Extending the Spectrum of Nonmotor Symptoms with Olfaction in Premotor Huntington's Disease: A Pilot Study

OBJECTIVE

The aim of this pilot study was to investigate change of olfactory functions in Huntington's disease (HD).

BACKGROUND

HD is a neurodegenerative disease characterized by motor, cognitive, and behavioral abnormalities. There are several studies reporting olfactory dysfunction in manifest and some studies in premanifest HD carriers, and a recent neuropathological study demonstrated HD-specific protein aggregation in the anterior olfactory nucleus in HD patients. In this study, we wanted to assess olfactory functions as a possible early nonmotor symptom of HD mutation carriers without disease-specific motor symptoms and HD patients.

METHODS

All participants had genetic confirmed HD and were prospectively recruited during their routine control in a specialized outpatient clinic of the Medical University of Innsbruck, Department of Neurology, Austria. Healthy controls (HCs) were caregivers from patients. They were only included if they were younger than 70 years, scored more than 24/30 points on the Mini Mental State Examination, and had no other disease compromising olfactory function. Furthermore, all participants were tested on the Sniffin' sticks 16-items identification test.

RESULTS

We included 23 patients with manifest HD, 13 HD mutation carriers, and 19 HCs. Mutation carriers showed significant impaired odor identification compared to HCs (p < 0.001), as well as Huntington's patients compared with both mutation carriers (p = 0.003) and HCs (p < 0.001).

CONCLUSIONS

The results of this pilot study suggest that olfactory dysfunction may be an early nonmotor symptom of HD and could be a potential marker to assess disease progression.

Synaptic, axonal damage and inflammatory cerebrospinal fluid biomarkers in neurodegenerative dementias

INTRODUCTION

Synaptic damage, axonal neurodegeneration, and neuroinflammation are common features in Alzheimer's disease (AD), frontotemporal dementia (FTD), and Creutzfeldt-Jakob disease (CJD).

METHODS

Unicentric cohort of 353 participants included healthy control (HC) subjects, AD continuum stages, genetic AD and FTD, and FTD and CJD. We measured cerebrospinal fluid neurofilament light (NF-L), neurogranin (Ng), 14-3-3, and YKL-40 proteins.

RESULTS

Biomarkers showed differences in HC subjects versus AD, FTD, and CJD. Disease groups differed between them except AD versus FTD for YKL-40. Only NF-L differed between all stages within the AD continuum. AD and FTD symptomatic mutation carriers presented differences with respect to HC subjects. Applying the AT(N) system, 96% subjects were positive for neurodegeneration if 14-3-3 was used, 94% if NF-L was used, 62% if Ng was used, and 53% if YKL-40 was used.

DISCUSSION

Biomarkers of synapse and neurodegeneration differentiate HC subjects from neurodegenerative dementias and between AD, FTD, and CJD. NF-L and 14-3-3 performed similar to total tau when AT(N) system was applied.

Differences between screen-detected and interval breast cancers among BRCA mutation carriers

BACKGROUND

BRCA mutation carriers have an elevated lifetime breast cancer risk and remain at risk for interval cancer development. We sought to compare BRCA mutation carriers with screen-detected versus interval breast cancers.

METHODS

Women with a known BRCA mutation prior to a breast cancer diagnosis were identified. Clinical and pathologic factors, and imaging within 18 months of diagnosis were compared among screen-detected versus interval cancers. Interval cancers were those detected by physical exam among women undergoing regular screening.

RESULTS

Of 124 breast cancers, 92 were screen and 22 clinically detected, of which 11 were interval cancers among regular screeners, and 10 were incidentally found on prophylactic mastectomy. Women with interval cancers were younger, had lower body mass indexes, and were more likely to be Black than those with screen-detected cancers (p < 0.05). Interval cancers were all invasive, larger, more likely to be node positive, and more likely to require axillary lymph node dissection and chemotherapy (p < 0.05). No significant differences were seen by BRCA mutation, mammographic density, MRI background parenchymal enhancement, tumor grade, or receptor status between cohorts. Women screened with both mammogram and MRI had significantly lower proportions of interval cancers compared to women screened with only mammogram or MRI alone (p < 0.05).

CONCLUSIONS

Interval breast cancers among BRCA mutation carriers have worse clinicopathologic features than screen-detected tumors, and require more-aggressive medical and surgical therapy. Imaging with mammogram and MRI is associated with lower interval cancer development and should be utilized among this high-risk population.

Hypertrophic cardiomyopathy: genotype-positive, phenotype-"almost" negative. Diagnostic role of exercise in provocation of left ventricular outflow tract gradient

It has been proposed to use exercise stress echocardiography in the upright position with left ventricular outflow tract gradient monitoring both during and after exercise as a marker of genotype-positive/phenotype negative hypertrophic cardiomyopathy (HCM). Doppler measurement of gradient has been a very helpful and diagnostic examination in several subgroups of subjects (especially in young persons, athletes). Recently, many noninvasive (bio)markers have been found to be very helpful in screening patients suspected of HCM before full expression of phenotype.

Gene-specific increase in the energetic cost of contraction in hypertrophic cardiomyopathy caused by thick filament mutations

AIMS

Disease mechanisms regarding hypertrophic cardiomyopathy (HCM) are largely unknown and disease onset varies. Sarcomere mutations might induce energy depletion for which until now there is no direct evidence at sarcomere level in human HCM. This study investigated if mutations in genes encoding myosin-binding protein C (MYBPC3) and myosin heavy chain (MYH7) underlie changes in the energetic cost of contraction in the development of human HCM disease.

METHODS AND RESULTS

Energetic cost of contraction was studied in vitro by measurements of force development and ATPase activity in cardiac muscle strips from 26 manifest HCM patients (11 MYBPC3mut, 9 MYH7mut, and 6 sarcomere mutation-negative, HCMsmn). In addition, in vivo, the ratio between external work (EW) and myocardial oxygen consumption (MVO2) to obtain myocardial external efficiency (MEE) was determined in 28 pre-hypertrophic mutation carriers (14 MYBPC3mut and 14 MYH7mut) and 14 healthy controls using [(11)C]-acetate positron emission tomography and cardiovascular magnetic resonance imaging. Tension cost (TC), i.e. ATPase activity during force development, was higher in MYBPC3mut and MYH7mut compared with HCMsmn at saturating [Ca(2+)]. TC was also significantly higher in MYH7mut at submaximal, more physiological [Ca(2+)]. EW was significantly lower in both mutation carrier groups, while MVO2 did not differ. MEE was significantly lower in both mutation carrier groups compared with controls, showing the lowest efficiency in MYH7 mutation carriers.

CONCLUSION

We provide direct evidence that sarcomere mutations perturb the energetic cost of cardiac contraction. Gene-specific severity of cardiac abnormalities may underlie differences in disease onset and suggests that early initiation of metabolic treatment may be beneficial, in particular, in MYH7 mutation carriers.