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Query: UMLS:C0038454 (stroke)
 147,016 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Some patients with anosognosia for hemiplegia, i.e. apparent unawareness of hemiplegia, have been clinically observed to show 'tacit' or 'implicit' awareness of their deficits. Here we have experimentally examined whether implicit and explicit responses to the same deficit-related material can dissociate. Fourteen stroke patients with right hemisphere lesions and contralesional paralysis were tested for implicit and explicit responses to brief sentences with deficit-related themes. These responses were elicited using: (i) a verbal inhibition test in which patients had to inhibit completing each sentence with an automatic response (implicit task) and (ii) a rating procedure in which patients rated the self-relevance of the same sentences (explicit task). A group of anosognosic hemiplegic patients was significantly slower than a control group of aware hemiplegic patients in performing the inhibition task with deficit-related sentences than with other emotionally negative themes (relative to neutral themes). This occurred despite their explicit denial of the self-relevance of the former sentences. Individual patient analysis showed that six of the seven anosognosic patients significantly differed from the control group in this dissociation. Using lesion mapping procedures, we found that the lesions of the anosognosic patients differed from those of the 'aware' controls mainly by involving the anterior parts of the insula, inferior motor areas, basal ganglia structures, limbic structures and deep white matter. In contrast, the anosognosic patient without implicit awareness had more cortical lesions, mostly in frontal areas, including lateral premotor regions, and also in the parietal and occipital lobes. These results provide strong experimental support for a specific dissociation between implicit and explicit awareness of deficits. More generally, the combination of our behavioural and neural findings suggests that an explicit, affectively personalized sensorimotor awareness requires the re-representation of sensorimotor information in the insular cortex, with possible involvement of limbic areas and basal ganglia circuits. The delusional features of anosognosia for hemiplegia can be explained as a failure of this re-representation.
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PMID:Implicit awareness in anosognosia for hemiplegia: unconscious interference without conscious re-representation. 2082 84

Anosognosia or lack of illness awareness is a clinical manifestation of both schizophrenia and right hemispheric lesions associated with stroke, neurodegeneration, or traumatic brain injury. It is thought to result from right hemispheric dysfunction or interhemispheric disequilibrium, which provides a neuroanatomical model for illness unawareness in schizophrenia. Lack of insight contributes to medication nonadherence and poor treatment outcomes and is often refractory to pharmacological and psychological interventions. We present the first report of transient illness awareness (<8 hours) after individual bilateral electroconvulsive therapy treatments in the case of a 39-year-old man with antipsychotic refractory schizophrenia. Electroencephalography demonstrated frontal slow wave activity with shifting frontotemporal predominance, which was concurrent with the patient's transient level of insight. A systematic review of the literature on electroconvulsive therapy-induced illness awareness in schizophrenia and psychotic disorders produced zero relevant results. Future research should focus on the prospective role of focal interventions, such as transcranial magnetic stimulation, in the development of a neurophysiological model for anosognosia reversal in schizophrenia that may, in turn, contribute to novel therapeutic developments targeting lack of illness awareness.
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PMID:Transient insight induction with electroconvulsive therapy in a patient with refractory schizophrenia: a case report and systematic literature review. 2096 68

Anosognosia for hemiplegia is a common and striking disorder following stroke. Because it is typically transient and variable, it remains poorly understood and has rarely been investigated at different times in a systematic manner. Our study evaluated a prospective cohort of 58 patients with right-hemisphere stroke and significant motor deficit of the left hemibody, who were examined using a comprehensive neuropsychological battery at 3 days (hyperacute), 1 week (subacute) and 6 months (chronic) after stroke onset. Anosognosia for hemiplegia was frequent in the hyperacute phase (32%), but reduced by almost half 1 week later (18%) and only rarely seen at 6 months (5%). Anosognosia for hemiplegia was correlated with the severity of several other deficits, most notably losses in proprioception, extrapersonal spatial neglect and disorientation. While multiple regression analyses highlighted proprioceptive loss as the most determinant factor for the hyperacute period, and visuospatial neglect and disorientation as more determinant for the subacute phase, patients with both proprioceptive loss and neglect had significantly higher incidence of anosognosia for hemiplegia than those with only one deficit or no deficits (although a few double dissociations were observed). Personal neglect and frontal lobe tests showed no significant relation with anosognosia for hemiplegia, nor did psychological traits such as optimism and mood. Moreover, anosognosia for neglect and prediction of performance in non-motor tasks were unrelated to anosognosia for hemiplegia, suggesting distinct monitoring mechanisms for each of these domains. Finally, by using a voxel-based statistical mapping method to identify lesions associated with a greater severity of anosognosia, we found that damage to the insula (particularly its anterior part) and adjacent subcortical structures was determinant for anosognosia for hemiplegia in the hyperacute period, while additional lesions in the premotor cortex, cingulate gyrus, parietotemporal junction and medial temporal structures (hippocampus and amygdala) were associated with the persistence of anosognosia for hemiplegia in the subacute phase. Taken together, these results suggest that anosognosia for hemiplegia is likely to reflect a multi-component disorder due to lesions affecting a distributed set of brain regions, which can lead to several co-existing deficits in sensation, attention, interoceptive bodily representations, motor programming, error monitoring, memory and even affective processing, possibly with different combinations in different patients.
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PMID:Anosognosia for hemiplegia: a clinical-anatomical prospective study. 2112 95

This article highlights the most recent findings regarding the rehabilitation interventions for the syndromes of visual neglect and anosognosia for hemiplegia that occur following right hemisphere stroke. We review papers published in the past 4 years pertaining to therapeutic approaches for these two syndromes in order to identify the trends in the development of effective interventions. Overall, it appears well recognized that visual neglect syndromes and awareness syndromes frequently co-occur and both include complex, multifaceted impairments leading to significant difficulties in daily life functioning following stroke. Thus, the interventions for these syndromes must be multifaceted in order to address the complex interplay of cognitive-behavioral-emotional components. There appears to be a trend for using combination therapeutic interventions that address these components.
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PMID:Recent trends in rehabilitation interventions for visual neglect and anosognosia for hemiplegia following right hemisphere stroke. 2133 36

Buchwald (1878 ) used the term 'mirror writing' to indicate writing in the reverse direction to what is normal in a particular language and in which the individual letters are also reversed. Cases of healthy individuals (i.e., Leonardo da Vinci and Lewis Carroll) as well as brain-damaged patients have been described in the literature. Here, we report the case of PM, a 70-year-old right-handed woman who showed right hemiplegia and mirror writing following a stroke in the left lenticular nucleus and internal capsulae. PM underwent a complete neuropsychological evaluation, which included copying, dictation and spontaneous writing in both hemispaces with both hands. She was also tested for topographical disorientation, visuo-spatial disorders and body schema deficits. We observed isolated mirror writing only when PM wrote with the left hand, without differences between hemispaces. She also showed a left-right disorientation, a body topological map disorder and an egocentric misrepresentation. The presence of mirror writing not confined to one hemispace and the co-presence of executive function disorders, as well as anosognosia, suggests damage to our patient's sub-cortical frontal network. As no previous interpretation fits with PM's symptoms, we hypothesize that mirror writing resulted from damage to her egocentric frame of reference. This hypothesis allows us to interpret the patient's array of disorders, including mirror writing, body topological map disorder, left-right confusion and egocentric representation.
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PMID:Mirror writing resulting from an egocentric representation disorder: a case report. 2183 Aug 64

The objective of this study is to report a new manifestation of acute stroke following antifibrinolytic agent administration in young women carrying heterozygosity for methylene-tetrahydrofolate reductase (MTHFR) C677T. The study included two young women who developed an acute ischaemic stroke following three days of tranexamic acid administration for bleeding gynaecological disorders. Case 1, a 44-year-old woman, presented left hemiplegia, mild dysarthria and anosognosia. Brain magnetic resonance imaging showed right ischaemic fronto-temporal lesion due to subocclusion of the right middle cerebral artery. Case 2, a 49-year-old woman, developed aphasia and right hemiplegia. Neuroimaging showed left capsular and periventricular infarcts due to near occlusion of the left internal carotid artery. Thrombophilia screening, coagulation parameters, homocysteine testing, 12-lead electrocardiography, and transthoracic and transoesophageal echocardiography were unremarkable. Genetic assay showed that both patients carried heterozygosity for MTHFR C677T, in which cytosine (C) is replaced by thymidine (T) at base position 677. To our knowledge, this is the first report describing the association between genetic factors and the onset of stroke following antifibrinolytic drugs intake. These data suggest a synergic effect of plasminogen activator inhibitor and heterozygosity for MTHFR C677T on the pathogenetic mechanisms leading to ischaemic stroke in young people.
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PMID:Ischaemic stroke following tranexamic acid in young patients carrying heterozygosity of MTHFR C677T. 2190 3

Somatoparaphrenia consists in abnormal or bizarre verbal reports about some parts of the body. Such a pathological condition usually lasts for days or weeks and is variably associated with other cognitive defects. In the present paper we describe exceptionally long-lasting somatoparaphrenia in two focal brain-damaged patients: GA who had a right hemorrhagic fronto-parieto-temporal stroke and AC who developed a left ischemic parieto-occipital lesion. The presence and severity of somatoparaphrenia did not change in either patient during a 2-year follow-up, whereas the two patients showed different evolution of anosognosia for motor disorders, severity of extrapersonal neglect and cognitive impairments. Moreover, impairment of position sense was associated with somatoparaphrenia in one patient only; neither patient showed personal neglect. The reported clinical observations suggest that somatoparaphrenia can be observed as a body-related chronic disorder and can outlast other cognitive defects, even if it arose in conjunction with them.
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PMID:Chronic somatoparaphrenia: a follow-up study on two clinical cases. 2193 Feb 65

How should stroke patients with poor motor awareness be managed? This question is important because unawareness (or anosognosia) is related to poor rehabilitation and prognosis. This narrative review provides a guide for clinicians and (applied) academics to understanding, assessing and managing anosognosia. Questions addressed are: What is anosognosia? What causes anosognosia? How can anosognosia be assessed? And how can anosognosia be managed? We suggest that anosognosia is a multifaceted disorder, with diverse neuroanatomical and psychopathological origins. Assessment should measure various aspects of awareness, and management should be multidimensional to address problems with motor function, awareness, and emotional/motivational disturbance.
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PMID:Unawareness after stroke: a review and practical guide to understanding, assessing, and managing anosognosia for hemiplegia. 2193 43

This is the case report of RB, a 68-year-old retired woman who, following an extensive right sided ischaemic stroke, showed hemiplegia, anosognosia and allochiria, but no somato-sensory deficits and no visuospatial neglect. A high resolution 3D MRI structural scan of her brain was acquired to define the structural damage in detail. Morphometric analyses of grey and white matter data revealed a large lesion which involved most of her right parietal, temporal, and mesial frontal cortex, with partial sparing of the right dorsolateral prefrontal cortex and part of the posterior corpus callosum. Detailed examination showed that RB attributed sensory stimuli, both on the left and on the right, to the opposite side of her body. This mirror reversed representation of her body caused misattribution of items even in the absence of stimulation, as for instance when the patient spontaneously reported pain in her right knee while pointing to her left knee. RB's neuropsychological profile showed normal or borderline performance on most cognitive tasks. Language comprehension was intact and she could tell left from right without difficulty in all instances except for those referable to her soma. To our knowledge this is the first description of severe allochiria for body representation in the absence of neglect. The evidence from this case supports the developing concept that the body representation is not simply a systematic registration of proprioceptive inputs, but that the brain has a more sophisticated high level representation of one's body map which is updated on the basis of multimodal information.
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PMID:Translocation of the embodied self without visuospatial neglect. 2234 42

The study evaluates the possible relations between cognitive impairment, persisting anosognosia for hemiplegia and peripersonal neglect. Thirty eight chronic right hemisphere stroke patients were divided in three age- and education-matched groups: A (n = 13) patients with left hemiparesis, peripersonal neglect, and anosognosia for hemiplegia; B (n = 12) patients with left hemiparesis and peripersonal neglect, and C (n = 13) patients with left hemiparesis only. We used MMSE and WAIS Verbal IQ and verbal subtests to assess cognitive impairment in patients, in order to avoid a bias due to visuospatial deficit, which is common in patients with neglect. VIQ, Information, Digit Span and Vocabulary WAIS subtests as well as MMSE were found to be significantly lower in group A versus group B. No difference was found in any test between groups B and C, indicating a general worse cognition in patients compared to those without anosognosia for hemiplegia. Patients with anosognosia for hemiplegia also showed larger brain lesions and, more frequently, frontal, parietal, temporal and basal ganglia involvement, particularly if they had low verbal IQ, indicating a relationship between cognitive impairment, persisting anosognosia for hemiplegia and large right hemisphere lesions.
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PMID:General intellectual impairment in chronic right hemisphere damaged patients with anosognosia: a group study. 2236 Feb 72


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