Faculty Bibliography
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354
Brain Injury Lesion Imaging Using Preconditioned Quantitative Susceptibility Mapping without Skull Stripping
BACKGROUND AND PURPOSE/OBJECTIVE:Identifying cerebral microhemorrhage burden can aid in the diagnosis and management of traumatic brain injury, stroke, hypertension, and cerebral amyloid angiopathy. MR imaging susceptibility-based methods are more sensitive than CT for detecting cerebral microhemorrhage, but methods other than quantitative susceptibility mapping provide results that vary with field strength and TE, require additional phase maps to distinguish blood from calcification, and depict cerebral microhemorrhages as bloom artifacts. Quantitative susceptibility mapping provides universal quantification of tissue magnetic property without these constraints but traditionally requires a mask generated by skull-stripping, which can pose challenges at tissue interphases. We evaluated the preconditioned quantitative susceptibility mapping MR imaging method, which does not require skull-stripping, for improved depiction of brain parenchyma and pathology. MATERIALS AND METHODS/METHODS:Fifty-six subjects underwent brain MR imaging with a 3D multiecho gradient recalled echo acquisition. Mask-based quantitative susceptibility mapping images were created using a commonly used mask-based quantitative susceptibility mapping method, and preconditioned quantitative susceptibility images were made using precondition-based total field inversion. All images were reviewed by a neuroradiologist and a radiology resident. RESULTS:Ten subjects (18%), all with traumatic brain injury, demonstrated blood products on 3D gradient recalled echo imaging. All lesions were visible on preconditioned quantitative susceptibility mapping, while 6 were not visible on mask-based quantitative susceptibility mapping. Thirty-one subjects (55%) demonstrated brain parenchyma and/or lesions that were visible on preconditioned quantitative susceptibility mapping but not on mask-based quantitative susceptibility mapping. Six subjects (11%) demonstrated pons artifacts on preconditioned quantitative susceptibility mapping and mask-based quantitative susceptibility mapping; they were worse on preconditioned quantitative susceptibility mapping. CONCLUSIONS:Preconditioned quantitative susceptibility mapping MR imaging can bring the benefits of quantitative susceptibility mapping imaging to clinical practice without the limitations of mask-based quantitative susceptibility mapping, especially for evaluating cerebral microhemorrhage-associated pathologies, such as traumatic brain injury.
PMCID:5895509
PMID: 29472296
ISSN: 1936-959x
CID: 3045822
Repetitive transcranial magnetic stimulation (rTMS) for treatment-resistant major depression (TRMD) Veteran patients: study protocol for a randomized controlled trial
BACKGROUND: Evaluation of repetitive transcranial magnetic stimulation (rTMS) for treatment-resistant major depression (TRMD) in Veterans offers unique clinical trial challenges. Here we describe a randomized, double-blinded, intent-to-treat, two-arm, superiority parallel design, a multicenter study funded by the Cooperative Studies Program (CSP No. 556) of the US Department of Veterans Affairs. METHODS: We recruited medical providers with clinical expertise in treating TRMD at nine Veterans Affairs (VA) medical centers as the trial local investigators. We plan to enroll 360 Veterans diagnosed with TRMD at the nine VA medical centers over a 3-year period. We will randomize participants into a double-blinded clinical trial to left prefrontal rTMS treatment or to sham (control) rTMS treatment (180 participants each group) for up to 30 treatment sessions. All participants will meet Diagnostic and statistical manual of mental disorders, 4 th edition (DSM-IV) criteria for major depression and will have failed at least two prior pharmacological interventions. In contrast with other rTMS clinical trials, we will not exclude Veterans with posttraumatic stress disorder (PTSD) or history of substance abuse and we will obtain detailed history regarding these disorders. Furthermore, we will maintain participants on stable anti-depressant medication throughout the trial. We will evaluate all participants on a wide variety of potential predictors of treatment response including cognitive, psychological and functional parameters. DISCUSSION: The primary dependent measure will be remission rate (Hamilton Rating Scale for Depression (HRSD24)
PMCID:5581925
PMID: 28865495
ISSN: 1745-6215
CID: 2705822
Susceptibility-Based Neuroimaging: Standard Methods, Clinical Applications, and Future Directions
The evaluation of neuropathologies using MRI methods that leverage tissue susceptibility have become standard practice, especially to detect blood products or mineralization. Additionally, emerging MRI techniques have the ability to provide new information based on tissue susceptibility properties in a robust and quantitative manner. This paper discusses these advanced susceptibility imaging techniques and their clinical applications.
PMCID:5501163
PMID: 28695062
ISSN: 2167-4825
CID: 2630252
Principal components analysis of agitation outcomes in Alzheimer's disease
BACKGROUND: We developed a composite measure of agitation as a secondary outcome of change over time in the Citalopram for Agitation in Alzheimer's disease study (CitAD). CitAD demonstrated a positive effect of citalopram on agitation on the Neurobehavioral Rating Scale agitation subscale (NBRS-A). CitAD included additional agitation measures such as the Cohen-Mansfield Agitation Inventory and the Neuropsychiatric Inventory. METHODS: We performed principal components analyses on change in individual item of these scales for the same, original CitAD subjects. RESULTS: The first principal component accounted for 12.6% of the observed variance and was composed of items that appear to reflect agitation. The effect size for citalopram calculated using this component was 0.53 (95% CI 0.22-0.83) versus 0.32 for the NBRS-A (95% CI 0.01-0.62). CONCLUSIONS: Results suggest that a composite measure of change in agitation might be more sensitive than change in a single primary agitation measure.
PMCID:4891245
PMID: 27115509
ISSN: 1879-1379
CID: 2120842
Heterogeneity of Treatment Response to Citalopram for Patients With Alzheimer's Disease With Aggression or Agitation: The CitAD Randomized Clinical Trial
OBJECTIVE: Pharmacological treatments for agitation and aggression in patients with Alzheimer's disease have shown limited efficacy. The authors assessed the heterogeneity of response to citalopram in the Citalopram for Agitation in Alzheimer Disease (CitAD) study to identify individuals who may be helped or harmed. METHOD: In this double-blind parallel-group multicenter trial of 186 patients with Alzheimer's disease and clinically significant agitation, participants were randomly assigned to receive citalopram or placebo for 9 weeks, with the dosage titrated to 30 mg/day over the first 3 weeks. Five planned potential predictors of treatment outcome were assessed, along with six additional predictors. The authors then used a two-stage multivariate method to select the most likely predictors; grouped participants into 10 subgroups by their index scores; and estimated the citalopram treatment effect for each. RESULTS: Five covariates were likely predictors, and treatment effect was heterogeneous across the subgroups. Patients for whom citalopram was more effective were more likely to be outpatients, have the least cognitive impairment, have moderate agitation, and be within the middle age range (76-82 years). Patients for whom placebo was more effective were more likely to be in long-term care, have more severe cognitive impairment, have more severe agitation, and be treated with lorazepam. CONCLUSIONS: Considering several covariates together allowed the identification of responders. Those with moderate agitation and with lower levels of cognitive impairment were more likely to benefit from citalopram, and those with more severe agitation and greater cognitive impairment were at greater risk for adverse responses. Considering the dosages used and the association of citalopram with cardiac QT prolongation, use of this agent to treat agitation may be limited to a subgroup of people with dementia.
PMID: 26771737
ISSN: 1535-7228
CID: 2100342
Effects of Citalopram on Neuropsychiatric Symptoms in Alzheimer's Dementia: Evidence From the CitAD Study
OBJECTIVE: Citalopram has been shown to improve agitation in patients with Alzheimer's disease. The authors evaluated whether other neuropsychiatric symptoms improve with citalopram treatment compared with placebo. METHOD: In this planned secondary analysis of the Citalopram for Agitation in Alzheimer's Disease study, the authors evaluated the effect of citalopram on the 12 neuropsychiatric symptom domains assessed by the Neuropsychiatric Inventory (NPI). They compared caregiver-reported NPI scores at week 9 in patients receiving citalopram (30 mg/day) or placebo with regard to both the presence or absence of individual neuropsychiatric symptoms and individual domain scores (reflecting severity) in participants who had symptoms at week 9. RESULTS: At week 9, participants treated with citalopram were significantly less likely to be reported as showing delusions (odds ratio=0.40), anxiety (odds ratio=0.43), and irritability/lability (odds ratio=0.38). A comparison of median scores of participants with symptoms present at week 9 showed significant differences favoring citalopram for hallucinations and favoring placebo for sleep/nighttime behavior disorders. CONCLUSIONS: While dosage constraints must be considered because of citalopram's adverse effect profile, this agent's overall therapeutic effects in patients with Alzheimer's disease and agitation, in addition to efficacy for agitation/aggression, included reductions in the frequency of irritability, anxiety, and delusions; among patients who had these symptoms at week 9, they included a reduction in the severity of hallucinations but an increase in the severity of sleep/nighttime behavior disorders.
PMID: 27032628
ISSN: 1535-7228
CID: 2100492
Sedation mediates part of Citalopram's effect on agitation in Alzheimer's disease
BACKGROUND: We found a benefit of citalopram for agitation in the Citalopram for Agitation in Alzheimer's Disease study (CitAD), and wondered if this was mediated by a sedative effect. CitAD was a randomized, placebo-controlled, double-blind, parallel group trial conducted at 8 academic centers in the United States and Canada from August 2009 to January 2013. One hundred sixty-two participants with probable Alzheimer's disease (AD) and clinically significant agitation were analyzed in this study. Participants received a psychosocial intervention and were randomized to receive either citalopram or placebo (approximately half assigned to each group). Participants were rated on the Neurobehavioral Rating Scale Agitation subscale and measures of sedation (i.e., fatigue and somnolence). METHODS: Using the MacArthur Foundation procedures for documenting a mediator effect, we performed a secondary analysis examining whether sedation mediates the effect of treatment on agitation outcome. RESULTS: We found a statistically significant mediating effect of sedation on agitation outcomes, but the magnitude of the effect was small, only explaining 11% of the variance in agitation, with a significant, but modest effect size of 0.16 (95% CI: 0.08 to 0.22). CONCLUSIONS: The benefit of citalopram was partly due to sedation but largely due to other mechanisms of action.
PMCID:4744510
PMID: 26736036
ISSN: 1879-1379
CID: 1936892
Ubiquity of Undiagnosed Sleep Disordered Breathing in Community-Dwelling Older Male Veterans
OBJECTIVE: To determine the point prevalence of sleep disordered breathing (SDB) in a community-based sample of older male veterans and to determine if common markers of SDB apply to this population. METHODS: Two hundred fourteen older male Veterans (age 55-89 years) were recruited for a study on post-traumatic stress disorder and cognitive decline. Questionnaires concerning anthropomorphic and psychological variables were obtained, as was an overnight polysomnographic examination of sleep. RESULTS: Only 13% of the participants lacked clinically meaningful SDB, whereas 33% had moderate SDB and 54% had severe SDB. Being overweight, self-reported snoring, and excessive daytime sleepiness all had good sensitivity (0.86-0.92) but very poor specificity (0.10-0.28) for the prediction of SDB. CONCLUSIONS: Undiagnosed SDB was more than threefold higher than expected in these community-dwelling older veterans. Traditional markers of SDB were not specific for predicting clinically relevant SDB.
PMID: 26778348
ISSN: 1545-7214
CID: 2043332
The influence of physical and mental health symptoms on Veterans' functional health status
Veterans who have been deployed to combat often have complex medical histories including some combination of traumatic brain injury (TBI); mental health problems; and other chronic, medically unexplained symptoms (i.e., chronic multisymptom illness [CMI] clusters). How these multiple pathologies relate to functional health is unclear. In the current study, 120 Veterans (across multiple combat cohorts) underwent comprehensive clinical evaluations and completed self-report assessments of mental health symptoms (Patient Health Questionnaire-2 [PHQ-2], PTSD Checklist-Civilian Version [PCL-C]) and functional health (Veterans Rand 36-Item Health Survey). Canonical correlation and regression modeling using split-sample permutation tests revealed that the PHQ-2/PCL-C composite variable (among TBI severity and number of problematic CMI clusters) was the primary predictor of multiple functional health domains. Two subscales, Bodily Pain and General Health, were associated with multiple predictors (TBI, PHQ-2/PCL-C, and CMI; and PHQ-2/PCL-C and CMI, respectively), demonstrating the multifaceted nature of how distinct medical problems might uniquely and collectively impair aspects of functional health. Apart from these findings, however, TBI and CMI were not predictors of any other aspects of functional health. Taken together, our findings suggest that mental health problems might exert ubiquitous influence over multiple domains of functional health. Thus, screening of mental health problems and education and promotion of mental health resources can be important to the treatment and care of Veterans.
PMID: 28273324
ISSN: 1938-1352
CID: 3079782
Change in agitation in Alzheimer's disease in the placebo arm of a nine-week controlled trial
BACKGROUND: Placebo responses raise significant challenges for the design of clinical trials. We report changes in agitation outcomes in the placebo arm of a recent trial of citalopram for agitation in Alzheimer's disease (CitAD). METHODS: In the CitAD study, all participants and caregivers received a psychosocial intervention and 92 were assigned to placebo for nine weeks. Outcomes included Neurobehavioral Rating Scale agitation subscale (NBRS-A), modified AD Cooperative Study-Clinical Global Impression of Change (CGIC), Cohen-Mansfield Agitation Inventory (CMAI), the Neuropsychiatric Inventory (NPI) Agitation/Aggression domain (NPI A/A) and Total (NPI-Total) and ADLs. Continuous outcomes were analyzed with mixed-effects modeling and dichotomous outcomes with logistic regression. RESULTS: Agitation outcomes improved over nine weeks: NBRS-A mean (SD) decreased from 7.8 (3.0) at baseline to 5.4 (3.2), CMAI from 28.7 (6.7) to 26.7 (7.4), NPI A/A from 8.0 (2.4) to 4.9 (3.8), and NPI-Total from 37.3 (17.7) to 28.4 (22.1). The proportion of CGI-C agitation responders ranged from 21 to 29% and was significantly different from zero. MMSE improved from 14.4 (6.9) to 15.7 (7.2) and ADLs similarly improved. Most of the improvement was observed by three weeks and was sustained through nine weeks. The major predictor of improvement in each agitation measure was a higher baseline score in that measure. CONCLUSIONS: We observed significant placebo response which may be due to regression to the mean, response to a psychosocial intervention, natural course of symptoms, or nonspecific benefits of participation in a trial.
PMCID:4669064
PMID: 26305876
ISSN: 1741-203x
CID: 1825162
