Differences in strength fatigue when using different donors in traumatic brachial plexus injuries.

BACKGROUND: The purpose of this study was to assess the results of elbow flexion strength fatigue, rather than the maximal power of strength, after brachial plexus re-innervation with phrenic and spinal accessory nerves. We designed a simple but specific test to study whether statistical differences were observed among those two donor nerves. METHOD: We retrospectively reviewed patients with severe brachial plexus palsy for which either phrenic nerve (PN) or spinal accessory nerve (SAN) to musculocutaneous nerve (MCN) transfer was performed. A dynamometer was used to determine the maximal contraction strength. One and two kilograms circular weights were utilized to measure isometrically the duration of submaximal and near-maximal contraction time. Statistical analysis was performed between the two groups. RESULTS: Twenty-eight patients were included: 21 with a PN transfer while 7 with a SAN transfer for elbow flexion. The mean time from trauma to surgery was 7.1 months for spinal accessory nerve versus 5.2 for phrenic nerve, and the mean follow-up was 57.7 and 38.6 months, respectively. Statistical analysis showed a quicker fatigue for the PN, such that patients with the SAN transfer could hold weights of 1 kg and 2 kg for a mean of 91.0 and 61.6 s, respectively, while patients with transfer of the phrenic nerve could hold 1 kg and 2 kg weights for just a mean of 41.7 and 19.6 s, respectively. Both differences were statistically significant (at p = 0.006 and 0.011, respectively). Upon correlation analysis, endurances at 1 kg and 2 kg were strongly correlated, with r = 0.85 (p < 0.001). CONCLUSIONS: Our results suggest that phrenic to musculocutaneous nerve transfer showed an increased muscular fatigue when compared with spinal accessory nerve to musculocutaneous transfer. Further studies designed to analyze this relation should be performed to increase our knowledge about strength endurance/fatigue and muscle re-innervation.

Treatment of neuropathic pain after peripheral nerve and brachial plexus traumatic injury.

Peripheral nerve and brachial plexus injuries typically cause severe impairment in the affected limb. The incidence of neuropathic pain is high, reaching up to 95% of cases, especially if cervical root avulsion has occurred. Neuropathic pain results from damage to the somatosensory system, and its progression towards chronicity depends upon disruptions affecting both the peripheral and central nervous system. Managing these painful conditions is complex and must be accomplished by a multidisciplinary team, starting with first-line pharmacological therapies like tricyclic antidepressants and calcium channel ligands, combined physical and occupational therapy, transcutaneous electrical stimulation and psychological support. For patients refractory to the initial measures, several neurosurgical options are available, including nerve decompression or reconstruction and ablative/modulatory procedures.

Age as a Predictor of Long-Term Results in Patients with Brachial Plexus Palsies Undergoing Surgical Repair.

BACKGROUND: Among other factors, like the time from trauma to surgery or the number of axons that reach the muscle target, a patient's age might also impact the final results of brachial plexus surgery. OBJECTIVE: To identify (1) any correlations between age and the 2 outcomes: elbow flexion strength and shoulder abduction range; (2) whether childhood vs adulthood influences outcomes; and (3) other baseline variables associated with surgical outcomes. METHODS: Twenty pediatric patients (under age 20 yr) who had sustained a traumatic brachial plexus injury were compared against 20 patients, 20 to 29 yr old, and 20 patients, 30 yr old or older. Univariate, univariate trend, and correlation analyses were conducted with patient age, time to surgery, type of injury, and number of injured roots included as independent variables. RESULTS: A statistically significant trend toward decreasing mean strength in elbow flexion, progressing from the youngest to oldest age group, was observed. This linear trend persisted when subjects were subdivided into 4 age groups (<20, 20-29, 30-39, ≥40). There were no differences by age group in final shoulder abduction range or the percentage achieving a good shoulder outcome. CONCLUSION: Our data suggest that age is somehow linked to the outcomes of brachial plexus surgery with respect to elbow flexion, but not shoulder abduction strength. Increasing age is associated with steadily worsening elbow flexion outcomes, perhaps indicating the need for earlier surgery and/or more aggressive repairs in older patients.