eMedicine Specialties > Physical Medicine and Rehabilitation > Plexopathy
Radiation-Induced Brachial Plexopathy: Differential Diagnoses & Workup
Updated: Jun 11, 2009
- Overview
- Differential Diagnoses & Workup
- Treatment & Medication
- Follow-up
Differential Diagnoses
Brachial Neuritis
Cervical Disc Disease
Cervical Myofascial Pain
Neoplastic Brachial Plexopathy
Traumatic Brachial Plexopathy
Other Problems to Be Considered
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Table
| Feature | Tumor infiltration | Radiation fibrosis | Transient radiation injury | Acute ischemic injury |
|---|---|---|---|---|
| Incidence of pain | 80% | 18% | 40% | Painless |
| Location of pain | Shoulder, upper arm, elbow, fourth and fifth fingers | Shoulder, wrist, hand | Hand, forearm | Hand, forearm |
| Nature of pain | Dull ache in shoulder, lancinating pains in elbow and ulnar aspect of hand; occasional paresthesias and dysesthesias | Ache in shoulder; prominent paresthesias in C-5/C-6 distribution of hand and arm | Ache in shoulder; prominent paresthesias in C-5/C-6 distribution of hand and arm | Paresthesias in C-5/C-6 distribution of hand and arm |
| Severity | Moderate to severe (severe in 98%) | Usually mild to moderate (severe in 20-35%) | Mild | Mild |
| Course | Progressive neurologic dysfunction; atrophy and weakness in C-7/T-1 distribution, persistent pain; occasional Horner syndrome | Progressive weakness; panplexus or upper plexus distribution; Horner syndrome uncommon | Translate weakness with complete resolution | Acute nonprogressive weakness and sensory loss |
| Study findings | ||||
| Magnetic resonance imaging | High signal intensity on T2-weighted images; may enhance with gadolinium | Low signal intensity on T2-weighted images; generally nonenhancing with gadolinium | No data | Normal |
| Computed tomography | Mass; circumscribed or diffuse tissue infiltration | Diffuse tissue infiltration | Normal | Angiography demonstrates subclavian artery segmental obstruction |
| Electromyography | Segmental slowing | Diffuse myokymia | Segmental slowing | Segmental slowing |
| Feature | Tumor infiltration | Radiation fibrosis | Transient radiation injury | Acute ischemic injury |
|---|---|---|---|---|
| Incidence of pain | 80% | 18% | 40% | Painless |
| Location of pain | Shoulder, upper arm, elbow, fourth and fifth fingers | Shoulder, wrist, hand | Hand, forearm | Hand, forearm |
| Nature of pain | Dull ache in shoulder, lancinating pains in elbow and ulnar aspect of hand; occasional paresthesias and dysesthesias | Ache in shoulder; prominent paresthesias in C-5/C-6 distribution of hand and arm | Ache in shoulder; prominent paresthesias in C-5/C-6 distribution of hand and arm | Paresthesias in C-5/C-6 distribution of hand and arm |
| Severity | Moderate to severe (severe in 98%) | Usually mild to moderate (severe in 20-35%) | Mild | Mild |
| Course | Progressive neurologic dysfunction; atrophy and weakness in C-7/T-1 distribution, persistent pain; occasional Horner syndrome | Progressive weakness; panplexus or upper plexus distribution; Horner syndrome uncommon | Translate weakness with complete resolution | Acute nonprogressive weakness and sensory loss |
| Study findings | ||||
| Magnetic resonance imaging | High signal intensity on T2-weighted images; may enhance with gadolinium | Low signal intensity on T2-weighted images; generally nonenhancing with gadolinium | No data | Normal |
| Computed tomography | Mass; circumscribed or diffuse tissue infiltration | Diffuse tissue infiltration | Normal | Angiography demonstrates subclavian artery segmental obstruction |
| Electromyography | Segmental slowing | Diffuse myokymia | Segmental slowing | Segmental slowing |
Workup
Laboratory Studies
- No laboratory studies help differentiate radiation-induced brachial plexopathy from other disorders involving the brachial plexus.
Imaging Studies
- Plain radiography does not have diagnostic value for detecting radiation-induced brachial plexopathy.
- Computed tomography (CT) scanning of the involved brachial plexus may reveal a diffuse infiltration of the tissue planes.
- Magnetic resonance imaging (MRI) often reveals low signal intensity on T2-weighted images; minimal changes are found with gadolinium.4,6
- All of these characteristics are in contrast to neoplastic processes, which would be identified by the presence of a focal mass. In addition, if traditional modalities demonstrate normal findings, positron emission tomography imaging may provide an additional tool for excluding suspected malignant plexopathy. Malignant etiologies of brachial plexopathy are associated with significantly increased uptake of 18-fluoro-2-deoxy-D-glucose, reflecting the increased metabolism associated with neoplastic processes.
Other Tests
- Electrodiagnostic testing can be used to distinguish between radiation-induced and neoplastic disorders of the brachial plexus. No significant differences between the 2 conditions are noted between results of sensory and motor conduction studies or late responses.
- Electromyography in radiation-induced brachial plexopathy reveals myokymia more often than in neoplastic-induced brachial plexopathy. Myokymia represents spontaneous discharges accompanied by wavelike muscle quivering. The frequency may be paroxysmal motor unit action potentials or a slow continuous discharge at 1-5 Hz in motor unit action potentials.4
- Evoked potential studies do not have any particular value for this diagnosis.
Procedures
- In some cases, surgical exploration and biopsy are required to distinguish between radiation-induced and tumor-induced brachial plexopathy. Nerve grafting has been attempted in animals with fair results, but data from human trials are lacking.1,7
- Surgical treatment options are aimed at breaking up fibrotic tissue to eliminate mechanical constriction of the plexus and its blood supply. Attempts have been made at exoneurolysis/endoneurolysis, with or without placement of an omental or latissimus dorsi flap as a source of well-perfused tissue. Unfortunately, these approaches have proven ineffective and even harmful. Indeed, dissection alone can lead to a significant worsening of symptoms. Some relief of pain may be achieved in a minority of patients, with little or no impact on other sensory or motor deficits.
Histologic Findings
- Fibrosis of the neural elements and surrounding soft tissues
- Chronic perineurial microvascular ischemia
More on Radiation-Induced Brachial Plexopathy |
| Overview: Radiation-Induced Brachial Plexopathy |
 Differential Diagnoses & Workup: Radiation-Induced Brachial Plexopathy |
| Treatment & Medication: Radiation-Induced Brachial Plexopathy |
| Follow-up: Radiation-Induced Brachial Plexopathy |
| References |
| Further Reading |
| « Previous Page | Next Page » |
References
Wong M, Tang AL, Umapathi T. Partial ulnar nerve transfer to the nerve to the biceps for the treatment of brachial plexopathy in metastatic breast carcinoma: case report. J Hand Surg Am. Jan 2009;34(1):79-82. [Medline].
Galecki J, Hicer-Grzenkowicz J, Grudzien-Kowalska M, et al. Radiation-induced brachial plexopathy and hypofractionated regimens in adjuvant irradiation of patients with breast cancer--a review. Acta Oncol. 2006;45(3):280-4. [Medline]. [Full Text].
Schierle C, Winograd JM. Radiation-induced brachial plexopathy: review. Complication without a cure. J Reconstr Microsurg. Feb 2004;20(2):149-52. [Medline].
Shimazaki H, Nakano I. [Radiation myelopathy and plexopathy]. Brain Nerve. Feb 2008;60(2):115-21. [Medline].
Forquer JA, Fakiris AJ, Timmerman RD, et al. Brachial plexopathy from stereotactic body radiotherapy in early-stage NSCLC: Dose-limiting toxicity in apical tumor sites. Radiother Oncol. May 17 2009;[Medline].
Sureka J, Cherian RA, Alexander M, et al. MRI of brachial plexopathies. Clin Radiol. Feb 2009;64(2):208-18. [Medline].
Tung TH, Liu DZ, Mackinnon SE. Nerve transfer for elbow flexion in radiation-induced brachial plexopathy: a case report. Hand (N Y). Jun 2009;4(2):123-8. [Medline].
Delanian S, Balla-Mekias S, Lefaix JL. Striking regression of chronic radiotherapy damage in a clinical trial of combined pentoxifylline and tocopherol. J Clin Oncol. Oct 1999;17(10):3283-90. [Medline].
Fathers E, Thrush D, Huson SM, Norman A. Radiation-induced brachial plexopathy in women treated for carcinoma of the breast. Clin Rehabil. Mar 2002;16(2):160-5. [Medline].
Garden FH. Radiation injury to the spinal cord and peripheral nerves. State of the art reviews PM&R. 1994;8:405-411.
Hoeller U, Rolofs K, Bajrovic A, et al. A patient questionnaire for radiation-induced brachial plexopathy. Am J Clin Oncol. Feb 2004;27(1):1-7. [Medline].
Jaeckle KA. Plexopathies in cancer patients. In: Levin, Victor A, ed. Cancer in the Nervous System. New York, NY: Churchill Livingstone; 1996:347-60.
Kori SH. Diagnosis and management of brachial plexus lesions in cancer patients. Oncology (Huntingt). Aug 1995;9(8):756-60; discussion 765. [Medline].
Mondrup K, Olsen NK, Pfeiffer P, Rose C. Clinical and electrodiagnostic findings in breast cancer patients with radiation-induced brachial plexus neuropathy. Acta Neurol Scand. Feb 1990;81(2):153-8. [Medline].
Pierce SM, Recht A, Lingos TI, et al. Long-term radiation complications following conservative surgery (CS) and radiation therapy (RT) in patients with early stage breast cancer. Int J Radiat Oncol Biol Phys. 1992;23(5):915-23. [Medline].
Posner JB. Side effects of radiation therapy. In: Neurologic Complications of Cancer. Philadelphia, Pa: FA Davis; 1995:311-37.
Stubgen JP. Neuromuscular disorders in systemic malignancy and its treatment. Muscle Nerve. Jun 1995;18(6):636-48. [Medline].
Further Reading
Related eMedicine topics:
Brachial Neuritis
Diabetic Lumbosacral Plexopathy
Neoplastic Brachial Plexopathy
Neoplastic Lumbosacral Plexopathy
Radiation-Induced Lumbosacral Plexopathy
Traumatic Brachial Plexopathy
Clinical guidelines:
ACR Appropriateness Criteria® plexopathy. American College of Radiology - Medical Specialty Society. 2006. 13 pages. NGC:005539
Clinical trials:
Stem Cell Therapy to Improve the Muscle Function of Patients With Partly Denervated Muscles of the Arm
Keywords
radiation-induced brachial plexopathy, brachial plexus, plexopathy, brachial plexopathy, radiation therapy, radiation treatment, breast cancer radiation therapy, breast radiation therapy, cancer radiation therapy, irradiation brachial plexopathy,
