Dona E.C. Locke

Longitudinal Modeling of Age-Related Memory Decline and the APOE ε4 Effect

BACKGROUND The APOE epsilon4 allele is associated with the risk of late-onset Alzheimers disease. The age at which memory decline diverges among persons who are homozygous for the APOE epsilon4 allele, those who are heterozygous for the allele, and noncarriers is unknown. METHODS Using local advertisements, we recruited cognitively normal subjects between the ages of 21 and 97 years, who were grouped according to their APOE epsilon4 status. We then followed the subjects with longitudinal neuropsychological testing. Anyone in whom mild cognitive impairment or dementia developed during follow-up was excluded. We compared the rates of decline in predetermined cognitive measures between carriers and noncarriers of the APOE epsilon4 allele, using a mixed model for longitudinal change with age. RESULTS We analyzed 815 subjects: 317 APOE epsilon4 carriers (79 who were homozygous for the APOE epsilon4 allele and 238 who were heterozygous) and 498 noncarriers. Carriers, as compared with noncarriers, were generally younger (mean age, 58.0 vs. 61.4 years; P<0.001) and were followed for a longer period (5.3 vs. 4.7 years, P=0.01), with an equivalent duration of formal education (15.4 years) and proportion of women (69%). Longitudinal decline in memory in carriers began before the age of 60 years and showed greater acceleration than in noncarriers (P=0.03), with a possible allele-dose effect (P=0.008). We observed similar although weaker effects on measures of visuospatial awareness and general mental status. CONCLUSIONS Age-related memory decline in APOE epsilon4 carriers diverges from that of noncarriers before the age of 60 years, despite ongoing normal clinical status.

Subjective Cognitive Decline: Self and Informant Comparisons

It is unclear whether self‐ or informant‐based subjective cognition better distinguishes emotional factors from early‐stage Alzheimers disease (AD).

Treatment of Depression in Patients with Epilepsy

Opinion statementIn this article, we review the current best evidence for the treatment of depression in patients with epilepsy. Depression is a common epilepsy comorbidity, but it is often unrecognized. The most important step in appropriately managing mood disorders in this population is making the diagnosis. Clinical vigilance and routine use of a validated screening tool can improve detection and quality of care. As is increasingly the case for the general population, persons with epilepsy are often interested in exploring alternative therapies for chronic conditions, including depression. Unfortunately, the benefit of complementary and alternative therapies for depression currently is largely unproven for persons with a seizure history, although an early study of exercise for mild depression has shown some benefit. Concerns about drug interactions, side effects, and expense may be barriers to the prescription of antidepressant medications for people requiring chronic antiepileptic drug (AED) therapy. For this reason, use of an AED with mood-stabilizing properties has appeal and may be appropriate for selected individuals with mild depressive symptoms. Undue fear of lowering seizure threshold should not preclude the prescription of an antidepressant medication, as the perceived risks are often overestimated and rarely outweigh the risk of leaving depression untreated. At present, the best evidence for efficacy and safety support the use of citalopram, sertraline, or mirtazapine as initial pharmacotherapy, whereas bupropion should be avoided. Start low, go slow, and use the lowest effective dose. Cognitive behavioral therapy is a valuable adjunct to antidepressant therapy in this population. For people with refractory partial epilepsy and refractory depression, vagus nerve stimulation has some appeal, in that it may be beneficial for both conditions, but the efficacy of vagus nerve stimulation in improving mood in patients with epilepsy remains unclear.

Cerebrovascular risk factors and preclinical memory decline in healthy APOE ε4 homozygotes

Objective: To characterize the effects of cerebrovascular (CV) risk factors on preclinical memory decline in cognitively normal individuals at 3 levels of genetic risk for Alzheimer disease (AD) based on APOE genotype. Methods: We performed longitudinal neuropsychological testing on an APOE ε4 enriched cohort, ages 21–97. The long-term memory (LTM) score of the Auditory Verbal Learning Test (AVLT) was the primary outcome measure. Any of 4 CV risk factors (CVany), including hypercholesterolemia (CHOL), prior cigarette use (CIG), diabetes mellitus (DM), and hypertension (HTN), was treated as a dichotomized variable. We estimated the longitudinal effect of age using statistical models that simultaneously modeled the cross-sectional and longitudinal effects of age on AVLT LTM by APOE genotype, CVany, and the interaction between the two. Results: A total of 74 APOE ε4 homozygotes (HMZ), 239 ε4 heterozygotes (HTZ), and 494 ε4 noncarriers were included. APOE ε4 carrier status showed a significant quadratic effect with age-related LTM decline in all models as previously reported. CVany was associated with further longitudinal AVLT LTM decline in APOE ε4 carriers (p = 0.02), but had no effect in noncarriers. When ε4 HTZ and HMZ were considered separately, there was a striking effect in HMZ (p < 0.001) but not in HTZ. In exploratory analyses, significant deleterious effects were found for CIG (p = 0.001), DM (p = 0.03), and HTN (p = 0.05) in APOE ε4 carriers only that remained significant only for CIG after correction for multiple comparisons. Conclusion: CV risk factors influence age-related memory decline in APOE ε4 HMZ.

Longitudinal modeling of frontal cognition in APOE ε4 homozygotes, heterozygotes, and noncarriers

Background: Fibrillar amyloid deposition preferentially affects the frontal lobes, temporal pole/neocortex, and posterior cingulate by age 65 years in APOE ε4 carriers prior to the diagnosis of mild cognitive impairment (MCI) and Alzheimer disease (AD), but is it impairing frontally mediated neuropsychological performance? Methods: A total of 71 ε4 homozygotes (HMZ), 194 ε4 heterozygotes (HTZ), and 356 ε4 noncarriers (NC) who did not differ significantly in mean age (56.6 years), years of education (15.6), gender (70% women), or follow-up duration (6.3 years) had neuropsychological testing every 2 years including the Auditory Verbal Learning Test (AVLT) and frontal/executive tasks sensitive to psychomotor speed, working memory, problem solving, and activity. A subset also received the Iowa Gambling Task (IGT). Findings were then tested in a clinical sample of 27 patients with incident MCI and AD. Results: APOE ε4 carriers had greater acceleration of decline (quadratic effect) than NC on the AVLT (p = 0.04) but not on any frontal test. APOE ε4 HMZ had greater velocity of decline (linear effects) than NC on all mental arithmetic tests: paced auditory serial attention task (PASAT) 3 second (p = 0.01) and 2 second (p = 0.004) versions; and Wechsler Adult Intelligence Scale–Revised arithmetic (p = 0.048). IGT performance did not differ between 12 ε4 HMZ, 27 ε4 HTZ, and 44 NC. Among 27 patients with incident MCI and AD, the PASAT showed progressive decline preceding diagnosis in 50%. Conclusions: No frontal cognitive effects were as robust as memory decline. APOE ε4 HMZ declined more quickly than NC on mental arithmetic tests related to frontal lobe–mediated working memory ability.

Comparison of Psychogenic Movement Disorders and Psychogenic Nonepileptic Seizures: Is Phenotype Clinically Important?

BACKGROUND Psychogenic non-epileptic seizures (PNES) and psychogenic movement disorders (PMDs) are common in neurology practice, yet it is not established whether clinically relevant differences between these two groups exist. METHODS In this retrospective chart review 172 patients were identified (PNES n = 116, PMD n = 56). RESULTS The whole group was characterized by female gender (82%), abuse history (45%), chronic pain (70%), depression (42%), subjective fatigue (47%), subjective cognitive complaints (55%), and referral for psychiatric evaluation (54%). Statistically significant differences (P <. 01) were found for age, education, frequency of symptoms, altered consciousness, developmental abuse, and coexisting anxiety. Clinical practice also differed for the two groups in history-taking and referrals for neuropsychological testing and/or psychiatric evaluation. CONCLUSIONS This retrospective study revealed more similarities than differences suggesting these are manifestations of the same psychopathology, with age and co-morbid anxiety potentially being important factors in predicting the symptomatic presentation. Prospective studies are needed to confirm our results. Future studies focusing more globally on somatoform disorders, rather than each phenotypic presentation, are likely needed to improve clinical care and outcomes.

The neuropsychology of normal aging and preclinical Alzheimer's disease.

A National Institute on Aging–sponsored work group on preclinical Alzheimers disease (AD) articulated the need to characterize cognitive differences between normal aging and preclinical AD.

Confirming psychogenic nonepileptic seizures with video-EEG: Sex matters

The influence of gender on psychogenic nonepileptic seizures (PNES) diagnosis was examined retrospectively in 439 subjects undergoing video-EEG (vEEG) for spell classification, of whom 142 women and 42 men had confirmed PNES. The epileptologists predicted diagnosis was correct in 72% overall. Confirmed epilepsy was correctly predicted in 94% men and 88% women. In contrast, confirmed PNES was accurately predicted in 86% women versus 61% men (p=0.003). Sex-based differences in likelihood of an indeterminate admission were not observed for predicted epilepsy or physiologic events, but were for predicted PNES (39% men, 12% women, p=0.0002). More frequent failure to record spells in men than women with predicted PNES was not explained by spell frequency, duration of monitoring, age, medication use, or personality profile. PNES are not only less common in men, but also more challenging to recognize in the clinic, and even when suspected more difficult to confirm with vEEG.

The Minnesota Multiphasic Personality Inventory-2-Restructured Form in the epilepsy monitoring unit

The Minnesota Multiphasic Personality Inventory-2-Restructured Form (MMPI-2-RF) is a restructuring of the MMPI-2 that has improved the psychometric characteristics of the test. The primary aim of this study was to provide diagnostic utility data on the MMPI-2-RF in an epilepsy monitoring unit population (N=429). Mean comparisons revealed group differences on Validity Scales Fs and FBS-r; Restructured Clinical Scales RC1 and RC3; and Somatic Scales MLS, GIC, HPC, and NUC. Diagnostic utility data are provided for those scales with the largest effect sizes: RC1, FBS-r, and NUC. On RC1, sensitivity was 76% and specificity was 60%, similar to values found when applying published decision rules to the MMPI-2. RC1 explains unique variance in diagnosis beyond that explained by demographic or medical history risk factors. We provide likelihood ratios for scores on RC1, FBS-r, and NUC that can be used by the clinician to calculate posttest odds and probability of nonepileptic seizures using the base rate of nonepileptic seizures in his/her population.

Comparing neuropsychological tasks to optimize brief cognitive batteries for brain tumor clinical trials

Neuropsychological tests are increasingly being used as outcome measures in clinical trials of brain tumor therapies. This study informs development of brief neurocognitive batteries for clinical trials by identifying cognitive tasks that detect effects on a group level in a mixed brain tumor population. This is a retrospective study of brain tumor patients who completed a standardized battery sampling multiple cognitive domains using twelve subtests with widely-used task formats (the Repeatable Battery for the Assessment of Neuropsychological Status). Sixty-eight patients with brain tumors were studied (60% high-grade glioma). Forty patients (58.8%) were impaired (>2 standard deviations below published means) on at least one subtest. A combination of four subtests (Figure Copy, Coding, List Recognition, and Story Recall) captured 90% of the impaired subgroup. These results suggest visuoconstruction, processing speed, and verbal memory measures may be the most important domains to assess when evaluating cognitive change in brain tumor clinical trials.