A simple method of implanting electrodes for long-term stimulation of peripheral nerve.

The present case study details sensations elicited by electrical stimulation of peripheral nerve axons using an implanted nerve cuff electrode, in a participant with a transhumeral amputation. The participant uses an osseointegrated electromechanical interface, which enables skeletal attachment of the prosthesis and long-term, stable, bidirectional communication between the implanted electrodes and prosthetic arm. We focused on evoking somatosensory percepts, where we tracked and quantified the evolution of perceived sensations in the missing hand, which were evoked from electrical stimulation of the nerve, for over 2 yr. These sensations included small, pointlike areas of either vibration or pushing, to larger sensations over wider areas, indicating the recruitment of a few and many afferents, respectively. Furthermore, we used a two-alternative forced choice paradigm to measure the level of discrimination between trains of brief electrical stimuli, to gauge what the participant could reliably distinguish between. At best, the participant was able to distinguish a 0.5-Hz difference and on average acquired a 3.8-Hz just-noticeable difference at a more stringent psychophysical level. The current work shows the feasibility for long-term sensory feedback in prostheses, via electrical axonal stimulation, where small and relatively stable percepts were felt that may be used to deliver graded sensory feedback. This opens up opportunities for signaling feedback during movements (e.g., for precision grip), but also for conveying more complex cutaneous sensations, such as texture. NEW & NOTEWORTHY We demonstrate the long-term stability and generation of sensations from electrical peripheral nerve stimulation in an amputee, through an osseointegrated implant. We find that perceived tactilelike sensations could be generated for over 2 yr, in the missing hand. This is useful for prosthetic development and the implementation of feedback in artificial body parts.

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ASSESSMENT OF A TEST OF ADRENOCORTICAL FUNCTION USING β1–25 CORTICOTROPHIN

Journal of Endocrinology ◽

10.1677/joe.0.0440513 ◽

1969 ◽

Vol 44 (4) ◽

pp. 513-516

Author(s):

K. WHALEY ◽

W. P. SOUTTER ◽

W. C. DICK ◽

G. NUKI ◽

W. W. DOWNIE

Keyword(s):

Adrenal Cortex ◽

Corticosteroid Therapy ◽

Adrenocortical Function ◽

Normal Range ◽

Simple Method ◽

Maximal Stimulation ◽

Synthetic Polypeptides ◽

Range Of Values ◽

Stimulation Of

SUMMARY In ten patients with a variety of rheumatic disorders the changes in plasma corticosteroid (11-OHCS) levels have been studied after adrenocortical stimulation by a continuous 5 hr. infusion of Synacthen (Ciba) or by a single i.v. injection of 200 i.u. (320 μg.) Pentacosactride (Sandoz). Comparable increases were obtained using both synthetic polypeptides. It is suggested that administration of Pentacosactride intravenously is a simple method of obtaining prolonged maximal stimulation of the adrenal cortex. A normal range of values of plasma 11-OHCS, obtained from 28 subjects, is given, and it is shown that the results are reproducible. The results of tests in six subjects with secondary adrenal atrophy due to long-term corticosteroid therapy indicate that the test can discriminate between normal and subnormal adrenocortical function.

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Peripheral Nerve Stimulation of the Thoracic Paravertebral Plexus for Chronic Neuropathic Pain

January 2018 - Pain Physician ◽

10.36076/ppj.2011/14/295 ◽

2011 ◽

Vol 3;14 (3;5) ◽

pp. 295-300

Author(s):

Dominic Hegarty

Keyword(s):

Neuropathic Pain ◽

Peripheral Nerve ◽

Nerve Stimulation ◽

Peripheral Nerve Stimulation ◽

Surgical Pain ◽

Increased Risk ◽

Clinical Awareness ◽

Term Management ◽

Stimulation Of

Persistent post surgical pain is reported in 70% of patients following thoracotomy and mastectomy. This pain is often neuropathic in nature and occasionally it is refractory to traditional medical and interventional management. Neurostimulation of peripheral nerves can be a highly effective clinical modality for the management of neuropathic pain. The placement of a percutaneously sited electrode in the thoracic paravertebral plexus offers a new and novel mode of managing refractory thoracic neuropathic pain. We present 2 cases that demonstrate the effectiveness of this intervention in the long-term management of this clinical dilemma. The first case presented is that of a 61-year-old female, with unilateral neuropathic pain for 6 years following mastectomy refractory to traditional interventions. Targeted field stimulation of the thoracic paravertebral plexus resulted in significant improvement for 12 years. The second case is that of a 65-year-old male, with Type II diabetes with neuropathic thoracic pain for 6 years following multiple rib fractures (T4-T7) who responded positively to neurostimulation of the thoracic paravertebral plexus. Both of these cases demonstrate a relative reduction in pain intensity (> 80%), the elimination of oral analgesics, and improved functionality directly related to the novel use of this intervention. Effective and reproducible pain relief is achieved by specifically using a low frequency (10 Hz) and low amplitude (2 mA) stimulation technique. Equally important is that these cases highlight the increased risk of inadvertent pleural puncture with the development of a pneumothorax that can be associated with this intervention. Possible clinical, investigative and equipment modifications that need to be considered are discussed. The limitations include only 2 case reports, considered as the lowest level of evidence available in the era of evidence-based medicine, and lack of utilization of multiple other modalities of treatments utilized in managing neuropathic pain. In conclusion, these cases demonstrate the effectiveness of peripheral nerve stimulation of the thoracic paravertebral plexus in the long-term management of refractory neuropathic pain. They also serve to underline the importance of clinical awareness in order to improve patient safety. Key words: Peripheral nerve stimulation, thoracic paravertebral plexus, persistent post surgical pain, neuropathic pain, pneumothorax

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Long-term stimulation of residual function in patients with visual field defects after post-chiasmatic lesions

Aktuelle Neurologie ◽

10.1055/s-2004-833405 ◽

2004 ◽

Vol 31 (S 1) ◽

Author(s):

I Mueller ◽

C Gall ◽

E Kasten ◽

BA Sabel

Keyword(s):

Visual Field ◽

Visual Field Defects ◽

Residual Function ◽

Field Defects ◽

Stimulation Of

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Individual mechanisms underlying peripheral nerve damage when exposed to metallic mercury

Russian Journal of Occupational Health and Industrial Ecology ◽

10.31089/1026-9428-2020-60-12-918-924 ◽

2020 ◽

Vol 60 (12) ◽

pp. 918-924

Author(s):

Dina V. Rusanova ◽

Oleg L. Lakhman ◽

Galina M. Bodienkova ◽

Irina V. Kudaeva ◽

Natalya G. Kuptsova

Keyword(s):

Peripheral Nerve ◽

Peripheral Nerves ◽

Blood Circulation ◽

The State ◽

Contact Period ◽

Peripheral Nerve Damage ◽

Demyelinating Disorders ◽

Peripheral Blood Circulation ◽

Antibodies To Dna

Introduction. There is a lack of knowledge of the pathophysiological mechanisms that form peripheral nerve disorders in mercury lesions of professional origin. The study aims to reveal the mechanisms underlying peripheral nerve damage in the long-term post-contact period of chronic mercury intoxication (CMI). Materials and methods. Fifty-one people had the diagnosis of a long-term period of CMI. The post-contact period was 8.5±2.6 years. The authors compared the results with a control group of 26 healthy men who had no contact with toxic substances. Stimulating electroneuromyography was performed. We studied the body systems that could contribute to the formation of disorders in the peripheral nerves. Changes in peripheral hemodynamics were studied using reovasography. The content of autoantibodies, neuron-specific enolase, serotonin, histamine, catecholamines (epinephrine, dopamine), metanephrine, and neurotrophin-3 was reviewed. The content of ceruloplasmin, secondary products of lipid peroxidation processes, reduced glutathione, the activity of superoxide dismutase and the content of nitric oxide levels were determined. Results. The study established pathogenetic structural links of peripheral nerve disorders. The autoimmune process's role was to increase the range of antibodies to the MAG protein and increase the level of antibodies to DNA. Violations of elastic-tonic properties of peripheral vessels could be associated with the functional state of motor axons. The increased content of neurotransmitters is related to the state of peripheral blood circulation; the most pronounced changes were on the legs, which could contribute to the occurrence and maintenance of vasoconstriction. The role of oxidative stress in the formation of demyelinating disorders in patients' peripheral nerves in the long-term period of CRI is possible. Conclusion. Neuroimmunological processes has an essential role in the development of peripheral nerve demyelination was shown, which consists in an increase in the content of antibodies to the MAG protein expressed on Schwann cells of peripheral nerves and in an increase in the level of antibodies to DNA involved in the formation of demyelinating changes when exposed to metallic mercury. The revealed pathological changes in the state of the peripheral blood circulation, characterized by a violation of the vessels' elastic-tonic properties, leading to demyelination of motor axons in patients in the long-term period of CMI. The increased content of neurotransmitters in the examined is of great importance in the state of peripheral circulation. Pronounced changes in blood circulation are established on the lower extremities, which may be associated with the predominance of α-adrenergic receptors in the arterial bed and may contribute to the occurrence and maintenance of vasoconstriction in the legs. The relationship between changes in indicators of oxidative stress, consisting of a decrease in the value of superoxide dismutase and reduced glutathione, and the formation of demyelinating disorders of peripheral nerves in patients in the long-term period of CMI has been proved.

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Deep brain stimulation of the posterior limb of the internal capsule in the treatment of central poststroke neuropathic pain of the lower limb: case series with long-term follow-up and literature review

Journal of Neurosurgery ◽

10.3171/2019.5.jns19227 ◽

2020 ◽

Vol 133 (3) ◽

pp. 830-838 ◽

Cited By ~ 1

Author(s):

Andrea Franzini ◽

Giuseppe Messina ◽

Vincenzo Levi ◽

Antonio D’Ammando ◽

Roberto Cordella ◽

...

Keyword(s):

Neuropathic Pain ◽

Lower Limb ◽

Internal Capsule ◽

Posterior Limb ◽

Vas Score ◽

The Mean ◽

Deep Brain ◽

Stimulation Of

OBJECTIVECentral poststroke neuropathic pain is a debilitating syndrome that is often resistant to medical therapies. Surgical measures include motor cortex stimulation and deep brain stimulation (DBS), which have been used to relieve pain. The aim of this study was to retrospectively assess the safety and long-term efficacy of DBS of the posterior limb of the internal capsule for relieving central poststroke neuropathic pain and associated spasticity affecting the lower limb.METHODSClinical and surgical data were retrospectively collected and analyzed in all patients who had undergone DBS of the posterior limb of the internal capsule to address central poststroke neuropathic pain refractory to conservative measures. In addition, long-term pain intensity and level of satisfaction gained from stimulation were assessed. Pain was evaluated using the visual analog scale (VAS). Information on gait improvement was obtained from medical records, neurological examination, and interview.RESULTSFour patients have undergone the procedure since 2001. No mortality or morbidity related to the surgery was recorded. In three patients, stimulation of the posterior limb of the internal capsule resulted in long-term pain relief; in a fourth patient, the procedure failed to produce any long-lasting positive effect. Two patients obtained a reduction in spasticity and improved motor capability. Before surgery, the mean VAS score was 9 (range 8–10). In the immediate postoperative period and within 1 week after the DBS system had been turned on, the mean VAS score was significantly lower at a mean of 3 (range 0–6). After a mean follow-up of 5.88 years, the mean VAS score was still reduced at 5.5 (range 3–8). The mean percentage of long-term pain reduction was 38.13%.CONCLUSIONSThis series suggests that stimulation of the posterior limb of the internal capsule is safe and effective in treating patients with chronic neuropathic pain affecting the lower limb. The procedure may be a more targeted treatment method than motor cortex stimulation or other neuromodulation techniques in the subset of patients whose pain and spasticity are referred to the lower limbs.

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