title: Hemispherectomy sustained before adulthood does not cause persistent hemispatial neglect.
abstract: BACKGROUND
  Hemispatial neglect has been well established in adults following acute ischemic stroke, but has rarely been investigated in children and young adults following brain injury. It is known that young brains have a tremendous potential for reorganization; however, there is controversy as to whether functions are assumed by the opposite hemisphere, or perilesional areas in the same hemisphere. Patients with intractable epilepsy who undergo hemispherectomy for treatment are missing the entire cortex on one side following surgery. In these patients, only the opposite hemisphere is available to assume function. Therefore, they provide the unique opportunity to determine in what cases the left or right hemisphere can take over the spatial attention functions of the opposite hemisphere following damage. The objective of this study was to determine the incidence and types of hemispatial neglect in children and young adults following both right- and left-sided hemispherectomy; which types of spatial attention functions can be assumed by the opposite hemisphere; and whether factors like their age at time of surgery, handedness, or gender influence recovery.
  
  
  METHODS
  Thirty-two children and young adults who had previously undergone hemispherectomy were administered two tests to evaluate for two types of hemispatial neglect: a gap detection test and a line cancellation test. Egocentric neglect was defined as significantly more omissions of targets on the contralesional versus ipsilesional side of the page (by chi square analysis; p<.05). Allocentric neglect was defined as significantly more errors in detecting contralesional versus ipsilesional gaps in circles.
  
  
  RESULTS
  Only one of the patients displayed statistically significant hemispatial egocentric neglect on the line cancellation test, and none of the patients displayed statistically significant egocentric or allocentric neglect on the gap detection test.
  
  
  CONCLUSIONS
  These results imply that reorganization to the contralateral hemisphere occurs peri-hemispherectomy, as there are no perilesional areas to assume function.
authors.affiliation: Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Elisabeth B
authors.initials: EB
authors.lastname: Marsh
authors.forename: Melissa
authors.initials: M
authors.lastname: Newhart
authors.forename: Jonathan T
authors.initials: JT
authors.lastname: Kleinman
authors.forename: Jennifer
authors.initials: J
authors.lastname: Heidler-Gary
authors.forename: Eileen P G
authors.initials: EP
authors.lastname: Vining
authors.forename: John M
authors.initials: JM
authors.lastname: Freeman
authors.forename: Eric H
authors.initials: EH
authors.lastname: Kossoff
authors.forename: Argye E
authors.initials: AE
authors.lastname: Hillis
mesh_terms: D000222:Adaptation, Physiological; D000223:Adaptation, Psychological; D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002648:Child; D003423:Critical Period, Psychological; D004827:Epilepsy / Q000601:surgery*; D005260:Female; D007839:Functional Laterality; D038421:Hemispherectomy / Q000009:adverse effects*; D006801:Humans; D008297:Male; D009473:Neuronal Plasticity; D010468:Perceptual Disorders / Q000209:etiology*; D020127:Recovery of Function; D055815:Young Adult