Musculocutaneous nerve injury in a high school pitcher

It's in the game: A review of neurological lesions associated with sports

INTRODUCTION

The practice of sports may lead to neurological injuries. While relatively uncommon (overall incidence of approximately 2.5%), and mostly benign and transient, some conditions may be life-threatening and permanent. Thus, both clinical neurologists and sports physicians should be aware of their existence and relevance. We aimed to review all sports-related neurological injuries and illnesses reported in the literature.

METHODS

Following SANRA guidelines, we performed a narrative review and searched PubMed and Scopus databases. Relevant sports were selected based on their recognition as an Olympic sport by the International Olympic Committee. Chronic traumatic encephalopathy (CTE) and other neurodegenerative disorders were not included.

RESULTS

A total of 292 studies were included concerning 33 different sports. The most reported neurological injury was damage to the peripheral nervous system. Traumatic injuries have also been extensively reported, including cerebral haemorrhage and arterial dissections. Non-traumatic life-threatening events are infrequent but may also occur, e.g. posterior reversible encephalopathy syndrome, cerebral venous thrombosis, and arterial dissections. Some conditions were predominantly reported in specific sports, e.g. yips in baseball and golf, raising the possibility of a common pathophysiology. Spinal cord infarction due to fibrocartilaginous embolism was reported in several sports associated with minor trauma.

CONCLUSION

Sports-related neurological injuries are increasingly receiving more social and medical attention and are an important cause of morbidity and mortality. This review may serve as a guide to physicians managing these challenging situations.

A Review of Upper Extremity Peripheral Nerve Injuries in Throwing Athletes

Peripheral nerve injuries in the upper extremities may be common in throwing athletes as the throwing motion places extreme stress on the dominant arm. The combination of extreme stress along with repetitive microtrauma from throwing uniquely places the throwing athlete at elevated risk of upper extremity peripheral nerve injury. However, because symptoms can be non-specific and frequent co-exist with pathology in the upper extremity, the diagnosis of peripheral nerve injury is often delayed. Diagnosis of peripheral nerve injuries may require a combination of history and physical exam, diagnostic imaging, electrodiagnostic testing, and diagnostic ultrasound guided injections. The primary management should include physical therapy focusing on throwing mechanics and kinetic chain evaluation. However, some athletes require surgical intervention if symptoms do not improve with conservative management. The purpose of this focused narrative review is to highlight upper extremity peripheral neuropathies reported in throwing athletes and to provide an overview of the appropriate clinical diagnosis and management of the throwing athlete with a peripheral nerve injury. This article is protected by copyright. All rights reserved.

RESIDENTS CASE REPORT: MUSCULOCUTANEOUS NERVE INJURY IN A COLLEGIATE BASEBALL PITCHER

Background

Literature regarding musculocutaneous nerve injuries among the athletic population is scarce, with only several reported clinical cases among baseball and softball pitchers.

Purpose

To present a unique case of a musculocutaneous nerve injury to aid in clinician awareness and propose innovative rehabilitation practices that may facilitate improved patient outcomes during recovery.

Case Description

A 23-year-old Division 1 NCAA collegiate baseball pitcher presented with vague anterior arm pain following a pre-season game. The athlete described the pain as an "intense stretch" of his right arm that occurred during his last pitch. The initial evaluation identified tenderness over the right distal bicep. All shoulder and elbow orthopedic tests to assess shoulder impingement, labral pathologies, and glenohumeral instability were unremarkable. Increased neural tension was also noted with upper limb neurodynamic testing of the median and ulnar nerves on the right arm compared bilaterally. Electromyography (EMG) testing confirmed a right upper and mid-brachial plexus stretch injury with the primary involvement of the musculocutaneous nerve. Rehabilitation focused on restoring strength deficits and diminishing neural tension. Blood flow restriction (BFR) was introduced on the uninvolved limb to reduce deficits in bicep musculature strength. Once the athlete regained bicep strength and forearm sensation, he was progressed from flat-ground throwing activities to throwing off the mound.

Outcomes

A reduction in neural tension during neurodynamic testing of the right arm, improvement of bicep brachii deficits seen between the right and left limbs, and restoration of sensation in the right lateral forearm enabled a progressive return to sport.

Discussion

Due to vague reports and inconclusive findings, the initial presentation of musculocutaneous nerve injuries may be mistaken for other conditions such as a biceps brachii strain. Further -documentation of this injury and rehabilitation procedures are needed to enhance patient outcomes.

Sonographic evaluation of uncommonly assessed upper extremity peripheral nerves: anatomy, technique, and clinical syndromes

Targeted ultrasound of the median, ulnar, and radial nerves is a well-established technique for suspected upper extremity peripheral neuropathy. However, sonographic imaging of the brachial plexus and smaller peripheral nerve branches is more technically difficult and the anatomy is less familiar to many radiologists. As imaging techniques improve, many clinicians refer patients for imaging of previously less-familiar structures. In addition, some patients may present with injuries that could involve local neurovascular structures. Finally, patients presenting with isolated peripheral neuropathies may be referred for perineural injections with local anesthetic for diagnostic purposes, or steroid for therapeutic reasons. This requires sonologists to have a firm understanding of the courses of these nerves and the surrounding anatomic landmarks that can be used to accurately identify and characterize them. We discuss clinical syndromes referable to specific peripheral nerve branches in the upper extremity, the relevant anatomy, and sonographic technique.