Observed patterns of cervical radiculopathy only followed the standard “Netter diagram” distribution in 54% of patients, and did not differ by the cervical level involved, in a recent study by Steven J McAnany (Hospital for Special Surgery, New York, USA) and John M Rhee (Emory University, Atlanta, USA). Their work appeared in the July 2019 issue of The Spine Journal.
McAnany and Rhee note that cervical radiculopathy is often thought to present with symptoms and signs in a standard, textbook, reproducible pattern as seen in a “Netter diagram”. However, it was their impression that patients with cervical radiculopathy often do not present to clinic with a textbook-like description of symptoms, and they wanted to investigate how often the actual presentation differed from the expected classic pattern. To date, they remark, no study has directly examined cervical radicular patterns attributable to single-level pathology.
The purpose of this retrospective study, therefore, was to examine cervical radiculopathy patterns in a surgical population and determine how often patients present with the standard textbook (i.e. Netter diagram) versus nonstandard patterns.
McAnany and Rhee included patients who had single-level radiculopathy with at least 75% improvement of preoperative symptoms following ACDF. Epidemiologic variables including age, sex, weight, body mass index, laterality of symptoms, duration of symptoms prior to operative intervention, and the presence of diabetes mellitus were collected.
The investigators identified all patients with single-level cervical radiculopathy operated on between March 2011 and March 2016 by six surgeons. The observed pattern of radiculopathy was compared to a standard textbook pattern of radiculopathy that strictly adheres to a dermatomal map.
The observed pattern of radiculopathy at presentation, including associated neck, shoulder, upper arm, forearm, and hand pain and/or numbness, was determined from chart review and patient-derived pain diagrams.
The authors specify that the Fisher exact test was used to analyse categorical data and Student t-test was used for continuous variables. In addition, a one-way ANOVA was used to determine differences in the observed versus expected radicular pattern and a logistic regression model assessed the effect of demographic variables on presentation with a nonstandard radicular pattern.
The investigators further report that when a nonstandard radicular pattern was present, it differed by 1.68 dermatomal levels from the standard (p<0.0001). Neck pain—found in 81% of patients—was the most prevalent symptom and did not differ by cervical level. Furthermore, in a logistic regression model, none of the demographic variables were found to significantly impact the likelihood of presenting with a nonstandard radicular pattern.
Based on the study, the authors state that surgeons must think broadly when diagnosing patients with cervical radiculopathy. According to Rhee, “Not infrequently, patients present with radicular patterns that simply do not fit the standard description. For example, many patients with a C6 radiculopathy do not have symptoms radiating into the thumb. Often, the symptoms may be limited to the ipsilateral neck, shoulder, or upper arm. Conversely, those with a C4 or C5 radiculopathy may sometimes get radiating pain into the hand. If we do not think broadly when evaluating such patients, we risk dismissing their symptoms as being inconsistent.”