Unawareness of deficit in acute stroke : Neuropsychological therapy matters

Abstract

Motor deficiency is the leading cause of disability following stroke and the main target of neurorehabilitation. However, the co-occurrence of certain cognitive deficits, such as unawareness (lack of insight into one’s stroke-induced symptoms) may impede rehabilitation and lead to poor functional outcome.1 Such patients are unaware of their rehabilitation needs and thus fail to comply with and benefit from interventions. Unawareness following stroke varies in severity, may concern different functional domains, or be specific to a given deficit (i.e. patients may fail to acknowledge one symptom [paralysis], but recognise another [memory problems]). A prototypical form of unawareness is ‘anosognosia for hemiplegia’ (AHP); the apparent inability to understand or acknowledge contralesional paralysis. Patients may falsely claim that they moved their paralysed limbs in front of the examiner, despite blatant evidence to the contrary. Some patients even attempt to get out of bed or engage in other activities that are clearly hazardous.2 AHP is commonly associated with righthemisphere lesions, although its occurrence after left-hemisphere strokes should not be ignored.3 AHP is reported to range from 33 to 58% of stroke victims, and persistent AHP may range from 10 to 17%.2 Sometimes these patients make comments that suggest partial or tacit awareness into their deficits4 and hence some clinicians or carers may believe that they are malingering or being ‘difficult’. However, these patients typically have genuine (neurologically-induced) unawareness and may even falsely ‘experience’ their limbs moving.