Arzu Hizay

The hypoglossal–facial nerve repair as a method to improve recovery of motor function after facial nerve injury

Nerve repair after facial nerve injury provides neural input to the distal facial nerve and facial musculature via a variety of motor nerves such as hypoglossal, spinal accessory, masseteric branch of the trigeminal nerve and motor branches of the cervical plexus. The most commonly used procedure is the hypoglossal-facial nerve transfer. This cross-nerve paradigm is a unique nerve repair method as one motor nerve takes over the function of another motor nerve. The hypoglossal-facial nerve repair was reviewed by means of history, terminology, technical variations, and its capacity for recovery of function.

Four-headed biceps brachii, three-headed coracobrachialis muscles associated with arterial and nervous anomalies in the upper limb

A four-headed biceps brachii muscle and three-headed coracobrachialis muscle, high-originated radial artery and communication between the median and musculocutaneous nerves have been well documented in the available literature. However co-existence of these variations is rare. In this study we aimed to describe multiple variations in the upper limb and discuss their co-existence from clinical and embryological points of view.

Hypoglossal-facial anastomosis (HFA) over a 10 mm gap bridged by a Y-tube-conduit enhances neurite regrowth and reduces collateral axonal branching at the lesion site

PURPOSE The outcome of severe peripheral nerve injuries requiring surgical repair (transection and suture) is usually poor. Recent work suggests that direct suture of nerves increases collagen production and provides unfavourable conditions for a proper axonal regrowth. We tested whether entubulation of the hypoglossal nerve into a Y-tube conduit connecting it with the zygomatic and buccal facial nerve branches would improve axonal pathfinding at the lesion site, quality of muscle reinnervation and recovery of vibrissal whisking. METHODS For hypoglossal-facial anastomosis (HFA) over a Y-tube (HFA-Y-tube) the proximal stump of the hypoglossal nerve was entubulated and sutured into the long arm of a Y-tube (isogeneic abdominal aorta with its bifurcation). The zygomatic and buccal facial branches were entubulated and sutured to the short arms of the Y-tube. Restoration of vibrissal motor performance, degree of collateral axonal branching at the lesion site and quality of neuro-muscular junction (NMJ) reinnervation were compared to animals receiving HFA-Coaptation (no entubulation) after 4 months. RESULTS HFA-Y-tube reduced collateral axonal branching. However it failed to reduce the proportion of polyinnervated NMJ and did not improve functional outcome when compared to HFA-Coaptation. CONCLUSION Elimination of compression by tightly opposed nerve fragments improved axonal pathfinding. However, biometric analysis of vibrissae movements did not show positive effects suggesting that polyneuronal reinnervation - rather than collateral branching - may be the critical limiting factor. Since polyinnervation of muscle fibers is activity-dependent and can be manipulated, the present findings raise hopes that clinically feasible and effective therapies after HFA could be soon designed and tested.

Use of a Y-tube conduit after facial nerve injury reduces collateral axonal branching at the lesion site but neither reduces polyinnervation of motor endplates nor improves functional recovery.

BACKGROUND Despite increased understanding of peripheral nerve regeneration, functional recovery after surgical repair remains disappointing. A major contributing factor is the extensive collateral branching at the lesion site, which leads to inaccurate axonal navigation and aberrant reinnervation of targets. OBJECTIVE To determine whether the Y tube reconstruction improved axonal regrowth and whether this was associated with improved function. METHODS We used a Y-tube conduit with the aim of improving navigation of regenerating axons after facial nerve transection in rats. RESULTS Retrograde labeling from the zygomatic and buccal branches showed a halving in the number of double-labeled facial motor neurons (15% vs 8%; P < .05) after Y tube reconstruction compared with facial-facial anastomosis coaptation. However, in both surgical groups, the proportion of polyinnervated motor endplates was similar (≈ 30%; P > .05), and video-based motion analysis of whisking revealed similarly poor function. CONCLUSION Although Y-tube reconstruction decreases axonal branching at the lesion site and improves axonal navigation compared with facial-facial anastomosis coaptation, it fails to promote monoinnervation of motor endplates and confers no functional benefit.

Metoptic canal and Warwick’s foramen: Incidence and morphometric analysis by several reference points in the human orbit

Objective Several canals and foramens in the human orbit are well known in the literature. However, little is known about some minor canals or structures including metoptic canal and Warwicks foramen. The aim of the present study was to make morphometric measurements and to determine the incidence of the metoptic canal and Warwicks foramen in the Turkish population. Materials and Methods Ninety-two dried human skulls were examined. All skulls were obtained from the Turkish population and collection of the Anatomy Department of the Akdeniz University. The metoptic canal and Warwicks foramen were identified in the skulls. Incidence of these structures and diameters were determined. Morphometric measurements were made using various reference points in the orbit. Results Of the 92 dry human skulls, the metoptic canal was detected in 20 of them. This canal was detected unilaterally. The metoptic canal was observed in 11 (11.9%) dry skulls in the right side, whereas it was observed in 9 (9.7%) dry skulls in the left side. There were no statistically significant differences according to the side for any of the measurements recorded (p>0.05). The Warwicks foramen was observed in 12 (13.0%) skulls of all dry skulls. This foramen was also present unilaterally and was right sided in 7 (7.6%) skulls and left sided in 5 (5.4%) skulls. Conclusion Determination of additional foramen in the orbit is contributed to the literature. The presence of the metoptic canal and Warwicks foramen and their relationship with other structures in the orbit may have clinical significance in surgical operations.

Occipital artery arising from the internal carotid artery: a case report.

Variations of the branches of the external carotid artery have been well documented in the available literature. However, variation of the occipital artery arising from the internal carotid artery is extremely rare case. A 42-year-old man patient who suffered from subarachnoid hemorrhage with suspicious vascular anomalies was found to have this variation on the right side by angiography during selective catheterisation of main carotid artery for vascular mapping. Our literature searches revealed that there was rare case such variations. We think that this variation should contribute to literature and should be kept in mind during surgical, radiological and diagnostic procedures.