Proteomics analysis of site- and stage-specific protein expression after peripheral nerve injury.

BACKGROUND: The peripheral nervous system has greater regenerative potential than the CNS. This fact suggests the existence of molecules that act as key factors in nerve regeneration during molecular changes in the peripheral nervous system. METHODS: The right sciatic nerve of female Sprague-Dawley rats was exposed and transected at the mid-thigh level. Animals were sacrificed at 5, 10 or 35 days after nerve transection. Proximal and distal nerve segments (1-cm in length) were dissected. We then sought to observe overall molecular changes after peripheral nerve injury using a proteomic approach. For an overview of the identified proteins, each protein was classified according to its biological and molecular functions. We identified a number of proteins showing site- and stage-specific patterns of expression. RESULTS: Both proximal and distal molecular changes at 5, 10 and 35 days after nerve transection were investigated, and a total of 2353 proteins were identified. Among the various expression patterns observed, aFGF and GAP-43 were found to increase in the proximal stump at 10 days after transection, and PN-1, RPL9 and prosaposin increased in the distal stump at 5 days after transection. Among these proteins, aFGF, GAP-43, PN-1 and prosaposin were found to be associated with nerve regeneration. CONCLUSION: We demonstrated that aFGF, GAP-43, PN-1 and prosaposin expression increased at specific stages and in specific sites, such as the proximal or distal stump, after nerve transection by comprehensive measurement using proteomics analysis. We believe that these specific expression patterns might play important roles during regeneration after nerve injury.

Metallothionein deficiency in the injured peripheral nerves of complex regional pain syndrome as revealed by proteomics.

Complex regional pain syndrome (CRPS) is characterized by persistent and severe pain after trauma or surgery; however, its molecular mechanisms in the peripheral nervous system are poorly understood. Using proteomics, we investigated whether injured peripheral nerves of CRPS patients have altered protein profiles compared with control nerves. We obtained nerve samples from 3 patients with CRPS-2 who underwent resection of part of an injured peripheral nerve. Sural nerves from fresh cadavers with no history of trauma or neuropathic pain served as controls. Proteomic analysis showed that the number and functional distribution of proteins expressed in CRPS and control nerves was similar. Interestingly, metallothionein was absent in the injured nerves of CRPS-2, although it was readily detected in control nerves. Western blotting further confirmed the absence of metallothionein in CRPS-2 nerves, and immunohistochemistry corroborated the deficiency of metallothionein expression in injured nerves from 5 of 5 CRPS patients and 2 of 2 patients with painful neuromas. In contrast, all control nerves, including 5 sural nerves from fresh cadavers and 41 nerves obtained from surgically resected tumors, expressed MT. Furthermore, expression of S100 as a marker for Schwann cells, and neurofilament M as a marker of axons was comparable in both CRPS-2 and controls. Metallothioneins are zinc-binding proteins that are probably involved in protection against injury and subsequent regeneration after CNS damage. Their absence from the injured peripheral nerves of patients with CRPS-2 suggests a potential pathogenic role in generating pain in the damaged peripheral nerves.

Pisotriquetral arthrosis after triquetral malunion: a case report.

We report a patient with chronic ulnar palmar wrist pain caused by malunion after isolated fracture of the triquetrum. Intra-articular malunion of the triquetrum body resulted in posttraumatic pisotriquetral arthrosis. The diagnosis was made by magnetic resonance imaging, computed tomography, bone scintigraphy, and wrist arthroscopy 5 months after the injury. The patient's symptoms were relieved by excision of the pisiform.

Adjacent segment stenosis after lumbar fusion requiring second operation.

BACKGROUND: Whereas degeneration of the segment adjacent to lumbar fusion has been often seen on radiographs, a small number of patients with such degenerative changes undergo reoperation. Most follow-up studies have focused on adjacent segment disease based on analysis of radiographs. The present study was conducted to understand the pathology of reoperation cases of adjacent segment disease and factors associated with this condition. Operative indication was consistently restricted to patients with neurological involvement. METHODS: The subjects were 117 patients who had undergone posterior lumbar fusion and were followed for a minimum of 2 years (mean 7 years). Among them, nine patients (7.7%) required a second operation owing to symptomatic adjacent segment disease (stenosis). The reoperation rate was assessed in relation to sex, age, initial pathologic condition, and initial spinal fusion and decompression methods. Data were analyzed in a 2 x 2 cross contingency table using Fisher's exact probability test. A probability of <0.05 was defined as statistically significant. RESULTS: Of the variables examined, only multilevel fusion was associated with a high rate of reoperation with statistical significance (P < 0.04). Two patients (100%) suffering from loss of coronal balance (degenerative scoliosis) also required a second operation. CONCLUSIONS: The reoperation rate of 7.7% for adjacent segment disease in this study was consistent with the prevalence of adjacent segment stenosis in the literature. Given the risk of later occurrence of adjacent segment stenosis following multisegment posterolateral fusion, correction of coronal and sagittal balance, preventive decompression of the adjacent segment, or selective decompression without fusion may have to be considered as an additional or alternative procedure.

Cubital tunnel syndrome in adolescent baseball players: a report of six cases with 3- to 5-year follow-up.

In this case report, we describe the clinical features and surgical outcome of cubital tunnel syndrome in adolescent baseball players. Two infielders, 2 pitchers, and 2 catchers who suffered cubital tunnel syndrome during adolescence (average age, 14 years) were surgically treated. Symptoms of medial elbow pain first appeared during throwing in competition games in summer or autumn seasons. After the onset, they suffered limitation of elbow extension and weakness on grabbing balls. They could not throw because of recurrent medial elbow pain. Laxity of the medial collateral ligament was not detected by stress radiography. Duration of symptoms from the onset to surgery was less than 6 months for 2 patients, 1 year for 2, and longer than 2 years for 2 patients. Anterior subcutaneous transposition of the ulnar nerve relieved symptoms up to 3.3 postoperative years. Medial protrusion of the triceps muscle was observed to cause irritation of the ulnar nerve. Fibrosis surrounding the ulnar nerve was observed without pseudoneuroma. Throwing performance returned completely to competitive level in 5 months postoperatively in 5 of 6 patients. Early diagnosis of cubital tunnel syndrome in adolescent baseball players is very important. Anterior subcutaneous transposition of the ulnar nerve relieves symptoms and restores throwing function.

Magnetic resonance imaging findings of refractory tennis elbows and their relationship to surgical treatment.

Treatment of tennis elbow is a problem. We performed magnetic resonance imaging (MRI) examinations of 11 elbows in 11 patients who were referred to us with refractory tennis elbow. Of the 11 elbows, 6 showed a high signal intensity focus on MRI T2 images in the tendon of the extensor carpi radialis brevis at the lateral epicondyle. The other 5 elbows showed various abnormal findings on MRI. The mean age of the 6 patients with a high T2 signal focus was 52.0 years, and the mean morbidity period was 25 months. We performed enucleation of the granulation focus through a surgical approach without detachment of the tendon origin of the extensor carpi radialis brevis. Pain was relieved and elbow function recovered in all 6 cases. This study demonstrates that MRI is an important decision-making tool in the surgical treatment of this condition. Enucleation of the granulation focus with high T2 signal has proved to be effective in 6 selected cases.