The primary progressive aphasias are a heterogeneous group of focal ‘language-led’ dementias that pose substantial challenges for diagnosis and management. Here we present a clinical approach to the progressive aphasias, based on our experience of these disorders and directed at non-specialists. We first outline a framework for assessing language, tailored to the common presentations of progressive aphasia. We then consider the defining features of the canonical progressive nonfluent, semantic and logopenic aphasic syndromes, including ‘clinical pearls’ that we have found diagnostically useful and neuroanatomical and other key associations of each syndrome. We review potential diagnostic pitfalls and problematic presentations not well captured by conventional classifications and propose a diagnostic ‘roadmap’. After outlining principles of management, we conclude with a prospect for future progress in these diseases, emphasising generic information processing deficits and novel pathophysiological biomarkers.Electronic supplementary materialThe online version of this article (10.1007/s00415-018-8762-6) contains supplementary material, which is available to authorized users.
The longitudinal (T1) and transverse (T2) proton (1H) nuclear magnetic resonance (NMR) relaxation times of pathological human and animal tissues in the frequency range 1-100 MHz are archived, reviewed, and analyzed as a function of tissue of origin, NMR frequency, temperature, species, and in vivo versus in vitro status. T1 data from specific disease states of the bone, brain, breast, kidney, liver, muscle, pancreas, and spleen can be characterized by simple dispersions of the form T1 = AvB in the range 1-100 MHz with A and B empirically determined pathology-dependent constants. Pathological tissue T2 values are essentially independent of NMR frequency. Raw relaxation data, best-fit T1 parameters A and B, and the mean T2 values, are tabulated along with standard deviations and sample size to establish the normal range of pathological tissue relaxation times applicable to NMR imaging or in vitro NMR examination. Statistical analysis of relaxation data, assumed independent, reveals that most tumor and edematous tissue T1 values and some breast, liver, and muscle tumor T2 values are significantly elevated (p greater than or equal to 0.95) relative to normal, but do not differ significantly from other tumors and pathologies. Statistically significant abnormalities in the T1 values of some brain, breast, and lung tumors, and most pathological tissue T2 values could not, however, be demonstrated in the presence of large statistical errors. Both T1 and T2 in uninvolved tissue from tumor-bearing animals or organs do not demonstrate statistically significant differences from normal when considered as a group, suggesting no appreciable systemic effects associated with the presence of tumors compared to the statistical uncertainty. Statistical prediction analysis for both T1 and T2 indicates that of all the tissues studied, only liver hepatoma can be reliably distinguished from normal liver based on a single T1 measurement (p greater than or equal to 0.95) given the scatter in the current published data. Indeed, data scatter, not easily attributable to temperature, species, in vivo versus in vitro status, the inclusion of implanted or chemical induced tumors, or the possible existence of multiple component relaxation, is recognized as the major factor inhibiting the diagnostic utility of quantitative NMR relaxation measurements. Malignancy indexes that combine T1 and T2 data as a diagnostic indicator suffer similar problems of uncertainty. The literature review reveals a dearth of information on the temperature and frequency dependence of pathological tissue relaxation and the possible existence of multiple relaxation components.(ABSTRACT TRUNCATED AT 400 WORDS)
BackgroundThe language profile of behavioral variant frontotemporal dementia (bvFTD) remains to be fully defined.ObjectiveWe aimed to quantify the extent of language deficits in this patient group.MethodsWe assessed a cohort of patients with bvFTD (n=24) in relation to patents with semantic variant primary progressive aphasia (svPPA; n=14), nonfluent variant primary progressive aphasia (nfvPPA; n=18) and healthy age-matched individuals (n=24) cross-sectionally and longitudinally using a comprehensive battery of language and general neuropsychological tests. Neuroanatomical associations of language performance were assessed using voxel-based morphometry of patients’ brain magnetic resonance images.ResultsRelative to healthy controls, and after accounting for nonverbal executive performance, patients with bvFTD showed deficits of noun and verb naming and single word comprehension, diminished spontaneous propositional speech and deterioration in naming performance over time. Within the bvFTD group, patients with MAPT mutations had more severe impairments of noun naming and single word comprehension than patients with C9orf72 mutations. Overall the bvFTD group had less severe language deficits than patients with PPA, but showed a language profile that was qualitatively similar to svPPA. Neuroanatomical correlates of naming and word comprehension performance in bvFTD were identified predominantly in inferior frontal and antero-inferior temporal cortices within the dominant hemispheric language network.ConclusionsbvFTD is associated with a language profile including verbal semantic impairment that warrants further evaluation as a novel biomarker.
Hearing deficits associated with cognitive impairment have attracted much recent interest, motivated by emerging evidence that impaired hearing is a risk factor for cognitive decline. However, dementia and hearing impairment present immense challenges in their own right, and their intersection in the auditory brain remains poorly understood and difficult to assess. Here, we outline a clinically oriented, symptom-based approach to the assessment of hearing in dementias, informed by recent progress in the clinical auditory neuroscience of these diseases. We consider the significance and interpretation of hearing loss and symptoms that point to a disorder of auditory cognition in patients with dementia. We identify key auditory characteristics of some important dementias and conclude with a bedside approach to assessing and managing auditory dysfunction in dementia.
The association between hearing impairment and dementia has emerged as a major public health challenge, with significant opportunities for earlier diagnosis, treatment and prevention. However, the nature of this association has not been defined. We hear with our brains, particularly within the complex soundscapes of everyday life: neurodegenerative pathologies target the auditory brain, and are therefore predicted to damage hearing function early and profoundly. Here we present evidence for this proposition, based on structural and functional features of auditory brain organization that confer vulnerability to neurodegeneration, the extensive, reciprocal interplay between ‘peripheral’ and ‘central’ hearing dysfunction, and recently characterized auditory signatures of canonical neurodegenerative dementias (Alzheimer’s disease, Lewy body disease and frontotemporal dementia). Moving beyond any simple dichotomy of ear and brain, we argue for a reappraisal of the role of auditory cognitive dysfunction and the critical coupling of brain to peripheral organs of hearing in the dementias. We call for a clinical assessment of real-world hearing in these diseases that moves beyond pure tone perception to the development of novel auditory ‘cognitive stress tests’ and proximity markers for the early diagnosis of dementia and management strategies that harness retained auditory plasticity.
Reductive rays: X‐ray photoelectron spectroscopy was employed to investigate the chemical change in self‐assembled films of 3‐(4‐nitrophenoxy)‐propyltrimethoxysilane (NPPTMS) on silicon (Si/SiO2) wafers upon X‐ray irradiation The results indicate conversion of the NO2 group into NH2. In order to confirm this, a self‐assembled multilayer of NPPTMS on silicon was subjected to reductive conditions (SnCl2/anhydrous EtOH) to convert the NO2 to the NH2 group. The graphic shows the time‐resolved X‐ray induced chemical reduction of the thin film on an SiO2 surface.
The new CMRI system provides clinically reliable evaluation of LV function and complements suboptimal echocardiography. In comparison with the conventional CMRI, the new CMRI system significantly reduces scan time, patient discomfort and associated cost.
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