Differences in the time course of recovery of anosognosia: evidence from a longitudinal study of two cases

Following right brain damage, some patients experience anosognosia, which is a deficit of self-awareness affecting motor, somatosensory, or visual functions on the left side of the body. While domain dissociations in anosognosia have been studied extensively, the time course of recovery remains poorly understood. This study examines the longitudinal recovery time course of anosognosia in two patients presenting hemiplegia, hemianesthesia, and visual field defect after right brain damage. Anosognosia was assessed using the Bisiach four-point scale, a self-assessment of daily life activities, and interview reports. At onset, both patients exhibited complete anosognosia for left motor, somatosensory and visual field deficit. Anosognosia for hemiplegia recovered first, and was followed by recovery of anosognosia for hemianesthesia, while anosognosia for visual field defect persisted longer. This study provides evidence for differences in the time course of recovery of anosognosia for motor and sensory deficits. These findings question underlying mechanisms of awareness deficits: domain-specific or unitary models.