“Four Legs of a Table”: Building a Stable Foundation and Systematic Approach to Diagnosing Peripheral Nerve Disorders

Management of patients with peripheral nerve disorders is multifaceted and complex; however, it fundamentally hinges upon first correctly localizing the problem. Peripheral nerve disorders may include injury, entrapment, inflammation, tumor, and pain. Differentiating a peripheral nerve condition from one that originates from the spinal or intracranial level is crucial to guiding proper management. A systematic and targeted approach to each patient is required for diagnosis. A comprehensive work-up includes: 1) detailed patient history; 2) thorough physical examination; 3) review of electrodiagnostic studies; and 4) incorporation of diagnostic imaging and (image-guided) diagnostic nerve blocks. Analogous to the “4 legs of a table,” the more findings in each domain that support the same diagnosis, the more certain the diagnosis and more stable the table (Figure 1). We present this framework as a tool for the localization, diagnosis, and treatment of all peripheral nerve issues.