Background Patients with asomatognosia generally describe parts of their body as missing or disappeared from corporeal awareness. This disturbance is generally attributed to damage in the right posterior parietal cortex. However, recent neuroimaging and electrophysiological studies suggest that corporeal awareness and embodiment of body parts are instead linked to the premotor cortex of both hemispheres.
Patient We describe a patient with asomatognosia of her left arm due to damage in the right premotor and motor cortices. The patient's pathological embodiment for her left arm was associated with mild left somatosensory loss, mild frontal dysfunction, and a behavioral deficit in the mental imagery of human arms.
Conclusion Asomatognosia may also be associated with damage to the right premotor cortex.
Asomatognosia is defined as a patient's feeling that parts of his or her body are “missing” or have disappeared from corporeal awareness.1 Evidence from patients with focal brain damage suggests that asomatognosia is linked to posterior parietal lesions, especially of the right hemisphere, and generally affects the contralesional body.1-8 Although experimental findings in patients with asomatognosia are rare, these studies showed that asomatognosia may be modified by touching the missing body part or by looking at it, suggesting multisensory mechanisms in awareness and embodiment of body parts.1,9
Herein we describe a patient with asomatognosia of her left arm due to 2 small lesions in the right premotor cortex (PMC) and the motor cortex. We discuss asomatognosia with respect to involved brain functions and regions.