Evaluation of the supinator muscle and deep branch of the radial nerve: impact on nerve compression.

PURPOSE: The aim of this study was to investigate the superficial head of supinator muscle (SM) and deep branch of the radial nerve (DBRN) course in SM to see whether the texture characteristics of the superficial head of SM might have a potential compressive effect on the nerve. MATERIALS AND METHODS: Elbow and proximal forearm region of 20 preserved cadavers (n 40, 12 M, 8 F) were dissected in order to measure total and part of DBRN lengths between some reference points. The texture characteristics of both the proximal (where DBRN enters SM) and distal arcade (where DBRN exits SM) of the superficial head of SM were evaluated based on its structure's being muscular, musculotendinous, tendinous, or membranous. RESULTS: The total length of DBRN between sexes without taking side (L/R) into consideration (P = 0.030) and left radiocapitellar joint (RCJ)-arcade of Frohse (AF) length between sexes (P = 0.050) were statistically significant. There was a gradual increase in caliber getting more flattened in every consecutive level which was statistically significant when every two consecutive levels were compared. When compared according to the texture type, there were also significant differences. CONCLUSIONS: Flattening of DBRN in the supinator canal suggests a chronic compression on the nerve. Differences in the texture of the superficial head of the supinator might facilitate this compression. An understanding of the anatomy and nerve topography is of utmost importance in the accurate diagnosis and effective management of peripheral nerve compression.

Anatomical variations of the foramen magnum, occipital condyle and jugular tubercle.

AIM: The foramen magnum (FM) is a unique and complex anatomical region. The occipital condyle (OC) and jugular tubercle (JT) are the main bony structures which obscure the anterolaterally situated lesions of the FM.The aim of this study was to revisit the anatomy of the FM region and assess variations of the surrounding structures. MATERIAL AND METHODS: Observations, on thirty dry skulls (dried specimens, 60 sides) and ten formalin-fixed cadaveric heads with perfused vessels, were carried out to define the microsurgical anatomy of the FM region. Morphometric analysis and variations of the FM, OC, JT and hypoglossal canal (HC) were noted. Radiological assessment (3D-computed tomography) of the OC, JT, HC were also conducted on dry skulls. RESULTS: The short and long OC were demonstrated in 5% and 33% of the specimens, respectively. Flat formation of the JT was determined in 10% and tall JT was found in 23% of the specimens. The comparison of the anatomical measurements and the correspondent radiological mean values did not achieve statistical significance. CONCLUSION: The OC and JT are the main bony prominences obstructing the anterolateral surface of the brainstem. Neurosurgeons should be familiar with variations of the structures surrounding the FM in order to perform the safest and widest exposure possible.

Comparison of thicknesses of the myocardial fibers of anencephalic and normal human fetuses.

When heart transplantation is needed in newborns, brain death should be confirmed, and the heart should not be exposed to hypoxia. The anencephalic newborn has been presented as a donor in heart transplantation. It is important, therefore, to evaluate possible morphological differences in the hearts of anencephalic cases. In this study, muscle fibers were studied in 10 anencephalic and 10 normal fetuses (27-35 weeks) and the results were compared. Random samples were taken from the upper 1/3 of the right ventricle's posterior wall and processed for light microscopic examination. Thicknesses of the 100 myocardial muscle fibers for each fetus were evaluated. There was statistically no significant difference between the anencephalic and normal fetus groups and the sex groups. Morphological features of the transplant probably affects the performance of the heart after operation. The anencephalic fetuses could be unique donors for heart transplantation.

Morphometric comparison of the human corpus callosum in professional musicians and non-musicians by using in vivo magnetic resonance imaging.

The purpose of this study was to determine the possible morphometrical differences of the corpus callosum between professional musicians and non-musicians. Certain callosal dimensions and areas were measured in 20 professional musicians and compared with 20 age-, sex- and handedness-matched control group by using in vivo magnetic resonance imaging (MRI). Sagittal T1-weighted midsagittal sections were traced with the digitizer and the metric scale of the system was used for the measurements. Results were statistically analysed by independent t test. There were significant differences between the two groups both for the anterior and posterior areas of the corpus callosum. Furthermore, significant differences between the two groups were found in the thicknesses of certain parts of the corpus callosum. Our results support the hypothesis that brain morphology is prone to plastic changes caused by environmental factors.