Save Your Time! Intelligently Streamlining the Neurological Exam
Abstract & Commentary
By Michael Rubin, MD, Professor of Clinical Neurology, Weill Cornell Medical College. Dr. Rubin reports that he receives grant/research support from Pfizer and is on the speaker's bureau of Athena Diagnostics.
Synopsis: Tinel's test, flexion compression, and ulnar nerve palpation in patients with ulnar neuropathy must be interpreted with caution, but omitting them and saving time doesn't appear to impact diagnostically.
Source: Beekman R, Schreuder T, Rozeman S, et al. The diagnostic value of provocative clinical tests in ulnar neuropathy at the elbow is marginal. J Neurol Neurosurg Psychiatry doi:10.1136/jnnp.2009.180844.
When attempting to localize ulnar neuropathy to the elbow, how useful are Tinel's test, the flexion compression test, or palpating the ulnar nerve for focal tenderness and thickening? Among patients referred to the Department of Neurology of Atrium Medical Centre, Heerlen, The Netherlands, between December 2006 and December 2008, and in whom a diagnosis of ulnar neuropathy at the elbow (UNE) was entertained, all underwent neurological examination followed by electrodiagnostic and sonographic study to determine if these provocative tests were of localizing value. Patients with tingling, numbness, or weakness in an ulnar distribution were included but not those with ulnar neuropathy due to acute trauma, or a history of polyneuropathy or hereditary neuropathy.
Tinel's test was performed by tapping the ulnar nerve at the medial epicondylar groove and was positive if it produced tingling in the fourth or fifth digits. Flexion compression was performed by maximally flexing the elbow for 60 seconds while manually compressing the forearm just proximal to the cubital tunnel and determining if tingling in the ulnar distribution occurred within 60 seconds. Palpation of the ulnar nerve around the elbow determined whether it was thickened or tender. Where warranted, additional studies including imaging of the cervical spine or brachial plexus were undertaken.
Patients who were found not to have ulnar neuropathy served as controls. UNE was diagnosed in the presence of one or more symptoms or signs, in conjunction with either a sonographically-demonstrable thickened ulnar nerve (diameter >2.5 cm, 2.6 cm, or 2.7 cm, at 2 cm proximal, or at 2 cm distal to the medial epicondyle, respectively), or electrodiagnostic evidence of ulnar neuropathy at the elbow (conduction block at the elbow as demonstrated by >16% amplitude drop between below and above elbow stimulation, across elbow ulnar motor velocity < 46 m/s, or >15 m/s slower than forearm segment). Statistical analysis included the Student t-test, Mann-Whitney test, and chi-square test.
Among 192 eligible patients who completed the study, UNE was diagnosed in 137, with 55 having other diagnoses including carpal tunnel syndrome (n = 10), cervical radiculopathy (n = 8), stroke (n = 2), brain metastases or myelopathy (n = 1 each), epicondylitis or nonspecific arm pain (n = 33). Although the positive predictive value of these tests was high, in the 72%84% range, the negative predictive value was low, in the 29%33% range, and logistic regression indicated that only minimal added value was accrued by these maneuvers over the routine clinical examination. Their diagnostic value is poor.
Commentary
Tinel's test is of equal dubious value in diagnosing carpal tunnel syndrome (CTS) where it is positive in 45% but may be elicited in 29% of normals.1 Phalen found that keeping the wrist in flexion for 60 seconds to elicit hand paresthesiae, Phalen's test, was positive in 80% of CTS.2 Dorsiflexing the wrist for the same amount of time, the reverse Phalen's test, has also been promoted but both may be negative in confirmed CTS. If performed, these tests must be interpreted with caution, but it would appear that omitting them and saving time will not impact diagnostically.
Reference
1. Stewart JD, Eisen AA. Tinels sign and the carpal tunnel syndrome. BMJ 1978;2:1125-1126
2. Phalen GS. The carpal-tunnel syndrome. Seventeen years' experience in diagnosis and treatment of six hundred fifty-four hands. J Bone Joint Surg 1966;48A; 211-228.
Tinel's test, flexion compression, and ulnar nerve palpation in patients with ulnar neuropathy must be interpreted with caution, but omitting them and saving time doesn't appear to impact diagnostically.You have reached your article limit for the month. Subscribe now to access this article plus other member-only content.
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