The Effect of Passive Movement for Paretic Ankle-Foot and Brain Activity in Post-Stroke Patients.

BACKGROUND: This study aims at investigating the short-term efficacy of the continuous passive motion (CPM) device developed for the therapy of ankle-foot paresis and to investigate by fMRI the blood oxygen level-dependent responses (BOLD) during ankle passive movement (PM). METHODS: Sixty-four stroke patients were investigated. Patients were assigned into 2 groups: 49 patients received both 15 min manual and 30 min device therapy (M + D), while the other group (n = 15) received only 15 min manual therapy (M). A third group of stroke patients (n = 12) was investigated by fMRI before and immediately after 30 min CPM device therapy. There was no direct relation between the fMRI group and the other 2 groups. All subjects were assessed using the Modified Ashworth Scale (MAS) and a goniometer. RESULTS: Mean MAS decreased, the ankle's mean plantar flexion and dorsiflexion passive range of motion (PROM) increased and the equinovalgus improved significantly in the M + D group. In the fMRI group, the PM of the paretic ankle increased BOLD responses; this was observed in the contralateral pre- and postcentral gyrus, superior temporal gyrus, central opercular cortex, and in the ipsilateral postcentral gyrus, frontal operculum cortex and cerebellum. CONCLUSION: Manual therapy with CPM device therapy improved the ankle PROM, equinovalgus and severity of spasticity. The ankle PM increased ipsi- and contralateral cortical activation.

Feasibility of Diffusion Tractography for the Reconstruction of Intra-Thalamic and Cerebello-Thalamic Targets for Functional Neurosurgery: A Multi-Vendor Pilot Study in Four Subjects.

Functional stereotactic neurosurgery by means of deep brain stimulation or ablation provides an effective treatment for movement disorders, but the outcome of surgical interventions depends on the accuracy by which the target structures are reached. The purpose of this pilot study was to evaluate the feasibility of diffusion tensor imaging (DTI) based probabilistic tractography of deep brain structures that are commonly used for pre- and perioperative targeting for functional neurosurgery. Three targets were reconstructed based on their significance as intervention sites or as a no-go area to avoid adverse side effects: the connections propagating from the thalamus to (1) primary and supplementary motor areas, (2) to somatosensory areas and the cerebello-thalamic tract (CTT). We evaluated the overlap of the reconstructed connectivity based targets with corresponding atlas based data, and tested the inter-subject and inter-scanner variability by acquiring repeated DTI from four volunteers, and on three MRI scanners with similar sequence parameters. Compared to a 3D histological atlas of the human thalamus, moderate overlaps of 35-50% were measured between connectivity- and atlas based volumes, while the minimal distance between the centerpoints of atlas and connectivity targets was 2.5 mm. The variability caused by the MRI scanner was similar to the inter-subject variability, except for connections with the postcentral gyrus where it was higher. While CTT resolved the anatomically correct trajectory of the tract individually, high volumetric variability was found across subjects and between scanners. DTI can be applied in the clinical, preoperative setting to reconstruct the CTT and to localize subdivisions within the lateral thalamus. In our pilot study, such subdivisions moderately matched the borders of the ventrolateral-posteroventral (VLpv) nucleus and the ventral-posterolateral (VPL) nucleus. Limitations of the currently used standard DTI protocols were exacerbated by large scanner-to-scanner variability of the connectivity-based targets.