The pathologic substrate predicted pre- and postsurgery differences in outcomes, with hemimegalencephaly (but not hemispheric cortical dysplasia) patients doing worse in several domains. Furthermore, shorter seizure durations, seizure control, and greater presurgery developmental quotients predicted better postsurgery developmental quotients in all patients, irrespective of pathology.

We analyzed postsurgery linguistic outcomes of 43 hemispherectomy patients operated on at UCLA. We rated spoken language (Spoken Language Rank, SLR) on a scale from 0 (no language) to 6 (mature grammar) and examined the effects of side of resection/damage, age at surgery/seizure onset, seizure control postsurgery, and etiology on language development. Etiology was defined as developmental (cortical dysplasia and prenatal stroke) and acquired pathology (Rasmussen's encephalitis and postnatal stroke). We found that clinical variables were predictive of language outcomes only when they were considered within distinct etiology groups. Specifically, children with developmental etiologies had lower SLRs than those with acquired pathologies (p =.0006); age factors correlated positively with higher SLRs only for children with acquired etiologies (p =.0006); right-sided resections led to higher SLRs only for the acquired group (p =.0008); and postsurgery seizure control correlated positively with SLR only for those with developmental etiologies (p =.0047). We argue that the variables considered are not independent predictors of spoken language outcome posthemispherectomy but should be viewed instead as characteristics of etiology.

Fifteen posthemispherectomy children were examined to assess residual motor function of the paretic side using the 74-point Fugl-Meyer Assessment of Motor Recovery scale. The degree of residual motor control differed for upper and lower extremities, with hand function being most severely impaired. Posthemispherectomy motor outcomes also differed as a function of etiology: cortical dysplasia, perinatal infarct, and Rasmussen's encephalitis. Children whose intractable seizures resulted from perinatal middle cerebral artery stroke demonstrated the most spared motor function. To detect cortical areas that represented motor control of the hemiparetic side, we focused on voluntary control of the affected lower extremity. Seven of our patients were able to carry out a foot dorsiflexion paradigm during functional magnetic resonance imaging, and these results were compared with activations found in normal controls. All children showed activations in the sensorimotor network ipsilateral to the affected side. The perinatal infarct group demonstrated greater activity in the cingulate cortex, whereas the Rasmussen's encephalitis group had significant activations in the insula, suggesting etiology-specific differences in reorganization. These findings are discussed in the framework of our understanding of mechanisms of cortical plasticity in the injured brain and its relevance to neurologic rehabilitation. We suggest that imaging techniques are important tools in identifying cortical regions underlying functional reorganization. Furthermore, detection of such areas might become a basis for specific training promoting the optimal reorganization of cortical networks to enhance motor control.

Purpose-This study examined whether locomotor training, which included body weightsupported treadmill therapy, improved walking and induced cortical representational adaptations using functional magnetic resonance imaging in the remaining sensorimotor network after cerebral hemispherectomy.Methods-Hemispherectomy patients (n = 12) under-went 2 weeks of gait training for at least 30 hours each. They were tested pre-and posttraining with the Fugl-Meyer Motor Assessment, unassisted single-limb stance time, and usual and fastest walking speeds. Three patients performed voluntary ankle movements as the functional magnetic resonance imaging activation task pre-and posttraining. Control subjects included 5 healthy children tested 2 weeks apart, 2 of whom trained on the treadmill, and 2 hemispherectomy patients who received upper extremity rehabilitation and no gait therapy.Results-Although patients reported improvements with gait training, behavioral outcomes did not significantly change. Training was associated with increased volume and intensity of cortical activation in the primary sensorimotor (S1M1), supplementary motor, motor cingulate, and secondary soma-tosensory cortex for the paretic foot, along with greater overlap in the representation for each moving foot in S1M1 and the supplementary motor area of the remaining hemisphere. Control subjects showed a decrease in activation in these cortical regions after training.Conclusions-Locomotor training of hemispherectomy patients improved mobility subjectively in association with functional magnetic resonance imaging evidence of cortical remodeling with ankle dorsiflexion. These findings support the notion that hemispherectomy patients may respond to rehabilitation interventions through mechanisms of activity-dependent cortical plasticity. The authors hypothesize that developmentally persistent descending ipsilateral and contralateral In patients with hemiparetic stroke or spinal cord trauma, recent studies support the concept that locomotor interventions can improve walking even if therapy begins years after injury. [5][6][7][8][9] The common factor that seems to lead to successful rehabilitation is repeated practice of task-related movements. 10,11 One such task-oriented intervention for walking is body weight-supported treadmill training (BWSTT). 12,13 This technique partially supports the weight of the patient to prevent the paretic leg from buckling at the knees and enables therapists to safely optimize the kinematic, kinetic, and temporal components of gait that are tied to the stance and swing phases of walking. Studies also suggest that motor gains with locomotor therapy are accompanied by cortical reorganization as observed by functional magnetic resonance imaging (fMRI). 14 For walking, fMRI during ankle dorsiflexion appears to be a good marker of training-induced cerebral plasticity. 15 The purpose of this study was to pursue these concepts in children long after hemispherectomy. We hypothesized that locomotor training that included BWSTT would be...

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