A neuroprosthesis for high tetraplegia.

BACKGROUND: This case report describes a neuroprosthesis that restored shoulder and elbow function in a 23-year-old man with chronic C3 complete tetraplegia. Before implementation of the neuroprosthesis, electrodiagnostic testing revealed denervation from C5 to T1, with the greatest degree of denervation in the C8 and T1 myotomes. Thirteen percutaneous intramuscular electrodes were implanted into muscles acting on the shoulder and elbow of one upper limb. Before functional testing, the subject underwent a conditioning regimen to maximize the strength and endurance of the implanted muscles. RESULTS: After completion of the 8-week exercise regimen, stimulated active range of motion against gravity included 60 degrees of shoulder abduction, 45 degrees of shoulder flexion, 10 degrees of shoulder external rotation with the shoulder passively abducted to 90 degrees, and 110 degrees of elbow flexion. Stimulated elbow extension lacked 20 degrees of full extension with gravity eliminated. After system setup, the subject was able to pick up mashed potatoes on a plate with a utensil and bring them to his mouth using the neuroprosthesis and a balanced forearm orthosis. A switch mounted on the headrest of the subject's wheelchair and a position sensor mounted on the contralateral shoulder allowed the subject to control movement of his upper limb.

Comparing stimulation-induced pain during percutaneous (intramuscular) and transcutaneous neuromuscular electric stimulation for treating shoulder subluxation in hemiplegia.

OBJECTIVE: To determine whether percutaneous (intramuscular) neuromuscular electric stimulation (perc-NMES) is less painful than transcutaneous neuromuscular electric stimulation (trans-NMES) for treating shoulder subluxation in hemiplegia. DESIGN: Double-blind, crossover trial. SETTING: University-affiliated tertiary care hospital. PARTICIPANTS: A convenience sample of 10 hemiplegic subjects with at least 1 fingerbreadth of glenohumeral subluxation. INTERVENTIONS: All subjects received 3 randomly ordered pairs of perc-NMES and trans-NMES to the supraspinatus and posterior deltoid muscles of the subluxated shoulder. Both types of stimulation were optimized to provide full joint reduction with minimal discomfort. MAIN OUTCOME MEASURES: Pain was assessed after each stimulation with a 10-cm visual analog scale (VAS) and the McGill Pain Questionnaire, using the Pain Rating Index (PRI) scoring method. Subjects were asked which type of stimulation they would prefer for 6 weeks of treatment. Wilcoxon's signed-rank test was used to compare median differences in VAS and PRI between perc-NMES and trans-NMES. RESULTS: Median VAS scores for perc-NMES and trans-NMES were 1 and 5.7, respectively (p = .007). Median PRI scores for perc-NMES and trans-NMES were 7 and 19.5, respectively (p = .018). Nine of the 10 subjects preferred perc-NMES to trans-NMES for treatment. CONCLUSION: Data suggest that perc-NMES is less painful than trans-NMES in the treatment of shoulder subluxation in hemiplegia.

Percutaneous intramuscular neuromuscular electric stimulation for the treatment of shoulder subluxation and pain in patients with chronic hemiplegia: a pilot study.

OBJECTIVE: To investigate the feasibility of percutaneous intramuscular neuromuscular electric stimulation (perc-NMES) for treating shoulder subluxation and pain in patients with chronic hemiplegia. DESIGN: Before-after trial. SETTING: University-affiliated tertiary care hospital. PARTICIPANTS: A convenience sample of 8 neurologically stable subjects with chronic hemiplegia and shoulder subluxation. INTERVENTION: Six weeks of perc-NMES to the subluxated shoulder. MAIN OUTCOME MEASURES: Shoulder subluxation (radiograph), shoulder pain (Brief Pain Inventory), motor impairment (Fugl-Meyer score), shoulder pain-free external rotation (handheld goniometer), and disability (FIM instrument) were assessed before treatment (T1), after 6 weeks of neuromuscular stimulation (T2), and at 3-month follow-up (T3). A 1-way, repeated-measures analysis of variance using the generalized estimating equation approach was used to evaluate differences from T1 to T2 and from T1 to T3 for all outcome measures. RESULTS: Subluxation (p =.0117), pain (p =.0115), shoulder pain-free external rotation (p <.0001), and disability (p =.0044) improved significantly from T1 to T2. Subluxation (p =.0066), pain (p =.0136), motor impairment (p <.0001), shoulder pain-free external rotation (p =.0234), and disability (p =.0152) improved significantly from T1 to T3. CONCLUSIONS: Perc-NMES is feasible for treating shoulder dysfunction in hemiplegia and may reduce shoulder subluxation, reduce pain, improve range of motion, enhance motor recovery, and reduce disability in patients with chronic hemiplegia and shoulder subluxation. Further investigation is warranted.

Development of an experimental animal model for reactive arthritis induced by Yersinia enterocolitica infection.

We attempted to induce experimental arthritis in rats by systematically testing the effect of Yersinia infections in five strains of rats, using the intragastric, intraperitoneal, and intravenous routes of inoculation. We observed that Lewis rats which were given 10(4) to 10(5) Yersinia enterocolitica WA organisms via the intravenous route consistently developed arthritis. The arthritis was most severe at 3 weeks and subsided at 6 weeks. No arthritis was observed when this bacterial strain was administered to Buffalo, Fisher, DA, and LDA rats. No replicable bacteria were detected in the joints. This aseptic characteristic parallels that seen in the human condition and establishes this as an animal model of Yersinia-induced arthritis. The probable reason for arthritis development in only the Lewis rats became apparent when we analyzed the numbers of live bacteria in the spleens and livers of these infected animals. The arthritis-susceptible Lewis rats harbored 10-fold more bacteria than the arthritis-resistant rat strains, and this systemic infection also persisted for a significantly longer period. Speculations as to why human subjects who develop Yersinia-induced arthritis are genetically predisposed have been centered principally around the role of the HLA-B27 histocompatibility antigens. The present study reveals a heretofore unrecognized critical factor: the susceptibility of the hosts to the virulence of the infectious organisms. In addition, the present animal model will provide the necessary tool for the investigation of this and other important host and bacterial factors.

Initial clinical trials of the subrenal capsule assay as a predictor of tumor response to chemotherapy.

Retrospective and prospective clinical trials were performed to determine the usefulness of the 6-day subrenal capsule (SRC) assay for the prediction of response to chemotherapy. Evaluable assays were obtained in 86% of 1000 consecutive specimens obtained from a variety of solid malignancies. Analysis of chemotherapeutic sensitivity in this assay gave reproducible and consistent results. The overall predictive accuracy of the assay in 62 retrospective clinical trials in 55 patients was 85%. Of 37 evaluable patients with chemotherapy refractory cancers treated in a prospective trial with single agent chemotherapy as determined by the assay, 14 (38%) responded. Greater degrees of tumor regression in the assay were associated with a higher probability of clinical response. The SRC assay shows potential value as a rapid predictive test for chemotherapeutic selection on an individual patient basis. However, additional prospective clinical trials are necessary to document its ultimate utility.