Machulda, Mary M.

AbstractBackground: hearing loss has been associated with mild cognitive impairment (MCI) and dementia. Studies have not assessed whether hearing difficulties (HD) that interfere with daily activities as reported by partners can be a marker for increased risk for cognitive decline and impairment.Objective: to assess the cross-sectional and longitudinal associations between informant-based HD, which interfere with daily activities and the risk for MCI and dementia.Methods: the study included 4812 participants without dementia, enrolled in the Mayo Clinic Study of Aging (mean age (SD) 73.7 (9.6) years) with cognitive evaluation and informant-based report on participant’s HD that interfere significantly with daily activities at baseline and for every 15 months. Cox proportional hazards models (utilising time-dependent HD status and age as the time scale) were used to examine HD and the risk for MCI or dementia, and mixed-effects models (allowing for random subject-specific intercepts and slopes) were used to examine the relationship between HD and cognitive decline.Results: about, 981 participants had HD and 612 (12.7%) had prevalent MCI at baseline; 759 participants developed incident MCI and 273 developed incident dementia. In cognitively unimpaired participants at baseline, those with HD had higher risk for MCI (hazard ratio [HR] = 1.29, 95% confidence interval [CI] (1.10, 1.51), P = 0.002; adjusting for sex, years of education). In participants without dementia, those with HD had higher risk for dementia (HR: 1.39, 95% CI, (1.08–1.79), P = 0.011; adjusting sex and education). In individuals with MCI, HD was associated with modestly greater cognitive decline.Conclusions: informant-based HD was associated with increased risk for MCI and dementia.

ABSTRACTBackgroundThe Movement Disorder Society clinical criteria for progressive supranuclear palsy (PSP) provide a framework for assessing the presence/severity of clinical symptoms and define a speech/language variant of PSP.ObjectivesTo evaluate the clinical criteria in a cohort of speech/language patients with longitudinal follow‐up.MethodsA total of 52 patients presenting with progressive apraxia of speech and/or agrammatic aphasia were followed longitudinally for up to 6 visits with clinical assessments and magnetic resonance imaging. We assessed oculomotor, postural instability, and akinesia diagnostic levels and determined whether patients met criteria for possible PSP‐speech/language or probable PSP at each visit. Kaplan‐Meier curves assessed time‐to‐event probabilities according to age. Statistical parametric mapping and midbrain volume were assessed according to disease progression.ResultsFew PSP symptoms were observed early in the disease, with oculomotor abnormalities and falls first observed 2 years after onset. Falls were more common than vertical supranuclear gaze palsy. Bradykinesia and rigidity commonly developed but axial was rarely greater than appendicular rigidity. During follow‐up, 54% met criteria for possible PSP‐speech/language, 38% for probable PSP‐Richardson's syndrome, and 38% for probable PSP‐parkinsonism, most commonly 6 to 6.9 years after onset. The probability of developing PSP was greater when onset was at an age older than 70 years. Patients who progressed to probable PSP had more parkinsonism and oculomotor impairment at baseline and greater midbrain atrophy when compared with those who did not develop probable PSP.ConclusionsSymptoms typical of PSP commonly develop in patients presenting with a progressive speech/language disorder. Older age appears to be an important prognostic factor in these patients.

Abstract Introduction We evaluated whether incident mild cognitive impairment (MCI) subtypes could be empirically derived in the Mayo Clinic Study of Aging. Methods We performed cluster analysis on neuropsychological data from 506 participants with incident MCI. Results The 3‐cluster solution resulted in (1) amnestic, (2) dysexecutive, (3) dysnomic subtypes. The 4‐cluster solution produced these same three groups and a fourth group with subtle cognitive impairment (SCI). The SCI cluster was a subset of the amnestic cluster and distinct from well‐matched cognitively unimpaired participants based on memory and global z‐score area under the receiver operating characteristic curve analyses and probability of progression to MCI/dementia. Discussion We empirically identified three neuropsychological subtypes of MCI that share some features with MCI subtypes identified in the Alzheimer's Disease Neuroimaging Initiative. The fourth subtype with SCI in the Mayo Clinic Study of Aging differed from the fourth cluster‐derived normal group in Alzheimer's Disease Neuroimaging Initiative and could represent a group to target with early interventions.

Abstract Agrammatic aphasia affects grammatical language production and can result from a neurodegenerative disease. Although it typically presents with concomitant apraxia of speech, this is not always the case. Little is known about the clinical course and imaging features of patients that present with agrammatism in the absence of apraxia of speech, which we will refer to as progressive agrammatic aphasia. We aimed to make a detailed description of the longitudinal clinical, linguistic, and neuroimaging features of a cohort of 11 patients with progressive agrammatic aphasia to provide a complete picture of this syndrome. All patients underwent detailed speech and language, neurological and neuropsychological assessments, 3 T structural and diffusion tensor imaging MRI, 18F-fluorodeoxyglucose and Pittsburgh compound B PET. The 11 patients were matched by age and gender to 22 patients who had mixed apraxia of speech and agrammatism. The progressive agrammatic aphasia patients performed abnormally on tests of language, general cognition, executive function, and functional ability at baseline and declined in these measures over time. Only two patients eventually developed apraxia of speech, while parkinsonism was absent-to-mild throughout all visits for all patients. When compared to the patients with mixed apraxia of speech and agrammatism, the patients with progressive agrammatic aphasia performed better on tests of motor speech and parkinsonism but more poorly, and declined faster over time, on tests of general aphasia severity, agrammatism, and naming. The patients with progressive agrammatic aphasia also showed different neuroimaging abnormalities, with greater atrophy, hypometabolism and white matter tract degeneration in the prefrontal and anterior temporal lobes compared to patients with mixed apraxia of speech and agrammatism. These differences were more pronounced as the disease progressed. These results demonstrate that progressive agrammatic aphasia has a different clinical disease course and different underlying neuroanatomical abnormalities than patients with the more common syndrome of mixed agrammatism and apraxia of speech. This supports the distinction of progressive agrammatic aphasia and has implications for the classification of patients with agrammatic aphasia.