The differential dependence of abstract and concrete words upon associative and similarity-based information: Complementary semantic interference and facilitation effects

We report mirror-image effects of interference and facilitation in the semantic processing of identical sets of abstract and concrete words in a patient F.B.I. with global aphasia following a large left middle cerebral artery stroke. Interference was elicited when the tasks involved comprehending the spoken form of each word, but facilitation was found when the patient read aloud the written forms of the same words. More importantly, irrespective of whether the dynamic effect was one of facilitation or interference, effects of semantic association were observed for abstract words, whilst effects primarily of semantic similarity were observed for concrete words. These results offer further neuropsychological evidence that the more abstract a word, the greater its dependence upon associative information and the smaller its dependence upon similarity-based information. The investigations also contribute to a converging body of evidence that suggests that this theory generalizes across different experimental paradigms, stimuli, and participants and also across different cognitive processes within individual patients. The data support a graded rather than binary or ungraded model of the relationships between concreteness, association, and similarity, and the basis for concrete words’ greater dependence upon similarity-based information is discussed in terms of the development of taxonomic structures and categorical thought in young children.     

Post-stroke depression among stroke survivors attending two hospitals in Kampala Uganda

Background

The burden of stroke worldwide is increasing rapidly. There is paucity of data on post-stroke depression (PSD) among stroke survivors in Uganda, despite the high prevalence of PSD reported elsewhere.

Methods

In a cross-sectional study, we assessed adult participants with confirmed first stroke with a standardized questionnaire. The Patient Health Questionnaire-9 was used to assess for depression among non-aphasic patients while the Aphasic Depression Rating Scale was administered to aphasic patients. Univariable and multivariable analyses performed to describe associations with PSD.

Results

Forty three females (58.9%) and 30 males (41.1%) who had a stroke participated. Fifty eight (79.5%) had ischemic strokes and 12 participants (16.4%) were aphasic. The prevalence of PSD among the study participants was 31.5%. PSD was higher among patients assessed within 6 months after the onset of stroke. PSD was strongly associated with the total Barthel index of activities of daily living (BIADL) score; p=0.001. There was no significant association between demographic characteristics and PSD.

Conclusion

There is a high prevalence of unrecognized post-stroke depression. Post-stroke depression was strongly associated with the patient''s inability to undertake activities of daily life. There is urgent need for integration of screening for and management of post-stroke depression among stroke survivors.     

The prevalence and management of central post-stroke pain at a hospital in Zimbabwe

BackgroundCentral post-stroke pain (CPSP) is a poorly diagnosed chronic pain. It is under-treated and usually mismanaged.ObjectiveTo establish the prevalence of CPSP and its management in stroke clinics at a tertiary hospital.MethodsThis was a cross-sectional design with stroke patients and health professionals from the stroke clinic at the tertiary hospital in Zimbabwe.ResultsOut of 166 stroke survivors, 8% had CPSP. Younger age (<60 years) was significantly associated with CPSP (P<0.003). Pain characteristics of CPSP were hyperaesthesia (10, 71%), electric shocks (9, 64%), temperature allodynia (9, 64%) and allodynia (12, 86%). Ten health professionals participated in the study: one (10%) reported using Douleur Neuropathique 4 (to diagnose neuropathic pain) and two (20%) reported using sensory tests. Four patients (44%) were on paracetamol (acetaminophen) and on weak opiates such as codeine. None of the patients were on anticonvulsants or antidepressants. Two medical doctors (50%) used weak opiates as second-line management. Five patients (36%) reported receiving a combination of massage, stretching, general exercise and moist heat or cryotherapy.ConclusionThe prevalence of CPSP in the study group is within international range. There is a need for appropriate management and use of tests and outcome measures for diagnosis of CPSP.     

Participants’ perceptions of an aphasia-friendly occupational therapy home program

Background: Upper extremity impairments post-stroke impact participation in valued occupations. Home programs are used to extend the frequency and amount of upper extremity practice for people post-stroke, but novel ways of increasing adherence to these programs is needed to ensure intense repetitive practice.

Objectives: The purpose of this process evaluation, was to examine the perceptions of people with aphasia as it relates to modifications to home programs that could influence participation, specifically listening to music and aphasia-friendly adaptations of written materials.

Methods: Seven people with chronic aphasia completed an upper extremity home program that included the use of music and aphasia-friendly modified materials (ClinicalTrials.gov ID:2016/06/18). After the home program, participants completed semi-structured interviews to understand their perceptions of the program and the modifications.

Results: Five themes were identified including (1) music, (2) activities, (3) instructions, (4) logistics, and (5) progress. Most participants perceived music as helpful, but a few reported it being distracting. Participants found the variety of activities helpful as well as specific characteristics of the instructions such as photographs and images. Some participants expressed elements of the home program to be barriers to practice such as using the activity monitors and logbook, which required assistance at times. Finally, participants noted their own progress resulting from the program and liked that they could adjust the intensity of the program as they progressed.

Conclusions: Overall participants in this study with aphasia perceived the modifications to home programs including aphasia friendly written instructions and music to facilitate successful home practice.     

Opportunities to say ‘yes’: Rare speech automatisms in a case of progressive nonfluent aphasia and apraxia

We describe the investigation of speech automatisms in a man with progressive nonfluent aphasia and apraxias. Occurrence of the automatisms yes and right, were analysed across a range of speech tasks varying in length, propositionality, lexical and articulatory complexity, whether tasks engaged internal generation or external triggering and articulatory distortions, and while completing pantomimes/gestures. No differences were found in occurrence across most tasks but there was a significant interaction between automatism production and apraxic speech errors and during limb praxic tasks, suggesting that production of the automatism was unrelated to linguistic or lexical variables, but was related to the presence of speech apraxia coupled with disinhibition.     

Anti-NMDA receptor encephalitis presenting as isolated aphasia in an adult

ABSTRACT

Anti-NMDA receptor (NMDA-r) encephalitis is a relatively rare cause of autoimmune encephalitis with divergent clinical presentations. We report a case of an adult patient with anti-NMDA-r encephalitis presenting with isolated, abrupt-onset aphasia. Her condition remained unaltered over a period of 6 months. The patients’ electroencephalogram findings were typical for NMDA-r encephalitis; however, her magnetic resonance imaging and cerebrospinal fluid analysis were normal. She responded well to immunotherapy, and aphasia eventually resolved. The natural course of the present case contradicts the rapidly progressive nature of typical NMDA-r encephalitis. Furthermore, it broadens the clinical spectrum of anti-NMDA-r encephalitis, to incorporate isolated, nonprogressive aphasia.     

Verbal adynamia in parkinsonian syndromes: behavioral correlates and neuroanatomical substrate

ABSTRACT

Verbal adynamia (impaired language generation, as during conversation) has not been assessed systematically in parkinsonian disorders. We addressed this in patients with Parkinson’s dementia, progressive supranuclear palsy and corticobasal degeneration. All disease groups showed impaired verbal fluency and sentence generation versus healthy age-matched controls, after adjusting for general linguistic and executive factors. Dopaminergic stimulation in the Parkinson’s group selectively improved verbal generation versus other cognitive functions. Voxel-based morphometry identified left inferior frontal and posterior superior temporal cortical correlates of verbal generation performance. Verbal adynamia warrants further evaluation as an index of language network dysfunction and dopaminergic state in parkinsonian disorders.     

Longitudinal study of single‐word comprehension in semantic dementia: A comparison with primary progressive aphasia and Alzheimer's disease

Background: Although semantic dementia (SD) is characterised by a multimodal loss of semantic knowledge, it has been demonstrated that lexical‐semantic representations are not equally disrupted in SD and that some categories may be recognised better than others. Little is known, however, about the pattern of the category‐specific comprehension deficits in SD and whether it differs from that of other forms of progressive aphasias.

Aims: This exploratory study aimed to investigate the evolution of category‐specific deficits of single‐word comprehension in progressive aphasias.

Methods & Procedures: A total of 19 patients with a clinical diagnosis of SD, 25 patients with primary progressive aphasia with agrammatic and relatively nonfluent speech (PPA), and 25 patients with Alzheimer's disease (AD) with aphasia were studied longitudinally with the Western Aphasia Battery (WAB). The Auditory Word Recognition subtest of the WAB was utilised to assess comprehension of words derived from different semantic categories.

Outcomes & Results: The analysis revealed that, over time, category‐specific deficits of single‐word comprehension were seen in all three groups of patients. Participants with SD as well as those with PPA and AD were impaired on both pointing to fingers and the right–left orientation task. However, patients with SD were the only group that showed defective recognition of their own body parts. Interestingly, individuals with SD had no difficulties identifying colours, letters, and numbers, even during the follow‐up testing. In addition, in all three groups the extent of category‐specific deficits was associated with the severity of aphasia.

Conclusions: These results indicate that category‐specific deficits of single‐word comprehension are frequently seen not only in patients with SD but also in individuals with PPA or AD, and that the extent of these deficits is associated with the severity of aphasia. However, the pattern of these deficits is often different in these three forms of neurodegenerative conditions and more dissociations between semantic categories are observed as each of these diseases progresses.