STUDY DESIGN: Systematic review.
OBJECTIVE: To determine the validity of the Hoffmann sign for the detection of degenerative cervical myelopathy (DCM) for patients presenting with cervical complaints.
SUMMARY OF BACKGROUND DATA: While physical examination maneuvers are often used to diagnose DCM, no previous review has synthesized diagnostic accuracy data.
METHODS: Medline, Embase, and HealthStar were searched for articles from January 1, 1947 to March 1, 2017 using the following terms: Spinal Cord Diseases, Spinal Cord Compression, Cervical Vertebrae, Signs and Symptoms, Physical Examination, Epidemiologic studies, Epidemiologic Research Design, Predictive Value of Tests, and Myelopathy. The Quality Assessment of Diagnostic Accuracy Studies (QUADAS) checklist was applied to determine the level of evidence. Articles included were published in English or French language, rated as QUADAS level 3 or higher with a minimum 10 patients presenting with cervical complaints having undergone the Hoffman sign. Excluded studies recruited patients with a nondegenerative type of cervical myelopathy, and/or no evaluation with magnetic resonance imaging.
RESULTS: A total of 589 articles were selected for review. Following the application of inclusion and exclusion criteria, 45 articles were analyzed using the QUADAS checklist. Only of three articles were of QUADAS quality 3 or higher. Analysis of combined data from 2/3 studies indicated that the Hoffman sign has a positive likelihood ratio of 2.2 (95% CI 1.5-3.3) and a negative likelihood ratio of 0.63 (95% CI 0.5-0.8).
CONCLUSION: A positive Hoffman alone is unlikely to lead to more than a small change in estimated probability of DCM as compared with the gold standard test (magnetic resonance imaging). Variability in results across individual studies may result from differences in study design. There are insufficient data to support use of the Hoffman sign alone to confirm or refute a diagnosis of DCM.
LEVEL OF EVIDENCE: 1.
I use the Hoffmann Sign and believe physical exams are important. The only important message of the article is that we need complete exams for best information.
This well-done review will likely do little to promote the practice of performing a careful clinical evaluation before referring for diagnostic testing, since the physical exam maneuver (Hoffman's sign) studied appears not to impact pre-test probability enough to deter ordering a cervical MRI when negative. A positive Hoffman's might add some impetus to getting an MRI, but most likely in cases where there is other clinical evidence that warrants imaging.
Clinical examination should reign! Unfortunately, we are all blinded by easy access to sophisticated imaging. The article gives great insight, but does not clarify whether the absence of a Hoffman Sign would rule out a cervical myelopathy.
The study confirms the mild contribution of the Hoffman Sign for diagnosing myelopathy. As the authors state, ruling cervical myelopathy in or out should not rest with the Hoffman reflex alone.