Distinguishing Radiculopathies from Mononeuropathies

Abstract

Identifying “where is the lesion” is particularly important in the approach to the patient with focal dysfunction where a peripheral localization is suspected. This article outlines a methodical approach to the neuromuscular patient in distinguishing focal neuropathies versus radiculopathies, both of which are common presentations to the neurology clinic. This approach begins with evaluation of the sensory examination to determine whether there are irritative or negative sensory signs in a peripheral nerve or dermatomal distribution. This is followed by evaluation of deep tendon reflexes to evaluate if differential hyporeflexia can assist in the two localizations. Finally, identification of weak muscle groups unique to a nerve or myotomal pattern in the proximal and distal extremities can most reliably assist in a precise localization. The article concludes with an application of the described method to the common scenario of distinguishing radial neuropathy versus C7 radiculopathy in the setting of a wrist drop and provides additional examples for self-evaluation and reference.

Flexor Carpi Radialis Muscle: Anatomic Features and Electromyography Technique Under Ultrasound Control

“…On the other hand, radial nerve proximal lesion between the brachial plexus and nerve division would cause wrist and fingers’ extension loss without any impairment of the FCRM. This is mainly caused by either surgical trauma or humeral fracture [ 13 , 14 ]. Thus, physicians consider that the FCRM is one of the key muscles in diagnosing the site of nerve damage causing upper limb extensors’ deficiency [ 3 ].…”

“…For example, C7 radiculopathy due to C6-C7 disc herniation would lead to triceps and wrist flexors deficiency, particularly in the FCRM [12,13]. On the other hand, radial nerve proximal lesion between the brachial plexus and nerve division would cause wrist and fingers' extension loss without any impairment of the FCRM.…”

“…On the other hand, radial nerve proximal lesion between the brachial plexus and nerve division would cause wrist and fingers' extension loss without any impairment of the FCRM. This is mainly caused by either surgical trauma or humeral fracture [13,14].…”

Irreparable Radial Nerve Palsy Due to Delayed Diagnostic Management of a Giant Lipoma at the Proximal Forearm Resulting in a Triple Tendon Transfer Procedure: Case report and Brief Review of Literature

“…Isolated non-traumatic or “non-trauma-related” RNP is a very rare entity. It can be caused by cervical spine disorders (C7 radiculopathy), acute peripheral neuropathy (Guillain-Barré syndrome), neuromuscular disorders (distal myasthenia), acute viral infection (Herpes zoster), focal non-specific inflammations (myositis or synovitis of the elbow), specific inflammatory diseases such as rheumatoid arthritis or lupus erythematosus associated with Jaccuod's arthritis, amyloidosis, and systemic malignancy such as non-Hodgkin's lymphoma [ 14 - 24 ]. Another important cause for the pathogenesis of isolated non-traumatic RNP can be local radial nerve entrapment by benign or malign tumors arising from the bone, nerve, and soft tissue that was described in single cases only [ 25 - 28 ].…”

A clinical review of hand manifestations of cervical myelopathy, cervical radiculopathy, radial, ulnar, and median nerve neuropathies

“…The Tinel’s test is a sign that can differentiate radial mononeuropathy from myelopathy or radiculopathy. Percussing the radial nerve at possible areas of compression in the upper extremity such as the spiral groove of the upper arm or as it is exiting the deep fascia of the forearm will elicit symptoms of paresthesias, numbness, tingling, or pain ( 22 ).…”