Managing Chronic Pain from Brachial Plexus Injury: Causes, Symptoms, and Advanced Treatment Options
The brachial plexus is a complex network of nerves formed by the anterior rami of the C5–C8 cervical nerves and the T1 thoracic nerve. In some cases, contributions from C4 or T2 may also be involved. Any injury affecting these nerve roots is classified as brachial plexus injury—a challenging type of peripheral nerve damage that often leads to severe upper limb dysfunction. This condition can result in lifelong disability, significantly impacting patients' quality of life and imposing substantial socioeconomic burdens.
Understanding Neuropathic Pain in Brachial Plexus Injuries
Injury to the brachial plexus typically results in immediate or delayed-onset pain, characterized by burning, crushing, or electric shock-like sensations. Patients frequently experience spontaneous pain, allodynia (pain from non-painful stimuli), and hyperalgesia (increased sensitivity to pain). These symptoms define a chronic, treatment-resistant neuropathic pain state that persists long after the initial trauma.
A study by Ryan Bailey et al. evaluated 49 patients using a 10 cm visual analog scale (VAS) for pain intensity. The average score was 5.1, indicating moderate-to-severe pain levels. Notably, around 40% of participants exhibited signs of depression—significantly higher than the 15–19% prevalence seen in the general population. This highlights the profound psychological toll of chronic pain associated with brachial plexus injuries, particularly among those suffering root avulsion injuries.
High Prevalence and Central Mechanisms of Pain
Pain occurs in up to 70% of brachial plexus injury cases. Research by Ciaramitaro and others shows that patients with root avulsion injuries are more likely to develop neuropathic pain compared to those with partial nerve injuries. While peripheral nerve damage contributes to pain, growing evidence points to central nervous system mechanisms playing a critical role in pain persistence and amplification.
Central sensitization (CS) is a key process where the central nervous system becomes hyperexcitable, leading to heightened pain perception. This phenomenon lowers pain thresholds (causing allodynia), increases response intensity (hyperalgesia), and allows pain to spread beyond the original injured nerve territory. Unlike localized nerve compression models, avulsion injuries trigger widespread bilateral mechanical and cold hypersensitivity in animal studies—indicating deep involvement of spinal cord and supraspinal pathways.
These findings suggest that avulsion-related pain cannot be fully explained by peripheral nerve damage alone. Instead, maladaptive changes within the spinal cord and brain contribute significantly to the chronicity and complexity of symptoms.
Phantom Limb Pain After Nerve Avulsion
Interestingly, many patients with complete brachial plexus avulsion still report sensation—and even pain—in their paralyzed limb. This condition, known as phantom limb pain (PLP), affects approximately 39.3% of such patients. Though less common than in amputees (where rates range from 54% to 85%), PLP following nerve avulsion shares similar underlying mechanisms: cortical reorganization in the somatosensory areas corresponding to the denervated limb.
This persistent, often radiating pain usually manifests as a continuous dull ache with intermittent sharp or shooting episodes. It reflects deafferentation pain—pain arising from loss of sensory input to the central nervous system—making it especially difficult to manage with conventional analgesics.
Comprehensive Management Strategies for Brachial Plexus Pain
Treating brachial plexus injury pain requires a multidisciplinary approach tailored to individual needs. Below are evidence-based strategies ranging from conservative care to advanced interventional therapies.
1. Conservative and Non-Surgical Treatments
Medication remains a cornerstone of early pain management. Drugs such as gabapentin, pregabalin, tricyclic antidepressants (e.g., amitriptyline), and opioids like oxycodone provide temporary relief but come with risks of dependence, sedation, and cognitive side effects when used long-term.
Physical therapy helps maintain joint mobility, prevent contractures, and improve functional use of the affected limb. Modalities such as transcutaneous electrical nerve stimulation (TENS), interferential current therapy, magnetic stimulation, and paraffin baths may offer symptomatic relief by modulating pain signals.
Psychological support is essential due to the high comorbidity of anxiety and depression. Cognitive behavioral therapy (CBT), mindfulness-based stress reduction, and biofeedback techniques empower patients to cope better with chronic pain and reduce emotional distress.
Complementary approaches such as acupuncture and manual therapy have shown promise in select patients and should be considered part of an integrative care plan.
2. Intrathecal Drug Delivery Systems
For patients unresponsive to oral medications, intrathecal drug delivery—also known as an implanted pain pump—offers a targeted alternative. By delivering opioids or local anesthetics directly into the cerebrospinal fluid via a catheter connected to a subcutaneously implanted pump, this method achieves effective pain control with lower systemic doses, reducing side effects.
Originally developed for cancer-related pain, this technique is now increasingly used for non-cancer chronic pain conditions, including refractory brachial plexus pain.
3. Surgical Interventions for Refractory Pain
When other treatments fail, neurosurgical procedures may be considered. These include:
- Peripheral nerve stimulation
- Dorsal root entry zone (DREZ) lesioning – with reported success rates of 70–90%
- Spinal cord stimulation (SCS)
- Deep brain stimulation (DBS)
- Cordotomy or rhizotomy procedures
Among these, DREZotomy and SCS demonstrate the most consistent outcomes in clinical practice.
Spinal Cord Stimulation: A Breakthrough in Chronic Pain Relief
Spinal cord stimulation (SCS) has emerged as a transformative therapy for chronic neuropathic pain, including long-standing brachial plexus injury pain. First introduced in the 1970s by Dooley and colleagues using percutaneous electrode placement, SCS initially faced limitations due to technological constraints. However, modern advancements in device design and neuromodulation science have dramatically improved efficacy and reliability.
Today's SCS systems consist of implanted electrodes placed in the epidural space, connected via extension wires to a pulse generator implanted in the abdomen or buttock. The device emits low-level electrical pulses that interfere with pain signal transmission through the dorsal columns of the spinal cord, effectively "masking" discomfort before it reaches the brain.
Real-World Success: A Case of 38-Year Pain Reversal
In one documented case in China, a patient suffered debilitating pain for 38 years following brachial plexus trauma. Despite repeated nerve blocks and prolonged use of pregabalin and extended-release oxycodone, pain persisted with increasing medication side effects. After undergoing SCS implantation, the patient experienced immediate and complete pain relief—demonstrating the potential of this technology to restore quality of life even decades after injury.
Global Evidence Supporting SCS Efficacy
Multiple studies confirm SCS effectiveness in treating chronic neuropathic pain. Kumar et al. reported that 88% of 100 patients with failed back surgery syndrome (FBSS) experienced significant pain reduction after SCS. Japan has also published promising data on SCS use for non-compressive extremity neuropathies, showing marked improvement in daily function and reduced reliance on opioids.
Beyond symptom control, SCS offers a major advantage: it reduces or eliminates the need for long-term opioid therapy, thereby avoiding addiction, tolerance, and gastrointestinal complications.
Who Should Not Receive SCS Therapy?
While SCS is safe for most candidates, certain conditions contraindicate its use:
- Recent myocardial infarction (within 3 months)
- Uncontrolled hypertension or diabetes
- Severe psychiatric disorders or unstable mental health
- Pregnancy
- Presence of implantable cardioverter-defibrillators (ICDs) or pacemaker dependency
- Active infection at the implant site
- Significant spinal anatomical abnormalities preventing electrode placement
- Anticoagulant therapy (high bleeding risk)
- History of substance abuse or opioid dependence
Thorough preoperative screening ensures patient safety and optimal outcomes.
The Two-Stage SCS Treatment Process Explained
SCS therapy involves two phases: a trial period and permanent implantation.
Step 1: Evaluation and Goal Setting
Before any procedure, patients meet with their pain specialist to discuss expectations, goals, and realistic outcomes. This shared decision-making process improves satisfaction and adherence post-treatment.
Step 2: Trial (Temporary) Stimulation – Phase I
In a minimally invasive outpatient procedure, temporary leads are inserted into the epidural space under imaging guidance. These connect to an external wearable stimulator, allowing real-time feedback during surgery. Patients immediately experience how different stimulation patterns affect their pain.
Step 3: Trial Period (Up to 14 Days)
Patients return to normal activities while testing the system in daily life. They adjust settings within physician-defined limits and assess pain relief, functionality, and comfort. This phase typically lasts 5–10 days; exceeding 14 days increases infection risk.
Step 4: Permanent Implantation – Phase II
If the trial reduces pain by at least 50%, the permanent system is implanted. The generator is placed under the skin, and leads are secured for long-term stability.
Step 5: Discharge and Self-Management
Patients go home with a handheld remote to control stimulation settings. Simple lifestyle adjustments help protect the device and maximize benefit.
Step 6: Ongoing Follow-Up
Regular check-ups every 6–12 months ensure proper function, battery monitoring, and programming adjustments as needed.
What Is the Trial (Experience) Phase All About?
The trial phase is a unique feature of SCS—it allows patients to "test drive" the therapy before committing to permanent implantation. Using a needle-guided technique similar to an epidural injection, doctors place a temporary lead without open surgery. Connected to an external controller, this system mimics the effect of a permanent implant.
During recovery, patients walk, sit, and perform routine tasks while adjusting stimulation levels. If the treatment provides meaningful relief, they proceed to full implantation. If not, the lead is simply removed with no lasting harm.
This reversible, patient-centered model makes SCS one of the safest and most personalized options available for managing intractable neuropathic pain.