Sedat Develi

The ratios of 2nd to 4th digit may be a predictor of schizophrenia in male patients

The production of androgens (mostly testosterone) during the early fetal stage is essential for the differentiation of the male brain. Some authors have suggested a relationship between androgen exposure during the prenatal period and schizophrenia. These two separate relationships suggest that digit length ratios are associated with schizophrenia in males. The study was performed in a university hospital between October 2012 and May 2013. One hundred and three male patients diagnosed with schizophrenia according to DSM‐IV using SCID‐I, and 100 matched healthy males, were admitted to the study. Scale for the Assessment of Positive Symptoms (SAPS), Scale for the Assessment of Negative Symptoms (SANS) and Brief Psychiatric Rating Scale (BPRS) were used to assess schizophrenia symptoms. The second digit (2D) and fourth digit (4D) asymmetry index (AI), and the right‐ and left‐hand 2D:4D ratios were calculated. All parametric data in the groups were compared using an independent t‐test. The predictive power of the AI was estimated by receiver operating characteristics analysis. The 2D:4D AI was statistically significantly lower in the patient group than the healthy control comparison group. There were significant differences between the schizophrenia and the control groups in respect of left 2D:4D and right 2D:4D. There was no correlation between AI, left, or right 2D:4D, BPRS, or SAPS in the schizophrenia group. However, there was a negative correlation between left 2nd digit (L2D):4D and the SANS score. Our findings support the view that the 2D:4D AI can be used as a moderate indicator of schizophrenia. Even more simply, the right or left 2D:4D can be used as an indicator. L2D:4D could indicate the severity of negative symptoms. Clin. Anat. 28:551–556, 2015.

Branching pattern of the external branch of the superior laryngeal nerve and its clinical importance

The external branch of the superior laryngeal nerve gives off many branches above the upper pole of the thyroid gland. Differentiating the branch innervating the cricothyroid muscle from the others may be important during surgery. Therefore, we aimed to demonstrate the branching pattern of this nerve in detail. In 34 human cadavers (59 sides), branches of the nerve were exposed and measurements related to them and neighboring structures were made. A cricothyroidal branch was present on all sides. This branch pierced the inferior pharyngeal constrictor muscle 3.9–17.6 mm above, 3.1–9.9 mm below, or at the level of the upper pole of the thyroid gland. On all sides, the nerve provided one or two thyroidal branches. The thyroidal branch was generally thinner than the cricothyroidal branch. But they were equal in size on three (5%) sides. The external laryngeal nerve provided two or three pharyngeal branches on all sides. These branches arose from the nerve 3.5–12.7 mm from the upper pole of the thyroid gland. Although the branch was generally thinner than the cricothyroidal branch, both branches were equal on four (6.7%) sides. Two cardiac branches were observed on two (3.3%) left sides. In conclusion, the cricothyroidal branch was generally thicker than the other branches. But on seven (11.8%) sides, thyroidal or pharyngeal branches and the cricothyroidal branch were equal in size. These data may be important during surgery as the surgeon may confuse the cricothyroidal branch with other branches of the external laryngeal nerve. Clin. Anat. 25:32–39, 2012.

A detailed study of the relationship between the external laryngeal nerve and superior thyroid artery, including its glandular branches

The external layrngeal nerve (ELN) may be at risk during thyroidectomy. Because the relationship between the ELN and superior thyroid artery (STA) can be variable, we aimed to investigate their relationship in detail. In human cadavers, 81 ELN and STA and their branches were carefully dissected. The position of the nerve was classified as medial (Group I, on 76.5% sides), lateral (Group II, on 20.9% sides), or posterior (Group III, on 2.4% sides) to the origin of the STA. In Group Ia, the nerve did not cross the artery while it did cross the artery in Group Ib. In Group II, the nerve was located lateral to the origin of the artery and crossed it. In Group III, the nerve coursed downward posterior to the artery. In conclusion, the topography of the ELN showed much more variability in its relationship to the STA than is described in the literature. Such variations should be kept in mind during surgery of the anterior neck. It is our hope that such data will decrease surgical morbidity following surgery of the anterior neck. Clin. Anat. 26:814–822, 2013.

Topographical anatomy of cricothyroid membrane and its relation with invasive airway access.

Cricothyroidotomy is a surgical procedure involving penetration through the skin and cricothyroid membrane to maintain airway patency during life‐threatening emergency conditions. Complications such as bleeding and laryngeal stenosis can result from it. Our aim in this study was to identify the anatomical structures located on the membrane and to ascertain whether there is a safe area on the membrane for this procedure. Thirty larynx specimens fixed with 10% formaldehyde in the Department of Anatomy were dissected. The cricothyroid artery, the cricothyroid vein, the common artery and vein formed by the cricothyroid vessels, the pyramidal lobe of the thyroid gland and lymph nodes were observed on the membrane. The cricothyroid membrane was divided into four quadrants and the most common locations of these anatomical structures on the membrane were recorded. The cricothyroid artery and vein were located on the upper half of the membrane, the common vein was found in the midline, coursing to the thyroid gland, and the lobus pyramidalis and lymph nodes were located on the left side of the midline. Overall, the anatomical structures were mostly located on the upper half and lower left quadrant of the cricothyroid membrane. Thus, the lower right quadrant seems safer for invasive procedures such as needle cricothyroidotomy or other cannulation techniques. Needle puncture or cannulation through the lower right quadrant of the cricothyroid membrane will injure fewer anatomical structures so there should be fewer complications due to degradation of the vascular supply to this region. Clin. Anat. 29:949–954, 2016.