Age-specific population frequencies of cerebral β-amyloidosis and neurodegeneration among people with normal cognitive function aged 50—89 years: a cross-sectional study

Background

As preclinical Alzheimer's disease becomes a target for therapeutic intervention, the overlap between imaging abnormalities associated with typical ageing and those associated with Alzheimer's disease needs to be recognised. We aimed to characterise how typical ageing and preclinical Alzheimer's disease overlap in terms of β-amyloidosis and neurodegeneration.

Methods

We measured age-specific frequencies of amyloidosis and neurodegeneration in individuals with normal cognitive function aged 50—89 years. Potential participants were randomly selected from the Olmsted County (MN, USA) population-based study of cognitive ageing and invited to participate in cognitive and imaging assessments. To be eligible for inclusion, individuals must have been judged clinically to have no cognitive impairment and have undergone amyloid PET, 18F-fluorodeoxyglucose (18F-FDG) PET, and MRI. Imaging results were obtained from March 28, 2006, to Dec 3, 2013. Amyloid status (positive [A+] or negative [A—]) was determined by amyloid PET with 11C Pittsburgh compound B. Neurodegeneration status (positive [N+] or negative [N—]) was determined by an Alzheimer's disease signature 18F-FDG PET or hippocampal volume on MRI. We determined age-specific frequencies of the four groups (amyloid negative and neurodegeneration negative [A—N—], amyloid positive and neurodegeneration negative [A+N—], amyloid negative and neurodegeneration positive [A—N+], or amyloid positive and neurodegeneration positive [A+N+]) cross-sectionally using multinomial regression models. We also investigated associations of group frequencies with APOE ɛ4 status (assessed with DNA extracted from blood) and sex by including these covariates in the multinomial models.

Findings

The study population consisted of 985 eligible participants. The population frequency of A—N— was 100% (n=985) at age 50 years and fell to 17% (95% CI 11—24) by age 89 years. The frequency of A+N— increased to 28% (24—32) at age 74 years, then decreased to 17% (11—25) by age 89 years. The frequency of A—N+ increased from age 60 years, reaching 24% (16—34) by age 89 years. The frequency of A+N+ increased from age 65 years, reaching 42% (31—52) by age 89 years. The results from our multinomial models suggest that A+N— and A+N+ were more frequent in APOE ɛ4 carriers than in non-carriers and that A+N+ was more, and A+N— less frequent in men than in women.

Interpretation

Accumulation of amyloid and neurodegeneration are nearly inevitable by old age, but many people are able to maintain normal cognitive function despite these imaging abnormalities. Changes in the frequency of amyloidosis and neurodegeneration with age, which seem to be modified by APOE ɛ4 and sex, suggest that pathophysiological sequences might differ between individuals.

Lancet Neurology 2014

Oral teriflunomide for patients with a first clinical episode suggestive of multiple sclerosis (TOPIC): a randomised, double-blind, placebo-controlled, phase 3 trial

Background

Teriflunomide is a once-daily oral immunomodulator approved for the treatment of relapsing-remitting multiple sclerosis. We aimed to assess the efficacy and safety of teriflunomide in patients with a first clinical episode suggestive of multiple sclerosis.

Methods

In this randomised, double-blind, placebo-controlled, parallel-group study, we enrolled patients aged 18—55 years with clinically isolated syndrome (defined as a neurological event consistent with demyelination, starting within 90 days of randomisation, and two or more T2-weighted MRI lesions ≥3 mm in diameter) from 112 centres (mostly hospitals) in 20 countries. Participants were randomly assigned (1:1:1) in a double-blind manner (by an interactive voice response system) to once-daily oral teriflunomide 14 mg, teriflunomide 7 mg, or placebo, for up to 108 weeks. Patients, staff administering the interventions, and outcome assessors were masked to treatment assignment. The primary endpoint was time to relapse (a new neurological abnormality separated by ≥30 days from a preceding clinical event, present for ≥24 h in the absence of fever or known infection), which defined conversion to clinically definite multiple sclerosis. The key secondary endpoint was time to relapse or new gadolinium-enhancing or T2 lesions on MRI, whichever occurred first. The primary outcome was analysed for the modified intention-to-treat population; safety analyses included all randomised patients who were exposed to the study drug, as treated. This trial is registered withClinicalTrials.gov, number NCT00622700.

Findings

Between Feb 13, 2008, and Aug 22, 2012, 618 patients were enrolled and randomly assigned to teriflunomide 14 mg (n=216), teriflunomide 7 mg (n=205), or placebo (n=197). Two patients in each of the teriflunomide groups did not receive the study drug, so the modified intention-to-treat population comprised 214 patients in the teriflunomide 14 mg group, 203 in the teriflunomide 7 mg group, and 197 in the placebo group. Compared with placebo, teriflunomide significantly reduced the risk of relapse defining clinically definite multiple sclerosis at the 14 mg dose (hazard ratio [HR] 0·574 [95% CI 0·379—0·869]; p=0·0087) and at the 7 mg dose (0·628 [0·416—0·949]; p=0·0271). Teriflunomide reduced the risk of relapse or a new MRI lesion compared with placebo at the 14 mg dose (HR 0·651 [95% CI 0·515—0·822]; p=0·0003) and at the 7 mg dose (0·686 [0·540—0·871]; p=0·0020). During the study, six patients who were randomly assigned to placebo accidently also received teriflunomide at some point: four received 7 mg and two received 14 mg. Therefore, the safety population comprised 216 patients on teriflunomide 14 mg, 207 on teriflunomide 7 mg, and 191 on placebo. Adverse events that occurred in at least 10% of patients in either teriflunomide group and with an incidence that was at least 2% higher than that with placebo were increased alanine aminotransferase (40 [19%] of 216 patients in the 14 mg group, 36 [17%] of 207 in the 7 mg group vs 27 [14%] of 191 in the placebo group), hair thinning (25 [12%] and 12 [6%] vs 15 [8%]), diarrhoea (23 [11%] and 28 [14%] vs 12 [6%]), paraesthesia (22 [10%] and 11 [5%] vs 10 [5%]), and upper respiratory tract infection (20 [9%] and 23 [11%] vs 14 [7%]). The most common serious adverse event was an increase in alanine aminotransferase (four [2%] and five [2%] vs three [2%]).

Interpretation

TOPIC is to our knowledge the first study to report benefits of an available oral disease-modifying therapy in patients with early multiple sclerosis. These results extend the stages of multiple sclerosis in which teriflunomide shows a beneficial effect.

Lancet Neurology 014

APOE, MAPT, and SNCA Genes and Cognitive Performance in Parkinson Disease

Importance  Cognitive impairment is a common and disabling problem in Parkinson disease (PD) that is not well understood and is difficult to treat. Identification of genetic variants that influence the rate of cognitive decline or pattern of early cognitive deficits in PD might provide a clearer understanding of the etiopathogenesis of this important nonmotor feature.

Objective  To determine whether common variation in the APOE, MAPT, and SNCA genes is associated with cognitive performance in patients with PD.

Design, Setting, and Participants  We studied 1079 PD patients from 6 academic centers in the United States who underwent assessments of memory (Hopkins Verbal Learning Test–Revised [HVLT-R]), attention and executive function (Letter-Number Sequencing Test and Trail Making Test), language processing (semantic and phonemic verbal fluency tests), visuospatial skills (Benton Judgment of Line Orientation test), and global cognitive function (Montreal Cognitive Assessment). Participants underwent genotyping for the APOE ε2/ε3/ε4 alleles, MAPT H1/H2 haplotypes, andSNCA rs356219. We used linear regression to test for association between genotype and baseline cognitive performance with adjustment for age, sex, years of education, disease duration, and site. We used a Bonferroni correction to adjust for the 9 comparisons that were performed for each gene.

Main Outcomes and Measures  Nine variables derived from 7 psychometric tests.

Results  The APOE ε4 allele was associated with lower performance on the HVLT-R Total Recall (P = 6.7 × 10−6; corrected P [Pc] = 6.0 × 10−5), Delayed Recall (P = .001; Pc = .009), and Recognition Discrimination Index (P = .004; Pc = .04); a semantic verbal fluency test (P = .002; Pc = .02); the Letter-Number Sequencing Test (P = 1 × 10−5; Pc = 9 × 10−5); and Trail Making Test B minus Trail Making Test A (P = .002; Pc = .02). In a subset of 645 patients without dementia, the APOE ε4 allele was associated with lower scores on the HVLT-R Total Recall (P = .005; Pc = .045) and the semantic verbal fluency (P = .005; Pc = .045) measures. Variants of MAPT and SNCA were not associated with scores on any tests.

Conclusions and Relevance  Our data indicate that the APOE ε4 allele is an important predictor of cognitive function in PD across multiple domains. Among PD patients without dementia, theAPOE ε4 allele was only associated with lower performance on word list learning and semantic verbal fluency, a pattern more typical of the cognitive deficits seen in early Alzheimer disease than PD.

JAMA Neurology 2014

The Clinical Meaning of Walking Speed as Measured by the Timed 25-Foot Walk in Patients With Multiple Sclerosis

Importance  Walking impairment, a common clinical manifestation of multiple sclerosis (MS), is often measured in clinical practice and clinical trials using the Timed 25-Foot Walk (T25-FW).

Objective  To evaluate the relationship between walking speed measured by the T25-FW and the Physical Component Summary (PCS) score of the 36-Item Short Form Health Survey (SF-36) to better understand the clinical meaning of T25-FW walking speed in MS.

Design, Setting, and Participants  We retrospectively analyzed data from 3 clinical trials (Natalizumab Safety and Efficacy in Relapsing-Remitting Multiple Sclerosis [AFFIRM], Safety and Efficacy of Natalizumab in Combination With Interferon Beta-1a in Patients With Relapsing-Remitting Multiple Sclerosis [SENTINEL], and International MS Secondary Progressive Avonex Controlled Trial [IMPACT]) that included T25-FW and SF-36 scores as outcomes in patients with MS. Patients had secondary-progressive MS and an Expanded Disability Status Scale score of 3.5 to 6.5 or relapsing-remitting MS and an Expanded Disability Status Scale score of 0 to 5.0.

Main Outcomes and Measures  We used Spearman rank correlation and Pearson product moment correlation (r ) and descriptive statistics to evaluate retrospectively the relationship between the SF-36 PCS score and T25-FW walking speed at baseline and the 2-year changes from baseline.

Results  Among all 2549 patients from the 3 trials, walking speed and SF-36 PCS score at baseline were significantly correlated (n = 2333; r = 0.48; P < .001). In placebo-treated patients at 2 years, the percentage of change from baseline in walking speed was significantly correlated with the change from baseline in SF-36 PCS score (r = 0.35; P < .001). Significant correlations between the change in SF-36 PCS scores and the percentage of change in walking speed at 2 years also were observed in groups receiving active treatment (r,  0.13-0.28; P ≤ .005). Among placebo-treated patients, 27.5% had a clinically meaningful worsening (≥5-point decrease) in SF-36 PCS scores during the 2 years. Walking speed declined by 21.8% in these patients after 2 years, but only by 5.4% in those without worsening of SF-36 PCS scores.

Conclusions and Relevance  In patients with MS, walking speed measured using the T25-FW correlated with SF-36 PCS scores such that a decline in walking speed of 20% to 25% corresponded to a clinically meaningful worsening of SF-36 PCS scores. A 20% to 25% decline in walking speed may be a clinically meaningful threshold for defining worsening using the T25-FW in MS clinical trials and for monitoring patients in clinical settings.

JAMA Neurology 2014

Influence of BDNF Val66Met on the relationship between physical activity and brain volume

Objective: To investigate the association between habitual physical activity levels and brain temporal lobe volumes, and the interaction with the brain-derived neurotrophic factor (BDNF) Val66Met polymorphism.

Methods: This study is a cross-sectional analysis of 114 cognitively healthy men and women aged 60 years and older. Brain volumes quantified by MRI were correlated with self-reported physical activity levels. The effect of the interaction between physical activity and the BDNF Val66Met polymorphism on brain structure volumes was assessed. Post hoc analyses were completed to evaluate the influence of the APOE ε4 allele on any found associations.

Results: The BDNF Val66Met polymorphism interacted with physical activity to be associated with hippocampal (β = −0.22, p = 0.02) and temporal lobe (β = −0.28, p = 0.003) volumes. In Val/Val homozygotes, higher levels of physical activity were associated with larger hippocampal and temporal lobe volumes, whereas in Met carriers, higher levels of physical activity were associated with smaller temporal lobe volume.

Conclusion: The findings from this study support higher physical activity levels in the potential attenuation of age- and disease-related hippocampal and temporal lobe volume loss in Val/Val homozygotes

Neurology 2014

Long-term follow-up in patients with CCFDN syndrome

Objective: We describe the 10-year follow-up in a cohort of 16 patients with genetically confirmed congenital cataracts, facial dysmorphism, and neuropathy (CCFDN) syndrome, providing new insights in the clinical course of the disease.

Methods: We performed a detailed clinical and paraclinical characterization and 10-year follow-up study in 16 patients with molecularly defined CCFDN syndrome, illustrating that CCFDN is a severe disabling disorder.

Results: All patients initially presented with congenital cataracts along with strabismus, facial dysmorphism, short stature, and demyelinating neuropathy. In all patients, paresis of small hand muscles and foot extensors worsened with disease progression, while ataxia scores remained stable or improved. Nerve conduction velocity was normal in early infancy up to 18 months, decreased to approximately 20 m/s around age 10 years, and then remained stable; distal motor latency was prolonged. Sensory nerve conduction velocities were slowed, and initially of normal amplitude. With disease progression, both sensory and motor nerves showed reduction of amplitudes indicating axonal loss. In 6 patients, acute severe proximal weakness and myalgia after febrile infections, along with rhabdomyolysis, myoglobinuria, and hyperCKemia, led to a less favorable outcome and permanent loss of ambulation in 3 patients.

Conclusions: CCFDN should be classified as a recessive demyelinating sensory-motor neuropathy, and axonal loss is a major determinant of long-term outcomes and disability. Patients benefit from early and ongoing physiotherapy, and should be thoroughly counseled regarding virus-triggered rhabdomyolysis and the risk of malignant hyperthermia. Whether supplementation with liposoluble vitamins results in a therapeutic benefit should be evaluated in further studies.

Neurology 2014

How transparent are migraine clinical trials?

Transparency in research requires public access to unbiased information prior to trial initiation and openly available results upon study completion. The Repository of Registered Migraine Trials is a global snapshot of registered migraine clinical trials and scorecard of results availability via the peer-reviewed literature, registry databases, and gray literature. The 295 unique clinical trials identified employed 447 investigational agents, with 30% of 154 acute migraine trials and 11% of 141 migraine prophylaxis trials testing combinations of agents. The most frequently studied categories in acute migraine trials were triptans, nonsteroidal anti-inflammatory drugs, antiemetics, calcitonin gene-related peptide antagonists, and acetaminophen. Migraine prophylaxis trials frequently studied anticonvulsants, β-blockers, complementary/alternative therapies, antidepressants, and botulinum toxin. Overall, 237 trials were eligible for a results search. Of 163 trials completed at least 12 months earlier, 57% had peer-reviewed literature results, and registries/gray literature added another 13%. Using logistic regression analysis, studies with a sample size below the median of 141 subjects were significantly less likely to have results, but the dominant factor associated with availability of results was time since study completion. In unadjusted models, trials registered on ClinicalTrials.govand trials with industry primary sponsorship were significantly more likely to have results. Recently completed trials rarely have publicly available results; 2 years after completion, the peer-reviewed literature contains results for fewer than 60% of completed migraine trials. To avoid bias, evidence-based therapy algorithms should consider factors affecting results availability. As negative trials are less likely to be published, special caution should be exercised before recommending a therapy with a high proportion of missing trial results.

Neurology 2014