Anosognosia

ABSTRACT Impaired self-awareness impacts outcomes for individuals with brain injury. Self-awareness is a complex construct, with little known about how its presentation differs across diagnostic groups, or how brain injury-related changes are expressed by individuals in the early phase post-brain injury. This study aims to identify differences and similarities in patterns of self-awareness between patients with different brain injury diagnoses, and provide a clinical account of how individuals with ABI describe changes to themselves arising from brain injury...

Although neurocognitive models have been proposed to explain anosognosia in Alzheimer's disease (AD), the neural cascade responsible for its origin in the human brain remains unknown. Here, we build on a mechanistic dual-path hypothesis that brings error-monitoring and emotional processing systems as key elements for self-awareness, with distinct impacts on the emergence of anosognosia in AD. Proceeding from the notion of anosognosia as a dimensional syndrome, varying between a lack of concern about one's own deficits (i...

Self-unawareness concerning current symptoms remains a clinical challenge in Alzheimer's disease. Reduced self-awareness likely depends on complex biopsychosocial mechanisms that comprise multiple cognitive processes, regulated by personal goals and values. We specifically reviewed the cognitive processes impaired in unaware participants with AD by emphasizing the related impaired brain activity observed during task-based fMRI. Unawareness can be explained by a failure in functioning of or in connection between brain regions that intervene in access, retrieval and updating of (present or extended) self-information (posterior midline, medial temporal, inferior parietal cortices), or in its monitoring, evaluation, or control (medial and lateral prefrontal cortices)...

To diagnose mild cognitive impairment, it is crucial to understand whether subjective cognitive complaints reflect objective cognitive deficits. This question has mostly been investigated in the memory domain, with mixed results. Our study was one of the first to address it for language. Participants were 55-to-93-year-old memory clinic patients ( n  = 163). They filled in a questionnaire about subjective language and memory complaints and performed two language tasks (naming-by-definition and sentence comprehension)...

Anton syndrome results from damage to the visual cortex of the occipital lobes, where the anterior visual pathways remain intact. This damage results in the characteristic triad of cortical blindness, visual anosognosia, and visual confabulation. This case describes an 80-year-old male with a background of renal transplant 7 years prior, admitted to hospital with worsening transplant function, and soon after developed sudden onset cortical blindness. On examination, the patient was found to be in denial of his blindness and showed signs of visual confabulation, both of which pointed toward a diagnosis of Anton syndrome...

OBJECTIVE: Traumatic Brain Injury (TBI) is a silent public health epidemic that begins as a medical condition ("neurometabolic cascade") that may develop into significant psychiatric symptoms that negatively impact community reintegration for survivors following injury ("neuropsychosocial cascade"). However, survivors may not seek medical attention for a variety of reasons (e.g., anosognosia, fear of retaliation, no insurance). Therefore, medical incidence does not necessarily reflect the community prevalence of TBI...

OBJECTIVE: Two studies were performed to validate a brief, new method for assessing informant-patient discrepancies to quantify cognitive insight, and to compare it to an empirically supported model - the Cognitive Awareness Model (CAM). METHOD: Study 1 included 31 (52% male; Mage = 69.42) patients from an outpatient neuropsychological assessment clinic. Seven patients were diagnosed with probable Alzheimer's dementia (PAD), 15 mild cognitive impairment (MCI), and 9 no diagnosis (i...

OBJECTIVE: Craniopharyngiomas are extremely rare (incidence rate of 1.34 per million). Due to its proximity to the sellar/suprasellar prefrontal regions region, cognitive impairment, behavioral changes, and adverse endocrinological outcomes are common. Further, surgery and radiotherapy can further impact functioning. Currently, there is no parsimonious cognitive profile of adult patients following interventions. This case highlights the role of neuropsychological evaluations in monitoring global psychological functioning and frontal behavioral syndrome in an adult with recurrent craniopharyngioma...

OBJECTIVE: Mutations in CACNA1A gene can cause rare neurodegenerative conditions [spinocerebellar ataxia type 6 (SCA6); episodic ataxia type 2 (EA2)] which are caused by autosomal dominant mutations located on chromosome 19p13. Research suggests triplet repeat mutations in the CACNA1A gene are associated with SCA6 characterized by late onset, slowly progressive cerebellar ataxia. On the other hand, CACNA1A mutation with specific protein variant R1661H involvement is associated with EA2, characterized by early onset ataxia, which may be accompanied by vertigo, diplopia, dysarthria, and generalized weakness...

Anton-Babinski syndrome (ABS) is a rare neuropsychiatric condition characterized by visual anosognosia (denial of vision loss) and confabulation in the presence of intact anterior visual tracts. The most common cause of ABS is a cerebrovascular accident involving bilateral occipital lobe injuries with varying degrees of cortical blindness. In this report, we present the case of a woman with suspected ABS following a recurrent ischemic stroke in Malaysia. Establishing a proper diagnosis of stroke is crucial for modifying rehabilitation goals to ensure improved functional outcomes...

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BACKGROUND: Though not originally developed for this purpose, the Healthy Aging Brain Care Monitor (HABC-M) seems a valuable instrument for assessing anosognosia in Alzheimer's disease (AD). OBJECTIVES: Our study aimed at 1) investigating the validity of the HABC-M (31 items), and its cognitive, psychological, and functional subscales, in discriminating AD patients from controls; 2) exploring whether the HABC-M discrepancy scores between the self-reports of patients/controls in these different domains and the respective ratings provided by their caregivers/informants correlate with an online measure of self-awareness; 3) determining whether the caregiver burden level, also derived from the HABC-M, could add additional support for detecting anosognosia...

OBJECTIVE: Brain lesions sometimes induce a failure of recognition of one's own deficits (anosognosia). Lack of deficit awareness may underlie damage of modality-specific systems, e.g., visual cortex for visual anosognosia or motor/premotor cortex for motor anosognosia. However, focal lesions induce widespread remote structural and functional disconnection, and anosognosia, independent of modality, may also involve common neural mechanisms. METHODS: Here, we study the neural correlates of Anton syndrome (AS), anosognosia of blindness, and compare them with anosognosia for hemiplegia to test if they share different or common mechanisms...

BACKGROUND: Cognitive impairment is present in 40-65% of patients with multiple sclerosis (pwMS). Objectively measured cognitive performance often does not match patients' subjective perception of their own performance. OBJECTIVE: We aimed to compare cognitive performance and subjective perception of cognitive deficits between pwMS and healthy controls (HCs), as well as the accuracy of subjective perception. METHODS: In total, 54 HC and 112 pwMS (relapsing-remitting, RRMS, and progressive PMS) underwent neuropsychological evaluation and completed perceived deficit, fatigue, and anxiety-depression scales...

The ability of the brain to recognize and orient attention to relevant stimuli appearing in the visual field is highlighted by a tuning process, which involves modulating the early visual system by both cortical and subcortical brain areas. Selective attention is coordinated not only by the output of stimulus-based saliency maps but is also influenced by top-down cognitive factors, such as internal states, goals, or previous experiences. The basal ganglia system plays a key role in implicitly modulating the underlying mechanisms of selective attention, favouring the formation and maintenance of implicit sensory-motor memories that are capable of automatically modifying the output of priority maps in sensory-motor structures of the midbrain, such as the superior colliculus...

Huntington's disease (HD) is an inherited disease that leads to an inexorable progression of motor, cognitive and psychiatric disturbances. In the initial stages, the symptoms are not clearly disabling, and the patient may present a lack of awareness about the symptoms themselves, which we call anosognosia. However, anosognosia might not justify all passivity of the HD patient in face of the diagnosis. Patients may also experience the denial of illness, as a stage of grief, expected to happen in the face of the diagnosis of any neurodegenerative disorder...

Unawareness of memory deficits is an early manifestation in patients with Alzheimer's disease (AD), which often delays diagnosis. This intriguing behavior constitutes a form of anosognosia, whose neural mechanisms remain largely unknown. We hypothesized that anosognosia may depend on a critical synaptic failure in the error-monitoring system, which would prevent AD patients from being aware of their own memory impairment. To investigate, we measured event-related potentials (ERPs) evoked by erroneous responses during a word memory recognition task in two groups of amyloid positive individuals with only subjective memory complaints at study entry: those who progressed to AD within the five-year study period (PROG group), and those who remained cognitively normal (CTRL group)...

Altered self-awareness or anosognosia may impact patients' everyday life by interfering with their safe and independent functioning. Symptom awareness has been linked to executive dysfunctions caused by damage to frontal regions. Apathy is a frequent neuropsychiatric manifestation of Parkinson's disease (PD) and is considered a consequence of altered functioning of cortico-subcortical circuitries connecting the prefrontal cortex (PFC) with the basal ganglia. Thus, apathetic PD patients may be not be fully aware of their condition due to shared neuropathophysiological mechanisms...

OBJECTIVE: Unawareness of a deficit, anosognosia, can occur for visual or motor deficits and lends insight into awareness itself; however, lesions associated with anosognosia occur in many different brain locations. METHODS: We analyzed 267 lesion locations associated with either vision loss (with and without awareness) or weakness (with and without awareness). The network of brain regions connected to each lesion location was computed using resting-state functional connectivity from 1,000 healthy subjects...

BACKGROUND: Impaired awareness of one's own functioning is highly common in people with Korsakoff's syndrome (KS). However, it is currently unclear how awareness relates to impairments in daily functioning and quality of life (QoL). METHODS: We assessed how impaired awareness relates to cognitive, behavioral, physical, and social functioning and QoL by applying a network analysis. We used cross-sectional data from 215 patients with KS or other severe alcohol-related cognitive deficits living in Dutch long-term care facilities (LTCFs)...