Brachial Plexus Injury Diagnosis and Management

Definition and Terminology

Brachial plexopathy is the medical term that describes any pathological condition affecting the brachial plexus, while brachial plexus injury specifically refers to traumatic damage to this nerve network 1, 2, 3
The term "plexopathy" is the broader medical terminology that encompasses all disorders affecting a nerve plexus, whether traumatic or non-traumatic in origin 2, 3

Brachial plexopathy/BPI can be classified based on etiology, with traumatic causes including blunt force injuries, penetrating injuries, and compression injuries 1
Non-traumatic causes include inflammatory conditions, such as Parsonage-Turner syndrome/brachial neuritis 4, neoplastic involvement 5, and radiation-induced plexopathy 5
Thoracic outlet syndrome is also a non-traumatic cause of brachial plexopathy 3

MRI of the brachial plexus is the gold standard for evaluation due to superior soft-tissue contrast and spatial resolution 6, 7
Imaging for traumatic cases should be delayed until approximately 1 month after injury to allow for resolution of hemorrhage and edema 1, 8

The American College of Radiology recommends that penetrating and open injuries often require early surgical exploration, while blunt and closed injuries may be managed operatively or non-operatively based on severity 1
Complete nerve ruptures generally have worse outcomes and often require early operative management 1
Clinical diagnosis can be challenging as symptoms may overlap with radiculopathy (single nerve root involvement) 2

The American College of Radiology recommends MRI of the brachial plexus without and with IV contrast as the preferred initial imaging modality due to superior soft-tissue contrast and spatial resolution 9, 10
MRI protocols should include orthogonal views through the oblique planes of the plexus, T1-weighted, T2-weighted, fat-saturated T2-weighted sequences, short tau inversion recovery (STIR) sequences, and fat-saturated T1-weighted postcontrast sequences 11, 12
CT neck with IV contrast may be appropriate when MRI is contraindicated, offering the next highest level of anatomic visualization 9, 10
FDG-PET/CT is recommended in cases with known malignancy or post-treatment syndrome 10
1.5T MRI may be beneficial when metal is present in the area to reduce artifact 13, 14

Parsonage-Turner syndrome (neuralgic amyotrophy) is typically managed conservatively with physical therapy to maintain range of motion and monitoring for recovery 9, 12

Routine neck, chest, spine, or pelvic MRI protocols are inadequate for proper evaluation of the brachial plexus; specialized brachial plexus protocols are required 11, 12

La American College of Radiology recomienda que la resonancia magnética (RM) del plexo braquial con protocolo dedicado es el estándar de oro para el diagnóstico, con sensibilidad del 81%, especificidad del 91%, y precisión del 88% 15
La RM puede detectar complicaciones postraumáticas que contribuyen a los síntomas, como hematomas regionales de tejidos blandos, neuromas traumáticos, cicatrización, y atrofia muscular degenerativa secundaria 15
La lesión quirúrgica puede ocurrir durante procedimientos en la región cervical o del hombro, y se debe considerar en el diagnóstico diferencial 15

In Guillain‑Barré syndrome (GBS) the typical presentation is an ascending, bilateral weakness with areflexia and symmetric sensory loss, contrasting with the usually unilateral, upper‑extremity‑limited weakness of Parsonage‑Turner syndrome (PTS). 16
Cerebrospinal fluid analysis shows albumino‑cytological dissociation in GBS, whereas CSF findings are normal in PTS. 16

Early electrodiagnostic studies (EMG/NCS) or MRI may be normal in the first two weeks of PTS; repeating these tests at 3–4 weeks after symptom onset markedly improves diagnostic yield. 16
When PTS is suspected, ordering only a cervical‑spine MRI is insufficient; a dedicated brachial‑plexus MRI protocol is required to visualize nerve pathology. 16
The appearance of bilateral facial palsy or an ascending pattern of weakness should prompt clinicians to consider GBS rather than PTS. 16

Vaccination (e.g., influenza, tetanus, COVID‑19) is a recognized trigger for PTS, with an attributable incidence of approximately 0.5–1 case per 100,000 tetanus‑toxoid recipients. 17
A history of prior PTS does not constitute an absolute contraindication to future vaccinations; the decision should be individualized based on the temporal relationship and severity of the previous episode. 17
The risk of a recurrent PTS episode after vaccination is extremely low, estimated at less than 1 case per 100,000 vaccine doses. 17