Abstract
We report a patient with severe anosognosia for hemiplegia, who recovered instantly and permanently when viewing herself in a video replay. We believe the observed dramatic reinstatement of the patient's awareness related to her self-observation ‘from the outside’ (3rd person perspective) and ‘off-line’ (at a time later than the actual attempt to execute a movement); her anosognosia had been unaltered when she observed her plegic arm in her ipsilateral visual field (self-observation from a 1st-person perspective and ‘on-line’). To our knowledge, the role of self-observation in videos or mirrors has not being assessed in AHP to date. Our study provides preliminary evidence that, when right hemisphere damage impairs the ability to update one's body representation, judgements relying on 3rd-person and off-line self-observation may be spared in some patients and may facilitate 1st person awareness.
Introduction
In humans, central neurological damage may lead to contralateral hemiplegia. This may sometimes be accompanied by a higher-order impairment of body awareness which, similarly to the hemiplegia, concerns the contralateral side of the body. Patients may falsely believe that they can move their paralysed limbs despite blatant evidence to the contrary, and they may even claim that they have moved to an examiner, when no such movement has taken place. This symptom, termed anosognosia for hemiplegia (Babinski, 1914) (AHP; apparent unawareness of paralysis) is often a transient phenomenon, with patients spontaneously recovering within days, weeks or months from onset. Nevertheless, the occurrence of AHP at the critical acute state following stroke may impede motor rehabilitation (Gialanella, Monguzzi, Santoro, & Rocchi, 2005) and limit accessibility to thrombolysis (Di Legge, Fang, Saposnik, & Hachinski, 2005). In addition, recent reviews suggest that approximately 30% of reported anosognosic patients remain unaware of their deficits beyond the acute phase of their illness (Orfei et al., 2007; Pia, Neppi-Modona, Ricci, & Berti, 2004). AHP occurs more frequently following right brain damage, usually in the frontoparietal cortex, but it has also been reported following subcortical and left-hemisphere lesions (Orfei et al., 2007 and Pia et al., 2004). No available treatment exists for AHP, although temporary remission has been reported following vestibular stimulation (Rubens, 1985).
Patients with AHP typically remain anosognosic when their plegic arm is brought into the ipsilateral visual field. However, to our knowledge, self-observation from a 3rd person perspective has not being used in the treatment of AHP to date. We report a patient with anosognosia, who recovered instantly and permanently from her anosognosia after viewing herself in a video replay. We believe this dramatic reinstatement of awareness related to the observation of herself ‘from the outside’ (3rd person perspective), and potentially also to the observation of oneself at a time later than the actual attempt to execute a movement (‘off-line’).
5. Conclusion
Our study provides preliminary evidence that, when right hemisphere damage impairs the ability to update 1st person body awareness, judgements relying on self-observation from a 3rd-person perspective and off-line may be spared, providing facilitating visual feedback to reinstate motor awareness. We therefore conclude that further studies in unaware patients should explore the usefulness and generalization of self-observation ‘from the outside’ and ‘off-line’. In particular, its optimal timing, orientation and spatial dimensions, and its relation to emotional factors, neglect and spontaneous recovery deserve further investigation.
