Neuromodulation : journal of the International Neuromodulation Society
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Objectives. There is ample and well-established evidence that direct electrical stimulation of the vagus nerve can change heart rate in animals and humans. Since tachyarrhythmias cannot always be controlled through medication, we sought, in this pilot study, to elucidate whether a clinical implantable lead system that is used in cervical vagus nerve stimulation therapy (VNS therapy) also can be used for control of heart rate, and tachycardia in particular. Materials and Methods. Experiments were carried out in three pigs (weight 21-26 kg) under general anesthesia. ⋯ No differences were found between stimulation of the right or left vagus nerve. Conclusion. VNS can be used effectively and rapidly to decrease heart rate, in acute settings, when connected to an external pacing system. Future devices that are fully implantable may be used for nonpharmacological treatment of illnesses in which tachycardia results in deterioration of cardiac function.
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Objectives. The aim of the study was to test the effectiveness of sacral nerve stimulation (SNS) performed by a transforamenal approach in patients with isolated chronic intractable pelvic pain. Materials. Sevenpatients with intractable pelvic pain underwent implantation of self-anchoring leads by way of the dorsal S3 foramen in four cases and of the dorsal S4 foramen in three cases. Patients with pain improvement > 50% underwent sacral nerve root stimulation device implantation. ⋯ VAS score improvement was evident in these patients and remained unchanged at 3, 6, and 12 months (median 8 months); SF-36 QoL questionnaire also revealed significant improvement in many domains of QoL including all the four physical domains and three of the four mental domains. There were three complications in our seven patients: one lead fracture, one lead displacement in the presacral space, and one patient who developed pain at the implantable pulse generator site. Conclusions. Transforamenal SNS is effective in relieving isolated pelvic pain but a high complication rate was found.
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Objectives. Traditional deep brain stimulation (DBS) at the subthalamic nucleus (STN) has proved to be efficacious on core Parkinsonian symptoms. However, very disabling l-dopa-induced abnormal involuntary movements (AIMs) and axial signs are slightly affected, suggesting that we target less conventional targets. Our candidates for DBS were the globus pallidus internus (GPi) plus the intralaminar thalamic complex (Pf or CM), given its extensive functional links with basal ganglia nuclei. ⋯ CM-Pf activation was only slightly effective in reducing rigidity and akinesia, but more efficacious on freezing. Not surprisingly, AIMs were peculiarly decreased by the activation of the permanent electro-catheter in the posteroventral GPi. Conclusions. These findings confirm that, in selected patients, it is conceivable to target structures other than the conventional STN in order to maximize clinical benefit.
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Objective. To evaluate the ability to relieve shoulder pain by implanting ceramic-case versions of radiofrequency microstimulators (RFM) in paralyzed shoulder muscles. Materials and Methods. A 66-year-old man, who had left-sided chronic hemiplegia due to a stroke five years previously, had developed shoulder subluxation resulting in pain. Two RFM devices were implanted, one next to the axillary nerve and one at the motor point of the middle deltoid muscle. ⋯ Results. During the treatment period of six months of stimulation, the patient's pain had reduced from 70 to 0 on the VAS. At six months after completion of the treatment, pain relief and effective evoked muscle contraction have remained. Conclusion. Although these results suggest that the feasibility of using RFM devices implanted both epineurally to the axillary nerve and next to the muscle motor point in this one patient, to relieve pain and elicit contraction, further investigation is needed to demonstrate the clinical feasibility of using RFMs for treating poststroke shoulder pain.