Biomarker disclosure protocols in prodromal Alzheimer's disease clinical trials

INTRODUCTION

The development of biomarkers for Alzheimer's disease (AD) has allowed researchers to increase sample homogeneity and test candidate treatments earlier in the disease. The integration of biomarker "screening" criteria should be met with a parallel implementation of standardized methods to disclose biomarker testing results to research participants; however, the extent to which protocolized disclosure occurs in trials is unknown.

METHODS

We reviewed the literature to identify prodromal AD trials published in the past 10 years. From these, we quantified the frequency of biomarker disclosure reporting and the depth of descriptions provided.

RESULTS

Of 30 published trials using positron emission tomography or cerebrospinal fluid-based amyloid positivity as an eligibility criterion, only one mentioned disclosure, with no details on methods.

DISCUSSION

Possible reasons for and implications of this information gap are discussed. Recommendations are provided for trialists considering biomarker screening as part of intervention trials focused on prodromal AD.

HIGHLIGHTS

Few prodromal Alzheimer's disease (AD) trial papers discuss biomarker disclosure. Disclosure has implications for participants, family members, and trial success. Disclosure must be consistently integrated and reported in prodromal AD trials. Best practice guidelines and training resources for disclosure are needed.

Identifying cardiovascular risk factors that impact cerebrovascular reactivity: An ASL MRI study

BACKGROUND

To maintain cerebral blood flow (CBF), cerebral blood vessels dilate and contract in response to blood supply through cerebrovascular reactivity (CR).

PURPOSE

Cardiovascular (CV) disease is associated with increased stroke risk, but which risk factors specifically impact CR is unknown.

STUDY TYPE

Prospective longitudinal.

SUBJECTS

Fifty-three subjects undergoing carotid endarterectomy or stenting.

FIELD STRENGTH/SEQUENCE

3T, 3D pseudo-continuous arterial spin labeling (PCASL) ASL, and T₁ 3D fast spoiled gradient echo (FSPGR).

ASSESSMENT

We evaluated group differences in CBF changes for multiple cardiovascular risk factors in patients undergoing carotid revascularization surgery.

STATISTICAL TESTS

PRE (baseline), POST (48-hour postop), and 6MO (6 months postop) whole-brain CBF measurements, as 129 CBF maps from 53 subjects were modeled as within-subject analysis of variance (ANOVA). To identify CV risk factors associated with CBF change, the CBF change from PRE to POST, POST to 6MO, and PRE to 6MO were modeled as multiple linear regression with each CV risk factor as an independent variable. Statistical models were performed controlling for age on a voxel-by-voxel basis using SPM8. Significant clusters were reported if familywise error (FWE)-corrected cluster-level was P < 0.05, while the voxel-level significance threshold was set for P < 0.001.

RESULTS

The entire group showed significant (cluster-level P < 0.001) CBF increase from PRE to POST, decrease from POST to 6MO, and no significant difference (all voxels with P > 0.001) from PRE to 6MO. Of multiple CV risk factors evaluated, only elevated systolic blood pressure (SBP, P = 0.001), chronic renal insufficiency (CRI, P = 0.026), and history of prior stroke (CVA, P < 0.001) predicted lower increases in CBF PRE to POST. Over POST to 6MO, obesity predicted lower (P > 0.001) and cholesterol greater CBF decrease (P > 0.001).

DATA CONCLUSION

The CV risk factors of higher SBP, CRI, CVA, BMI, and cholesterol may indicate altered CR, and may warrant different stroke risk mitigation and special consideration for CBF change evaluation.

LEVEL OF EVIDENCE

1 Technical Efficacy: Stage 5 J. Magn. Reson. Imaging 2020;51:734-747.

Common and dissociable regional cerebral blood flow differences associate with dimensions of psychopathology across categorical diagnoses

The high comorbidity among neuropsychiatric disorders suggests a possible common neurobiological phenotype. Resting-state regional cerebral blood flow (CBF) can be measured noninvasively with magnetic resonance imaging (MRI) and abnormalities in regional CBF are present in many neuropsychiatric disorders. Regional CBF may also provide a useful biological marker across different types of psychopathology. To investigate CBF changes common across psychiatric disorders, we capitalized upon a sample of 1042 youths (ages 11-23 years) who completed cross-sectional imaging as part of the Philadelphia Neurodevelopmental Cohort. CBF at rest was quantified on a voxelwise basis using arterial spin labeled perfusion MRI at 3T. A dimensional measure of psychopathology was constructed using a bifactor model of item-level data from a psychiatric screening interview, which delineated four factors (fear, anxious-misery, psychosis and behavioral symptoms) plus a general factor: overall psychopathology. Overall psychopathology was associated with elevated perfusion in several regions including the right dorsal anterior cingulate cortex (ACC) and left rostral ACC. Furthermore, several clusters were associated with specific dimensions of psychopathology. Psychosis symptoms were related to reduced perfusion in the left frontal operculum and insula, whereas fear symptoms were associated with less perfusion in the right occipital/fusiform gyrus and left subgenual ACC. Follow-up functional connectivity analyses using resting-state functional MRI collected in the same participants revealed that overall psychopathology was associated with decreased connectivity between the dorsal ACC and bilateral caudate. Together, the results of this study demonstrate common and dissociable CBF abnormalities across neuropsychiatric disorders in youth.

The Impact of Latino Values and Cultural Beliefs on Brain Donation: Results of a Pilot Study to Develop Culturally Appropriate Materials and Methods to Increase Rates of Brain Donation in this Under-Studied Patient Group

OBJECTIVES

Increasing the number of Latino persons with dementia who consent to brain donation (BD) upon death is an important public health goal that has not yet been realized. This study identified the need for culturally sensitive materials to answer questions and support the decision-making process for the family.

METHODS

Information about existing rates of BD was obtained from the Alzheimer's Disease Centers. Several methods of data collection (query NACC database, contacting Centers, focus groups, online survey, assessing current protocol and materials) were used to give the needed background to create culturally appropriate BD materials.

RESULTS

A decision was made that a brochure for undecided enrollees would be beneficial to discuss BD with family members. For those needing further details, a step-by-step handout would provide additional information.

CONCLUSIONS

Through team collaboration and engagement of others in the community who work with Latinos with dementia, we believe this process allowed us to successfully create culturally appropriate informational materials that address a sensitive topic for Hispanic/Latino families.

CLINICAL IMPLICATIONS

Brain tissue is needed to further knowledge about underlying biological mechanism of neurodegenerative diseases, however it is a sensitive topic. Materials assist with family discussion and facilitate the family's follow-through with BD.

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^thedition (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) ≤ 10), and secondary analyses will be conducted on other indices. Comparisons between the rTMS and the sham groups will be made at the end of the acute treatment phase to test the primary hypothesis. The unique challenges to performing such a large technically challenging clinical trial with Veterans and potential avenues for improvement of the design in future trials will be described.

Trial registration

ClinicalTrials.gov, NCT01191333. Registered on 26 August 2010. This report is based on the protocol version 4.6 amended in February 2016. All items from the World Health Organization Trial Registration Data Set are listed in Appendix A.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-2125-y) contains supplementary material, which is available to authorized users.

Volume of subclinical embolic infarct correlates to long-term cognitive changes after carotid revascularization

OBJECTIVE

Carotid intervention is safe and effective in stroke prevention in appropriately selected patients. Despite minimal neurologic complications, procedure-related subclinical microemboli are common and their cognitive effects are largely unknown. In this prospective longitudinal study, we sought to determine long-term cognitive effects of embolic infarcts.

METHODS

The study recruited 119 patients including 46% symptomatic patients who underwent carotid revascularization. Neuropsychological testing was administered preoperatively and at 1 month, 6 months, and 12 months postoperatively. Rey Auditory Verbal Learning Test (RAVLT) was the primary cognitive measure with parallel forms to avoid practice effect. All patients also received 3T brain magnetic resonance imaging with a diffusion-weighted imaging (DWI) sequence preoperatively and within 48 hours postoperatively to identify procedure-related new embolic lesions. Each DWI lesion was manually traced and input into a neuroimaging program to define volume. Embolic infarct volumes were correlated with cognitive measures. Regression models were used to identify relationships between infarct volumes and cognitive measures.

RESULTS

A total of 587 DWI lesions were identified on 3T magnetic resonance imaging in 81.7% of carotid artery stenting (CAS) and 36.4% of carotid endarterectomy patients with a total volume of 29,327 mm³. Among them, 54 DWI lesions were found in carotid endarterectomy patients and 533 in the CAS patients. Four patients had transient postoperative neurologic symptoms and one had a stroke. CAS was an independent predictor of embolic infarction (odds ratio, 6.6 [2.1-20.4]; P < .01) and infarct volume (P = .004). Diabetes and contralateral carotid severe stenosis or occlusion had a trend of positive association with infarct volume, whereas systolic blood pressure ≥140 mm Hg had a negative association (P = .1, .09, and .1, respectively). There was a trend of improved RAVLT scores overall after carotid revascularization. Significantly higher infarct volumes were observed among those with RAVLT decline. Within the CAS cohort, infarct volume was negatively correlated with short- and long-term RAVLT changes (P < .05).

CONCLUSIONS

Cognitive assessment of procedure-related subclinical microemboli is challenging. Volumes of embolic infarct correlate with long-term cognitive changes, suggesting that microembolization should be considered a surrogate measure for carotid disease management.

Right frontal gamma and beta band enhancement while solving a spatial puzzle with insight

Solving a problem with an "a-ha" effect is known as insight. Unlike incremental problem solving, insight is sudden and unique, and the question about its distinct brain activity, intrigues many researchers. In this study, electroencephalogram signals were recorded from 12 right handed, human participants before (baseline) and while they solved a spatial puzzle known as the '10 coin puzzle' that could be solved incrementally or by insight. Participants responded as soon as they reached a solution and reported whether the process was incremental or by sudden insight. EEG activity was recorded from 19 scalp locations. We found significant differences between insight and incremental solvers in the Gamma and Beta 2 bands in frontal areas (F8) and in the alpha band in right temporal areas (T6). The right-frontal gamma indicates a process of restructuring which leads to an insight solution, in spatial problems, further suggesting a universal role of gamma in restructuring. These results further suggest that solving a spatial puzzle via insight requires exclusive brain areas and neurological-cognitive processes which may be important for meta-cognitive components of insight solutions, including attention and monitoring of the solution.

Microembolization is associated with transient cognitive decline in patients undergoing carotid interventions

OBJECTIVE

Carotid interventions are important in helping to reduce the risk of stroke for patients with high-grade carotid artery stenosis; however, subclinical cerebral microemboli can occur during these procedures. Associations have been found between the incidence of microemboli and postoperative decline in memory. We therefore sought to determine whether this decline persisted long-term and to assess changes in other cognitive domains.

METHODS

Patients were prospectively recruited under an Institutional Review Board-approved protocol at a single academic center. Neuropsychological testing was administered preoperatively and at 1-month and 6-month intervals postoperatively. Cognitive domains that were evaluated included verbal memory, visual memory, psychomotor speed, dexterity, and executive function. Diffusion-weighted magnetic resonance imaging sequencing was performed preoperatively and ≤48 hours postoperatively to identify procedure-related microemboli. Univariate and multivariate regression models were used to identify relationships among microembolization, demographics, and cognition.

RESULTS

Included were 80 male patients with an average age of 69 years. Forty patients underwent carotid artery stenting and 40 underwent carotid endarterectomy. Comorbidities included diabetes in 45%, coronary artery disease in 50%, and prior neurologic symptoms in 41%. New postoperative microemboli were found in 45 patients (56%). Microembolization was significantly more common in the carotid artery stenting cohort (P < .005). Univariate analysis demonstrated that patients with procedurally related embolization showed decline 1 month postoperatively in verbal memory and Trail Making A measures. Multivariate analysis demonstrated that procedurally related embolization (odds ratio [OR], 2.8; P = .04) and preoperative symptomatic stenosis (OR, 3.2; P = .026) were independent predictors of decline for the Rey Auditory Verbal Learning Test Short Delay measure at 1 month. At 6 months, no significant relationship was found between emboli and decline on Rey Auditory Verbal Learning Test Short Delay, but age (OR, 1.1, P = .005) and chronic obstructive pulmonary disease (OR, 7.1, P = .018) were significantly associated with decline at 6 months after the intervention.

CONCLUSIONS

Microembolization that is associated with carotid artery intervention predicts short-term cognitive decline. However, some of these cognitive deficits persist at 6 months after the intervention, and further investigation is warranted to determine individual patient risk factors that may affect recovery.

Different Diagnosis, Shared Vulnerabilities: The Value of Cross Disorder Validation of Capacity to Consent

A screening measure of capacity to consent can provide an efficient method of determining the appropriateness of including individuals from vulnerable patient populations in research, particularly in circumstances in which no caregiver is available to provide surrogate consent. Seaman et al. (2015) cross-validate a measure of capacity to consent to research developed by Jeste et al. (2007). They provide data on controls, caregivers, and patients with mild cognitive impairment and dementia. The study demonstrates the importance of validating measures across disorders with different domains of incapacity, as well as the need for timely and appropriate follow-up with potential participants who yield positive screens. Ultimately clinical measures need to adapt to the dimensional diagnostic approaches put forward in DSM 5. Integrative models of constructs, such as capacity to consent, will make this process more efficient by avoiding the need to test measures in each disorder. Until then, cross-validation studies, such as the work by Seaman et al. (2015) are critical.

Genetic Polymorphisms Influence Cognition in Patients Undergoing Carotid Interventions

While carotid interventions help decrease the risk of stroke, nearly 40% of patients experience cognitive deterioration. Genetic polymorphism in apolipoprotein E (ApoE) and brain-derived neurotrophic factor (BDNF) have been implicated in cognitive impairment; however, it is unclear whether they may influence cognitive changes in patients undergoing carotid intervention. In this study, we seek to assess the role of genetic polymorphisms in carotid intervention-related cognitive change. Polymorphisms related to cognitive function were chosen for this preliminary analysis. Over 2 years, patients undergoing carotid interventions were prospectively recruited. Patients underwent neuropsychological testing 2 weeks prior to and at 1 month following their procedure. Saliva samples were collected for genetic analysis. Logistic regressions were used to identify associations between polymorphisms and cognitive measures. A total of 91 patients were included; all were male with an average age of 70 years. The majority of patients exhibited hypertension (95%) and a history of smoking (81%). Presence of ApoE 4 allele was associated with depression (p= 0.047). After correcting for age and genetic polymorphisms in BDNF and serotonin transporter (5-HTT), ApoE 4 allele was associated with depression (p= 0.044) and showed a trend with baseline cognitive impairment (p= 0.10). Age ≥ 70 years was associated with baseline cognitive impairment after adjusting for the three genetic polymorphisms (p= 0.03). Patients with ApoE 4 and BDNF A polymorphisms performed less well on the visual and verbal memory measures, respectively. Polymorphisms in ApoE and BDNF may provide insight on cognition in patients undergoing carotid interventions; however, the mechanism of this relationship remains unclear.

Recovery entails bridging the multiple realms of best practice: towards a more integrated approach to evidence-based clinical treatment and psychosocial disability support for mental health recovery

While mental health recovery is a very personal process, the approach also offers possibilities as a meta-framework for improving quality of services to support people with severe and enduring mental illness. This paper explores how a recovery paradigm offers opportunities to better understand how efforts within the personal, clinical, and psychosocial disability domains of well-being relate and need bridging and integration with an evidence-based framework of practice to optimise outcomes. Recovery from a severe and persisting mental illness such as schizophrenia is optimised by a holistic approach integrating the domains of clinical treatment and psychosocial rehabilitation with the personal efforts of individuals. For service providers, a monolithic or single paradigm approach with an exclusive or predominant biological, psychological, social, or cultural focus is unable to offer effective guidance on the treatment and rehabilitation support needed to enable community participation and ameliorate the impact which problems associated with mental illness have on individuals, their families, and their wider communities. Moreover, recovery-oriented services need to be effective, embracing evidence-based policy, practice and service delivery by providing treatment and support which actually work to improve outcomes for consumers and families.

A computerised third molar surgery simulator--results of supervision by different professionals

The purpose of the study was to investigate which supervisory approach afforded the most efficient learning method for undergraduate students in oral and maxillofacial surgery (OMS) using a computerised third molar surgery simulator. Fifth year dental students participated voluntarily in a randomised experimental study using the simulator. The amount of time required and the number of trials used by each student were evaluated as a measure of skills development. Students had the opportunity to practise the procedure until no further visible improvements were achieved. The study assessed four different types of supervision to guide the students. The first group was where they were supported by a teacher/specialist in OMS, the second by a teaching assistant, the third group practised without any supervision and the fourth received help from a simulator technician/engineer. A protocol describing assessment criteria was designed for this purpose, and a questionnaire was completed by all participating students after the study. The average number of attempts required to virtually remove a third molar tooth in the simulator was 1.44 times for the group supervised by an OMS teacher; 1.5 times for those supervised by a teaching assistant; 2.8 times for those who had no supervision; and 3.6 times when support was provided only by a simulator technician. The results showed that the most efficient experience of the students was when they were helped by an OMS teacher or a teaching assistant. In a time and cost-effective perspective, supervision by a teaching assistant for a third molar surgery simulator would be the optimal choice.

Abstract 129: Predicting Patients Who Will Have Cognitive Decline After Carotid Endarterectomy or Stenting Using Structural Connectivity Graph Analysis

Objectives: Many CEA and CAS patients experience postoperative neurocognitive decline. We sought to apply structural connectivity metrics to identify patients at increased risk for postoperative decline based solely on preoperative imaging.

Methods: Under an IRB approved protocol 28 patients underwent presurgical T1 structural and 30 direction diffusion tensor imaging (DTI) MRI and neuropsychological tests before and 1 month after surgery. Patients with decline showed decreased performance on the Rey-AVLT on 1 month follow up. The T1 images were processed using FreeSurfer 5.3, with resulting segmentations reviewed and edited as needed under neuroradiologist supervision. Whole brain tractography was performed using Diffusion Toolkit and visually inspected. Connectivity matrices were then generated, and graph metrics were computed using the Brain Connectivity Toolbox.

Results: Controlling for age, classifiers using the graph analysis metrics “weighted optimal community structure” & “binary component sizes” were able to identify patients that would experience cognitive decline with 81% sensitivity 83% and specificity (p<.05, false discovery rate .05). These two measures were computed at 10 proportion edge thresholds from .1 to 1 at intervals of .1 in weighted and binary networks respectively.

Conclusions: Applying preoperative structural connectivity analysis in CEA and CAS patients may identify patients at increased risk for postoperative cognitive decline, and in so doing may help risk stratify patients and guide them to preventive interventions.

Nasogastric vs. intravenous rehydration in children with gastroenteritis and refusal to drink: a randomized controlled trial

BACKGROUND

Nasogastric rehydration therapy (NGRT) is the recommended therapy in moderately dehydrated children with gastroenteritis and refusal to drink, since it is supposed to be as effective if not better than intravenous rehydration therapy (IVRT). However, in clinical practice IVRT is often favored. We conducted a clinical trial to determine whether IVRT is not inferior to NGRT.

PATIENTS AND METHODS

Children 3 months to 6 years of age with moderate dehydration and refusal to drink secondary to gastroenteritis were recruited. After clinical assessment of the degree of dehydration, patients were assigned randomly to receive either IVRT or NGRT over 6 h on the hospital ward.

RESULTS

Recruitment did not yield the estimated number of patients. Mainly, non-enrollment was due to failure to obtain parental consent because IVRT was expected. 97 patients were enrolled in the study, 46 were randomized to NGRT and 51 to IVRT. There was no difference between IVRT and NGRT groups concerning length of hospital stay (2.2±1.1 days vs. 2.4±1.1 days), success of rehydration (78 vs. 76%) and adverse events.

DISCUSSION

Since we had to terminate the study ahead of schedule due to a low recruiting rate, our results are not reliable. However, data from the literature shows that the widespread described superiority of NGRT over IVRT is seriously influenced by studies from developing countries questioning the applicability of the results to a setting available in high-income countries nowadays.

CONCLUSION

Our study demonstrates the difficulties performing such a study in a high-income country to come to an objective and clearly evident final conclusion.

Long-term successful healing of ulcerated necrobiosis lipoidica after topical therapy with becaplermin

We report a case of chronic leg ulceration occurring in a patient with necrobiosis lipoidica (NL). After many topical treatments had failed to achieve healing, treatment with topical becaplermin was started, which resulted in rapid improvement and ultimately complete healing of the ulceration. Treatment of ulcerated NL is often disappointing. Many topical and systemic drugs have been tried. Becaplermin is a platelet-derived growth factor indicated for the treatment of neuropathic diabetic ulcers measuring < 50 mm in size. To our knowledge, this is only the second case reported in the literature of ulcerated NL successfully treated with becaplermin.

Abstract 507: Genetic Correlates of Cognitive Change in Patients Undergoing Carotid Interventions

OBJECTIVES

Carotid interventions have been shown to decrease stroke risk and improve cerebral perfusion. However, nearly 40% of patients who undergo carotid revascularization procedures experience cognitive deterioration. We have demonstrated that subclinical microembolization is associated with memory decline, but whether genetic factors plays a role in post-procedural cognitive change is unclear. We herein seek to assess genetic determinants as potential risk factors for these procedures.

METHODS

Over one year period, patients undergoing carotid interventions at a single academic institution were recruited to participate. Patients underwent neuropsychological testing two weeks prior to and at one month following their procedure and MRI prior to and within 48 hours following their procedure. Saliva samples were collected for genetic testing and demographics were recorded. Logistic regressions were used to search for associations.

RESULTS

34 patients were included (18 CAS, 16 CEA); all were male with a mean age of 68. The majority of patients exhibit hypertension (94%) and have a history of smoking (76%). Other co-morbidities included diabetes (47%), obesity (35%), and CAD (44%). Consistent with previous findings, CAS was associated with higher incidence of microemboli (p=.0005) and with susceptibility to memory decline (p=.0085). Negative univariate associations were found for 5-HTT (serotonin transporter) short alleles with memory decline (p=.016) and brain-derived neurotrophic factor (BDNF) polymorphism with incidence of microemboli (p=.018). After adjusting for apolipoprotein E (ApoE) risk alleles, incidence of microemboli trended with memory decline (p=.099).

CONCLUSIONS

Despite a small number of patients, our study showed that genetic polymorphisms such as 5-HTT, BDNF, and ApoE may provide additional insight on post-operative changes in cognition. Further investigation of these polymorphisms is warranted to understand and potentially prevent cognitive deterioration following carotid revascularization procedures.

Risk factors predictive of carotid artery stenting-associated subclinical microemboli

Subclinical microemboli documented on diffusion-weighted magnetic resonance imaging (DWI) are common following carotid artery stenting (CAS) procedures despite absence of neurological symptoms. This study was to evaluate risk factors predictive of microemboli in patients undergoing protected CAS with a distal embolic protection device. All CAS patients who received pre- and postprocedural magnetic resonance imaging (MRI) evaluations for carotid interventions at a single academic institution from July 2004 to December 2008 were examined. Microemboli were defined by new hyperintensities on postoperative DWI with corresponding decreased diffusion. Risk factors including patient demographics, medical comorbidities, clinical symptoms, lesion morphologies, and perioperative information were examined, and logistic regression analyses were utilized to determine predictors of CAS-related microemboli. A total of 204 patients underwent carotid interventions (76 CAS and 128 carotid endarterectomies) during the study period; 167 of them, including 67 CAS patients, received both preoperative and postoperative MRIs. Among those who underwent protected CAS, the incidence of microemboli was 46.3% despite a relative low incidence of associated neurological symptoms (2.9%). Univariate and multivariate regression analyses showed that date of procedure (odds ratio [OR] 30.6 and p = 0.019) and preoperative transient ischemic attack symptoms (OR 9.24 and p = 0.009) were independent predictors of developing postoperative changes on DWI in the ipsilateral hemisphere, and age >76 years was predictive of having new lesions on DWI in the contralateral hemisphere (OR 6.11 and p = 0.026). Our study underscores that certain risk factors are significantly associated with CAS-related microemboli and that physician experience and patient selection are essential in improving outcome of CAS procedures.

Prospective neurocognitive evaluation of patients undergoing carotid interventions

OBJECTIVE

Distal cerebral embolization is a known complication of carotid interventions. We prospectively investigated whether subclinical microembolization seen on postoperative magnetic resonance imaging (MRI) leads to cognitive deficits in patients undergoing carotid revascularization procedures.

METHODS

Patients undergoing carotid interventions and eligible for MRI scanning were recruited. Among 247 patients who received preoperative and postoperative MRI evaluations, 51 also completed neuropsychologic testing before and at 1 month after their procedure. Cognitive evaluation included the Rey Auditory Verbal Learning Test (RAVLT) for memory evaluation and the Mini-Mental State Examination (MMSE) for general cognitive impairment screening.

RESULTS

The 51 patients (all men), comprising 16 with carotid artery stenting (CAS) and 35 with carotid endarterectomy (CEA), were a mean age of 71 years (range, 54-89 years). Among them, 27 patients (53%) were symptomatic preoperatively, including 11 who had prior stroke and 16 who had prior preoperative transient ischemic attack symptoms. Most patients had significant medical comorbidities, including hypertension (96%), diabetes (31.3%), coronary artery disease (47%), and chronic obstructive pulmonary disease (15.7%). Two patients (4%) had prior ipsilateral CEA and eight had contralateral carotid occlusion (15.7%). Memory decline evident on RAVLT was identified in eight CAS patients and 13 CEA patients. Eleven patients had evidence of procedure-related microemboli. Although there was no significant difference in baseline cognitive function or memory change between the CEA and CAS cohorts, the CAS cohort had a significantly higher incidence of microembolic lesions. Multivariate regression analysis showed that procedure-related microembolization was associated with memory decline (P = .016) as evident by change in RAVLT. A history of neurologic symptoms was significantly associated with poor baseline cognitive function (MMSE; P = .03) and overall cognitive deterioration (change in MMSE; P = .026), as determined by Wilcoxon rank sum test and linear regression analysis, respectively.

CONCLUSIONS

Although CEA and CAS are effective in stroke prevention, with minimal neurologic complication, neurocognitive effects remain uncertain. Procedure-associated microembolization and pre-existing neurologic symptoms are associated with poor baseline cognitive function and memory decline after the procedures. Further comprehensive cognitive evaluation to determine the benefit of carotid interventions is warranted.

MR spectroscopy for assessment of memantine treatment in mild to moderate Alzheimer dementia

OBJECTIVES

Magnetic Resonance Spectroscopy (MRS) may provide a precise and reliable assessment of the extent and severity of neural tissue loss caused by various diseases. In particular, the N-Acetyl Aspartate (NAA) and Creatine (Cr) ratio has been found to be an indicator of the degree of neuronal loss in Alzheimer's disease (AD). Memantine is thought to benefit the AD brain by stabilizing the NMDA receptors on neurons in turn reducing excitotoxicity. Despite its effectiveness in treating moderate to severe AD, memantine has not had similar success in the treatment of mildly demented AD patients. The objective of this study was to test whether memantine would slow or prevent the loss of neurons in mild to moderate AD patients.

METHODS

A double-blind placebo-controlled study was designed to measure the effect of a year-long course of memantine in patients with a probable AD diagnosis with mild to moderate dementia. The primary outcome measure was stipulated to be change in MRS NAA/Cr ratio in inferior parietal cortex in memantine relative to the placebo treatment condition. The secondary outcome measures were changes in cognitive and function scale scores.

RESULTS

This pilot study failed to demonstrate a benefit of memantine on the primary outcome measure, the inferior parietal NAA/Cr ratio, or the secondary outcome measures.

CONCLUSIONS

More studies are needed to determine the effect of memantine on regions of the brain significantly affected by AD pathology.

Severe encephalopathy, lactic acidosis, vegetative instability and neuropathy with 5-Fluorouracil treatment - pyrimidine degradation defect or beriberi?

We present the case of a 19-year-old female with nasopharyngeal carcinoma, who received two courses of chemotherapy with 5-fluorouracil (5-FU) in combination with folic acid and cisplatin. Upon developing esophageal strictures in the course of her radiotherapy, she required total parenteral nutrition. In the course of therapy, the patient developed severe multisystem failure with encephalopathy, lactic acidosis, vegetative instability and neuropathy. The treatment with 5-FU can lead to severe toxicity due to enzyme deficiencies in the degradation of pyrimidines, but it can also lead to thiamine deficiency with the classic symptoms of beriberi. Beriberi is a rare disorder, usually attributed to malnutrition or alcoholism. 5-FU has been shown to induce thiamine depletion. Reduced food intake or total parenteral nutrition devoid of vitamin supplements may aggravate symptoms. We were unable to find a genetic cause for increased 5-FU toxicity in our patient, ruling out deficiencies of dihydropyrimidine dehydrogenase, dihydropyrimidinase or β-ureidopropionase and double-strand break repair deficits. We come to the conclusion that, even without any definable enzyme deficiency, treatment with 5-FU can lead to high toxicity due to thiamine deficiency if vitamin supplementation is not undertaken.

Imaging the Alzheimer brain

This supplement to the Journal of Alzheimer's Disease contains more than half of the chapters from The Handbook of Imaging the Alzheimer Brain, which was first presented at the International Conference on Alzheimer's Disease in Paris, in July, 2011.

While the Handbook contains 27 chapters that are modified articles from 2009, 2010, and 2011 issues of the Journal of Alzheimer's Disease, this supplement contains the 31 new chapters of that book and an introductory article drawn from the introductions to each section of the book.

The Handbook was designed to provide a multilevel overview of the full field of brain imaging related to Alzheimer's disease (AD). The Handbook, as well as this supplement, contains both reviews of the basic concepts of imaging, the latest developments in imaging, and various discussions and perspectives of the problems of the field and promising directions.

The Handbook was designed to be useful for students and clinicians interested in AD as well as scientists studying the brain and pathology related to AD.

Long-term outcome of loose seton for complex anal fistula: a two-centre study of patients with and without Crohn's disease

OBJECTIVE

Complex anal fistulas traverse a significant portion of the external sphincter muscle, making their treatment a surgical challenge. Several surgical options are used with conflicting results. The aim of this study was to analyse the results of permanent loose seton in the management of high anal fistulas in Crohn's disease (CD) patients and two-stage seton fistulotomy in patients without CD.

METHOD

We retrospectively reviewed the clinical records of 77 patients with complex anal fistula treated by loose seton over a 4-year period, in two medical centres. Recorded parameters included demographics, medical history, type of fistula, disease duration, previous surgery, morbidity, recurrence and mortality.

RESULTS

Sixty patients without CD underwent 107 fistula-related surgical procedures, and 17 CD patients underwent 29 procedures. Early postoperative complications were recorded in eight (10%) patients. Perioperative complications, mainly local sepsis or bleeding, were recorded in eight (10%) patients. Long-term complications were observed in nine non-CD and four CD patients. During a median follow-up period of 24 months, the recurrence rate was 40% in CD patients and 47% in patients without CD. Five patients (four non-CD patients and one CD patient) developed some degree of faecal incontinence.

CONCLUSION

The fistula recurrence rate following two-stage seton fistulotomy in non-CD patients was high. In CD patients the use of permanent loose seton is effective in controlling local sepsis in about half of patients and has low rates of subsequent incontinence.