Michał Harciarek

Neuropsychological differences between frontotemporal dementia and Alzheimer's disease: a review.

This paper surveys the similarities and differences between frontotemporal dementia (FTD) and Alzheimers disease (AD). The review covers findings primarily from neuropsychological studies on memory, language, attention/executive function, and visuospatial abilities. However, neuropsychiatric and neuroimaging data are also briefly discussed. Distinguishing features of both FTD and AD are described in order to present a comprehensive clinical picture of these dementing diseases, which is essential for the process of differential diagnosis. The cause of specific cognitive deficits is also considered. Our comprehensive review of the empirical literature reveals that AD is characterized by early memory loss and visuospatial problems, while among the main features of FTD are behavioral abnormalities and executive dysfunctions.

Primary progressive aphasias and their contribution to the contemporary knowledge about the brain-language relationship.

Primary progressive aphasia (PPA), typically resulting from a neurodegenerative disease such as frontotemporal dementia/Pick Complex or Alzheimer’s disease, is a heterogeneous clinical condition characterized by a progressive loss of specific language functions with initial sparing of other cognitive domains. Based on the constellation of symptoms, PPA has been classified into a nonfluent, semantic, or logopenic variant. This review of the literature aims to characterize the speech and language impairment, cognition, neuroimaging, pathology, genetics, and epidemiology associated with each of these variants. Some therapeutic recommendations, theoretical implications, and directions for future research have been also provided.

Self-awareness of Motor Dysfunction in Patients with Huntington's Disease in Comparison to Parkinson's Disease and Cervical Dystonia

Individuals suffering from Huntingtons disease (HD) have been shown to present with poor self-awareness of a variety of symptoms. The aim of this study was to better assess the self-awareness of motor symptoms and activities of daily living (ADL) impairment in HD, in comparison to Parkinsons disease (PD) and cervical dystonia (CD). In particular, the anosognosia/anosodiaphoria of involuntary movements has been investigated. Self-awareness was tested in 23 patients with HD by comparing patient and caregiver ratings in reference to clinical control groups (25 PD with dyskinesias, PDdys; 21 PD without dyskinesias, PDndys; and 20 with CD). Patients were assessed neurologically by relevant rating scales. Self-awareness was tested using a scale based on 15 films demonstrating 3 types of motor symptoms (chorea/dyskinesias, parkinsonism, torticollis) as well as the Self-Assessment Parkinsons Disease Disability Scale. General cognitive status, verbal learning, cognitive control, and mood were also analyzed. Our results indicate that self-awareness of choreic movements was affected more severely in HD than in PDdys, despite comparable cognitive status. Patient-proxy agreement on ADL impairment was roughly similar in all clinical groups. The results are discussed in the context of orbitofrontal-limbic pathology as a potential trigger of anosognosia/anosodiaphoria in individuals with HD.

Defective comprehension of emotional faces and prosody as a result of right hemisphere stroke: modality versus emotion-type specificity.

Studies of patients with brain damage, as well as studies with normal subjects have revealed that the right hemisphere is important for recognizing emotions expressed by faces and prosody. It is unclear, however, if the knowledge needed to perform recognition of emotional stimuli is organized by modality or by the type of emotion. Thus, the purpose of this study is to assess these alternative a priori hypotheses. The participants of this study were 30 stroke patients with right hemisphere damage (RHD) and 31 normal controls (NC). Subjects were assessed with the Polish adaptation of the Right Hemisphere Language Battery of Bryan and the Facial Affect Recognition Test based on work of Ekman and Friesen. RHD participants were significantly impaired on both emotional tasks. Whereas on the visual-faces task the RHD subjects recognized happiness better than anger or sadness, the reverse dissociation was found in the auditory-prosody test. These results confirm prior studies demonstrating the role of the right hemisphere in understanding facial and prosodic emotional expressions. These results also suggest that the representations needed to recognize these emotional stimuli are organized by modality (prosodic-echoic and facial-eidetic) and that some modality specific features are more impaired than others.

Schizophrenia and frontotemporal dementia: Shared causation?

Abstract The relationship between specific genes and particular diseases in neuropsychiatry is unclear, and newer studies focus on shared domains of neurobiological and cognitive pathology across different disorders. This paper reviews the evidence for an association between schizophrenia and frontotemporal dementia, including symptom similarity, familial co-morbidity, and neuroanatomical changes. Genetic as well as epigenetic findings from both schizophrenia and frontotemporal dementia are also discussed. As a result, we introduce the hypothesis of a shared susceptibility for certain subgroups of schizophrenia and frontotemporal dementia. This common causation may involve the same gene(s) at different stages of life: early in schizophrenia and late in frontotemporal dementia. Additionally, we provide a rationale for future research that should emphasize both genetic and cognitive parallels between certain forms of schizophrenia and frontotemporal dementia in a synergistic, coordinated way, placing both in the context of aberrant lateralization patterns.

Language, executive function and social cognition in the diagnosis of frontotemporal dementia syndromes

Abstract Frontotemporal dementia (FTD) represents a spectrum of non-Alzheimers degenerative conditions associated with focal atrophy of the frontal and/or temporal lobes. Frontal and temporal regions of the brain have been shown to be strongly involved in executive function, social cognition and language processing and, thus, deficits in these domains are frequently seen in patients with FTD or may even be hallmarks of a specific FTD subtype (i.e. relatively selective and progressive language impairment in primary progressive aphasia). In this review we have attempted to delineate how language, executive function, and social cognition may contribute to the diagnosis of FTD syndromes, namely the behavioural variant FTD as well as the language variants of FTD including the three subtypes of primary progressive aphasia (PPA): non-fluent/agrammatic, semantic and logopenic. This review also addresses the extent to which deficits in these cognitive areas contribute to the differential diagnosis of FTD versus Alzheimer’s disease (AD). Finally, early clinical determinants of pathology are briefly discussed and contemporary challenges to the diagnosis of FTD are presented.

“Keep up the good work!”: A case study of the effects of a specific cognitive training in Alzheimer’s disease

Alzheimer’s disease (AD) is a neurodegenerative condition characterized by significant impairment in multiple cognitive domains. In recent years, the development of cognitive trainings in AD has received significant attention. In the present case study we designed a cognitive training program (GEO, Geographical Exercises for cognitive Optimization) based on an errorless paradigm and tailored to the patient’s cultural interests. The aim of this training was to investigate the potential for acquiring and possibly retaining both procedural and verbal knowledge in early-stage AD. This study involved an 80-year-old female patient diagnosed with early-stage AD, and 10 matched healthy subjects. Participants were asked to perform the two GEO training tasks: a “puzzle-like” task for procedural memory, and an “association” task for verbal memory. Both the patient and the healthy controls were subsequently trained with GEO using the same two tasks for 2 months. Although the patient’s performance before training in both tasks was poor compared to healthy controls, after the training these differences disappeared. Our results showed that the patient was able to acquire new procedural abilities and verbal knowledge, and that her achievements were stable at the follow-up testing scheduled 3 months after the end of the intervention. This case study suggests a potentially useful strategy for cognitive training in AD.

The contribution of anterior and posterior regions of the right hemisphere to the recognition of emotional faces

To investigate the contribution of posterior and anterior parts of the right hemisphere (RH) to emotional facial recognition, we studied 11 participants with anterior strokes of the right hemisphere (ASRH), 16 patients with posterior strokes of the right hemisphere (PSRH), and 31 normal controls. All individuals were right-handed and nondemented. The ability to recognize emotional facial expressions was assessed by using Ekman and Friesens (1976) Pictures of Facial Affect. Analysis revealed that both groups of patients presented with an impaired recognition of emotional faces. However, patients with PSRH were able to identify facial expressions better than participants with ASRH. In comparison to participants sustaining PSRH, patients with ASRH were particularly impaired on recognizing faces of negative valence. Thus, our results suggest that anterior parts of the RH seem to play an important role in the recognition of emotional facial expressions.

Risk factors for selective cognitive decline in dialyzed patients with end-stage renal disease: evidence from verbal fluency analysis.

Although dialyzed patients often have cognitive problems, little is known about the nature of these deficits. We hypothesized that, in contrast to semantic fluency relying mainly on temporal lobes, phonemic fluency, preferentially depending on functions of frontal-subcortical systems, would be particularly sensitive to the constellation of physiological pathological processes associated with end-stage renal disease and dialysis. Therefore, we longitudinally compared phonemic and semantic fluency performance between 49 dialyzed patients and 30 controls. Overall, patients performed below controls only on the phonemic fluency task. Furthermore, their performance on this task declined over time, whereas there was no change in semantic fluency. Moreover, this decline was related to the presence of hypertension and higher blood urea nitrogen. We suggest that these findings may be due to a combination of vascular and topic effects that impact more on fronto-subcortical than temporal lobe networks, but this speculation requires direct confirmation.

The patterns of progression in primary progressive aphasia—Implications for assessment and management

Background: Primary progressive aphasia (PPA) is a progressive language disorder with preserved cognitive function for at least 2 years from onset. The main variants currently distinguished are: non-fluent/agrammatic (nfvPPA), semantic (svPPA), and logopenic (lvPPA). Patients with initial language presentation may subsequently develop other symptoms, such as behavioural dysfunction or apraxia. The clinical pattern of PPA depends on the location of atrophy, the underlying pathology, and the stage of the disease. Aims: This review aims at characterising longitudinal changes in clinical presentations of different PPA variants and at presenting implications of these changes for the assessment, diagnosis, and management. Main contribution: The three PPA variants differ not only in terms of language impairment, but also with regard to cognitive and behavioural profile. Apraxia and rigidity frequently occur in the course of nfvPPA. Patients with lvPPA seem to follow the pattern of aphasic Alzheimer’s disease, where language impairment is accompanied by episodic memory deficit. Individuals diagnosed with svPPA often develop behavioural dysfunction similar to that observed in behavioural variant of frontotemporal dementia. Conclusions: Implications for patient care are dependent on PPA variant and on the stage of the disease. In svPPA, emphasis should be on the management of semantic and behavioural problems in daily life. Caregivers of nfvPPA patients should be informed about the possible emergence of apraxia and other movement disorders. In contrast, families of individuals with lvPPA should be made aware of and trained to cope with an episodic memory decline and possible progression to other varieties of PPA.