significant changes using previously validated reliable change indices and proprietary Advanced Clinical Solutions software. Seizure outcome data were evaluated using Engel classification.

RESULTS

Postsurgery neuropsychological evaluation demonstrated that all 15 patients experienced at least 1 clinically significant decline in either verbal or visual memory. Ten patients in this series, including five with dominant-hemisphere surgery, demonstrated decline in delayed memory for narrative information (Logical Memory II). By contrast, the Boston Naming Test demonstrated more favorable results after surgery. Two of nine patients demonstrated a clinically significant increase in naming ability, and only one of nine patients demonstrated a clinically significant decline in naming ability. With at least 6months of follow-up after surgery, 33% reported seizure freedom.

CONCLUSION

Stereotactic laser ablation can result in clinically significant and meaningful decline in verbal and visual memory when comparing patients to their own presurgical baseline. Naming ability, conversely, is much less likely to be impacted by stereotactic laser ablation and may improve after the procedure.

Quality of life one year after epilepsy surgery

BACKGROUND

The aim of surgery for medically intractable epilepsy was to achieve seizure freedom and improve overall quality of life (QOL) in patients. This investigation looked at changes in QOL one year after epilepsy surgery and the relationship of changes to mood, language, and seizure outcomes.

METHOD

Depressive symptoms, QOL, and naming were measured in 25 patients with temporal lobe epilepsy before and one year after dominant temporal lobe resection. The Quality of Life in Epilepsy-89 (QOLIE-89), Beck Depression Inventory II (BDI-II), and Boston Naming Test (BNT) were used, respectively, and seizure outcome was reported according to the Engel classifications. Minimum clinically important differences (MCID) and reliable change indices (RCI) were used to assess the proportion of patients who achieved meaningful improvement or worsening in the respective areas of functioning, and the relationship between outcomes was evaluated. Changes on the 17 individual items of the QOLIE-89 were also assessed.

RESULTS

Overall, there was a significant improvement in QOL, reduction in depressive symptoms, and decline in naming one year after surgery. Positive clinically important improvement in QOL was achieved in 76% of patients, meaningful reduction of depressive symptoms was achieved in 20%, and clinically important naming declines were observed in 48% of the cohort. Sixteen patients were seizure-free one year after surgery, but there was no significant correlation between changes in QOL and seizure outcome, depressive symptoms, or naming.

CONCLUSION

The results in the reported cohort of patients showed that surgical treatment of temporal lobe epilepsy in the dominant hemisphere resulted in clinically meaningful improvement in overall QOL and declines in naming but no significant reduction of mood disturbance.

Neuropsychological Assessment: Past and Future

Neuropsychological assessment tools are the staple of our field. The development of standardized metrics sensitive to brain-behavior relationships has shaped the neuropsychological questions we can ask, our understanding of discrete brain functions, and has informed the detection and treatment of neurological disorders. We identify key turning points and innovations in neuropsychological assessment over the past 40-50 years that highlight how the tools used in common practice today came to be. Also selected for emphasis are several exciting lines of research and novel approaches that are underway to further probe and characterize brain functions to enhance diagnostic and treatment outcomes. We provide a brief historical review of different clinical neuropsychological assessment approaches (Lurian, Flexible and Fixed Batteries, Boston Process Approach) and critical developments that have influenced their interpretation (normative standards, cultural considerations, longitudinal change, common metric batteries, and translational assessment constructs). Lastly, we discuss growing trends in assessment including technological advances, efforts to integrate neuropsychology across disciplines (e.g., primary care), and changes in neuropsychological assessment infrastructure. Neuropsychological assessment has undergone massive growth in the past several decades. Nonetheless, there remain many unanswered questions and future challenges to better support measurement tools and translate assessment findings into meaningful recommendations and treatments. As technology and our understanding of brain function advance, efforts to support infrastructure for both traditional and novel assessment approaches and integration of complementary brain assessment tools from other disciplines will be integral to inform brain health treatments and promote the growth of our field. (JINS, 2017, 23, 778-790).

Age at surgery as a predictor of cognitive improvements in patients with drug-resistant temporal epilepsy

Temporal lobe epilepsy (TLE) surgery is an effective procedure that can produce cognitive changes. However, the prognostic factors related with cognitive outcomes need to be better understood. The aim of the present study is to know if age at surgery is a reliable predictor of verbal memory competence and considering factors such as: hemisphere; type of surgery; pre-surgical seizure frequency; and epilepsy duration. Sixty-one typically dominant patients with drug-resistant TLE (34 with left TLE [L-TLE] and 27 with right TLE [R-TLE]) underwent a neuropsychological assessment before and a year after surgery. Results showed that R-TLE patients had better evolution in short- and long-term verbal memory and naming than L-TLE patients (for all, p >.04). L-TLE patients also more frequently showed a strong and reliable decline in these functions than R-TLE patients. No effects for gender or type of surgery were found. From a multivariate approach, patients with improvements in verbal competence underwent surgery at earlier ages and suffered epilepsy for less time (for all, p <0.4). The relevance of age at surgery was confirmed as a predictor of long-term verbal memory changes, although the frequency of partial seizures also explains, at least partially, these changes. In addition, the frequency of partial seizures explains short-term verbal memory changes. These results emphasize the importance of early intervention, independently of the resected hemisphere, in order to minimize the cognitive side-effects of epilepsy treatment, as well the need to consider cognitive functions as related processes and network dependent.

Neuropsychological outcome following frontal lobectomy for pharmacoresistant epilepsy in adults

OBJECTIVE

This retrospective cohort study characterized cognitive and motor outcomes in a large sample of adults who underwent frontal lobe resections for treatment of pharmacoresistant epilepsy.

METHODS

Ninety patients who underwent unilateral frontal lobe resection for epilepsy (42 language-dominant hemisphere/48 nondominant hemisphere) between 1989 and 2014 completed comprehensive preoperative and postoperative neuropsychological evaluations that included measures of verbal and nonverbal intellectual functioning, attention/working memory, processing speed, language, executive functioning, verbal and visual memory, and motor functioning. Objective methods were used to assess meaningful change across a wide range of abilities and to identify factors associated with neuropsychological decline following frontal lobectomy. Detailed postoperative neuroimaging analysis was conducted to characterize region, extent, and volume of resection.

RESULTS

Forty-eight percent of patients did not demonstrate meaningful postoperative declines in cognition and an additional 42% demonstrated decline in 1 or 2 cognitive domains. When cognitive decline was observed, it usually occurred on measures of intelligence, visuomotor processing speed, or executive functioning. Side and site of resection were unrelated to cognitive outcome, but played a role in decline of contralateral manual dexterity following supplementary motor area resection. Higher preoperative ability, older age at surgery, absence of a malformation of cortical development on MRI, and poor seizure outcome were related to cognitive decline on some measures, but had poor sensitivity in identifying at-risk patients.

CONCLUSIONS

The vast majority of patients who undergo frontal lobectomy for treatment of pharmacoresistant epilepsy demonstrate good cognitive and motor outcomes.

The course of language functions after temporal lobe epilepsy surgery: a prospective study

BACKGROUND AND PURPOSE

Anterior temporal lobectomy (ATL) within the language-dominant hemisphere can impair naming. This prospective study examined the pre-operative to post-operative course of different language components, clarifying which changes are relevant within the short-term and long-term outcome of language.

METHODS

Patients with drug-resistant temporal lobe epilepsy (TLE) were evaluated using the Token, Boston Naming and Word Fluency tests assessing sentence comprehension and word-finding on visual, semantic or phonemic cues.

RESULTS

A total of 106 patients were evaluated before and 6 months, 1 and 2 years after ATL; 60 patients were also evaluated after 5 years and 38 controls were assessed at baseline. Seizure outcome was comparable between the left and right TLE patients. Before surgery, naming and word fluency were impaired in the left and right TLE patients, whereas sentence comprehension was normal. After left or right ATL, word fluency progressively improved, naming showed early worsening and late improvement after left ATL and progressive improvement after right ATL, and sentence comprehension did not change. At the 5-year follow-up, naming improvement was clinically significant in 31% and 71% of the left and right TLE patients, respectively. Pre-operative naming, ATL laterality, schooling, and post-operative seizure frequency and number of antiepileptic drugs predicted post-operative naming. Pre-operative word fluency and schooling predicted post-operative word fluency.

CONCLUSIONS

Left or right TLE can impair word-finding but not sentence comprehension. After ATL, word-finding may improve for a long time, depending on TLE laterality, seizure control and mental reserve. These findings may clarify prognosis prior to treatment.

Measuring Clinical Significance in Rehabilitation Research

Measurement of clinically significant change is critical for rehabilitation research because it can enhance the credibility of rehabilitation efforts and guide evidence-based practices. The practical appeal of clinically significant change is that it can bridge research and clinical practice by focusing on individual rather than group differences. In response to current challenges in rehabilitation outcome measurement, the authors describe methods and strategies for the analysis of clinically significant change. The complementary approaches of reliable change index scores as proposed by Jacobson and Truax (1991) and regression-based z scores as proposed by McSweeney, Naugle, Chelune, and Luders (1993) are highlighted. The article concludes with a case example and discussion of implications for future directions in rehabilitation research.

Laser interstitial thermal therapy for medically intractable mesial temporal lobe epilepsy

OBJECTIVE

To describe mesial temporal lobe ablated volumes, verbal memory, and surgical outcomes in patients with medically intractable mesial temporal lobe epilepsy (mTLE) treated with magnetic resonance imaging (MRI)-guided stereotactic laser interstitial thermal therapy (LiTT).

METHODS

We prospectively tracked seizure outcome in 20 patients at Thomas Jefferson University Hospital with drug-resistant mTLE who underwent MRI-guided LiTT from December 2011 to December 2014. Surgical outcome was assessed at 6 months, 1 year, 2 years, and at the most recent visit. Volume-based analysis of ablated mesial temporal structures was conducted in 17 patients with mesial temporal sclerosis (MTS) and results were compared between the seizure-free and not seizure-free groups.

RESULTS

Following LiTT, proportions of patients who were free of seizures impairing consciousness (including those with auras only) are as follows: 8 of 15 patients (53%, 95% confidence interval [CI] 30.1-75.2%) after 6 months, 4 of 11 patients (36.4%, 95% CI 14.9-64.8%) after 1 year, 3 of 5 patients (60%, 95% CI 22.9-88.4%) at 2-year follow-up. Median follow-up was 13.4 months after LiTT (range 1.3 months to 3.2 years). Seizure outcome after LiTT suggests an all or none response. Four patients had anterior temporal lobectomy (ATL) after LiTT; three are seizure-free. There were no differences in total ablated volume of the amygdalohippocampus complex or individual volumes of hippocampus, amygdala, entorhinal cortex, parahippocampal gyrus, and fusiform gyrus between seizure-free and non-seizure-free patients. Contextual verbal memory performance was preserved after LiTT, although decline in noncontextual memory task scores were noted.

SIGNIFICANCE

We conclude that MRI-guided stereotactic LiTT is a safe alternative to ATL in patients with medically intractable mTLE. Individualized assessment is warranted to determine whether the reduced odds of seizure freedom are worth the reduction in risk, discomfort, and recovery time. Larger prospective studies are needed to confirm our preliminary findings, and to define optimal ablation volume and ideal structures for ablation.

Utility of Green's Word Memory Test Free Recall Subtest as a Measure of Verbal Memory: Initial Evidence from a Temporal Lobe Epilepsy Clinical Sample

This study investigated the Word Memory Test (WMT) Free Recall (FR) subtest as a conventional memory measure. Nineteen participants with pharmacoresistant left temporal lobe epilepsy (LTLE) and 16 with right temporal lobe epilepsy (RTLE) completed the WMT, Rey Auditory Verbal Learning Test (RAVLT), and Wechsler Memory Scale-Fourth Edition Logical Memory (LM) subtest during presurgical evaluation. LTLE participants performed significantly worse on FR subtest (p < .05, [Formula: see text]) and RAVLT Trial 7 (p < .01, [Formula: see text]), but not on LM subtest. Age was a significant covariate for FR (p < .01, [Formula: see text]). Logistic regression revealed FR plus age and RAVLT age-adjusted T-scores both yielded 77.1% classification accuracy and respective diagnostic odds ratios of 11.36 and 11.84. Receiver operating characteristic curves to classify seizure laterality found that RAVLT and FR were significant (area under the curve [AUC] = 0.82 and 0.74), whereas LM was nonsignificant (AUC = 0.67). Cut scores and positive/negative predictive values were established for improved clinical classification.

Hippocampal-dependent neurocognitive impairment following cranial irradiation observed in pre-clinical models: current knowledge and possible future directions

We reviewed the literature for studies pertaining to impaired adult neurogenesis leading to neurocognitive impairment following cranial irradiation in rodent models. This compendium was compared with respect to radiation dose, converted to equivalent dose in 2 Gy fractions (EQD2) to allow for direct comparison between studies. The effects of differences between animal species and the dependence on animal age as well as for time after irradiation were also considered. One of the major sites of de novo adult neurogenesis is the hippocampus, and as such, this review also focuses on assessing evidence related to the expression and potential effects of inflammatory cytokines on neural stem cells in the subgranular zone of the dentate gyrus and whether this correlates with neurocognitive impairment. This review also discusses potential strategies to mitigate the detrimental effects on neurogenesis and neurocognition resulting from cranial irradiation, and how the rationale for these strategies compares with the current outcome of pre-clinical studies.

Functional MRI, resting state fMRI, and DTI for predicting verbal fluency outcome following resective surgery for temporal lobe epilepsy

OBJECTIVE

Predicting cognitive function following resective surgery remains an important clinical goal. Each MRI neuroimaging technique can potentially provide unique and distinct insight into changes that occur in the structural or functional organization of "at-risk" cognitive functions. The authors tested for the singular and combined power of 3 imaging techniques (functional MRI [fMRI], resting state fMRI, diffusion tensor imaging) to predict cognitive outcome following left (dominant) anterior temporal lobectomy for intractable epilepsy. METHODS; The authors calculated the degree of deviation from normal, determined the rate of change in this measure across the pre- and postsurgical imaging sessions, and then compared these measures for their ability to predict verbal fluency changes following surgery.

RESULTS

The data show that the 3 neuroimaging techniques, in a combined model, can reliably predict cognitive outcome following anterior temporal lobectomy for medically intractable temporal lobe epilepsy.

CONCLUSIONS

These findings suggest that these 3 imaging modalities can be used effectively, in an additive fashion, to predict functional reorganization and cognitive outcome following anterior temporal lobectomy.

Effect of invasive EEG monitoring on cognitive outcome after left temporal lobe epilepsy surgery

OBJECTIVES

The objective of this cohort study was to compare neuropsychological outcomes following left temporal lobe resection (TLR) in patients with epilepsy who had or had not undergone prior invasive monitoring.

METHODS

Data were obtained from an institutional review board-approved, neuropsychology registry for patients who underwent epilepsy surgery at Cleveland Clinic between 1997 and 2013. A total of 176 patients (45 with and 131 without invasive EEG) met inclusion criteria. Primary outcome measures were verbal memory and language scores. Other cognitive outcomes were also examined. Outcomes were assessed using difference in scores from before to after surgery and by presence/absence of clinically meaningful decline using reliable change indices (RCIs). Effect of invasive EEG on cognitive outcomes was estimated using weighting and propensity score adjustment to account for differences in baseline characteristics. Linear and logistic regression models compared surgical groups on all cognitive outcomes.

RESULTS

Patients with invasive monitoring showed greater declines in confrontation naming; however, when RCIs were used to assess clinically meaningful change, there was no significant treatment effect on naming performance. No difference in verbal memory was observed, regardless of how the outcome was measured. In secondary outcomes, patients with invasive monitoring showed greater declines in working memory, which were no longer apparent using RCIs to define change. There were no outcome differences on other cognitive measures.

CONCLUSIONS

Results suggest that invasive EEG monitoring conducted prior to left TLR is not associated with greater cognitive morbidity than left TLR alone. This information is important when counseling patients regarding cognitive risks associated with this elective surgery.

Differential neuropsychological outcomes following targeted responsive neurostimulation for partial-onset epilepsy

OBJECTIVE

Responsive neurostimulation decreases the frequency of disabling seizures when used as an adjunctive therapy in patients with medically refractory partial-onset seizures. The effect of long-term responsive neurostimulation on neuropsychological performance has not yet been established.

METHODS

Neuropsychological data were collected from subjects participating in the open-label arm of a randomized controlled trial of responsive neurostimulation with the RNS(®) System. Primary cognitive outcomes were the Boston Naming Test (BNT) and Rey Auditory Verbal Learning (AVLT) test. Neuropsychological performance was evaluated at baseline and again following 1 and 2 years of RNS System treatment. Follow-up analyses were conducted in patients with seizure onset restricted to either the mesial temporal lobe or neocortex.

RESULTS

No significant cognitive declines were observed for any neuropsychological measure through 2 years. When examined as a function of seizure onset region, a double dissociation was found, with significant improvement in naming across all patients (p < 0.0001), and for patients with neocortical seizure onsets (p < 0.0001) but not in patients with mesial temporal lobe (MTL) seizure onsets (p = 0.679). In contrast, a significant improvement in verbal learning was observed across all patients (p = 0.03), and for patients with MTL seizure onsets (p = 0.005) but not for patients with neocortical onsets (p = 0.403).

SIGNIFICANCE

Treatment with the RNS System is not associated with cognitive decline when tested through 2 years. In fact, there were small but significant beneficial treatment effects on naming in patients with neocortical onsets and modest improvements in verbal learning for patients with seizure onsets in MTL structures. These results suggest that there are modest cognitive improvements in some domains that vary as a function of the region from which seizures arise.

Reliable change indices and standardized regression-based change score norms for evaluating neuropsychological change in children with epilepsy

Reliable change indices (RCIs) and standardized regression-based (SRB) change score norms permit evaluation of meaningful changes in test scores following treatment interventions, like epilepsy surgery, while accounting for test-retest reliability, practice effects, score fluctuations due to error, and relevant clinical and demographic factors. Although these methods are frequently used to assess cognitive change after epilepsy surgery in adults, they have not been widely applied to examine cognitive change in children with epilepsy. The goal of the current study was to develop RCIs and SRB change score norms for use in children with epilepsy. Sixty-three children with epilepsy (age range: 6-16; M=10.19, SD=2.58) underwent comprehensive neuropsychological evaluations at two time points an average of 12 months apart. Practice effect-adjusted RCIs and SRB change score norms were calculated for all cognitive measures in the battery. Practice effects were quite variable across the neuropsychological measures, with the greatest differences observed among older children, particularly on the Children's Memory Scale and Wisconsin Card Sorting Test. There was also notable variability in test-retest reliabilities across measures in the battery, with coefficients ranging from 0.14 to 0.92. Reliable change indices and SRB change score norms for use in assessing meaningful cognitive change in children following epilepsy surgery are provided for measures with reliability coefficients above 0.50. This is the first study to provide RCIs and SRB change score norms for a comprehensive neuropsychological battery based on a large sample of children with epilepsy. Tables to aid in evaluating cognitive changes in children who have undergone epilepsy surgery are provided for clinical use. An Excel sheet to perform all relevant calculations is also available to interested clinicians or researchers.

Indications and expectations for neuropsychological assessment in routine epilepsy care: Report of the ILAE Neuropsychology Task Force, Diagnostic Methods Commission, 2013-2017

The International League Against Epilepsy (ILAE) Diagnostic Methods Commission charged the Neuropsychology Task Force with the job of developing a set of recommendations to address the following questions: (1) What is the role of a neuropsychological assessment? (2) Who should do a neuropsychological assessment? (3) When should people with epilepsy be referred for a neuropsychological assessment? and (4) What should be expected from a neuropsychological assessment? The recommendations have been broadly written for health care clinicians in established epilepsy settings as well as those setting up new services. They are based on a detailed survey of neuropsychological assessment practices across international epilepsy centers, and formal ranking of specific recommendations for advancing clinical epilepsy care generated by specialist epilepsy neuropsychologists from around the world. They also incorporate the latest research findings to establish minimum standards for training and practice, reflecting the many roles of neuropsychological assessment in the routine care of children and adults with epilepsy. The recommendations endorse routine screening of cognition, mood, and behavior in new-onset epilepsy, and describe the range of situations when more detailed, formal neuropsychological assessment is indicated. They identify a core set of cognitive and psychological domains that should be assessed to provide an objective account of an individual's cognitive, emotional, and psychosocial functioning, including factors likely contributing to deficits identified on qualitative and quantitative examination. The recommendations also endorse routine provision of feedback to patients, families, and clinicians about the implications of the assessment results, including specific clinical recommendations of what can be done to improve a patient's cognitive or psychosocial functioning and alleviate the distress of any difficulties identified. By canvassing the breadth and depth of scope of neuropsychological assessment, this report demonstrates the pivotal role played by this noninvasive and minimally resource intensive investigation in the care of people with epilepsy.

Memory outcome following left anterior temporal lobectomy in patients with a failed Wada test

PURPOSE

This study aimed to compare the memory outcome following left anterior temporal lobectomy (ATL) between patients with a failed Wada test and patients who passed the Wada test.

METHODS

From 1996 to 2002, we performed the Wada test on all patients with unilateral left mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS) and concordant electroclinical data before ATL. We used a 12-item recognition paradigm for memory testing and awarded a score of +1 for each correct response and -0.5 for each incorrect response. No patient was denied surgery on the basis of Wada scores. We assessed cognitive and memory functions using the Wechsler Adult Intelligence Scale and the Wechsler Memory Scale preoperatively and at one year after ATL. We compared the number of patients who showed decline in memory scores, as per the published reliable change indices, between the patients with a failed Wada test and the patients who passed the Wada test.

RESULTS

Out of the 116 eligible patients with left MTLE-HS, 88 underwent bilateral Wada test, while 28 underwent ipsilateral Wada test. None of them developed postoperative amnesia. Approximately, one-third of patients with a failed Wada memory test when the failure was defined as a contralateral score of <4, as an ipsilateral score of >8, and as an asymmetry score of <0. The patients with Wada memory failure had a longer pre-ATL duration of epilepsy (p<0.003). The memory and quality-of-life outcomes did not differ between the group with a failed Wada memory test and the group who passed the Wada memory test. The results remained the same when analyses were repeated at various other cutoff points.

CONCLUSION

The patients with left MTLE-HS with concordant electroclinical, MRI, and neuropsychological data should not be denied ATL solely on the basis of Wada memory test results.

Epilepsy surgery in bifrontal injury from prior craniopharyngioma resections

Epilepsy surgery in frontal lobe epilepsy (FLE) has less favorable seizure-free outcomes than temporal lobe epilepsies. Possible contributing factors include fast propagation patterns and large clinically silent areas which are characteristics of the frontal lobes. Bilateral frontal lobe abnormalities on MRI are another relative contraindication to epilepsy surgery. For example, bilateral encephalomalacia may be a presupposition to bilateral or multifocal epilepsy. The possibility of potential disinhibition with already poor reserves may be another deterrent to consideration for resective epilepsy surgery. As such, conventional surgical approaches to intractable epilepsy with bilateral frontal injury may be limited to palliative procedures like vagus nerve stimulation and corpus callosotomy. We present a case in which the epileptogenic zone was a subset of the acquired, bilateral, cystic encephalomalacia. This iatrogenic injury resulted from two prior craniotomies for excision of craniopharyngioma and its recurrence.

Following the initial bilateral and subsequent unilateral, subdural grid- and depth electrode-based localization and resection, our patient has remained seizure-free 2 years after epilepsy surgery with marked improvement in her quality of life, as corroborated by her neuropsychological test scores. Our patient's clinical course is testament to the potential role for resective strategies in selected cases of intractable epilepsy associated with bifrontal injury. Reversal of behavioral deficits with frontal lobe epilepsy surgery such as in this patient provides a unique opportunity to further our understanding of the complex nature of frontal lobe function.

Limited practice effects and evaluation of expectation for change: MATRICS Consensus Cognitive Battery

Understanding of the impact of antipsychotic medications on cognition requires differentiating between treatment effects and practice effects. This prospective study examines expectations for change on neuropsychological assessments and possible differential practice effects in community dwelling schizophrenia patients (n=27) who are clinically stable and on a stable medication regimen when compared to demographically similar psychiatrically healthy controls (n=29). All participants were administered the MATRICS Consensus Cognitive Battery (MCCB) twice over a period of four weeks. The use of Regression Based Norms for Change (RBNC) and Reliable Change Index (RCI) was completed to anchor estimates of meaningful change to a demographically similar control group. A repeated measures ANOVA was used to examine the effects of time and diagnosis on MCCB composite scores. A repeated measures MANOVA was used to examine the effects of time and diagnosis, and their interaction for MCCB subtests. Estimates of meaningful change are provided. A significant main effect was observed for time; no significant interactions were observed. There was no support for differential practice effects. In the absence of any behavioral, cognitive, or pharmaceutical interventions, these findings suggest limited change in performance over time in either group.