Repetitive peripheral magnetic stimulation improves severe upper limb paresis in early acute phase stroke survivors.

BACKGROUND: It is very difficult for patients with severe upper extremity (UE) paresis after stroke to achieve full recovery because of the lack of a definitive approach for improving severe UE paresis immediately after onset. OBJECTIVE: to investigate the effects of repetitive peripheral magnetic stimulation (rPMS) on severe UE paresis during early acute phase of stroke. METHODS: Nineteen participants with severe UE disability met the criteria. 10 subjects received 15-20 minutes of rPMS prior to standard care per session, while 9 age- and severity-matched subjects received two times 20 minutes of standard care. Outcome measures included UE motor section of the Fugl-Meyer Motor Assessment Scale (FMA-UE), Wolf motor function test (WMFT), and box and block test (BBT). RESULTS: The rPMS group received treatment (average sessions: 7.8) after a median 9.2 days from stroke (16.5 sessions after 5 days for control). To adjust the different treatment durations, we defined "progress rate" as the gains of UE function scores divided by treatment duration. The progress rate was significantly different in FMA-UE and WMFT, but not in BBT. CONCLUSIONS: The present study suggested beneficial effects of rPMS on severe UE paresis during early acute phase of stroke.

Upper limb recovery in early acute phase stroke survivors by coupled EMG-triggered and cyclic neuromuscular electrical stimulation.

BACKGROUND: Few patients with severe upper extremity (UE) paresis after stroke achieved full recovery, because of the lack of a definitive approach to improve severe UE paresis immediately after onset. OBJECTIVE: to investigate the effects of coupled EMG-triggered and cyclic neuromuscular electrical stimulation (NMES) on UE paresis during early acute phase of stroke. METHODS: Seventeen participants with severe UE disability met the criteria. 8 subjects received 20 minutes of NMES prior to standard care per session, while 9 age- and severity-matched subjects received two times 20 minutes of standard care. Outcome measures included UE motor section of the Fugl-Meyer Motor Assessment Scale (FMA-UE), Wolf motor function test (WMFT), and box and block test (BBT). RESULTS: The NMES group received treatment (average session: 10.87) after a median 7 days from stroke (16.5 sessions after 5 days for control). To adjust the different treatment durations, we defined "progress rate" as the gains of UE function scores divided by treatment duration. The progress rate was significantly different in FMA-UE, but not in WMFT and BBT. CONCLUSIONS: The present study suggested beneficial effects of coupled NMES on UE paresis during early acute phase of stroke.

The effects of electromyography-controlled functional electrical stimulation on upper extremity function and cortical perfusion in stroke patients.

OBJECTIVE: The relation was investigated between hemiparetic arm function improvement and brain cortical perfusion (BCP) change during voluntary muscle contraction (VOL), EMG-controlled FES (EMG-FES) and simple electrical muscle stimulation (ES) before and after EMG-FES therapy in chronic stroke patients. METHODS: Sixteen chronic stroke patients with moderate residual hemiparesis underwent 5 months of task-orientated EMG-FES therapy of the paretic arm once or twice a week. Before and after treatment, arm function was clinically evaluated and BCP during VOL, ES and EMG-FES were assessed using multi-channel near-infrared spectroscopy. RESULTS: BCP in the ipsilesional sensory-motor cortex (SMC) was greater during EMG-FES than during VOL or ES; therefore, EMG-FES caused a shift in the dominant BCP from the contralesional to ipsilesional SMC. After EMG-FES therapy, arm function improved in most patients, with some individual variability, and there was significant improvement in Fugl-Meyer (FM) score and maximal grip strength (GS). Clinical improvement was accompanied by an increase in ipsilesional SMC activation during VOL and EMG-FES condition. CONCLUSION: The EMG-FES may have more influence on ipsilesional BCP than VOL or ES alone. SIGNIFICANCE: The sensory motor integration during EMG-FES therapy might facilitate BCP of the ipsilesional SMC and result in functional improvement of hemiparetic upper extremity.

Extension of corticocortical afferents into the anterior bank of the intraparietal sulcus by tool-use training in adult monkeys.

When humans use a tool, it becomes an extension of the hand physically and perceptually. Common introspection might occur in monkeys trained in tool-use, which should depend on brain operations that constantly update and automatically integrate information about the current intrinsic (somatosensory) and the extrinsic (visual) status of the body parts and the tools. The parietal cortex plays an important role in using tools. Intraparietal neurones of naïve monkeys mostly respond unimodally to somatosensory stimuli; however, after training these neurones become bimodally active and respond to visual stimuli. The response properties of these neurones change to code the body images modified by assimilation of the tool to the hand holding it. In this study, we compared the projection patterns between visually related areas and the intraparietal cortex in trained and naïve monkeys using tracer techniques. Light microscopy analyses revealed the emergence of novel projections from the higher visual centres in the vicinity of the temporo-parietal junction and the ventrolateral prefrontal areas to the intraparietal area in monkeys trained in tool-use, but not in naïve monkeys. Functionally active synapses of intracortical afferents arising from higher visual centres to the intraparietal cortex of the trained monkeys were confirmed by electron microscopy. These results provide the first concrete evidence for the induction of novel neural connections in the adult monkey cerebral cortex, which accompanies a process of demanding behaviour in these animals.

Synthesis and evaluation of 3-(4-chlorobenzyl)-8-[11C]methoxy-1,2,3,4-tetrahydrochromeno[3,4-c]pyridin-5-one: a PET tracer for imaging sigma(1) receptors.

3-(4-Chlorobenzyl)-8-methoxy-1,2,3,4-tetrahydrochromeno[3,4-c]pyridin-5-one (1), a putative dopamine D(4) receptor antagonist (k(i) = 8.7 nM), was labeled by positron-emitter (11C) and its pharmacological evaluation was carried out with in vitro quantitative autoradiography and positron emission tomography (PET). 11C-Methylation of a corresponding desmethyl precursor (2) with [11C]CH(3)I gave [11C]1 with >or=98% of radiochemical purity after HPLC purification and 67-90 GBq/micromol of specific activity at the end of synthesis. The in vitro autoradiography using rat brain sections demonstrated that [11C]1 shows no specific binding to the D(4) receptors, but a high specific binding to sigma(1) receptors (IC(50) = 105 nM). In the PET study with monkey brain, [11C]1 was highly taken up by the brain and trapped in the brain for at least 90 min. The distribution pattern of radioactivity in the brain was striatum > thalamus > frontal cortex > cerebellum, which was same as the result of in vitro autoradiography. Pre-treatment with non-radioactive 1 (1 mg/kg) produced a significant reduction of radioactivity in all the regions including the cerebellum. Pre-treatment with (+)pentazocine (1 mg/kg), a selective sigma(1) receptor agonist, also reduced the radioactivity in the same regions to a similar extent. These results indicate that [11C]1 may have some specific binding to the sigma(1) receptors, which is consistent with the result of in vitro autoradiography.