What is mine? Behavioral and anatomical dissociations between
somatoparaphrenia and anosognosia for hemiplegia
Issue title: Primary Progressive Aphasia and Post-Stroke
Aphasia: Some Complementary Insights into Brain-Behavior
Relationships/Hemispatial Neglect and Related Disorders
Affiliations: Psychology Department, University of Milano-Bicocca,
Milan, Italy | Psychology Department, University of Pavia, Pavia,
Italy | Cognitive Neuropsychology Laboratory, Niguarda Ca'
Granda Hospital, Milan, Italy | IRCCS Galeazzi, Milan, Italy
Note: [] Corresponding author: Eraldo Paulesu, Psychology Department,
University of Milano Bicocca, Piazza dell'Ateneo Nuovo 1, Milano, Italy.
E-mail: eraldo.paulesu@unimib.it
Abstract: We describe the clinical manifestations and the lesion patterns of
five patients with somatoparaphrenia, the denial of ownership for a paralyzed
limb, who showed the rare dissociation from anosognosia for hemiplegia. Similar
cases have been only occasionally cited in the literature with scanty
descriptions of their symptoms and no detailed anatomical assessment. All
patients had extrapersonal and at least mild personal neglect. The lesions
pattern was mainly subcortical, with a significant involvement of the right
thalamus, the basal ganglia and the internal capsule. A formal comparison
between the anatomical pattern previously associated with anosognosia in a
study performed in 2005 by Berti and colleagues, and the lesion distribution of
each patient clearly shows that our pure somatoparaphrenic patients had a
sparing of most of the regions associated with anosognosia for hemiplegia. The
behavioral dissociation between SP and anosognosia for hemiplegia, together
with this new anatomical evidence, suggests that motor awareness is not
sufficient to build up a sense of ownership and therefore these two cognitive
abilities are at least in part functionally independent and qualitatively
different.
