Sex significantly predicts medial temporal volume when controlling for the influence of ApoE4 biomarker and demographic variables: A cross-ethnic comparison

OBJECTIVE

To explore the relationship between age, education, sex, and ApoE4 (+) status to brain volume among a cohort with amnestic mild cognitive impairment (aMCI).

METHOD

One hundred and twenty-three participants were stratified into Hispanic (n = 75) and White non-Hispanic (WNH, N = 48). Multiple linear regression analyses were conducted with age, education, sex, and ApoE4 status as predictor variables and left and right combined MRI volumes of the hippocampus, parahippocampus, and entorhinal cortex as dependent variables. Variations in head sizes were corrected by normalization with a total intracranial volume measurement.

RESULTS

Bonferroni-corrected results indicated that when controlling for ApoE4 status, education, and age, sex was a significant predictor of hippocampal volume among the Hispanic group (β = .000464, R2 = .196, p < .01) and the WNH group (β = .000455, R2 = .195, p < .05). Education (β = .000028, R2 = .168, p < .01) and sex (β = .000261, R2 = .168, p < .01) were significant predictors of parahippocampal volume among the Hispanic MCI group when controlling for the effects of ApoE4 status and age. One-way ANCOVAs comparing hippocampal and parahippocampal volume between males and females within groups revealed that females had significantly larger hippocampal volumes (p < .05). Hispanic females had significantly larger hippocampal (p < .001) and parahippocampal (p < .05) volume compared to males. No sex differences in parahippocampal volume were noted among WNHs.

CONCLUSIONS

Biological sex, rather than ApoE4 status, was a greater predictor of hippocampal volume among Hispanic and WNH females. These findings add to the mixed literature on sex differences in dementia research and highlight continued emphasis on ethnic populations to elucidate on neurodegenerative disparities.

A - 41 The Association between Education, Literacy, and Performance on the Loewenstein-Acevedo Scale for Semantic Interference and Learning (LASSI-L) in African American (AA) Older Adults

OBJECTIVE

The LASSI-L, a cognitive challenge test, has been found to be highly discriminative between AA elders with amnestic mild cognitive impairment (aMCI) versus cognitively unimpaired (CU) counterparts. Given potentially lower levels of formal education and literacy in some AA groups, it is important to determine whether such factors might adversely influence performance.

METHODS

41 AA adults (53.7% males), with a mean age of 63.9 (SD = 5.1 years, range = 54-83) were deemed to be CU after a clinical interview resulted in a CDR = 0, and scores from a neuropsychological battery were deemed normal by experienced neuropsychologists. The LASSI-L was not used in diagnosis.

RESULTS

Level of educational attainment was 13.3 (SD = 2.3 years: range = 9-20). Level of reading literacy, as assessed by the WRAT-4, yielded an average grade equivalent (GE) of 9.6 (SD = 3.5 range = 2.0-12.9); substantially lower than reported educational attainment. Association between formal education and literacy was 0.52 which accounted for 27% of the shared variance. There were no statistically significant correlations between formal education or WRAT-4 scores in any LASSI-L variables, including initial learning (Cued Recall 2 List A), proactive semantic interference (PSI) (Cued List B1-List B2), failure to recover from PSI, or semantic intrusion errors.

CONCLUSIONS

Performance on the LASSI-L among AA-CU did not suggest biases associated with formal education or word literacy, making it a promising tool for research. Many neuropsychological measures do not have acceptable diagnostic accuracy when used among individuals that are racially diverse, have lower-education levels, and lower socioeconomic status. This is important in consideration for potential use of LASSI-L in clinical settings.

A-144 A Cross-Validation Study of Memory and Non-Memory Neuropsychology Measures with Spanish-Speaking Older Adults

Objective: To evaluate the clinical utility of the Spanish versions of memory vs. non-memory instruments in a Spanish-speaking sample; specifically, the comparative performance for the English versions in amnestic MCI (aMCI) and cognitively unimpaired (CU) elders.

Method: 255 Non-Hispanic English speakers (NH-ES; 157 CU; 98 aMCI) and 201 Hispanic Spanish speakers (H-SS; 103 CU; 98 aMCI) were classified using the Clinical Dementia Rating Scale and a validated culturally fair test. ANCOVA procedures were used to test for differences between four groups across languages adjusting for age, sex, and education for memory (e.g., Hopkins Verbal Learning Test-HVLT-R; NACC Logical Memory) and non-memory measures (e.g., Trail-Making Test A-B, Category and Phonemic Fluency).

Results: For memory measures, CU older adults were statistically differentiated from aMCI counterparts regardless of language. No significant differences between H-SS aMCI and NH-ES aMCI groups’ on HVLT-R and NACC story passages immediate/delayed conditions. No significant differences found between H-SS CU and NH-ES CU on memory indices. Conversely, Bonferroni corrected means (p&lt;.05) revealed that even after adjustment for demographic covariates, ES CU outperformed H-SS CU counterparts on Trails A-B, and Category/Phonemic Fluencies. NH-ES aMCI groups scored better than H-SS aMCI on Trails B.

Conclusions: Results indicate that memory measures experience less bias when employed among different linguistic/cultural groups regardless of cognitive status. In contrast, CU H-SS groups scored lower on all non-memory measures. Factors that lead to potential bias, particularly among CU are discussed. Trails-B evidenced bias for both Hispanic CU and MCI, making this a measure that requires the judicious use of appropriate norms.

Phase 1 Safety Trial of Autologous Human Schwann Cell Transplantation in Chronic Spinal Cord Injury

A phase 1 open-label, non-randomized clinical trial was conducted to determine feasibility and safety of autologous human Schwann cell (ahSC) transplantation accompanied by rehabilitation in participants with chronic spinal cord injury (SCI). Magnetic resonance imaging (MRI) was used to screen eligible participants to estimate an individualized volume of cell suspension to be implanted. The trial incorporated standardized multi-modal rehabilitation before and after cell delivery. Participants underwent sural nerve harvest, and ahSCs were isolated and propagated in culture. The dose of culture-expanded ahSCs injected into the chronic spinal cord lesion of each individual followed a cavity-filling volume approach. Primary outcome measures for safety and trend-toward efficacy were assessed. Two participants with American Spinal Injury Association Impairment Scale (AIS) A and two participants with incomplete chronic SCI (AIS B, C) were each enrolled in cervical and thoracic SCI cohorts (n = 8 total). All participants completed the study per protocol, and no serious adverse events related to sural nerve harvest or ahSC transplantation were reported. Urinary tract infections and skin abrasions were the most common adverse events reported. One participant experienced a 4-point improvement in motor function, a 6-point improvement in sensory function, and a 1-level improvement in neurological level of injury. Follow-up MRI in the cervical (6 months) and thoracic (24 months) cohorts revealed a reduction in cyst volume after transplantation with reduced effect over time. This phase 1 trial demonstrated the feasibility and safety of ahSC transplantation combined with a multi-modal rehabilitation protocol for participants with chronic SCI.

Safety of Autologous Human Schwann Cell Transplantation in Subacute Thoracic Spinal Cord Injury

The rationale for implantation of autologous human Schwann cells (SCs) in persons with subacute spinal cord injury (SCI) is based on evidence that transplanted SCs are neuroprotective, support local axonal plasticity, and are capable of myelinating axons. A Phase I clinical trial was conducted to evaluate the safety of autologous human SC transplantation into the injury epicenter of six subjects with subacute SCI. The trial was an open-label, unblinded, non-randomized, non-placebo controlled study with a dose escalation design and standard medical rehabilitation. Participants were paraplegics with neurologically complete, trauma-induced spinal lesions. Autologous SCs were cultured in vitro from a sural nerve harvested from each participant and injected into the epicenter of the spinal lesion. Outcome measures for safety were protocol compliance, feasibility, adverse events, stability of neurological level, absence of detectable mass lesion, and the emergence of clinically significant neuropathic pain or muscle spasticity no greater than expected for a natural course cohort. One year post-transplantation, there were no surgical, medical, or neurological complications to indicate that the timing or procedure for the cell transplantation was unsafe. There were no adverse events or serious adverse events related to the cell therapy. There was no evidence of additional spinal cord damage, mass lesion, or syrinx formation. We conclude that it is feasible to identify eligible candidates, appropriately obtain informed consent, perform a peripheral nerve harvest to obtain SCs within 5-30 days of injury, and perform an intra-spinal transplantation of highly purified autologous SCs within 4-7 weeks of injury.

Performance-based and Observational Assessments in Clinical Trials Across the Alzheimer's Disease Spectrum

Assessment of the earlier stages of Alzheimer's disease requires different strategies than those previously developed for fully syndromal Alzheimer's disease . This challenge is further magnified in very early stages, where symptomatology may be minimal and functional deficits very subtle to absent. This paper reviews strategies for performance-based assessment of the early stages of Alzheimer's disease, including assessments of cognition, functional capacity, and social cognition. Meetings with an International Society for CNS Clinical Trials and Methodology working group served as the basis for this paper and its companion. The current state of the art of detection and staging-oriented assessments is presented, and information is provided regarding the practicality and validity of these approaches, with a special focus on their usefulness in clinical trials for new medication development.

Outcomes Assessment in Clinical Trials of Alzheimer's Disease and its Precursors: Readying for Short-term and Long-term Clinical Trial Needs

An evolving paradigm shift in the diagnostic conceptualization of Alzheimer's disease is reflected in its recently updated diagnostic criteria from the National Institute on Aging-Alzheimer's Association and the International Working Group. Additionally, it is reflected in the increased focus in this field on conducting prevention trials in addition to improving cognition and function in people with dementia. These developments are making key contributions towards defining new regulatory thinking around Alzheimer's disease treatment earlier in the disease continuum. As a result, the field as a whole is now concentrated on exploring the next-generation of cognitive and functional outcome measures that will support clinical trials focused on treating the slow slide into cognitive and functional impairment. With this backdrop, the International Society for CNS Clinical Trials and Methodology convened semi-annual working group meetings which began in spring of 2012 to address methodological issues in this area. This report presents the most critical issues around primary outcome assessments in Alzheimer's disease clinical trials, and summarizes the presentations, discussions, and recommendations of those meetings, within the context of the evolving landscape of Alzheimer's disease clinical trials.

Proactive Semantic Interference is Associated with Total and Regional Abnormal Amyloid Load in Non-Demented Community-Dwelling Elders: A Preliminary Study

OBJECTIVE

To evaluate the relationship between susceptibility to proactive semantic interference (PSI) and retroactive semantic interference (RSI) and brain amyloid load in non-demented elders.

METHODS

27 participants (11 cognitively normal [CN] with subjective memory complaints, 8 CN without memory complaints, and 8 with mild cognitive impairment [MCI]) underwent complete neurological and neuropsychological evaluations. Participants also received the Semantic Interference Test (SIT) and AV-45 amyloid PET imaging.

RESULTS

High levels of association were present between total amyloid load, regional amyloid levels, and the PSI measure (in the entire sample and a subsample excluding MCI subjects). RSI and other memory measures showed much weaker associations or no associations with total and regional amyloid load. No associations between amyloid levels and non-memory performance were observed.

CONCLUSIONS

In non-demented individuals, vulnerability to PSI was highly associated with total and regional beta-amyloid load and may be an early cognitive marker of brain pathology.

The utility of age-specific cut-offs for visual rating of medial temporal atrophy in classifying Alzheimer's disease, MCI and cognitively normal elderly subjects

Background: New research criteria for diagnosing Alzheimer's disease (AD) in the mild cognitive impairment stage (MCI-AD) incorporate biomarkers to assign a level of certainty to the diagnosis. Structural MRI is widely available but greatly under-utilized for assessing atrophy of structures affected in early AD, such as the hippocampus (HP), because the quantification of HP volumes (HP-v) requires special expertise, and normative values have not been established.

Methods: Elderly subjects (n =273) from the Florida ADRC were classified as having no cognitive impairment (cognitively normal, CN), amnestic mild cognitive impairment (aMCI) or AD. Volumes for the hippocampus (HP-v) were measured on structural MRI scans. A validated visual rating system for measuring medial temporal atrophy (VRS-MTA), including hippocampal, entorhinal cortex and perirhinal cortex atrophy was employed. The participants were subdivided into younger (less than or equal to 75 years of age) and older (greater than 75 years of age) subgroups.

Results: Volumetric and VRS-MTA measures were equivalent in predicting classification of CN vs. aMCI for older (area under the receiver operator curves [aROC]: 0.652 vs. 0.723) and younger subjects (aROC: 0.764 vs. 0.736). However, for younger AD subjects, aROC values were significantly higher for VRS-MTA measures (0.920) than for volumetric measures (0.847). Relative to HP-v, VRS-MTA score was significantly more correlated to impairment on a range of memory tests and was more associated with progression of aMCI to AD than HP-v.

Conclusion: Structural MRI with VRS-MTA assessment can serve as a biomarker for supporting the diagnosis of MCI-AD. Age-adjusted VRS-MTA scores are at least as effective as HP-v for distinguishing aMCI and AD from CN and for predicting progression from aMCI to AD. VRS-MTA is convenient for use in the clinic as well as for clinical trials and can readily be incorporated into a standardized radiological report.

Randomised trial of low-dose amiodarone in severe congestive heart failure. Grupo de Estudio de la Sobrevida en la Insuficiencia Cardiaca en Argentina (GESICA)

In severe heart failure many deaths are sudden and are presumed to be due to ventricular arrhythmias. The GESICA trial evaluated the effect of low-dose amiodarone on two-year mortality in patients with severe heart failure. Our prospective multicentre trial included 516 patients on optimal standard treatment for heart failure. Patients were randomised to 300 mg/day amiodarone (260) or to standard treatment (256). Intention-to-treat analysis showed 87 deaths in the amiodarone group (33.5%) compared with 106 in the control group (41.4%) (risk reduction 28%; 95% CI 4%-45%; log rank test p = 0.024). There were reductions in both sudden death (risk reduction 27%; p = 0.16) and death due to progressive heart failure (risk reduction 23%; p = 0.16). Fewer patients in the amiodarone group died or were admitted to hospital due to worsening heart failure (119 versus 149 in the control group; risk reduction 31%; 95% CI 13-46%; p = 0.0024). The decrease in mortality and hospital admission was present in all subgroups examined and independent of the presence of non-sustained ventricular tachycardia. Side-effects were reported in 17 patients (6.1%); amiodarone was withdrawn in 12. Low-dose amiodarone proved to be an effective and reliable treatment, reducing mortality and hospital admission in patients with severe heart failure independently of the presence of complex ventricular arrhythmias.

Positive inotropic effects mediated by alpha 1 adrenoceptors in intact human subjects

The role of alpha 1-adrenergic receptors (adrenoceptors) on cardiac contractility was investigated in human subjects. The effect of methoxamine, a selective alpha-adrenoceptor agonist, and angiotensin II, on cardiac contractility was determined by means of noninvasive assessment of the slope of the end-systolic pressure (ESP)/end-systolic dimension (ESD) relationship. The slope (m) of this ratio was significantly higher with methoxamine (17.0; SD = 9.0 mm Hg/mm) than with angiotensin II (4.8; SD = 1.9 mm Hg/mm) (p less than 0.05). Slopes with methoxamine were higher when heart rates (HRs) were reflexly reduced, and were significantly diminished when reflex bradycardia was prevented by atropine (p less than 0.05) or atrial pacing (p less than 0.01). Previous treatment with propranolol did not modify m values with methoxamine (m = 15.5; SD = 4.4 mm Hg/mm). Phentolamine, given at peak methoxamine effect, did not consistently modify m values, resulting in an average slope not significantly different from that obtained with methoxamine alone. However, the addition of phentolamine did not cause an increase in ESDs at each level of ESP with respect to methoxamine. In the same subjects, infusion of phentolamine after angiotensin did not modify ESDs at comparable ESP levels. These findings suggest the existence of a positive inotropic effect mediated by alpha 1 adrenoceptors in the intact human heart.

The cardiovascular effects of acute hypoxemia as a diagnostic aid

Acute hypoxemia produces opposite effects on the pulmonary and systemic vascular resistance. To assess the influence of acute hypoxemia on cardiac murmurs, 36 patients with a single valvular or congenital heart lesion were studied. As expected from these hemodynamic effects, right-sided regurgitant type murmurs increased in intensity during acute hypoxemia, while stenotic type murmurs were reduced. In contrast, left-sided murmurs remained constant or changed in opposite direction to their equivalent type from the right side. Additionally, acute hypoxemia produced a marked reduction of the murmurs due to left-to-right shunts and allowed an adequate differentiation of the murmurs due to ventricular septal defect from those due to mitral incompetence.

Effect of acute administration of propranolol on ventricular function in hypertrophic obstructive cardiomyopathy measured by non-invasive techniques

Seventeen patients with hypertropic obstructive cardiomyopathy, were studied using non-invasive techniques before and after the intravenous injection of 5 mg propranolol. The folloeing were analysed: left ventricular ejection time index, derived from the carotid pulse and heart rate; the isovolumic relaxation time, derived from the apex cardiogram and phonocardiogram; the diastolic closure rate of the mirtal valve; and the left ventricular diameters, systolic and diastolic, both measured by echocardiography. Propranolol produced shortening of the isovolumic relaxation time, increase in both the diastolic closure rate of the mitral valve and left ventricular systolic and left ventricular diastolic diameters. These results show that propranolol increases the rate of filling and the volume of the left ventricle, indicating that an improvement in distensibility is produced by beta-adrenergic blockade.

The use of echocardiography to measure isometric contraction time

The current methods for estimating isometric contraction time were discussed. Ultrasonically derived isometric contraction time, using external carotid pulse tracing, phonocardiogram, and the B-point of the mitral echogram was also measured. Recordings were performed in 10 normal subjects, and 15 patients. Hypertrophic cardiomyopathy (5), congestive cardiomyopathy (6), and ischemic heart disease (4). In 11 patients, the results were correlated with the internal isometric contraction time. The ultrasound isometric contraction time showed good correlation with the internal isometric contraction time (r equals 0.92, P less than 0.01). The external isometric contraction time showed less correlation with the internal isometric contraction time and was significantly shorter (P less than 0.01). The ultrasound isometric contraction time showed a superior discriminating value to the external isometric contraction time for differentiation the normal subjects from the patients' group.