title: Predicting hand function after hemidisconnection.
abstract: Hemidisconnections (i.e. hemispherectomies or hemispherotomies) invariably lead to contralateral hemiparesis. Many patients with a pre-existing hemiparesis, however, experience no deterioration in motor functions, and some can still grasp with their paretic hand after hemidisconnection. The scope of our study was to predict this phenomenon. Hypothesizing that preserved contralateral grasping ability after hemidisconnection can only occur in patients controlling their paretic hands via ipsilateral corticospinal projections already in the preoperative situation, we analysed the asymmetries of the brainstem (by manual magnetic resonance imaging volumetry) and of the structural connectivity of the corticospinal tracts within the brainstem (by magnetic resonance imaging diffusion tractography), assuming that marked hypoplasia or Wallerian degeneration on the lesioned side in patients who can grasp with their paretic hands indicate ipsilateral control. One hundred and two patients who underwent hemidisconnections between 0.8 and 36 years of age were included. Before the operation, contralateral hand function was normal in 3/102 patients, 47/102 patients showed hemiparetic grasping ability and 52/102 patients could not grasp with their paretic hands. After hemidisconnection, 20/102 patients showed a preserved grasping ability, and 5/102 patients began to grasp with their paretic hands only after the operation. All these 25 patients suffered from pre- or perinatal brain lesions. Thirty of 102 patients lost their grasping ability. This group included all seven patients with a post-neonatally acquired or progressive brain lesion who could grasp before the operation, and also all three patients with a preoperatively normal hand function. The remaining 52/102 patients were unable to grasp pre- and postoperatively. On magnetic resonance imaging, the patients with preserved grasping showed significantly more asymmetric brainstem volumes than the patients who lost their grasping ability. Similarly, these patients showed striking asymmetries in the structural connectivity of the corticospinal tracts. In summary, normal preoperative hand function and a post-neonatally acquired or progressive lesion predict a loss of grasping ability after hemidisconnection. A postoperatively preserved grasping ability is possible in hemiparetic patients with pre- or perinatal lesions, and this is highly likely when the brainstem is asymmetric and especially when the structural connectivity of the corticospinal tracts within the brainstem is asymmetric.
authors.affiliation: 1 Department of Paediatric Neurology and Developmental Medicine, Children's Hospital, University of Tübingen, Germany Hanna.Kuepper@med.uni-tuebingen.de.
authors.forename: Hanna
authors.initials: H
authors.lastname: Küpper
authors.affiliation: 2 Neurosurgery Clinic and Clinic for Epilepsy Surgery, Schön Klinik Vogtareuth, Germany.
authors.forename: Manfred
authors.initials: M
authors.lastname: Kudernatsch
authors.affiliation: 3 Clinic for Neuropaediatrics and Neurorehabilitation, Epilepsy Centre for Children and Adolescents, Schön Klinik, Vogtareuth, Germany.
authors.forename: Tom
authors.initials: T
authors.lastname: Pieper
authors.affiliation: 1 Department of Paediatric Neurology and Developmental Medicine, Children's Hospital, University of Tübingen, Germany.
authors.forename: Samuel
authors.initials: S
authors.lastname: Groeschel
authors.affiliation: 4 Biomedical Engineering Department, King's College London, UK.
authors.forename: Jacques-Donald
authors.initials: JD
authors.lastname: Tournier
authors.affiliation: 5 Florey Institute of Neuroscience and Mental Health, Heidelberg, Victoria, Australia.
authors.forename: David
authors.initials: D
authors.lastname: Raffelt
authors.affiliation: 3 Clinic for Neuropaediatrics and Neurorehabilitation, Epilepsy Centre for Children and Adolescents, Schön Klinik, Vogtareuth, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Winkler
authors.affiliation: 3 Clinic for Neuropaediatrics and Neurorehabilitation, Epilepsy Centre for Children and Adolescents, Schön Klinik, Vogtareuth, Germany.
authors.forename: Hans
authors.initials: H
authors.lastname: Holthausen
authors.affiliation: 1 Department of Paediatric Neurology and Developmental Medicine, Children's Hospital, University of Tübingen, Germany 3 Clinic for Neuropaediatrics and Neurorehabilitation, Epilepsy Centre for Children and Adolescents, Schön Klinik, Vogtareuth, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Staudt
mesh_terms: D000293:Adolescent; D000328:Adult; D001933:Brain Stem / Q000000981:diagnostic imaging*; D002648:Child; D002675:Child, Preschool; D056324:Diffusion Tensor Imaging / Q000379:methods; D005260:Female; D006225:Hand / Q000503:physiopathology*; D038421:Hemispherectomy / Q000009:adverse effects*; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D017063:Outcome Assessment, Health Care; D010291:Paresis / Q000151:congenital / Q000503:physiopathology*; D011183:Postoperative Complications / Q000000981:diagnostic imaging / Q000503:physiopathology; D011379:Prognosis; D011712:Pyramidal Tracts / Q000000981:diagnostic imaging*; D055815:Young Adult
keywords: congenital hemiparesis; diffusion-weighted MRI tractography; hemidisconnection; ipsilateral (re)organization