An uncommon mechanism of brachial plexus injury. A case report

PURPOSE

To report a case of brachial plexus injury occurring on the contralateral side in a patient undergoing surgery for acoustic neuroma through translabrynthine approach.

CLINICAL FEATURES

A 51-yr-old woman underwent surgery for acoustic neuroma through translabrynthine approach in the left retroauricular area. She had a short neck with a BMI of 32. Under anesthesia, she was placed in supine position with Sugita pins for head fixation. The head was turned 45 degrees to the right side and the neck was slightly flexed for access to the left retroauricular area, with both arms tucked by the side of the body. Postoperatively, she developed weakness in the right upper extremity comparable with palsy of the upper trunk of the brachial plexus. Hematoma at the right internal jugular vein cannulation site was ruled out by CAT scan and MRI. The only remarkable finding was considerable swelling of the right sternocleidomastoid and scalene muscle group, with some retropharyngeal edema. An EMG confirmed neuropraxia of the upper trunk of brachial plexus. She made a complete recovery of sensory and motor power in the affected limb over the next three months with conservative treatment and physiotherapy.

CONCLUSIONS

Brachial plexus injury is still seen during anesthesia despite the awareness about its etiology. Malpositioning of the neck during prolonged surgery could lead to compression of scalene muscles and venous drainage impedance. The resultant swelling in the structures surrounding the brachial plexus may result in a severe compression.

Analgesic effect of interscalene block using low-dose bupivacaine for outpatient arthroscopic shoulder surgery

BACKGROUND AND OBJECTIVES

Although interscalene brachial plexus block (ISBPB) is often used to provide anesthesia for arthroscopic shoulder surgery, its selective analgesic effect, provided by low-dose local anesthetic, has not been studied. We hypothesized that ISBPB using a low volume and low concentration of bupivacaine can provide effective postoperative analgesia for shoulder surgery without producing significant sensory or motor block elsewhere.

METHODS

In this double-blind study, 30 outpatients scheduled to undergo shoulder arthroscopy were randomly assigned to receive either an ISBPB with 10 mL 0.125% bupivacaine with epinephrine 1:400,000 (n = 15) or 10 mL of normal saline (n = 15). The block was performed preoperative, prior to a standardized general anesthetic. Postoperative pain scores, imorphine and oral analgesic consumption, recovery profile, and patient satisfaction were recorded.

RESULTS

In the ISBPB group, verbal analog pain scores within 120 minutes after surgery were lower, morphine consumption in the postanesthesia care unit was significantly lower (2.7+/-2.6 mg vs 9.5+/-5.2 mg), the time to postoperative administration of the first systemic or oral analgesic was significantly longer (141+/-182 minutes vs 13+/-10 minutes), the degree of motor and sensory block 120 minutes after surgery was minimal, time to reach hospital discharge criteria was earlier, and patient satisfaction with postoperative analgesia at 24-hour follow-up was greater. Thirty-three percent of the patients receiving ISBPB did not require any analgesic prior to hospital discharge.

CONCLUSIONS

Interscalene brachial plexus block with low-dose bupivacaine is a useful and selective analgesic technique for outpatient shoulder arthroscopic surgery.

Elevations in cathepsin B protein content and enzyme activity occur independently of glycosylation during colorectal tumor progression

Western blots, enzyme assays, protein glycosylation studies, and immunohistochemical staining were used to characterize cathepsin B expression at successive stages of colorectal tumor progression. In normal colon mucosa and premalignant adenomas, cathepsin B expression was predominantly due to mature two-chain protein detected on Western blots as the nonglycosylated 27-kDa form, with overexpression of this protein occurring in only 4 of 18 adenomas. Overexpression increased significantly in Dukes A and B carcinomas (26 of 37 cases), with cathepsin B protein generally detectable in carcinomas as a combination of both 27-kDa nonglycosylated and 28-kDa glycosylated mature two-chain forms. Glycosylated cathepsin B protein in carcinoma extracts was sensitive to PNGase F but resistant to Endo H, indicating a pattern consistent with complex rather than high mannose type glycosylation. When sorted by advancing tumor stage, peak expression of cathepsin B protein occurred in carcinomas involved in local invasion compared with adenomas or metastatic cancers. At all stages, cathepsin B activity correlated significantly with the levels of heavy chain mature cathepsin B protein (r = 0.6682, p < 0.0001) irrespective of glycosylation. Immunohistochemical staining of cathepsin B protein revealed fine diffuse cytoplasmic staining in both adenomas and carcinomas compared with coarse granular cytoplasmic staining (typical of lysosomes) seen in matched normal mucosa. Our results demonstrate several sequential, apparently independent changes in cathepsin B expression during colorectal tumor progression including early changes in subcellular localization, up-regulation of cathepsin B protein and activity in invasive cancers, and altered protein glycosylation detected in malignant tumors at all stages.

Immunotherapy of tumors with autologous tumor-derived heat shock protein preparations

Immunotherapy of mice with preexisting cancers with heat shock protein preparations derived from autologous cancer resulted in retarded progression of the primary cancer, a reduced metastatic load, and prolongation of life-span. Treatment with heat shock protein preparations derived from cancers other than the autologous cancer did not provide significant protection. Spontaneous cancers (lung cancer and melanoma), chemically induced cancers (fibrosarcoma and colon carcinoma), and an ultraviolet radiation-induced spindle cell carcinoma were tested, and the results support the efficacy of autologous cancer-derived heat shock protein-peptide complexes in immunotherapy of cancers without the need to identify specific tumor antigenic epitopes.

Purification of immunogenic heat shock protein 70-peptide complexes by ADP-affinity chromatography

Adenosine triphosphate (ATP)-affinity chromatography has been widely used to purify molecules of the Hsp70 family. This procedure leads to dissociation of peptides from Hsp70 molecules, resulting in Hsp70 preparations devoid of immunological activity. We report that substitution of ATP-affinity chromatography by ADP-affinity chromatography results in isolation of Hsp70 molecules which are still associated with peptides and are immunogenic. The Hsp70 preparations thus obtained contain the constitutive Hsp73 and the inducible Hsp72 molecules. These observations furnish a basis for an analysis of the structural heterogeneity among the members of the Hsp70 family and of the antigenic peptides associated with individual members of this family. They also provide a practical method for the isolation of large quantities of immunologically active Hsp70-peptide preparations.

[The analysis of abnormal auditory brainstem responses]

The abnormal auditory brainstem responses (ABR) of 56 cases who had different retrocochlear disorders were analysed. These disease included acoustic neuroma, glioma, cholesteatoma, astrocytoma, meningoma in cerebellopontile angle (CPA), chromaffin tumor of jugular foramen, intracranial metastatic tumor, demyelinating disease, multiple cranial nerve paralysis, hepatolenticular degeneration, other CPA tumors, expansion or stenosis of internal auditory meatus (IAM), and so on. The ABR features were varied in these diseases, even in same disease. In general, the wave latencies and interwave periods prolonged in the disorders which occupied place in CPA, the differentiation of wave was not clear and/or the wave was not well repeated in the disorders which spreaded all over the brain. The cause of abnormal ABRin which CT and/or MRI were normal was also analysed. The ABR detection is a sensitive indication in retrocochlear lesions.

Generic queries for meeting clinical information needs

This paper describes a model for automated information retrieval in which questions posed by clinical users are analyzed to establish common syntactic and semantic patterns. The patterns are used to develop a set of general-purpose questions called generic queries. These generic queries are used in responding to specific clinical information needs. Users select generic queries in one of two ways. The user may type in questions, which are then analyzed, using natural language processing techniques, to identify the most relevant generic query; or the user may indicate patient data of interest and then pick one of several potentially relevant questions. Once the query and medical concepts have been determined, an information source is selected automatically, a retrieval strategy is composed and executed, and the results are sorted and filtered for presentation to the user. This work makes extensive use of the National Library of Medicine's Unified Medical Language System (UMLS): medical concepts are derived from the Metathesaurus, medical queries are based on semantic relations drawn from the UMLS Semantic Network, and automated source selection makes use of the Information Sources Map. The paper describes research currently under way to implement this model and reports on experience and results to date.

From ICD9-CM to MeSH using the UMLS: a how-to guide

One purpose of the Unified Medical Language System (UMLS) is to facilitate conversion of terms from one controlled medical vocabulary to another. We examined our ability to convert International Classification of Diseases, 9th Edition, Clinical Modifications (ICD9-CM) to Medical Subject Headings (MeSH) using the UMLS. We describe a method which mapped 30.4% of ICD9-CM to UMLS. Of these, 95.0% were linked to MeSH, of which translation was straightforward in 90.4%. We discuss the use of these translations for retrieval from MeSH-indexed databases, such as Medline.

Interpreting natural language queries using the UMLS

This paper describes AQUA (A QUery Analyzer), the natural language front end of a prototype information retrieval system. AQUA translates a user's natural language query into a representation in the Conceptual Graph formalism. The graph is then used by subsequent components to search various resources such as databases of the medical literature. The focus of the parsing method is on semantics rather than syntax, with semantic restrictions being provided by the UMLS Semantic Net. The intent of the approach is to provide a method that can be emulated easily in applications that require simple natural language interfaces.