Pain syndromes after missile-caused peripheral nerve lesions: part 1--clinical characteristics

Assessment, patient selection, and rehabilitation of nerve transfers

Peripheral nerve injuries are common and can have a devastating effect on physical, psychological, and socioeconomic wellbeing. Peripheral nerve transfers have become the standard of care for many types of peripheral nerve injury due to their superior outcomes relative to conventional techniques. As the indications for, and use of, nerve transfers expand, the importance of pre-operative assessment and post-operative optimization increases. There are two principal advantages of nerve transfers: (1) their ability to shorten the time to reinnervation of muscles undergoing denervation because of peripheral nerve injury; and (2) their specificity in ensuring proximal motor and sensory axons are directed towards appropriate motor and sensory targets. Compared to conventional nerve grafting, nerve transfers offer opportunities to reinnervate muscles affected by cervical spinal cord injury and to augment natural reinnervation potential for very proximal injuries. This article provides a narrative review of the current scientific knowledge and clinical understanding of nerve transfers including peripheral nerve injury assessment and pre- and post-operative electrodiagnostic testing, adjuvant therapies, and post-operative rehabilitation for optimizing nerve transfer outcomes.

A Brief History of Peripheral Nerve Surgery in Serbia

Peripheral nerve surgery in Serbia has become the most fruitful subsection of national neurosurgery, with international recognition of Serbian surgeons and institutions. We chronicle landmark events in the history of the field in Serbia, highlighting the development of the field over time and outlining future prospects. This manuscript provides an example of the development of peripheral nerve surgery and associated training in a challenging social, political, and economic context and may guide the development of peripheral nerve surgery care and training in other settings.

Resident peripheral nerve surgery competence: An assessment of procedural exposure, self-reported competence and technical ability

BACKGROUND

Identifying peripheral nerve surgery procedure (PNSP) competencies is crucial to ensure adequate resident training. We examine PNSP training at neurosurgical centers in the US and Canada to compare resident-reported competence, PNSP exposure, and resident technical abilities in performing 3 peripheral nerve coaptations (PNC).

METHODS

Resident-reported PNSP competence and PNSP exposure data were collected using questionnaires from neurosurgical residents at North American neurosurgical training centers. Exposure and self-reported competency were correlated with technical skills. Technical PNC variables collected included: time-to-completion, nerve-handling from video-analysis, independent and blinded visual-analog-scale (VAS) PNC quality grading by 3 judges, and training level.

RESULTS

A total of 40 neurosurgical residents participated in the study. Although self-reported competency scores correlated with procedural exposure (P < 0.01, rs = 0.88), a discrepancy was found between the degree of self-reported competency and amount of exposure. The discrepancy was greater in senior residents. A significant VAS difference was found between PNC types with the direct-suture and connector-assister groups scoring higher than connector-only (P = 0.02, P < 0.01, respectively). No difference was observed between training level and VAS grading, nor time-to completion (P = 0.33 and 0.25, respectively). No correlation was found between self-reported competency performing PNSPs and PNC VAS scores, nor nerve handling.

CONCLUSIONS

Despite more exposure and a higher self-reported PNSP competency in senior residents, no difference was seen between senior/junior residents in PNC quality. A discrepancy in PNSP exposure and self-reported competency exists. This information will provide guidance for the direction of resident PNS training.

MANAGEMENT OF BRACHIAL PLEXUS MISSILE INJURIES

SUMMARY – Missile injuries are among the most devastating injuries in general traumatology. Traumatic brachial plexus injuries are the most difficult injuries in peripheral nerve surgery, and most complicated to be surgically treated. Nevertheless, missile wounding is the second most common mechanism of brachial plexus injury. The aim was to evaluate functional recovery after surgical treatment of these injuries. Our series included 68 patients with 202 nerve lesions treated with 207 surgical procedures. Decision on the treatment modality (exploration, neurolysis, graft repair, or combination) was made upon intraoperative finding. Results were analyzed in 60 (88.2%) patients with 173 (85.6%) nerve lesions followed-up for two years. Functional recovery was evaluated according to functional priorities. Satisfactory functional recovery was achieved in 90.4% of cases with neurolysis and 85.7% of cases with nerve grafting. Insufficient functional recovery was verified in ulnar and radial nerve lesions after neurolysis, and in median and radial nerve lesions when graft repair was done. We conclude that the best time for surgery is between two and four months after injury, except for the gunshot wound associated with injury to the surrounding structures, which requires immediate surgical treatment. The results of neurolysis and nerve grafting were similar.

Neurological disorders in complex humanitarian emergencies and natural disasters

Complex humanitarian emergencies include the relatively acute, severe, and overwhelming health consequences of armed conflict, food scarcity, mass displacement, and political strife. Neurological manifestations of complex humanitarian emergencies are important and underappreciated consequences of emergencies in populations worldwide. This review critically assesses the existing knowledge of the range of neurological disorders that accompany complex humanitarian emergencies and natural disasters in both the acute phase of crisis and the "long shadow" that follows.

[The intern's vein--the patient's nightmare?]

BACKGROUND

Punction of blood vessels is a necessity in modern medicine, but there is a paucity of knowledge about the close relation between vessels and nerves.

MATERIAL AND METHODS

We refer to two cases that show possible consequences of cannulation of v. cephalica and a. radialis.

RESULTS

Both patients developed clinical symptoms and neurological findings indicating injury of the radial nerve. One of the patients is not likely to develop chronic neuropathic pain, but in the other patient the similar injury of the radial nerve has lead to chronic and disabling pain.

INTERPRETATION

We advise against using the distal part of v. cephalica (the intern's vein) as the first choice for training of inexperienced students. The vein should only be used in patients that lack other venous alternatives and in acute situations where quick infusions or blood transfusions are needed.

Systematic review of the literature on pain in patients with polytrauma including traumatic brain injury

OBJECTIVE

To review the literature addressing the assessment and management of pain in patients with polytraumatic injuries including traumatic brain injury (TBI) and blast-related headache, and to identify patient, clinician and systems factors associated with pain-related outcomes.

DESIGN

Systematic review.

METHODS

We conducted searches in MEDLINE of literature published from 1950 through July 2008. Due to a limited number of studies using controls or comparators, we included observational and rigorous qualitative studies. We systematically rated the quality of systematic reviews, cohort, and case-control design studies.

RESULTS

One systematic review, 93 observational studies, and one qualitative research study met inclusion criteria. The literature search yielded no published studies that assessed measures of pain intensity or pain-related functional interference among patients with cognitive deficits due to TBI, that compared patients with blast-related headache with patients with other types of headache, or that assessed treatments for blast-related headache pain. Studies on the association between TBI severity and pain reported mixed findings. There was limited evidence that the following factors are associated with pain among TBI patients: severity, location, and multiplicity of injuries; insomnia; fatigue; depression; and post-traumatic stress disorder.

CONCLUSIONS

Very little evidence is currently available to guide pain assessment and treatment approaches in patients with polytrauma. Further research employing systematic observational as well as controlled intervention designs is clearly indicated.

From the battlefront: peripheral nerve surgery in modern day warfare

Warfare historically causes a large number of peripheral nerve injuries. During the current global war on terror, an increased use of advanced regional anesthesia techniques appears to have significantly reduced pain syndromes that have been previously reported with missile-induced nerve injuries. Additionally, a new program has been established to develop advanced prosthetic devises that can interface with neural tissue to obtain direct neural control. As this technology matures, the functional restoration gained from these new generation prosthetic devices may exceed that which can be obtained by standard nerve repair techniques.

Governing role of primary afferent drive in increased excitation of spinal nociceptive neurons in a model of sciatic neuropathy

Previously we reported that the cuff model of peripheral neuropathy, in which a 2 mm polyethylene tube is implanted around the sciatic nerve, exhibits aspects of neuropathic pain behavior in rats similar to those in humans and causes robust hyperexcitation of spinal nociceptive dorsal horn neurons. The mechanisms mediating this increased excitation are not known and remain a key unresolved question in models of peripheral neuropathy. In anesthetized adult male Sprague-Dawley rats 2-6 weeks after cuff implantation we found that elevated discharge rate of single lumbar (L(3-4)) wide dynamic range (WDR) neurons persists despite acute spinal transection (T9) but is reversed by local conduction block of the cuff-implanted sciatic nerve; lidocaine applied distal to the cuff (i.e. between the cuff and the cutaneous receptive field) decreased spontaneous baseline discharge of WDR dorsal horn neurons approximately 40% (n=18) and when applied subsequently proximal to the cuff, i.e. between the cuff and the spinal cord, it further reduced spontaneous discharge by approximately 60% (n=19; P<0.05 proximal vs. distal) to a level that was not significantly different from that of naive rats. Furthermore, in cuff-implanted rats WDR neurons (n=5) responded to mechanical cutaneous stimulation with an exaggerated afterdischarge which was reversed entirely by proximal nerve conduction block. These results demonstrate that the hyperexcited state of spinal dorsal horn neurons observed in this model of peripheral neuropathy is not maintained by tonic descending facilitatory mechanisms. Rather, on-going afferent discharges originating from the sciatic nerve distal to, at, and proximal to the cuff maintain the synaptically-mediated gain in discharge of spinal dorsal horn WDR neurons and hyperresponsiveness of these neurons to cutaneous stimulation. Our findings reveal that ectopic afferent activity from multiple regions along peripheral nerves may drive CNS changes and the symptoms of pain associated with peripheral neuropathy.