Spatial correspondence of cortical activity measured with whole head fNIRS and fMRI: Toward clinical use within subject

Functional near infrared spectroscopy (fNIRS) and functional magnetic resonance imaging (fMRI) both measure the hemodynamic response, and so both imaging modalities are expected to have a strong correspondence in regions of cortex adjacent to the scalp. To assess whether fNIRS can be used clinically in a manner similar to fMRI, 22 healthy adult participants underwent same-day fMRI and whole-head fNIRS testing while they performed separate motor (finger tapping) and visual (flashing checkerboard) tasks. Analyses were conducted within and across subjects for each imaging approach, and regions of significant task-related activity were compared on the cortical surface. The spatial correspondence between fNIRS and fMRI detection of task-related activity was good in terms of true positive rate, with fNIRS overlap of up to 68 % of the fMRI for analyses across subjects (group analysis) and an average overlap of up to 47.25 % for individual analyses within subject. At the group level, the positive predictive value of fNIRS was 51 % relative to fMRI. The positive predictive value for within subject analyses was lower (41.5 %), reflecting the presence of significant fNIRS activity in regions without significant fMRI activity. This could reflect task-correlated sources of physiologic noise and/or differences in the sensitivity of fNIRS and fMRI measures to changes in separate (vs. combined) measures of oxy and de-oxyhemoglobin. The results suggest whole-head fNIRS as a noninvasive imaging modality with promising clinical utility for the functional assessment of brain activity in superficial regions of cortex physically adjacent to the skull.

T1-/T2-weighted ratio reveals no alterations to gray matter myelination in temporal lobe epilepsy

Short-range functional connectivity in the limbic network is increased in patients with temporal lobe epilepsy (TLE), and recent studies have shown that cortical myelin content correlates with fMRI connectivity. We thus hypothesized that myelin may increase progressively in the epileptic network. We compared T1w/T2w gray matter myelin maps between TLE patients and age-matched controls and assessed relationships between myelin and aging. While both TLE patients and healthy controls exhibited increased T1w/T2w intensity with age, we found no evidence for significant group-level aberrations in overall myelin content or myelin changes through time in TLE.

A graph theoretic approach to neurodegeneration: five data-driven neuropsychological subtypes in mild cognitive impairment

Mild cognitive Impairment (MCI) is notoriously heterogenous in terms of clinical presentation, neuroimaging correlates, and subsequent progression. Predicting who will progress to dementia, which type of dementia, and over what timeframe is challenging. Previous work has attempted to identify MCI subtypes using neuropsychological measures in an effort to address this challenge; however, there is no consensus on approach, which may account for some of the variability. Using a hierarchical community detection approach, we examined cognitive subtypes within an MCI sample (from the Alzheimer's Disease Neuroimaging Initiative [ADNI] study). We then examined whether these subtypes were related to biomarkers (e.g., cortical volumes, fluorodeoxyglucose (FDG)-positron emission tomography (PET) hypometabolism) or clinical progression. We identified five communities (i.e., cognitive subtypes) within the MCI sample: 1) predominantly memory impairment, 2) predominantly language impairment, 3) cognitively normal, 4) multidomain, with notable executive dysfunction, 5) multidomain, with notable processing speed impairment. Community membership was significantly associated with 1) cortical volume in the hippocampus, entorhinal cortex, and fusiform cortex; 2) FDG PET hypometabolism in the posterior cingulate, angular gyrus, and inferior/middle temporal gyrus; and 3) conversion to dementia at follow up. Overall, community detection as an approach appears a viable method for identifying unique cognitive subtypes in a neurodegenerative sample that were linked to several meaningful biomarkers and modestly with progression at one year follow up.

Association of neighborhood deprivation with white matter connectome abnormalities in temporal lobe epilepsy

OBJECTIVE

Social determinants of health, including the effects of neighborhood disadvantage, impact epilepsy prevalence, treatment, and outcomes. This study characterized the association between aberrant white matter connectivity in temporal lobe epilepsy (TLE) and disadvantage using a US census-based neighborhood disadvantage metric, the Area Deprivation Index (ADI), derived from measures of income, education, employment, and housing quality.

METHODS

Participants including 74 TLE patients (47 male, mean age = 39.2 years) and 45 healthy controls (27 male, mean age = 31.9 years) from the Epilepsy Connectome Project were classified into ADI-defined low and high disadvantage groups. Graph theoretic metrics were applied to multishell connectome diffusion-weighted imaging (DWI) measurements to derive 162 × 162 structural connectivity matrices (SCMs). The SCMs were harmonized using neuroCombat to account for interscanner differences. Threshold-free network-based statistics were used for analysis, and findings were correlated with ADI quintile metrics. A decrease in cross-sectional area (CSA) indicates reduced white matter integrity.

RESULTS

Sex- and age-adjusted CSA in TLE groups was significantly reduced compared to controls regardless of disadvantage status, revealing discrete aberrant white matter tract connectivity abnormalities in addition to apparent differences in graph measures of connectivity and network-based statistics. When comparing broadly defined disadvantaged TLE groups, differences were at trend level. Sensitivity analyses of ADI quintile extremes revealed significantly lower CSA in the most compared to least disadvantaged TLE group.

SIGNIFICANCE

Our findings demonstrate (1) the general impact of TLE on DWI connectome status is larger than the association with neighborhood disadvantage; however, (2) neighborhood disadvantage, indexed by ADI, revealed modest relationships with white matter structure and integrity on sensitivity analysis in TLE. Further studies are needed to explore this relationship and determine whether the white matter relationship with ADI is driven by social drift or environmental influences on brain development. Understanding the etiology and course of the disadvantage-brain integrity relationship may serve to inform care, management, and policy for patients.

Late dominance of the right hemisphere during narrative comprehension

PET and fMRI studies suggest that auditory narrative comprehension is supported by a bilateral multilobar cortical network. The superior temporal resolution of magnetoencephalography (MEG) makes it an attractive tool to investigate the dynamics of how different neuroanatomic substrates engage during narrative comprehension. Using beta-band power changes as a marker of cortical engagement, we studied MEG responses during an auditory story comprehension task in 31 healthy adults. The protocol consisted of two runs, each interleaving 7 blocks of the story comprehension task with 15 blocks of an auditorily presented math task as a control for phonological processing, working memory, and attention processes. Sources at the cortical surface were estimated with a frequency-resolved beamformer. Beta-band power was estimated in the frequency range of 16-24 Hz over 1-sec epochs starting from 400 msec after stimulus onset until the end of a story or math problem presentation. These power estimates were compared to 1-second epochs of data before the stimulus block onset. The task-related cortical engagement was inferred from beta-band power decrements. Group-level source activations were statistically compared using non-parametric permutation testing. A story-math contrast of beta-band power changes showed greater bilateral cortical engagement within the fusiform gyrus, inferior and middle temporal gyri, parahippocampal gyrus, and left inferior frontal gyrus (IFG) during story comprehension. A math-story contrast of beta power decrements showed greater bilateral but left-lateralized engagement of the middle frontal gyrus and superior parietal lobule. The evolution of cortical engagement during five temporal windows across the presentation of stories showed significant involvement during the first interval of the narrative of bilateral opercular and insular regions as well as the ventral and lateral temporal cortex, extending more posteriorly on the left and medially on the right. Over time, there continued to be sustained right anterior ventral temporal engagement, with increasing involvement of the right anterior parahippocampal gyrus, STG, MTG, posterior superior temporal sulcus, inferior parietal lobule, frontal operculum, and insula, while left hemisphere engagement decreased. Our findings are consistent with prior imaging studies of narrative comprehension, but in addition, they demonstrate increasing right-lateralized engagement over the course of narratives, suggesting an important role for these right-hemispheric regions in semantic integration as well as social and pragmatic inference processing.

Sensitivity of functional connectivity to periaqueductal gray localization, with implications for identifying disease-related changes in chronic visceral pain: A MAPP Research Network neuroimaging study

Previous studies examining the resting-state functional connectivity of the periaqueductal gray (PAG) in chronic visceral pain have localized PAG coordinates derived from BOLD responses to provoked acute pain. These coordinates appear to be several millimeters anterior of the anatomical location of the PAG. Therefore, we aimed to determine whether measures of PAG functional connectivity are sensitive to the localization technique, and if the localization approach has an impact on detecting disease-related differences in chronic visceral pain patients. We examined structural and resting-state functional MRI (rs-fMRI) images from 209 participants in the Multidisciplinary Approach to the Study of Chronic Pelvic Pain (MAPP) Research Network study. We applied three different localization techniques to define a region-of-interest (ROI) for the PAG: 1) a ROI previously-published as a Montreal Neurological Institute (MNI) coordinate surrounded by a 3 mm radius sphere (MNI-sphere), 2) a ROI that was hand-traced over the PAG in a MNI template brain (MNI-trace), and 3) a ROI that was hand-drawn over the PAG in structural images from 30 individual participants (participant-trace). We compared the correlation among the rs-fMRI signals from these PAG ROIs, as well as the functional connectivity of these ROIs with the whole brain. First, we found important non-uniformities in brainstem rs-fMRI signals, as rs-fMRI signals from the MNI-trace ROI were significantly more similar to the participant-trace ROI than to the MNI-sphere ROI. We then found that choice of ROI also impacts whole-brain functional connectivity, as measures of PAG functional connectivity throughout the brain were more similar between MNI-trace and participant-trace compared to MNI-sphere and participant-trace. Finally, we found that ROI choice impacts detection of disease-related differences, as functional connectivity differences between pelvic pain patients and healthy controls were much more apparent using the MNI-trace ROI compared to the MNI-sphere ROI. These results indicate that the ROI used to localize the PAG is critical, especially when examining brain functional connectivity changes in chronic visceral pain patients.

Functional Near-Infrared Spectroscopy and Its Clinical Application in the Field of Neuroscience: Advances and Future Directions

Similar to functional magnetic resonance imaging (fMRI), functional near-infrared spectroscopy (fNIRS) detects the changes of hemoglobin species inside the brain, but via differences in optical absorption. Within the near-infrared spectrum, light can penetrate biological tissues and be absorbed by chromophores, such as oxyhemoglobin and deoxyhemoglobin. What makes fNIRS more advantageous is its portability and potential for long-term monitoring. This paper reviews the basic mechanisms of fNIRS and its current clinical applications, the limitations toward more widespread clinical usage of fNIRS, and current efforts to improve the temporal and spatial resolution of fNIRS toward robust clinical usage within subjects. Oligochannel fNIRS is adequate for estimating global cerebral function and it has become an important tool in the critical care setting for evaluating cerebral oxygenation and autoregulation in patients with stroke and traumatic brain injury. When it comes to a more sophisticated utilization, spatial and temporal resolution becomes critical. Multichannel NIRS has improved the spatial resolution of fNIRS for brain mapping in certain task modalities, such as language mapping. However, averaging and group analysis are currently required, limiting its clinical use for monitoring and real-time event detection in individual subjects. Advances in signal processing have moved fNIRS toward individual clinical use for detecting certain types of seizures, assessing autonomic function and cortical spreading depression. However, its lack of accuracy and precision has been the major obstacle toward more sophisticated clinical use of fNIRS. The use of high-density whole head optode arrays, precise sensor locations relative to the head, anatomical co-registration, short-distance channels, and multi-dimensional signal processing can be combined to improve the sensitivity of fNIRS and increase its use as a wide-spread clinical tool for the robust assessment of brain function.

Cognitive slowing and its underlying neurobiology in temporal lobe epilepsy

Cognitive slowing is a known but comparatively under-investigated neuropsychological complication of the epilepsies in relation to other known cognitive comorbidities such as memory, executive function and language. Here we focus on a novel metric of processing speed, characterize its relative salience compared to other cognitive difficulties in epilepsy, and explore its underlying neurobiological correlates. Research participants included 55 patients with temporal lobe epilepsy (TLE) and 58 healthy controls from the Epilepsy Connectome Project (ECP) who were administered a battery of tests yielding 14 neuropsychological measures, including selected tests from the NIH Toolbox-Cognitive Battery, and underwent 3T MRI and resting state fMRI. TLE patients exhibited a pattern of generalized cognitive impairment with very few lateralized abnormalities. Using the neuropsychological measures, machine learning (Support Vector Machine binary classification model) classified the TLE and control groups with 74% accuracy with processing speed (NIH Toolbox Pattern Comparison Processing Speed Test) the best predictor. In TLE, slower processing speed was associated predominantly with decreased local gyrification in regions including the rostral and caudal middle frontal gyrus, inferior precentral cortex, insula, inferior parietal cortex (angular and supramarginal gyri), lateral occipital cortex, rostral anterior cingulate, and medial orbital frontal regions, as well as three small regions of the temporal lobe. Slower processing speed was also associated with decreased connectivity between the primary visual cortices in both hemispheres and the left supplementary motor area, as well as between the right parieto-occipital sulcus and right middle insular area. Overall, slowed processing speed is an important cognitive comorbidity of TLE associated with altered brain structure and connectivity.

Abstract OT1-01-05: Endocrine treatment alone as primary treatment for elderly patients with estrogen receptor positive good prognosis operable breast cancer: A single arm phase II, single institution study

Background: It is estimated that approximately 46,000 women age >75 are diagnosed annually with breast cancer. Due to competing co-morbidities, there is wide variation in treatment recommendations which can lead to over- or under-treatment. Though surgery for breast cancer is considered low-morbidity, many elderly women given a choice, choose not to have surgery. Previous randomized trials comparing surgery with tamoxifen versus endocrine therapy alone in women age >70 unselected for ER status demonstrated similar overall survival with poorer local control in the latter group. A new standard of care needs to be defined for elderly women with good prognosis ER+ tumors, since these women may benefit from endocrine therapy alone to treat their cancer without compromising local and distant control.

Hypothesis: We hypothesize that endocrine therapy alone provides adequate local and systemic control of breast cancer in a subpopulation of women age 70 or older with ER+ breast cancer and good prognostic characteristics.

Primary Objective

To correlate response to neoadjuvant endocrine treatment at 6 months with Oncotype DX Recurrence Score (RS) in women with early-stage ER+ breast cancer who are age >70.

Secondary Objective

1. To determine the breast cancer-specific survival of women with early-stage ER+ breast cancer, age >70, treated with endocrine therapy alone.

2. To determine the rate of overall survival of women with early-stage ER+ breast cancer, age >70 treated with endocrine therapy alone.

Study Design: This is a prospective single arm phase II study. Patients with clinical stage I/II ER+ breast cancer, grade 1-2, Ki67<30 or RS <18 (performed on the diagnostic core biopsy) continue to be enrolled and followed for time to progression. A Kaplan-Meier model will be used to estimate the 5-year local progression rate. If the true 5-year progression rate is 10%, then 50 patients will provide power = .90 at a one-sided .05 significance level to demonstrate that the rate is less than 25.5%. Exploratory objectives include: evaluation of the molecular characteristics of breast cancers of responders versus non-responders, determine compliance with medications, evaluate cost-effectiveness, and quality of life.

Results: Between February 2017 and April 2018, 11 patients were enrolled into the study. Two patients could not tolerate endocrine therapy and received standard of care treatment. For the 9 patients on study, average tumor size was 1.7cm, average Ki67 was 15%, average RS was 14. All of the patients received an aromatase inhibitor. At 6 months, 71% of the patients had a partial response, 28% had stable disease. None of the patients developed progressive disease.

Conclusion: A new standard of care needs to be defined for women age >70 with good prognosis ER+ tumors, since these women may benefit from endocrine therapy alone to treat their cancer without compromising local and distant control. We continue to enroll patients to determine the optimal tumor markers for identifying women who can be treated with PET only to control their cancer.

Citation Format: Aft R, Cherian M, Frith A, Suresh R, Glover-Collins K, Naughton M, Moon C, Conant L, Ma C. Endocrine treatment alone as primary treatment for elderly patients with estrogen receptor positive good prognosis operable breast cancer: A single arm phase II, single institution study [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr OT1-01-05.

A council of elders: creating a multi-voiced dialogue in a community of care

In an era of 'medical care delivery systems', there is an increasing need for the patient's voice to be heard, for it to be invited, listened to, and taken seriously. This challenge is particularly evident in geriatrics education, a domain of clinical training in which educators and clinicians alike must struggle to overcome adverse attitudes towards the elderly ('ageism'). In this paper we introduce a 'Council of Elders' as an educational innovation in which we invited community elders to function as our 'Senior Faculty', to whom medical residents present their challenging and heartfelt dilemmas in caring for elder patients. In the conversations that ensue, the elders come to function not simply as teachers, but collaborators in a process in which doctors, researchers, and elders together create a community of resources, capable of identifying novel ways to overcome health-related difficulties which might not have been apparent to either group separately. Using the first meeting of the Council as an exemplar, we describe and discuss the special nature of such meetings and also the special preparations required to build a dialogic relationship between participants from very different worlds--different generations, different cultures (including the professional culture and the world of lived experience). Meetings with the council have become a required part of the primary care residency program--a very different kind of 'challenging case conference' in which moral dilemmas can be presented, discussed and reflected upon. It is not so much that elders give good advice in their responses--although they often do--as that they provide life world and value orientation as young residents gain a better sense of the elder's experience and what matters most to them. This project has been particularly worthwhile in addressing the problem of ageism--a way to render visible stereotypes and adverse physician values, with implications for decision-making with the patient, not for the patient.

The role of hospice philosophy of care in nonhospice settings

Many advances in public health and medical technology have contributed to the improved wellbeing and overall longevity of Americans. Such benefits, however, have been offset by a change in the nature and prolongation of the dying process. Daniel Callahan offers a challenge to caregivers in his observation of violent death by technological attenuation, and he sets an agenda to identify a more appropriate approach to the needs of the dying.

Over the past quarter century, hospice has increasingly been used as a resource for care at the end of life. However, according to 1995 estimates by the National Hospice Organization (NHO), hospice care presently accounts for only about 15 percent of the care of terminally ill patients in the United States. We will review issues of access and use of hospice services and examine the various institutional, professional, societal, and cultural barriers to hospice principles of care, and consider various options to promote optimal care at the end of life.

Using proxies to evaluate quality of life. Can they provide valid information about patients' health status and satisfaction with medical care?

Instruments using interview data to measure health status have been increasingly used to measure patient outcomes. To assess the potential utility of proxy responses about health status when subjects are unable to respond, the authors compared the responses of 60 subject and proxy pairs on instruments measuring overall current health, functional status, social activity, emotional health, and satisfaction with medical care. Proxies were asked to respond as they thought the subject would. Subject and proxy responses were strongly correlated with each other for overall health, functional status, social activity, and emotional health (P less than .001), and moderately correlated for satisfaction (P less than .005). Proxies reported lower emotional health and satisfaction than did subjects (P less than .005). Proxy and subject mean responses were generally similar for overall health, functional status, and social activity. However, those proxies who spent more time per week helping the subject rated the subject's functional status and social activity as more impaired than did the subject (P less than .05). Subjects who had poorer overall health tended to rate their health relatively lower than did the proxies (P less than .05). These results suggest that use of proxies intermingled with subjects to measure health status through interview may lead to biased results.

Indicators of recovery from fractures of the hip

Patients with similar injuries who were at a similar level of function before the injury differ in the extent of recovery. In an attempt to identify important factors that affect recovery, we collected extensive physical, psychological and sociological data on a group of 108 elderly people with fractures of the hip in order to study the influence of the many variables on their recovery. We found that of all the items studied, those that best indicated the degree of recovery were: (1) the physical therapist's rating of functional ability; (2) how often the patient got outside the home prior to injury; (3) the patient's mental clarity.