Influence of Injection Volume on Rate of Subsequent Intervention in Carpal Tunnel Syndrome Over 1-Year Follow-Up.

PURPOSE: The optimal volume and dose of corticosteroid injections for treatment of carpal tunnel syndrome (CTS) have not yet been established. It is unknown whether the volume of injectate influences the outcome of carpal tunnel injection. The purpose of this study was to assess whether there is an association between the volume of injectate and subsequent intervention in the treatment of CTS. METHODS: This study evaluated residents of Olmsted County, MN, who were treated with a corticosteroid injection for CTS between 2001 and 2010. Failure of treatment was the primary outcome, defined as a subsequent intervention: either a second injection or carpal tunnel release within 1 year of initial injection. General estimating equations logistic regression was used to assess the association between injectate volume and rate of treatment failure, adjusting for age, sex, effective dose of steroid, type of steroid injected, electrodiagnostic severity, and the presence of comorbidities such as rheumatoid arthritis, diabetes mellitus, peripheral neuropathy, and radiculopathy. RESULTS: There were 856 affected hands in 651 patients. A total of 56% (n = 484) of treated hands received subsequent treatment within 1 year. Multivariable analysis showed that a larger injectate volume was significantly associated with reduced rate of treatment failure within 1 year. Rheumatoid arthritis and ultrasound-guided procedures were also associated with a reduced rate of treatment failure, whereas severe electrodiagnostic results were associated with an increased rate of failure. CONCLUSIONS: This study showed that a larger volume of corticosteroid injection is associated with reduced odds of subsequent intervention after a single corticosteroid injection in CTS. Further research is needed to determine the optimal volume for steroid injections in the treatment of CTS. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic IV.

Central hyperadrenergic state after lightning strike.

OBJECTIVE: To describe and review autonomic complications of lightning strike. METHODS: Case report and laboratory data including autonomic function tests in a subject who was struck by lightning. RESULTS: A 24-year-old man was struck by lightning. Following that, he developed dysautonomia, with persistent inappropriate sinus tachycardia and autonomic storms, as well as posttraumatic stress disorder (PTSD) and functional neurologic problems. INTERPRETATION: The combination of persistent sinus tachycardia and episodic exacerbations associated with hypertension, diaphoresis, and agitation was highly suggestive of a central hyperadrenergic state with superimposed autonomic storms. Whether the additional PTSD and functional neurologic deficits were due to a direct effect of the lightning strike on the central nervous system or a secondary response is open to speculation.

Correlates of upper extremity disability in medical transcriptionists.

OBJECTIVE: To investigate the association between disability and personal/lifestyle, medical, and psychosocial risk factors for upper extremity musculoskeletal symptoms and disorders (UEMSDs) in medical transcriptionists. METHODS: A web-based survey involving the Disabilities of the Arm, Shoulder and Hand (DASH), Perceived Stress Scale (PSS) and Overall Job Satisfaction (OJS) questionnaires of all medical transcriptionists working at a large healthcare facility. RESULTS: Responses were received from 80% (251 of 314) possible participants. Mean DASH, PSS, and OJS scores for those working at their current position for at least 1 year were 8.5 +/- 10.1, 14.3 +/- 6.7 and 5.3 +/- 0.9. Personal/lifestyle factors including age (P < 0.001), lower educational level (P = 0.014), current or previous smoking (P = 0.012), and limited exercise (P = 0.013); medical conditions including diabetes mellitus (P = 0.015), carpal tunnel syndrome (P < 0.001), prior treatment for upper extremity symptoms (P < 0.001); prior workstation evaluation (P < 0.001) and psychosocial factors of perceived stress (P < 0.001), are associated with increased DASH scores. In these workers, multivariate analysis suggests that medical conditions (finger or other upper extremity symptoms requiring treatment or workstation evaluation; and diabetes mellitus) have a larger effect on the DASH than personal/lifestyle or psychosocial factors (age; previous or current smoking; and perceived stress). CONCLUSIONS: Prior upper extremity musculoskeletal symptoms requiring treatment or ergonomic assessment, high perceived stress and a history of smoking are associated with self-reported disability. Diabetics have significantly higher levels of upper extremity disability than non-diabetics. Prospective studies are needed to see if interventions addressing these factors will prevent future work disability.

Relative Motion of the Connective Tissue in Carpal Tunnel Syndrome: The Relation with Disease Severity and Clinical Outcome.

Excursion of the median nerve and the surrounding subsynovial connective tissue (SSCT) is diminished in patients with carpal tunnel syndrome (CTS). This study sought to determine if SSCT excursion could be utilized to predict surgical outcome. Idiopathic CTS patients were reviewed with ultrasound and electrodiagnostic tests at baseline. A speckle tracking algorithm was used to determine SSCT relative to tendon motion (shear index). Analysis of variance tests were used to compare SSCT motion with disease severity at baseline. Adjusted linear regressions were used to test the association with patient-reported outcome. A total of 90 CTS patients were analyzed and found to have an average shear index of 79% (95% confidence interval: 76.3%-81.6%). SSCT motion was lower in CTS patients with increasing electrophysiological severity (p = 0.0475). There was no significant association of pre-operative SSCT motion with symptomatic improvement (p = 0.268). Overall, SSCT motion is decreased in CTS patients, but exhibits limited correlation with clinical severity.

Rehabilitating the Injured/Ill Worker to Maximum Medical Improvement (MMI).

The concepts associated with work disability are not identical to those associated with medical disability. In addition to a worker's medical condition, the resultant functional limitations, and loss of participation in society, the injured or ill worker must often navigate a complex administrative system that often seems adversarial. This process is made less adversarial with the willingness to participate of knowledgeable clinicians. This article informs the interested clinician in regard to the unique aspects of work disability, including the issues of work accommodations, restrictions, and fitness for duty; prolonged work disability; and other return-to-work considerations at maximum medical improvement.

Median Nerve Transverse Mobility and Outcome after Carpal Tunnel Release.

Nerve movement is decreased in patients with carpal tunnel syndrome and can be assessed with ultrasound. In addition to morphologic features, this study describes a novel approach in which nerve movement and the association with short-term patient-reported outcome are assessed. Ultrasound images at the carpal tunnel inlet were acquired during finger and wrist flexion. Linear regression models were used with the Boston Carpal Tunnel Questionnaire as main outcome. Eighty-five patients were included; 93% completed the 3-mo follow-up. Pre-surgical mean nerve area was 14.5 ± 4.2 mm2 and decreased to 13.3 ± 3.8 mm2 (p < 0.001). Displacement in dorsal direction with wrist flexion increased from 1.9 ± 1.3 to 2.4 ± 1.3 mm (p < 0.01). A pre-surgical larger nerve area was associated with more functional improvement (ß = -0.024, p = 0.02), but baseline mobility was not. Change in excursion with finger flexion was associated with symptomatic improvement, but with a small effect (ß = -0.05, p = 0.01). This indicates that there is limited prognostic potential for dynamic transverse ultrasound in carpal tunnel syndrome.

Corticosteroid Injections for Carpal Tunnel Syndrome: Long-Term Follow-Up in a Population-Based Cohort.

BACKGROUND: Corticosteroid injection is a recommended treatment option for carpal tunnel syndrome, before considering surgery. Nevertheless, injections remain controversial because there is strong evidence of only short-term benefits. This study aimed to determine the reintervention rate and to identify prognostic indicators for subsequent treatment after corticosteroid injection for carpal tunnel syndrome. METHODS: This study evaluated residents of Olmsted County treated with a corticosteroid injection for carpal tunnel syndrome between 2001 and 2010. Treatment failure was the primary outcome of interest. Two definitions for failure were examined: (1) the patient receiving subsequent procedural intervention and (2) the patient undergoing carpal tunnel release. Survival was estimated using Kaplan-Meier methods, and association of covariates with increased failure was modeled using Cox proportional hazards regression. RESULTS: The study included 774 affected hands in 595 patients. The median follow-up period was 7.4 years. Reintervention was performed in 68 percent of cases, of which 63 percent resulted in eventual surgery. Injectate volume was significant for the outcome of any retreatment [hazard ratio, 0.879 (95 percent CI, 0.804 to 0.96)] and surgery [hazard ratio, 0.906 (95 percent CI, 0.827 to 0.99)]. Rheumatoid arthritis was also significant in both models, with a hazard ratio of 0.627 (95 percent CI, 0.404 to 0.97) for any retreatment and 0.493 (95 percent CI, 0.292 to 0.83) for surgery. CONCLUSIONS: In this cohort, 32 percent of patients did not receive subsequent treatment after a single injection, which indicates that there is a therapeutic role for corticosteroid injections in treating carpal tunnel syndrome. Further research is necessary to identify those patients who will benefit from an injection, to provide more individually tailored treatment. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, III.

Effectiveness of Ultrasound-Guided Compared to Blind Steroid Injections in the Treatment of Carpal Tunnel Syndrome.

OBJECTIVE: To compare the effectiveness of ultrasound-guided injections to blind injections in the treatment of carpal tunnel syndrome (CTS) in a large community-based cohort. METHODS: This study evaluated residents of Olmsted County, Minnesota, treated with a corticosteroid injection for CTS between 2001 and 2010. The proportion of patients receiving retreatment and the duration of retreatment-free survival between blind and ultrasound-guided injections were compared. Propensity score matching was used to control for confounding by indication. RESULTS: In the matched data set consisting of 234 (of 600) hands treated with a blind injection and 87 (of 89) ultrasound-guided injection cases, ultrasound guidance was associated with a reduced hazard of retreatment (hazard ratio 0.59 [95% confidence interval (95% CI) 0.37-0.93]). In addition, ultrasound guidance was associated with 55% reduced odds of retreatment within 1 year compared to blind injections (adjusted odds ratio 0.45 [95% CI 0.24-0.83]). CONCLUSION: This study indicates that ultrasound-guided injections are more effective in comparison to blind injections in the treatment of CTS.