Chronic anosognosia: a case report and theoretical account.

Unawareness of motor disorders (anosognosia) has often been reported after brain lesions, and it has been considered a temporary condition common in the acute and post-acute phases. The presence of anosognosia in a chronic phase (i.e. lasting more than few weeks) is a rare occurrence, thought to be the result of reasoning deficits which prevent patients from performing an adequate check of reality. Although this assumption is widely shared amongst researchers, only a few studies have actually addressed this issue. We report on the case of a patient (NS) who was still showing anosognosia for hemiplegia 1 year after a traumatic brain-head injury, while his reasoning abilities were well preserved. By means of a series of tests and experiments, we evaluated the main theoretical approaches. NS's long-lasting anosognosia is discussed in terms of a combination of clinical manifestations, whereby personal neglect and motor-sensory information play a key role in preventing awareness, whereas memory difficulties in updating pre-existing personal schema may be crucial in maintaining NS's anosognosic status.