Faculty Bibliography

Background: Walking impairments are one of the most impactful consequences of multiple sclerosis (MS). Recently, physical rehabilitation research has focused on developing synergistic protocols to enhance clinical benefit. Recent studies have shown that transcranial direct current stimulation (tDCS) and aerobic physical activity (PA) have converging activation pathways and when completed simultaneously, they may promote cortical neuroplasticity.
Objective(s): To harness cortical plasticity to improve gait for individuals with MS.
Aim(s): To investigate the effects of multiple sessions of PA with simultaneously administered tDCS on walking abilities.
Method(s): MS participants (EDSS: 1-6.5, Relapsing-Remitting or Secondary-Progressive subtype) with clinically significant gait deviations were recruited for a randomized controlled trial of 10 sessions of either active or sham tDCS paired with unloaded cycling for 20 minutes. Stimulation was administered over the primary motor cortex (2.5 mA-2.0 mA; anode over C3/cathode over FP2). Walking speed was assessed quantitatively by using a single inertial sensor placed on the lower back and perceived walking abilities were evaluated using the 12-Item MS Walking Scale (MSWS-12), a self-report questionnaire. Measurements were collected at baseline, the end of tDCS intervention, and 4-weeks post-intervention. Two-way repeated measures-ANOVA (Time, Treatment) was performed to investigate differences between active and sham conditions.
Result(s): Thirty-two participants were enrolled in the study, 22 underwent active treatment. No demographic differences were detected between active and sham groups (active:EDSS 4.3+/-1.2, age 55.5+/-10.3; sham:EDSS 4.5+/-1.5, age 49.7+/-13.9). Statistical analysis showed significant Treatment by Time interactions for gait speed and MSWS-12 score. Post-hoc analysis revealed that gait speed increased significantly after active treatment (Baseline vs. End Treatment, 0.98 vs. 1.16 m/s, p< 0.001; Baseline vs. Follow-up, 0.98 vs. 1.20 m/s, p< 0.001). Active group further reported significant improvement in self-report measure (Baseline vs. End Treatment, 58.04 vs. 49.73, p< 0.05). No significant difference was detected after sham stimulation.
Conclusion(s): Our results indicate that multiple sessions of tDCS administered simultaneously with PA induce cumulative and selfreport improvement in walking and benefits persisted until 4-week post-intervention

Introduction: Cognitive impairment in pediatric onset multiple sclerosis (POMS) occurs in up to one third of cases.
Objective(s): To screen for cognitive impairment early in the disease course of POMS, measure predictive factors, and determine the effect of relapse on cognitive processing speed.
Aim(s): To identify cognitive processing speed impairment among POMS and pediatric clinically isolated (CIS) patients enrolled in the US Pediatric MS and Other Demyelinating Disease Registry. In March 2014, the Symbol Digit Modalities Test (SDMT) scores were analyzed from March 2014, when the SDMT was added to the clinical evaluation through July 2018, when the data set was locked.
Method(s): SDMT raw scores were converted to age-normative z-scores using validated age and sex adjusted means. Processing speed impairment was defined with z-score increments of-1.0. Clinically meaningful decline in longitudinal analyses was defined by a z-score decrease of 1.0 or more.
Result(s): For the POMS (n=500) and CIS (n=116) with at least one SDMT, the mean age at symptom onset was 13.5 years and the mean (+SD) disease duration at the initial SDMT assessment was 3.0 + 2.9 years. A total of 23.4% of MS and 16.4% of CIS patients had impaired processing speed at initial assessment. SDMT impairment was predicted by worse EDSS, longer disease duration, and lower level of mother's educational achievement. On longitudinal follow-up (n=383, mean follow-up: 1.8 years), 14.1% had clinically meaningful decline predicted by older age of MS onset, male gender, and longer test-retest interval. Disease relapse and steroid use were associated with transient SDMT worsening.
Conclusion(s): Early in the disease course, a subgroup of POMS patients are at risk for cognitive impairment and subsequent decline. Screening for cognitive slowing is critical for prompt identification of potential cognitive deficits and initiation of additional services

OBJECTIVE:Critical decisions regarding resection boundaries for epilepsy surgery are often based on results of electrical stimulation mapping (ESM). Despite the potentially serious implications for postoperative functioning, age-referenced data that might facilitate the procedure are lacking. Age might be particularly relevant, as pediatric ESM studies have shown a paucity of language sites in young children followed by a rapid increase at approximately 8-10 years. Beyond adolescence, it has generally been assumed that the language system remains stable, and therefore, potential age-related changes across the adult age span have not been examined. However, increasing age during adulthood is associated with both positive and negative language-related changes, such as a broadening vocabulary and increased word finding difficulty. Because most patients who undergo ESM are adults, we aimed to determine the potential impact of age on the incidence of ESM-identified naming sites across the adult age span in patients with refractory epilepsy. METHODS:We analyzed clinical language ESM results from 47 patients, ages 17-64 years, with refractory dominant-hemisphere epilepsy. Patients had comparable location and number of cortical sites tested. The incidence of naming sites was examined as a function of age, and compared between younger and older adults. RESULTS:Significantly more naming sites were found in older than younger adults, and age was found to be a significant predictor of number of naming sites identified. SIGNIFICANCE/CONCLUSIONS:Unlike the developmental changes that coincide with increased naming sites in children, increased naming sites in older adults might signify greater vulnerability of the language system to disruption. Because preservation of language sites can limit the extent of the resection, and thereby reduce the likelihood of seizure freedom, further work should aim to determine the clinical relevance of increased naming sites in older adults.

Abstract: Introduction: Fatigue is one of the most prevalent and under-assessed non-motor symptoms in Parkinson's disease (PD). Current therapies have limited effectiveness. Presently, tDCS has shown potential to improve certain symptoms of PD. We designed a tDCS protocol to allow study participation from the patient's home, while maintaining clinical trial standards. We utilized a live video-conferencing platform and specially designed equipment that 'unlocks' one session at a time. Study objective: To assess feasibility and explore the therapeutic potential of remotely supervised tDCS (RS-tDCS) paired with cognitive training (CT) for PD patients suffering from fatigue.
Method(s): Double-blind, randomized, sham controlled study of RS-tDCS paired with CT. Participants completed 10 daily tDCS sessions (20-minute, 2.0-mA, bi-frontal, F3-F4 montage, left anodal), with the option of 10 additional open label sessions. Evaluation of preliminary clinical effects with the fatigue severity scale (FSS) along with tolerability, safety and compliance were completed.
Result(s): Eighteen participants were screened, 17 enrolled (Table 1), one screen failure. Incidence of the systematically recorded side effects were 22.4% tingling, 11.5% burning sensation, 8.2% itching, 3.3% headache, 0.9% nausea, 0.3% dizziness and 0.3% sleepiness. No serious adverse events reported. Compliance and tolerability were 100%. Preliminary fatigue clinical effects of 10 sessions showed a significant decrease of mean FSS only in the real RS-tDCS group of 8.0 (SD 9.82) points (p < 0.05). Further analysis of 20 RS-tDCS sessions (10 DoubleBlind-real+10 Open-label) showed a further significant decrease in mean FSS of 11.47 (SD 10.7) points (p < 0.05).
Conclusion(s): At-home RS-tDCS therapy paired with CT is safe and well tolerated by PD patients, with the advantages of ease of recruitment and optimal subject compliance. At-home RS-tDCS therapy paired with CT shows potential to remediate fatigue symptoms in PD, but the small sample size limits efficacy conclusions. Our paradigm may be influential in designing future studies. [Figure presented] Introduction: Parkinson's Disease (PD) is a progressively disabling disease that affects patients and their caregivers' quality of life. PD is a chronic neurodegenerative disease affecting a large number of dopaminergic neurons in the nigrostriatal pathway, responsible for common motor dysfunction such as slowness, tremor and rigidity. The disease also leads to various non-motor symptoms, in particular, fatigue and cognitive disability. The available pharmacotherapy often allows for a relatively good control of symptoms, but complications could arise from the side effects of medications, or the progressive nature of the disease [1]. Certain alternative therapies have emerged such as non-invasive brain stimulation (NIBS) that may potentially improve declining function. Transcranial direct current stimulation (tDCS) is a low-cost, safe and practical treatment compared to other NIBS. tDCS is a portable device that utilizes a weak electrical current to modulate neuronal membrane potentials and cortical excitability [2-3]. Fatigue is a highly prevalent symptom that is largely unrecognized in PD with no current evidence-based treatment [4]. Since tDCS has shown beneficial effects in motor, mood and cognitive symptoms in PD, it may have potential to ameliorate fatigue in PD.
Method(s): The study design is a double blind randomized, sham controlled trial using at-home tDCS paired with CT. Remote supervision of tDCS sessions was performed through a video-conferencing platform. The tele-rehabilitation design has been recently validated and allows participation of patients from the comfort of their homes [5]. Feasibility and preliminary effects of RS-tDCS in PD were tested using a dorsolateral prefrontal cortex (DLPFC) montage (F3-F4 from the EEG 10x20 system). All participants received a baseline physical, neurological, fatigue and cognitive assessments. Participants were asked to complete 10 daily sessions. Once finalized, they were offered 10 additional open label (OpL) sessions. Using a detailed study "stop" criteria [6, 7] flow chart, participants were cleared at each step for their participation to proceed. The primary objectives of the study were to determine the feasibility of RS tDCS paired with CT and explore the potential to ameliorate fatigue in PD. Clinical effects on fatigue were measured with the fatigue severity scale (FSS), a scale largely validated and recommended for this population [4]. FSS was obtained at baseline and after 10 tDCS sessions of 20 minutes with 2 milliamperes (mA) intensity, while participants engaged in computerized based CT. During the visits, acceptability of therapy, tolerability, side effects and other adverse events (AEs) were collected. An optional OpL period allows for a more comprehensive exploratory evaluation of RS-tDCS effects beyond 10 sessions.
Result(s): Eighteen patients were screened and seventeen were enrolled (one screen failure). Only one participant decided to opt out of the OpL portion of the study. Patient demographic characteristics did not differ between groups (Table 1). Pain tolerability of 2.0 mA stimulation with <=6 on visual analog scale for pain (VAS-Pain) was 100%. Incidence of the systematically recorded side effects were 22.4% tingling, 11.5% burning sensation, 8.2% itching, 3.3% headache, 0.9%, nausea, 0.3% dizziness and 0.3% sleepiness. Other adverse events (AEs) are listed in figure 1. No serious AEs were reported. All required visits were completed with no attrition or interruptions (100% compliance). Preliminary fatigue clinical effects of 10 sessions showed a significant decrease of mean FSS only in the real RS-tDCS group of 8.0 (SD 9.82) points (p < 0.05). Further analysis of 20 RS-tDCS sessions (10 DoubleBlind-real+10 Open-label) showed a further significant decrease in mean FSS of 11.47 (SD 10.7) points (p < 0.05) (Figure 2). [Figure presented] Discussion and
Conclusion(s): This novel design of remotely supervised tDCS has allowed conducting tDCS sessions safely and away from the lab setting, in the comfort of participant's homes. This paradigm of NIBS is particularly suited for medical conditions limiting mobility like PD, participants with busy schedules or living far distances from clinics. The initial results of this study showed that this protocol is feasible, acceptable and safe in PD with no major adverse events. [Figure presented] Our study has shown that RS-tDCS holds therapeutic potential for fatigue in people with PD, and showed 20 sessions seemed more favorable than 10 sessions. Trials with a greater sample size and extended treatment duration might be more suitable to establish the real efficacy for this therapy as a treatment of fatigue. Study Supported by Grant No. PDF-TRG-1722 from the Parkinson's Foundation. References [1] Kalia, L. V., & Lang, A. E. Parkinson's disease. Lancet, 386(9996), 896-912. (2015) [2] Priori, A., Berardelli, A., Rona, S., Accornero, N., & Manfredi, M. Polarization of the human motor cortex through the scalp. Neuroreport, 9(10), 2257-2260. (1998) [3] Nitsche, M. A., & Paulus, W. Excitability changes induced in the human motor cortex by weak transcranial direct current stimulation. J Physiol, 527 Pt 3, 633-639. (2000) [4] Friedman, J. H., Beck, J. C., Chou, K. L., et al. Fatigue in Parkinson's disease: report from a mutidisciplinary symposium. NPJ Parkinsons Dis, 2. (2016) [5] Biagioni, M. C., Sharma, K., Migdadi, H. A., & Cucca, A. Non-Invasive Neuromodulation Therapies for Parkinson's Disease. IntechOpen, DOI: 10.5772/intechopen.75052. (2018) [6] Kasschau, M., Sherman, K., Haider, L., et al. A Protocol for the Use of Remotely-Supervised Transcranial Direct Current Stimulation (tDCS) in Multiple Sclerosis (MS). J Vis Exp(106), e53542. (2015) [7] Charvet, L. E., Kasschau, M., Datta, A., et al. Remotely-supervised transcranial direct current stimulation (tDCS) for clinical trials: guidelines for technology and protocols. Frontiers in Systems Neuroscience, 9(26). (2015)
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BACKGROUND:Growing evidence supports the efficacy of restorative cognitive training in people with multiple sclerosis (PwMS), but the effects vary across individuals. Differences in treatment efficacy may be related to baseline individual differences. We investigated clinical characteristics and MRI variables to predict response to a previously validated approach to home-based restorative cognitive training. METHODS:In a single-arm repeated measures study, 51 PwMS completed a 12-week at-home restorative cognitive training program called BrainHQ, shown to be effective in a placebo-controlled clinical trial. Baseline demographic, clinical, neuropsychological, and brain MRI factors were captured and the effects of treatment were quantified with Symbol Digit Modalities Test (SDMT). Also measured were indices of treatment compliance. Regression modeling was employed to identify the factors associated with greatest SDMT improvement. RESULTS:As a group, patients improved significantly after training: mean SDMT improving from 49.6 ± 14.7 to 52.6 ± 15.6 (t = 3.91, p<0.001). Greater SDMT improvement correlated positively with treatment exposure (r = 0.38, p = 0.007). Increased post-rehabilitation improvement on SDMT was predicted by baseline relapsing-remitting course (β=-0.34, p = 0.017), higher trait Conscientiousness-Orderliness (β=0.29, p = 0.040), and higher baseline gray matter volume (GMV; β=0.31, p = 0.030). CONCLUSION/CONCLUSIONS:The study was designed to explore the variables that predict favorable outcome in a home-based application of a validated restorative cognitive training program. We find good outcomes are most likely in patients with higher trait Conscientiousness-Orderliness, and relapsing-remitting course. The same was found for individuals with higher GMV. Future work in larger cohorts is needed to support these findings and to investigate the unique needs of individuals according to baseline factors.

Magnetic resonance imaging (MRI)-negative temporal lobe epilepsy (TLE) may be a distinct syndrome from TLE with mesial temporal sclerosis (TLE-MTS). Imaging and neuropsychological features of TLE-MTS are well-known; yet, these features are only beginning to be described in MRI-negative TLE. This study examined whether a quantitative measure of cortical gray and white matter blurring (GWB) was elevated in the temporal lobes ipsilateral to the seizure onset zone of individuals with MRI-negative TLE relative to TLE-MTS and healthy controls (HCs) and whether GWB elevations were associated with neuropsychological comorbidity. Gray-white matter blurring from 34 cortical regions and hippocampal volumes were quantified and compared across 28 people with MRI-negative TLE, 15 people with TLE-MTS, and 51 HCs. Declarative memory was assessed with standard neuropsychological tests and the intracarotid amobarbital procedure (IAP). In the group with MRI-negative TLE (left and right onsets combined), hippocampal volumes were within normal range but GWB was elevated, relative to HCs, across several mesial and lateral temporal lobe regions ipsilateral to the seizure onset zone. Gray-white matter blurring did not differ between the groups with TLE-MTS and HC or between the groups with TLE-MTS and MRI-negative TLE. The group with MRI-negative TLE could not be distinguished from the group with TLE-MTS on any of the standard neuropsychological tests; however, ipsilateral hippocampal volumes and IAP memory scores were lower in the group with TLE-MTS than in the group with MRI-negative TLE. The group with left MRI-negative TLE had lower general cognitive abilities and verbal fluency relative to the HC group, which adds to the characterization of neuropsychological comorbidities in left MRI-negative TLE. In addition, ipsilateral IAP memory performance was reduced relative to contralateral memory performance in MRI-negative TLE, indicating some degree of ipsilateral memory dysfunction. There was no relationship between hippocampal volume and IAP memory scores in MRI-negative TLE; however, decreased ipsilateral IAP memory scores were correlated with elevated GWB in the ipsilateral superior temporal sulcus of people with left MRI-negative TLE. In sum, GWB elevations in the ipsilateral temporal lobe of people with MRI-negative TLE suggest that GWB may serve as a marker for reduced structural integrity in regions in or near the seizure onset zone. Although mesial temporal abnormalities might be the major driver of memory dysfunction in TLE-MTS, a loss of structural integrity in lateral temporal lobe regions may contribute to IAP memory dysfunction in MRI-negative TLE.

BACKGROUND:Migraine and epilepsy are comorbid conditions. While it is well known that epilepsy can have an impact on cognitive abilities, there is conflicting evidence in the literature on the relationship between migraine and cognitive function. The aim of this study was to assess whether migraine comorbidity in patients with newly diagnosed focal epilepsy is associated with cognitive dysfunction. METHODS:This is a post hoc analysis of data prospectively collected for the Human Epilepsy Project (HEP). There were 349 participants screened for migraine with the 13 questions used in the American Migraine Prevalence and Prevention (AMPP) study. Participants were also screened for depression using the Neurological Disorder Depression Inventory for Epilepsy (NDDI-E) and the Center for Epidemiologic Studies Depression Scale (CES-D) and for anxiety using the Generalized Anxiety Disorder-7 (GAD-7) scale. Cognitive performance was assessed with the Cogstate Brief Battery and Aldenkamp-Baker Neuropsychological Assessment Schedule (ABNAS). RESULTS:About a fifth (21.2%) of patients with a new diagnosis of focal epilepsy screened positive for migraine. There were more women and less participants employed full time among the participants with comorbid migraine. They reported slightly more depressive and anxious symptoms than the participants without migraine. Migraine comorbidity was associated with ABNAS memory score (median: 2, range: 0-12, Mann Whitney U p-value: 0.015). However, migraine comorbidity was not associated with Cogstate scores nor ABNAS total scores or other ABNAS domain scores. In linear regressions, depression and anxiety scores were associated with the ABNAS memory score. CONCLUSION/CONCLUSIONS:In this study, there was no association between migraine comorbidity and objective cognitive scores in patients with newly diagnosed focal epilepsy. The relationship between migraine comorbidity and subjective memory deficits seemed to be mediated by the higher prevalence of depression and anxiety symptoms in patients with epilepsy with comorbid migraine.

In our first paper in this series (Epilepsia 2015; 56(5): 674-681), we published recommendations for the indications and expectations for neuropsychological assessment in routine epilepsy care. This partner paper provides a comprehensive overview of the more specialist role of neuropsychological assessment in the pre and postoperative evaluation of epilepsy surgery patients. The paper is in two parts. The first part presents the framework for the mandatory role of neuropsychologists in the presurgical evaluation of epilepsy surgery candidates. A preoperative neuropsychological assessment should be comprised of standardised measures of cognitive function in addition to wider measures of behavioural and psychosocial function. The results from the presurgical assessment are used to: (1) establish a baseline against which change can be measured following surgery; (2) provide a collaborative contribution to seizure characterization, lateralization and localization; (3) provide evidence-based predictions of cognitive risk associated with the proposed surgery; and (4) provide the evidence base for comprehensive preoperative counselling, including exploration of patient expectations of surgical treatment. The second part examines the critical role of the neuropsychologist in the evaluation of postoperative outcomes. Neuropsychological changes following surgery are dynamic and a comprehensive, long-term assessment of these changes following surgery should form an integral part of the postoperative follow-up. The special considerations with respect to pre and postoperative assessment when working with paediatric populations and those with an intellectual disability are also discussed. The paper provides a summary checklist for neuropsychological involvement throughout the epilepsy surgery process, based on the recommendations discussed.

BACKGROUND:Fatigue is one of the most commonly experienced symptoms in multiple sclerosis (MS). The neural correlates of fatigue in MS, in general and specifically in early onset, remain poorly understood. This study employed resting-state fMRI (rsfMRI) to investigate the functional connectivity of fatigue in MS patients with early age onset. METHODS:Twenty-seven relapsing-remitting MS patients (20 ± 7yo at the age of diagnosis and 26.0 ± 5.5yo at the time of study) were recruited and 22 patients were studied. Structural and rsfMRI sequences were performed on a 3-Tesla Seimens MRI scanner. Seed-based analysis was performed using CONN Functional Connectivity Toolbox for Statistic Parametric Mapping. The Fatigue Severity Scale (FSS) and the Modified Fatigue Impact scale (MFIS) as well as EDSS, Beck Depression Inventory, and symptomatology were measured. Non-fatigued (N = 12) and fatigued patients (N = 10) were separated based on FSS scores, with a score of 5 or greater being classified as fatigued. Group differences in rsfMRI between non-fatigued and fatigued patients were analyzed. Correlations between these functional connectivity differences and behavioral fatigue scores were also analyzed. RESULTS: = 0.402, p = 0.006). Correlations remained significant after accounting for depression scores. CONCLUSIONS:rsfMRI identified Alterations in two distinct connections (the connectivity between insula and posterior cingulate gyrus and between the right thalamus and right precentral gyrus) that differed between fatigued and non-fatigued patients, as well as correlated with cognitive fatigue severity. These findings suggest that disruption of sensorimotor, high-order motor, and non-motor executive function likely contributes to the neural mechanism of fatigue in MS. Knowledge of the neural mechanisms of underlying MS fatigue could inform more effective treatment strategies.