Risk factors for neonatal brachial plexus palsy attributed to anatomy, physiology, and evolution

Abstract

The inherent variable anatomy of the neonate and the uniquely-shaped maternal birth canal that is associated with the evolution of human bipedalism constitute risk factors for neonatal brachial plexus palsy (NBPP). For example, those neonates with a prefixed brachial plexus (BP) are at greater risk of trauma due to lateral neck traction during delivery than those with a normal or postfixed BP. Compared to adults, neonates also have extremely large and heavy heads (high head: body ratio) set upon necks with muscles and ligaments that are weak and poorly developed. Accordingly, insufficient cranial stability can place large torques on the cervical spinal nerves. In addition, the pelvic changes necessary for habitual bipedal posture resulted in a uniquely-shaped, obstruction-filled, sinusoidal birth canal, requiring the human fetus to complete a complicated series of rotations to successfully traverse it. Furthermore, although there are many risk factors that are known to contribute to NBPP, the specific anatomy and physiology of the neonate, except for macrosomia, is not considered to be one of them. In fact, currently, the amount of lateral traction applied to the neck during delivery is the overwhelming legal factor that is used to evaluate whether a birth attendant is liable in cases of permanent NBPP. Here, we suggest that the specific anatomy and physiology of the neonate and mother, which are clearly not within the control of the birth attendant, should also be considered when assessing liability in cases of NBPP.

Multimodal magnetic resonance imaging in the diagnosis of cervical cancer and its correlation with the differentiation process of cervical cancer

“…The study shows that there was significant difference in ADC values between the menopausal and non menopausal groups of cervical cancer, indicating that menstrual conditions have a significant impact on ADC values [ 7 ]. It may be the result of the hormone content and blood flow perfusion status [ 8 ].…”

Reducing rate of macrosomia in Iceland in relation to changes in the labor induction rate

“…25,26 Taka ber fram að í þessari rannsókn var gagnsemi framköllunar með tilliti til fylgikvilla maeðra eða nýbura ekki metin og faeðingarþyngd gaeti verið slaemur maelikvarði á líkamsbyggingu nýbura sem talin er skipta máli fyrir haettuna á axlarklemmu við faeðingu. 27 Því er þörf á stórum slembiröðuðum íhlutandi rannsóknum til að meta hvort framköllun faeðinga strax eftir áaetlaðan faeðingardag kvenna með meðgöngusykursýki verndar nýbura gegn faeðingaráverka.…”

The Brachial Plexus and The Anterior Scalene Muscle: A Bilaterally Different Variation and Its Clinical Significance

“…Con rming the location of the variation and the adjacency of each nerve in the BP clinically essential for diagnosing a BP injury, correctly identifying anatomical variations in surgical repair, and selecting appropriate methods for neck and upper extremity surgery. [2] Herein, a case of a variation in the bilateral C5 in relation to the ASM is described. The report is as follows.…”

“…[1] Usually, the BP passes through the scalene space, forming three trunks, and then travels outward and downward (posterior to the clavicle) and enters the axillary fossa. [2] The upper trunk of the BP is usually formed by C5 and C6; the middle trunk is usually formed by C7; and the inferior trunk is usually formed by C8 and T1. The anterior scalene muscle (ASM, arising from the transverse processes of vertebrae and terminating at the Lisfranc tubercle of the rst rib), the middle scalene muscle (MSM, arising from the transverse processes of vertebrae and terminating at the rst rib posterior to subclavian artery sulcus) and the rst rib constitute the anterior, posterior and inferior bounds of the scalene space, respectively.…”