Hoffmann Sign Clinical Correlation of Neurological Imaging Findings in the Cervical Spine and Brain

Study Design. Retrospective validity study. Objective. To investigate the relationship between Hoffmann sign and radiographical evidence of cervical spinal cord compression and brain lesions. Summary of Background Data. Clinical significance of Hoffmann sign remains controversial with conflicting reports regarding its sensitivity and specificity and its usefulness. Methods. Patients were divided into 2 groups according to the presence of Hoffmann sign on physical examination. Imaging studies were blindly examined by 2 observers for possible cervical and brain lesions. The sensitivity, specificity, positive predictive value, negative predictive value, as well as accuracy for Hoffmann sign as it relates to cervical spinal cord compression and brain pathology, were calculated. Results. Of the 91 patients with a positive Hoffmann sign, 32 (35%) showed severe cervical cord compression and/or myelomalacia. Forty-seven of these patients had brain imaging studies, and 5 (10%) had positive findings. There were 80 patients in the negative Hoffmann sign or control group. Twenty-one (27%) of them had severe cervical cord compression and/or myelomalacia. Twenty-three of these control patients underwent neurological imaging of the brain, and 2 (8%) had positive findings. Hoffmann sign was found to have 59% sensitivity, 49% specificity, 35% positive predictive value, and 72% negative predictive value for cervical cord compression. For brain pathology, sensitivity was 71%, specificity 33%, positive predictive value 10%, and negative predictive value 95%. Conclusion. Hoffmann sign has too low a positive predictive value to be relied upon as a stand-alone physical examination finding and is not a reliable screening tool for solely predicting the presence of cervical spinal cord compression or brain pathology.