Comparison of Symptoms From C6 and C7 Radiculopathy

Study Design. Case series. Objective. This study compared the locations of arm pain, sensory symptoms, and subjective complaints of arm weakness in patients with cervical radiculopathy from MRI confirmed C6 and C7 nerve root compression. Summary of Background Data. Cervical radiculopathy is defined as arm pain, sensory and motor symptoms caused by irritation of a cervical nerve root. The C6 and C7 roots are most commonly involved, and differentiating symptoms associated with each root has proven difficult. Cervical MRI allows accurate identification of nerve root compression and therefore makes it possible to explore symptom patterns that may differentiate C6 from C7 radiculopathy. Methods. A total of 122 patients with symptoms suggestive of cervical radiculopathy were recruited. Of these, 30 patients had MRI confirmed C6 and 39 patients C7 nerve root compression. By completing a study questionnaire, patients reported specific arm weakness, and marked the location of arm pain and tingling/numbness on graphic representations of the arm. Marked areas were interpreted by superimposing a grid that divided the arm into 54 distinct areas. The frequencies of reported symptoms with C6 and C7 were totaled and then compared with likelihood rations. Power analysis calculated that 27 patients would be needed in each group based on the assumption that a 30 percentage point difference in frequency of specific symptom would be clinically useful for differentiating C6 from C7 radiculopathy. Results. Arm pain and sensory symptoms were diffuse, and were not distinctly different for C6 or C7 radiculopathy. Some weakness was reported by 41 percent of patients, with specific descriptions of weakness having limited value for differentiating between radiculopathies. Conclusion. The location of pain and sensory symptoms, and specific weakness complaints associated with symptomatic C6 and C7 nerve root compression overlap to the extent that caution should be exercised when predicting root involvement based on symptoms.