Individuals with different subtypes of primary progressive aphasia (PPA), a common clinical presentation of frontotemporal dementia characterized by language disturbances, often show overlapping...Show moreIndividuals with different subtypes of primary progressive aphasia (PPA), a common clinical presentation of frontotemporal dementia characterized by language disturbances, often show overlapping clinical symptoms, such that accurate diagnosis can be difficult. Prior studies indicate that social cognitive abilities, in particular emotion recognition, may improve the diagnostic process. Therefore, this study investigated emotion recognition deficits across different emotions and emotional intensities by means of the Emotion Recognition Task (ERT) among patients with a PPA subtype (semantic (svPPA), non-fluent (nfvPPA) or logopenic (lvPPA)), and behavioural frontotemporal dementia (bvFTD). The ERT is a neuropsychological test consisting of dynamic, naturalistic videos of the six basic facial emotional expressions (anger, disgust, fear, happiness, sadness and surprise) across different intensity levels (40, 60, 80 and 100%). In total, emotion recognition abilities were assessed in 152 participants (10 svPPA, 20 nfvPPA, 6 lvPPA, 63 bvFTD, 53 controls). Results of an ANCOVA controlling for age, sex, and education level showed emotion recognition deficits in patients with a PPA subtype and bvFTD compared to controls. Among the patient groups, patients with bvFTD were poorer in overall emotion recognition than patients with nfvPPA. Among the PPA subtypes emotion recognition did not differ. Patients with svPPA were worse in recognizing anger than patients with bvFTD, nfvPPA and lvPPA. In addition, patients with svPPA and bvFTD were worse in recognizing disgust than patients with nfvPPA. Besides, patients with svPPA and controls were better in recognizing happiness, than patients with bvFTD, nfvPPA and lvPPA. Results of a three-way mixed ANOVA showed that emotion recognition abilities improved with higher emotional intensity and group differences were not the largest at the lowest intensity. In conclusion, our findings demonstrate emotion recognition deficits in PPA and bvFTD, and hint towards specific impairments for recognizing anger and disgust in patients with svPPA. These insights can help to improve clinical distinction among the PPA subtypes and bvFTD, which could ultimately lead to better differential diagnosis.Show less
Background: Alzheimer’s disease (AD) and amnestic mild cognitive impairment (aMCI; a preclinical stage of AD) are mostly associated with cognitive impairments. These cognitive challenges have been...Show moreBackground: Alzheimer’s disease (AD) and amnestic mild cognitive impairment (aMCI; a preclinical stage of AD) are mostly associated with cognitive impairments. These cognitive challenges have been linked to hippocampal decline. Prior work suggests additional motor impairments affecting fine and complex motor skills, motor coordination, and basic mobility. Recently impairments in motor learning have been proposed, concerning motor sequence learning (i.e., learning to perform a series of motor actions) and learning to learn (i.e., learning something about a learning process, which can be applied to another learning process). This master thesis investigates whether these two motor learning abilities are affected in AD and aMCI compared to healthy controls. In addition, we evaluate whether hippocampal volume, which is a known biomarker for AD, can predict motor sequence learning and learning to learn. Methods: A motor sequence learning task was performed by 28 AD patients, 33 aMCI patients, and 52 healthy controls. They were presented alternating blocks of randomly vs. sequentially ordered stimuli, to which they responded via button presses. The difference in reaction times of random vs. sequence blocks was used to measure motor learning. Two different sequences were presented, with one sequence measuring motor sequence learning in the first half of the task, and another sequence in the second half assessing learning to learn. Hippocampal volume was determined via a structural MRI scan. Results: Although patients with AD generally responded slower than individuals with aMCI and controls, no significant group differences were found in motor sequence learning and learning to learn. AD patients had smaller hippocampal volume than patients with aMCI and controls. Patients with aMCI displayed smaller volume than controls. However, hippocampal volume did not predict motor sequence learning measures. Conclusion: The findings indicate that motor sequence learning and learning to learn are intact in AD and aMCI. Hippocampal volume can be seen as a differentiating factor for the stages of AD progression of healthy individuals, aMCI, and AD. However, it did not predict motor learning measures. Rehabilitation programs should target on utilizing motor learning functions to improve activities of daily living in individuals with AD and aMCI.Show less
