By Michael Rubin, MD
Professor of Clinical Neurology, Weill Cornell Medical College
Dr. Rubin reports no financial relationships relevant to this field of study.
SYNOPSIS: In a randomized treatment trial of steroid injection into the cubital tunnel for ulnar neuropathy, there was no difference in outcome compared to placebo.
SOURCE: vanVeen KEB, et al. Corticosteroid injection in patients with ulnar neuropathy at the elbow: A randomized, double-blind, placebo-controlled trial. Musc Nerve 2015;52:380-385.
Conservative management for ulnar neuropathy at the elbow (UNE) is preferable to surgical treatment, and includes splinting or padding the elbow, modification of activities, avoiding provocative factors, and nerve gliding exercises. However, none of these conservative treatments are of proven benefit. In a Cochrane review of randomized or quasi-randomized controlled clinical trials, no difference was found between simple decompression and transposition of the ulnar nerve for either clinical or neurophysiological improvement,1 and in the single trial evaluating conservative treatments, night splinting and nerve gliding exercises added no benefit over simply avoiding prolonged movements or positions. Are glucocorticoid injections, often used for carpal tunnel syndrome, of any benefit for UNE?
In this randomized, double-blind, placebo-controlled trial, patients with UNE seen at the Medical Center Haaglanden, The Hague, between September 2009 and April 2014, were recruited for evaluation. Inclusion criteria comprised motor or sensory symptoms of ulnar neuropathy, coupled with positive electrodiagnostic or ultrasonography findings for UNE, with patients excluded if they were < 18 years of age, had a history of prior ulnar nerve subluxation or UNE, were taking oral corticosteroids or anticoagulants, or had prednisolone allergy. Electrodiagnostic criteria for UNE required either motor nerve conduction velocity (MNCV) across the elbow slower than 43 m/s, slowing of MNCV across the elbow by more than 15 m/s compared to the forearm segment, or motor conduction block across the elbow of greater than 16%, comparing above to below elbow stimulation. Ultrasonography (US) was considered positive for UNE if the cross-sectional area (CSA), examined in perpendicular planes from at least 2 cm proximal to 2 cm distal to the medial epicondyle was > 10 mm. Patients were randomized to receive, by US guided injection, 1 mL containing either NaCL 0.9% or 40 mg depo-medrol (methylprednisolone acetate and 10 mg lidocaine hydrochloride). Subjective improvement at 6 months, as defined by a 6-point scale, was the primary outcome measure, with changes in electrodiagnostic studies and US findings comprising the secondary outcome measures. Statistical analysis included the chi-square test, the Mann-Whitney U-test, and Wilcoxon signed rank test.
Among 63 patients included in the study, which was halted due to slow recruitment, five were lost to follow-up, leaving 27 men and 28 women, with a mean age of 55 years, for analysis. No significant difference was found between the treatment vs placebo groups for either the primary or electrodiagnostic secondary outcome. Nerve CSA decreased significantly in the depo-medrol group, from 11.9 mm2 to 10.9 mm2. Neither symptoms nor neurological findings differed, comparing findings at 3 months to those at study initiation. Four depo-medrol patients reported complications, including hand swelling or pain, swelling, or depigmentation at the injection site, compared to one patient in the placebo group with pain at the injection site. US-guided corticosteroid injection in UNE is no better than placebo.
COMMENTARY
What causes ulnar neuropathy at the elbow? Among 117 patients with confirmed UNE, prospectively recruited, and seen by four blinded examiners who each performed separate neurologic evaluations and electrodiagnostic and ultrasound studies, 73% and 27% had lesions at the retro-epicondylar groove (REG) or under the humero-ulnar aponeurosis (HUA), respectively. HUA ulnar neuropathy was associated with manual labor, dominant arm involvement, and older age, whereas REG ulnar neuropathy was due to compression, mainly affecting the non-dominant arm of younger administrative personnel. These findings may assist in the prevention of UNE.
REFERENCE
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Caliandro P, et al. Treatment for ulnar neuropathy at the elbow. Cochrane Database Syst Rev 2012;7:CD006839.
