Individual patterns of functional reorganization in the human cerebral cortex after capsular infraction

  title={Individual patterns of functional reorganization in the human cerebral cortex after capsular infraction},
  author={Cornelius Weiller and S C Ramsay and Richard J. S. Wise and Karl J. Friston and R. S. J. Frackowiak},
  journal={Annals of Neurology},
We have previously shown bilateral activation of motor pathways and the recruitment of additional motor areas in studies of groups of patients with recovery from motor stroke. We have now deveoloped a new positron emission tomographic technique to measure the changes in regional cerebral blood flow elicated duringsd a motor task in individual patients, relative to the cerebral activatuion found in normal subjects. The patterns of cerebral activation in each of 8 individual patients with… 

Cerebellar hemispheric activation ipsilateral to the paretic hand correlates with functional recovery after stroke.

Functional MRI results support a role for the cerebellum in mediating functional recovery from stroke and suggest a possible link between cerebellar activation and behavioural recovery from hand weakness from stroke.

Multimodal imaging of brain reorganization in motor areas of the contralesional hemisphere of well recovered patients after capsular stroke.

Effective recovery is based on enhanced utilization of ipsi- and contralesional resources, basic corticospinal commands arise from the lesioned hemisphere without recruitment of ('latent') uncrossed corticOSPinal tract fibres and increased contralsional activity probably facilitates control of recovered motor function by operating at a higher-order processing level, similar to but not identical with the extended network concerned with complex movements in healthy subjects.

Pilot study of functional MRI to assess cerebral activation of motor function after poststroke hemiparesis.

The explanation offered for the findings is that preexisting uncrossed motor neural pathways may be accessed or recruited to compensate for damage to the crossed motor pathways after ischemic stroke.

Contralesional Motor Cortex Activation Depends on Ipsilesional Corticospinal Tract Integrity in Well-Recovered Subcortical Stroke Patients

There may be beneficial reorganization in contralesional secondary motor areas with increasing damage to the corticospinal tract after subcortical stroke with implications for motor recovery processes.

Reorganization of the human ipsilesional premotor cortex after stroke.

Results indicate that PMdAH participates as a substrate mediating functional recovery of executive motor function in patients with focal lesions of corticospinal outflow originating in M1 and good motor recovery, consistent with the hypothesis that the dorsal premotor cortex of the affected hemisphere can reorganize to control basic parameters of movement usually assigned to M1 function.

Reorganization of sensory and motor systems in hemiplegic stroke patients. A positron emission tomography study.

Passive movements in hemiplegic stroke patients before clinical recovery elicit some of the brain activation patterns that have been described during active movements after substantial motor recovery.

Pattern of cortical reorganization in amyotrophic lateral sclerosis: a functional magnetic resonance imaging study

The results demonstrate a general pattern of functional changes after motor neuron degeneration and support the concept of a structurally parallel and functionally specialized organization of voluntary motor control.

Cortical motor and somatosensory representation: effect of cerebral lesions.

Central lesions are more frequently associated with altered patterns in activation than lesions in noncentral locations, and the absence of activation in gyri adjacent to the sensorimotor strip has clinical significance for the planning of resections in the central area.

The role of ipsilateral premotor cortex in hand movement after stroke

Slowing of reaction time after premotor cortex TMS in the patients correlated inversely with the relative hemispheric lateralization of functional magnetic resonance imaging activation in PMd, suggesting that the increased activation in ipsilateral cortical motor areas during movements of a paretic hand represents a functionally relevant, adaptive response to the associated brain injury.



Functional reorganization of the brain in recovery from striatocapsular infarction in man

It is shown that bilateral activation of motor pathways and the recruitment of additional sensorimotor areas and of other specific cortical areas are associated with recovery from motor stroke due to striatocapsular infarction.

The functional anatomy of motor recovery after stroke in humans: A study with positron emission tomography

The results suggest that ipsilateral motor pathways may play a role in the recovery of motor function after ischemic stroke.

Motor responses after transcranial electrical stimulation of cerebral hemispheres with a degenerated pyramidal tract

Motor responses were evoked in the thenar muscles by transcranial electrical cortex stimulation in 5 stroke patients with an isolated lacuna in the internal capsule, in whom wallerian degeneration of the pyramidal tract was demonstrated in vivo and polysynaptic corticoreticulospinal connections are suggested.

Regional cerebral blood flow during voluntary arm and hand movements in human subjects.

The data indicate that neither "fractionation" nor distal movement per se cause selective activation of sensorimotor cortex, and this finding does not prove unequivocally a "selective" role of the nonprimary motor areas in proximal movement.

The role of cerebral cortex in the generation of voluntary saccades: a positron emission tomographic study.

The frontal eye fields were discrete cortical regions consistently active during the generation of voluntary SEMs and uninfluenced by target presence, type of cue, or task complexity, indicating a predominantly motor function.

Reshaping the cortical motor map by unmasking latent intracortical connections

During pharmacological blockade of cortical inhibition in one part of the MI representation, movements of neighboring representations were evoked by stimulation in adjacent MI areas, suggesting that intracortical connections form a substrate for reorganization of cortical maps and that inhibitory circuits are critically placed to maintain or readjust the form of cortical motor representations.

The position and organization of motor fibers in the internal capsule found during stereotactic surgery.

The results obtained indicate that pyramidal fibers are organized into a rostral-caudal face-arm-leg sequence and occupy a short compact band in the caudal third of the posterior limb of the internal capsule.

Tracing of Neuronal Connections in the Human Brain by Magnetic Resonance Imaging in vivo

In two patients with pure motor strokes due to small ischaemic lesions restricted to the internal capsule, magnetic resonance imaging disclosed a narrow band of pathological signal increase descending band‐like into the brain stem and ascending to the precentral gyrus, which corresponded to the well‐known path of the pyramidal tract.

Posterior parietal cortex in rhesus monkey: II. Evidence for segregated corticocortical networks linking sensory and limbic areas with the frontal lobe

The main finding is that each subdivision of parietal cortex is connected with a unique set of frontal areas, and although they are most prominent within a hemisphere, notable interhemispheric connections are also present.