-
Brain Structure & Function Dec 2022Motor awareness is a complex, multifaceted construct involving the awareness of both (i) one's motor state while executing a movement or remaining still and (ii) one's... (Review)
Review
Motor awareness is a complex, multifaceted construct involving the awareness of both (i) one's motor state while executing a movement or remaining still and (ii) one's motor abilities. The analysis of neurological syndromes associated with motor disorders suggests the existence of various different components which are, however, integrated into a model of motor awareness. These components are: (i) motor intention, namely, a conscious desire to perform an action; (ii) motor monitoring and error recognition, that is, the capacity to check the execution of the action and identify motor errors; and (iii) a general awareness of one's own motor abilities and deficits, that is, the capacity to recognize the general state of one's motor abilities about the performance of specific actions and the potential consequences of motor impairment. Neuroanatomical correlates involving the parietal and insular cortices, the medial and lateral frontal regions, and subcortical structures (basal ganglia and limbic system) support this multi-component model. Specific damage (or disconnections) to these structures results in a number of different disorders in motor awareness, such as anosognosia for hemiplegia and apraxia, and a number of symptoms which are specific to motor intention disorders (e.g., the Anarchic Hand Syndrome and Tourette's Syndrome) or motor monitoring (e.g., Parkinson's and Huntington's diseases). All of these clinical conditions are discussed in the light of a motor awareness model.
Topics: Humans; Functional Laterality; Awareness; Syndrome; Neuropsychological Tests; Agnosia
PubMed: 36064864
DOI: 10.1007/s00429-022-02558-y -
Cortex; a Journal Devoted To the Study... Oct 2017
Review
Topics: Agnosia; Brain; Brain Injuries; Humans; Paralysis; Rare Diseases; Research
PubMed: 28389005
DOI: 10.1016/j.cortex.2017.03.002 -
Rehabilitation Nursing : the Official... 2020Anosognosia for hemiplegia (AHP) after stroke is a complex cognitive behavioral disorder that removes awareness of one-sided paralysis (hemiplegia). As a result, stroke...
BACKGROUND
Anosognosia for hemiplegia (AHP) after stroke is a complex cognitive behavioral disorder that removes awareness of one-sided paralysis (hemiplegia). As a result, stroke survivors afflicted with AHP may be more likely to have unrealistic expectations for stroke rehabilitation, display unsafe behaviors and experience falls, and ultimately suffer the physical and psychological consequences of frequent falling.
OBJECTIVE
The purpose of this article is to describe AHP by discussing anosognosia within the context of contemporary theoretical understandings, examining current imaging evidence of the disorder, and summarizing emerging interventions designed to reinstate self-awareness in anosognosic patients.
METHOD
Systematic review with a focus on defining and describing AHP based on human experimental studies was conducted within a 10-year period.
RESULTS
Eleven studies were identified. The content and foci of the 11 studies fell into one of three categories: theory testing, imaging evidence, and interventions for individuals with AHP.
Topics: Aged; Agnosia; Female; Hemiplegia; Humans; Male; Stroke
PubMed: 30086101
DOI: 10.1097/rnj.0000000000000185 -
Brain : a Journal of Neurology Oct 1996Somaesthetic, motor and cognitive functions were studied in a man with impaired tactile object-recognition (TOR) in his left hand due to a right parietal convexity...
Somaesthetic, motor and cognitive functions were studied in a man with impaired tactile object-recognition (TOR) in his left hand due to a right parietal convexity meningeoma which had been surgically removed. Primary motor and somatosensory functions were not impaired, and discriminative abilities for various tactile aspects and cognitive skills were preserved. Nevertheless, the patient could often not appreciate the object's nature or significance when it was placed in his left hand and was unable to name or to describe or demonstrate the use of these objects. Therefore, he can be regarded as an example of associative tactile agnosia. The view is taken and elaborated that defective modality-specific meaning representations account for associative tactile agnosia. These meaning representations are conceptualized as learned unimodal feature-entity relationships which are thought to be defective in tactile agnosia. In line with this hypothesis, tactile feature analysis and cross-modal matching of features were largely preserved in the investigated patient, while combining features to form entities was defective in the tactile domain. The alternative hypothesis of agnosia as deficit of cross-modal association of features was not supported. The presumed distributed functional network responsible for TOR is thought to involve perception of features, object recognition and related tactile motor behaviour interactively. A deficit leading primarily to impaired combining features to form entities can therefore be expected to result in additional minor impairment of related perceptual-motor processes. Unilaterality of the gnostic deficit can be explained by a lateralized organization of the functional network responsible for tactile recognition of objects.
Topics: Agnosia; Fingers; Hand; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Parietal Lobe; Psychomotor Performance
PubMed: 8931580
DOI: 10.1093/brain/119.5.1565 -
European Neurology 2002Transient topographical disorientation (TTD) is a short-lasting inability to find one's way in a familiar environment, while the patient remains conscious and is able to...
Transient topographical disorientation (TTD) is a short-lasting inability to find one's way in a familiar environment, while the patient remains conscious and is able to recall what happened. We report the study of 10 patients with episodes of TTD, studied on the days following the last episode. The episodes of TTD could be separated into two types: the patients either reported difficulties in spatial orientation with preserved abilities to recognize landmarks and objects, or the difficulties appeared with the recognition of landmarks. Tests exploring spatial orientation, as well as higher visuoperceptive capacities were altered in most of the patients and brain SPECT showed hypoperfusion of the right hemisphere in all patients, which could also be demonstrated 2 years later in some cases. Altogether, our findings suggest that TTD is frequently associated with a more persistent right hemisphere dysfunction of unknown cause. This chronic alteration could represent either a sequel of the acute episode or a preexisting right hemisphere deficit, which inclined the acute insult to be manifested as TTD.
Topics: Adult; Aged; Agnosia; Electroencephalography; Female; Follow-Up Studies; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Neuropsychological Tests; Orientation; Recovery of Function; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed
PubMed: 12422066
DOI: 10.1159/000066173 -
Psychogeriatrics : the Official Journal... May 2020Alzheimer's disease (AD) is a neurodegenerative disease characterised by neurocognitive impairments, especially memory impairment, as core symptoms linked to reductions... (Review)
Review
Alzheimer's disease (AD) is a neurodegenerative disease characterised by neurocognitive impairments, especially memory impairment, as core symptoms linked to reductions in activities of daily life. As marginal symptoms, neuropsychiatric symptoms (NPSs) appear during the progressive course of the disease. A lack of self-awareness (anosognosia) of cognitive and functional impairments is often seen in patients with AD, and associations between anosognosia and other NPSs have been previously reported. To account for anosognosia pathogenesis neurocognitively, the cognitive awareness model (CAM) has been helpful for explaining the stream of events from sensory input to behavioural/affective and metacognitive outputs. According to CAM, there are three types of anosognosia: (i) primary anosognosia, (ii) executive anosognosia, and (iii) mnemonic anosognosia. These types of anosognosia are generated from different neurocognitive modulations leading to metacognitive outputs or behavioural/affective regulations. Primary anosognosia is considered to be caused by deficits in the metacognitive awareness system (MAS). While preserved MAS function is associated with milder depression and anxiety in AD, a severer depressive mood in patients with mild AD can inversely cause self-underestimation. The modulation of executive anosognosia is thought to be associated with dangerous/disinhibition behaviours and apathy among NPS sub-symptoms, via impairments of comparator mechanism (Cm) within the central executive system. Other neurobehavioral reactions linked to self-awareness include 'denying' and 'confabulation', and each of these reactions is thought to be affected by the MAS and a Cm. Denial of one's own memory impairments appears as a defensive reaction to protect against dysphoric feelings, and the confabulatory comment is instantly reaction constructed by fabrications according to misinterpretations of memory information about oneself. Similarly, the innovative development of a theoretical model (CAM) has contributed to explaining the mechanism of anosognosia and some neurobehavioral outputs from a neurocognitive perspective.
Topics: Aged; Agnosia; Alzheimer Disease; Awareness; Cognitive Dysfunction; Depression; Depressive Disorder; Humans; Memory Disorders; Neurodegenerative Diseases; Neuropsychological Tests
PubMed: 31930617
DOI: 10.1111/psyg.12507 -
Seminars in Neurology 2000Limb apraxia is an impairment in the ability to perform skilled, purposive limb movements as the result of neurological dysfunction. In right-handed individuals, limb... (Review)
Review
Limb apraxia is an impairment in the ability to perform skilled, purposive limb movements as the result of neurological dysfunction. In right-handed individuals, limb apraxia is associated with left hemisphere lesions. This article reviews the subtypes and neuroanatomic correlates of limb apraxia, including limb kinetic apraxia, ideomotor apraxia, ideational apraxia, and conceptual apraxia. The functional impact of limb apraxia on the individual is discussed. Strategies for the assessment and management of this disorder are reviewed.
Topics: Agnosia; Apraxia, Ideomotor; Cerebral Cortex; Humans; Movement; Neural Pathways
PubMed: 11149703
DOI: 10.1055/s-2000-13180 -
Cortex; a Journal Devoted To the Study... Dec 2018
Topics: Agnosia; Deglutition Disorders; Humans; Male; Middle Aged; Neuropsychological Tests
PubMed: 30292345
DOI: 10.1016/j.cortex.2018.08.023 -
Acta Oto-laryngologica Jul 2011A 27-year-old female showed auditory agnosia after long-term severe hydrocephalus due to congenital spina bifida. After years of hydrocephalus, she gradually suffered...
A 27-year-old female showed auditory agnosia after long-term severe hydrocephalus due to congenital spina bifida. After years of hydrocephalus, she gradually suffered from hearing loss in her right ear at 19 years of age, followed by her left ear. During the time when she retained some ability to hear, she experienced severe difficulty in distinguishing verbal, environmental, and musical instrumental sounds. However, her auditory brainstem response and distortion product otoacoustic emissions were largely intact in the left ear. Her bilateral auditory cortices were preserved, as shown by neuroimaging, whereas her auditory radiations were severely damaged owing to progressive hydrocephalus. Although she had a complete bilateral hearing loss, she felt great pleasure when exposed to music. After years of self-training to read lips, she regained fluent ability to communicate. Clinical manifestations of this patient indicate that auditory agnosia can occur after long-term hydrocephalus due to spina bifida; the secondary auditory pathway may play a role in both auditory perception and hearing rehabilitation.
Topics: Adult; Agnosia; Auditory Pathways; Auditory Perception; Diagnosis, Differential; Evoked Potentials, Auditory, Brain Stem; Female; Follow-Up Studies; Humans; Hydrocephalus; Neuroimaging; Otoacoustic Emissions, Spontaneous; Spinal Dysraphism; Time Factors
PubMed: 21413843
DOI: 10.3109/00016489.2011.553631 -
Behavioural Brain Research May 1985Apperceptive visual agnosia is normally held to be a specific deficit in 'apperception' - a hypothetical postsensory stage in visual processing. This paper describes the...
Apperceptive visual agnosia is normally held to be a specific deficit in 'apperception' - a hypothetical postsensory stage in visual processing. This paper describes the investigation of a patient diagnosed as suffering from a classical apperceptive agnosia resulting from carbon monoxide poisoning. Controlled behavioural testing confirmed the apparent agnosia but revealed that he could be trained to make a number of visual discriminations which had not been apparent from routine clinical examination and that he suffered a number of subtle sensory impairments which likewise had not hitherto been apparent. Evoked potential recording to grating patterns showed a complex pattern of brain responses involving interactions between spatial frequency, orientation and hemisphere recorded from. The data suggested that the agnosia was caused by sensory impairments rather than a deficit in apperception. We proposed that the impairments were caused by loss of certain spatial frequency and orientation information but rejected an interpretation based on the concept of processing channels in favour of one based on object contour masking by a peppery field defect caused by disseminated lesions. This interpretation received some support from fine grain static perimetry, contrast sensitivity function measurement and orientation discrimination in the two hemifields. Qualitatively similar results were obtained in normal subjects whose field was artificially masked. The results have implications for theories of visual agnosia and for theories of vision based on the concept of processing channels.
Topics: Agnosia; Brain Mapping; Carbon Monoxide Poisoning; Discrimination, Psychological; Evoked Potentials, Visual; Humans; Male; Orientation; Perceptual Masking; Visual Fields; Visual Pathways; Visual Perception
PubMed: 4005031
DOI: 10.1016/0166-4328(85)90177-9