The spatial side of somatoparaphrenia: a case study.
The perception of the bodily self in space is a composite cognitive function requiring a dynamic integrated brain mechanism. Somatoparaphrenia (SP), a delusional belief concerning the experienced disownership for the contralesional paralyzed arm, represents the disruption of such mechanism. In two experiments, we have investigated the alteration of limb disownership after spatial manipulations in a right-brain-damaged patient affected by chronic SP. In experiment 1 the patient's spatial attention was switched between the left and right sides of space. SP signs worsened when the patient was interviewed from the left compared to the right bedside. In the second experiment we showed the first systematic transient remission of SP using left caloric vestibular stimulation (CVS), a physiologic manipulation mainly acting on the spatial frame of reference. Taken together, these results shed further light on the spatial nuance of SP and on the importance of vestibular signals for the generation of a coherent body representation. Furthermore, our case study demonstrated the possibility of eliciting more severe SP signs if the patient is interviewed from the left bedside. Additionally, CVS applications may have an important impact on the rehabilitation of these symptoms.
a Department of Brain and Behavioral Sciences , University of Pavia , Pavia , Italy.|b Milan Center for Neuroscience , Milan , Italy.|c Department of Neurology and Stroke Unit , Niguarda Ca' Granda Hospital , Milan , Italy.
Gerardo
G
Salvato
a Department of Brain and Behavioral Sciences , University of Pavia , Pavia , Italy.|b Milan Center for Neuroscience , Milan , Italy.|c Department of Neurology and Stroke Unit , Niguarda Ca' Granda Hospital , Milan , Italy.
Martina
M
Gandola
d Department of Neurorehabilitation Sciences , Casa Cura Policlinico , Milan , Italy.
Laura
L
Veronelli
c Department of Neurology and Stroke Unit , Niguarda Ca' Granda Hospital , Milan , Italy.
Elio Clemente
EC
Agostoni
e Neuroradiology Department , Niguarda Ca' Granda Hospital , Milan , Italy.
Maurizio
M
Sberna
d Department of Neurorehabilitation Sciences , Casa Cura Policlinico , Milan , Italy.
Massimo
M
Corbo
a Department of Brain and Behavioral Sciences , University of Pavia , Pavia , Italy.|b Milan Center for Neuroscience , Milan , Italy.|c Department of Neurology and Stroke Unit , Niguarda Ca' Granda Hospital , Milan , Italy.
Gabriella
G
Bottini
D000369:Aged, 80 and over; D002540:Cerebral Cortex / Q000473:pathology*; D003702:Delusions / Q000150:complications*; D005260:Female; D007839:Functional Laterality; D006801:Humans; D009460:Neurologic Examination; D009483:Neuropsychological Tests; D010468:Perceptual Disorders / Q000503:physiopathology*; D012027:Reflex, Vestibulo-Ocular / Q000502:physiology; D013028:Space Perception / Q000502:physiology*; D015898:Tomography Scanners, X-Ray Computed
Somatoparaphrenia; caloric vestibular stimulation; right brain damage; space