Hypoglossal-facial Nerve Research Articles

Microsurgical anatomy of the facial nerve trunk.

Dissection and manipulation of the facial nerve (FN) trunk between its exit from the cranial base through the stylomastoid foramen (SMF) and its bifurcation is a critical step in various otologic, plastic and neurosurgical procedures. This study demonstrates the anatomical relationships and variability of the FN trunk with emphasis on some important morphometric data, particularly with relevance to hypoglossal-facial nerve anastomosis (HFA). Bilateral microsurgical dissection was performed on twenty-three human cadavers fixed with formalin. The whole trunk of the FN was exposed, its diameter at the SMF and its length were measured, its branches were observed and the site of its bifurcation was determined. Anastomotic connections with other nerves and blood supply of the trunk were studied. The FN invariably emerged from the cranial base through the SMF. Its diameter upon its emergence from the foramen was 2.66 +/- 0.55 mm. Two branches consistently originated from the trunk: the posterior auricular nerve and the nerve to the digastric muscle. Less consistent were the communicating branch with the glossopharyngeal nerve and the nerve to the stylohyoid muscle. The bifurcation of the FN occurred before its penetration into the parotid gland in 15% of cases and within the gland in 85%. The length of the FN trunk was 16.44 +/- 3.2 mm. Anastomoses between the FN and other nerves were observed in one-third of the dissections. The blood supply to the FN trunk was provided by the stylomastoid artery that was identified in 91% of cases. Understanding the microsurgical anatomy of the FN trunk is essential for performing any surgical procedure in the relevant region. Surgical implications of this study are presented with emphasis on HFA surgery.

Reanimation of the Paralyzed Face by Indirect Hypoglossal-facial Nerve Anastomosis

Abstract Background: The results of indirect hypoglossal facial nerve anastomosis with interposition of a free nerve graft, end-to-end to the periferal facial nerve stump, and end-to-side to the hypoglossal nerve are prospectively evaluated. This technique is supposed to overcome loss of hypoglossal function. Methods: Tongue function in 39 consecutive patients and facial reanimation in 29 patients who completed 24 months follow-up were assessed. Facial nerve function was judged using the House-Brackmann (HB) grading system. Results: Tongue movements were normal in all operated on patients. Initial facial movements occurred on average 7.5 months postoperatively. The results were graded HB II in 6 (20.9%), HB III in 13 (44.6%), HB IV in 7 (24.1%), HB V in 2 (6.8%) patients, and HB VI in 1 (3.4%) patient. The results were significantly better in young patients and when a short time interval between paralysis and surgery existed. Conclusions: Indirect hypoglossal-facial anastomosis is the preferred technique in most patients for whom the classical direct hypoglossofacial anastomosis is indicated.

Effect of Delayed Hypoglossal-facial Nerve Anastomosis on the Facial Nerve Regeneration in the Rat

Guntinas-Lichius, O; Rüger, M A.; Pechuel-Loesche, S; Effenberger, C; Angelov, D N.; Neiss, W F.; Streppel, M; Stennert, E Author Information

Effect of Physical Therapy for Hypoglossal-facial Nerve Anastomosis

Effect of Physical Therapy for Hypoglossal-facial Nerve Anastomosis

Reanimation of the paralyzed face by indirect hypoglossal-facial nerve anastomosis

Background: The results of indirect hypoglossal facial nerve anastomosis with interposition of a free nerve graft, end-to-end to the periferal facial nerve stump, and end-to-side to the hypoglossal nerve are prospectively evaluated. This technique is supposed to overcome loss of hypoglossal function. Methods: Tongue function in 39 consecutive patients and facial reanimation in 29 patients who completed 24 months follow-up were assessed. Facial nerve function was judged using the House-Brackmann (HB) grading system. Results: Tongue movements were normal in all operated on patients. Initial facial movements occurred on average 7.5 months postoperatively. The results were graded HB II in 6 (20.9%), HB III in 13 (44.6%), HB IV in 7 (24.1%), HB V in 2 (6.8%) patients, and HB VI in 1 (3.4%) patient. The results were significantly better in young patients and when a short time interval between paralysis and surgery existed. Conclusions: Indirect hypoglossal-facial anastomosis is the preferred technique in most patients for whom the classical direct hypoglossofacial anastomosis is indicated.

Hypoglossal-facial nerve anastomosis: assessment of clinical results and patient benefit for facial nerve palsy following acoustic neuroma excision.

Despite advances in neuro-otological techniques permanent complete facial palsy may still occur in up to 10% of patients undergoing removal of cerebellopontine angle tumours. Hypoglossal-facial nerve anastomosis is the procedure of choice in our unit for facial reanimation in such patients and below we report the results of hypoglossal-facial nerve anastomosis performed on 29 patients. Assessment of patient benefit from hypoglossal-facial nerve anastomosis was obtained using a questionnaire based on the Glasgow Benefit Inventory. The results showed all patients to have an improvement in their House Brackmann grade following hypoglossal-facial anastomosis with 65% achieving grade III or better. Of the 20 patients who completed the questionnaire, 18 showed a positive benefit (median score 59.5, range 40-77). There was a significant correlation (P < 0.045) between the Glasgow benefit inventory score and House Brackmann grade. Outcome was not affected by the time interval between the acoustic neuroma surgery and performing the hypoglossal-facial nerve anastomosis, sex or length of follow-up. However the Glasgow benefit score was significantly influenced by age (P = 0.023) with younger patients showing more benefit independent of improvement in facial nerve function.

Delayed Rat Facial Nerve Repair Leads to Accelerated and Enhanced Muscle Reinnervation with Reduced Collateral Axonal Sprouting during a Definite Denervation Period Using a Cross-Anastomosis Paradigm

To establish the influence of prolonged denervation on the recovery of a motor nerve, the rat facial nerve was transected and denervated for 0 to 224 days. Then, the freshly transected hypoglossal nerve was sutured to the predegenerated facial nerve (hypoglossal–facial nerve anastomosis, HFA). Using this nerve cross-anastomosis paradigm we analyzed the nerve regeneration and muscle reinnervation 7 to 112 days post-suture operation (DPSO). After HRP injection into the whiskerpad 931 ± 27 hypoglossal neurons were labeled at 112 DPSO after immediate HFA. Following 14 to 112 days denervation the number of labeled neurons increased to 138% (14 days delay), 154% (56 days), and 145% (112 days). In contrast, the reinnervation was poorer after 7 days denervation with the number of neurons increasing to 84%, and after long-term denervation of 224 days the number of neurons increased to 81%. The increase in amplitude of evoked electromyography wave after nerve suture correlated with the number of labeled neurons. After immediate HFA each regenerated motoneuron established on average 5.1 myelinated sprouts at 112 DPSO. The number of sprouts remained constant after delayed suture of 14 to 112 days, whereas the slower reinnervation after 7 or 224 days delay was accompanied by a massive sprouting of 9.1 or 8.1, respectively, sprouts per neuron. The muscles showed recovery after any denervation time. The muscle cross-sectional area continuously decreased with longer denervation time. This decrease was only significant after 224 days denervation (67% of the normal value). We conclude that motor nerve reconstruction achieves better functional results after a definite period of denervation when using a nerve cross-anastomosis paradigm.

Results of Hypoglossal-facial Nerve Anastomosis for Facial Palsy Following Acoustic Neuroma Excision

Clinical Otolaryngology & Allied SciencesVolume 25, Issue 1 p. 91-91 Results of Hypoglossal-facial Nerve Anastomosis for Facial Palsy Following Acoustic Neuroma Excision S. Sood, S. Sood (Departments of Otolaryngology andSearch for more papers by this authorJ.J. Homer, J.J. Homer (Departments of Otolaryngology andSearch for more papers by this authorR. Anthony, R. Anthony (Departments of Otolaryngology andSearch for more papers by this authorP. Van Hille, P. Van Hille (Departments of Otolaryngology andSearch for more papers by this author S. Sood, S. Sood (Departments of Otolaryngology andSearch for more papers by this authorJ.J. Homer, J.J. Homer (Departments of Otolaryngology andSearch for more papers by this authorR. Anthony, R. Anthony (Departments of Otolaryngology andSearch for more papers by this authorP. Van Hille, P. Van Hille (Departments of Otolaryngology andSearch for more papers by this author First published: 10 August 2009 https://doi.org/10.1046/j.1365-2273.2000.00337-12.xRead the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Volume25, Issue1February 2000Pages 91-91 RelatedInformation

Variations on the "baby-sitter" procedure for reconstruction of facial paralysis.

Four cases of fresh facial paralysis were treated using the "baby-sitter" procedure, with fairly satisfactory results obtained. This procedure involves a combination of cross-face nerve grafting and a nerve cross-over technique such as using a hypoglossal-facial nerve or accessory-facial nerve anastomosis. Two stages are required. Nerve cross-over and cross-face nerve grafting using the sural nerve are performed in the first stage. After 1 year nerve anastomosis between the stump of the cross-face nerve graft and that of a buccal branch in the paralyzed cheek is performed during the second stage. The recovery of facial animation through this method is good, with patients able to create a near-natural smile. Electromyography demonstrates double innervation in the paralyzed cheek area.

Histological Rearrangement in the Facial Nerve and Central Nuclei Following Immediate and Delayed Hypoglossal-Facial Nerve Anastomosis

The timing of hypoglossal-facial nerve anastomosis is controversial. The present study was performed to clarify the influence of the timing of hypoglossal-facial nerve anastomosis on histological changes in the facial nerve and central nuclei using guinea pigs. The facial nerve was transected first at the labyrinthine portion, and then transected again at the stylomastoid foramen. Hypoglossal-facial nerve anastomosis was carried out immediately or 3 months later. Nerve regeneration and survival of the neurons in the facial and hypoglossal nuclei were evaluated by toluidine blue staining and horseradish peroxidase (HRP). Immediate anastomosis resulted in better nerve regeneration of the facial nerve, but the numbers of surviving neurons in the facial and hypoglossal nuclei were almost the same in both the immediate and delayed anastomosis groups.

Surgical anatomy for direct hypoglossal-facial nerve side-to-end "anastomosis".

In this study the authors investigated the histomorphometric background and microsurgical anatomy associated with surgically created direct hypoglossal-facial nerve side-to-end communication or nerve "anastomosis." Histomorphometric analyses of the facial and hypoglossal nerves were performed using 24 cadaveric specimens and three surgically obtained specimens of severed facial nerve. Both the hypoglossal nerve at the level of the atlas and the facial nerve just distal to the external genu were monofascicular. The number of myelinated axons in the facial nerve (7228 +/- 950) was 73.2% of those in the normal hypoglossal nerve (9778 +/- 1516). Myelinated fibers in injured facial nerves were remarkably decreased in number. The cross-sectioned area of the normal facial nerve (0.948 mm2) accounted for 61.5% of the area of the hypoglossal nerve (1.541 mm2), whereas that of the injured facial nerve (0.66 mm2) was less than 50% of the area of the hypoglossal nerve. Surgical dissection and morphometric measurements were performed using 18 sides of 11 adult cadaver heads. The length of the facial nerve from the pes anserinus to the external genu ranged from 22 to 42 mm (mean 30.5 +/- 4.4 mm). The distance from the pes anserinus to the nearest point on the hypoglossal nerve ranged from 14 to 22 mm (mean 17.3 +/- 2.5 mm). The former was always longer than the latter; the excess ranged from 6 to 20 mm (mean 13.1 +/- 3.4 mm). Surgical anatomy and procedures used to accomplish the nerve connection are described. The size of a half-cut end of the hypoglossal nerve matches a cut end of the injured facial nerve very well. By using the technique described, a length of facial nerve sufficient to achieve a tensionless communication can consistently be obtained.

The facial-hypoglossal nerve indirect anastomosis

The facial-hypoglossal nerve indirect anastomosis

Clinical and electrophysiologic studies of facial nerve function after hypoglossal-facial nerve anastomosis

The functional and cosmetic results after hypoglossal-facial nerve anastomosis (HFA) have primarily been described using a subjective grading system of good, fair, or poor. To obtain more objective results, the postoperative mimic function was investigated using a combination of clinical and electrophysiological methods. A total of 29 patients with hypoglossal-facial anastomosis were evaluated using a standardized questionnaire and the Stennert's paralysis index as clinical scoring system and electroneurography (NMG/ENoG) and electromyography (EMG) as electrophysiological assessments. Twenty-six of 29 patients (89%) judged their own facial function as very good or good, and three as poor. Under resting tone conditions, no patient showed a difference between palpebral fissures (> 3 mm), an ectropium, a substantial loss of nasolabial fold, or a drop of angulus oris (> 3 mm). With attempted movement, the lid closure was complete in 76% of patients, and the cornea was lid-covered in 100%. Sixty-seven percent of the patients were able to whistle. The second upper incisor was visible (full width) in 19%. No patient could frown sufficiently or expose the upper and lower canine teeth. The mean Stennert's score decreased from 9 to 4 after surgery. The relative amplitudes of the NMGs were increased in patients with low clinical indices. Patients with a complete eye closure showed a higher density of EMG patterns in their orbicularis oculi muscles. No significant differences for clinical or electrophysiological parameters could be observed based on age, sex, or time point of operation. Combining the Stennert's paralysis index with NMG and EMG allows a more objective assessment of functional and cosmetic results after HFA.

Long-Term Prognosis of Profound Facial Nerve Paralysis Secondary to Acoustic Neuroma Resection

The long-term prognosis of profound facial nerve paralysis was reviewed in 107 patients who, despite preserved nerve continuity, showed no facial movement after acoustic neuroma resection. Spontaneous recovery occurred in 77 patients. However, there was no apparent recovery in 30 patients. Twenty-two of these patients underwent hypoglossal-facial nerve anastomosis 7–33 months after tumor resection. When spontaneous recovery occurred, the first sign of remission was observed between 3 and 4 months after surgery in nearly half of the patients. Such a sign did not appear after 12 months. The recovery of facial movement deteriorated depending on how long remission onset was delayed. However, the quality of facial movement in patients with such delayed remission was still identical or better than that in those after hypoglossal-facial nerve anastomosis. These results showed that hypoglossal-facial nerve anastomosis should be performed approximately 1 year after tumor resection if no sign of remission has been observed by then.

New technique of side-to-end hypoglossal-facial nerve attachment with translocation of the infratemporal facial nerve.

The goal of this study was to assess the clinical results of hypoglossal-facial nerve attachment (HFA), which was primarily performed in patients following excision of tumors of the cerebellopontine angle. In six of the patients a new side-to-end procedure was used. The authors have performed a retrospective study of 33 patients who underwent HFA, including 24 classic end-to-end, three May, and six side-to-end procedures. For the latter procedure, a hemihypoglossal-facial nerve attachment was performed by rerouting the intratemporal facial nerve; this avoided the jump-cable graft used in May's technique. The goal of the new procedure is to reduce the incidence of morbidity due to hemilingual paralysis (difficulty in chewing, speaking, and swallowing). The incidence of hemilingual paralysis was evaluated based on the findings of a questionnaire that was completed by the patients. The patient's facial mobility was assessed using the House and Brackmann grading system and the author's analytic scoring system. The HFA offers good functional results. Of the 28 cases evaluated, nine had House and Brackmann Grade III, 17 Grade IV, and only two Grade V at 18 months. When the new technique of side-to-end hemihypoglossal-facial nerve attachment was used, there was considerable reduction, if not complete disappearance, of lingual morbidity and the facial functional results were constant and satisfactory: there were five patients with House and Brackmann Grade III and one with Grade IV, and their mean percentage of facial mobility was 43.3%.

Reflexes elicited from cutaneous and mucosal trigeminal afferents in normal human subjects

It has been shown that in patients in whom the central stump of the hypoglossal nerve has been anastomosed to the peripheral stump of a lesioned facial nerve, supraorbital nerve stimulation can elicit a short-latency reflex (12.5±0.6 ms; mean±S.D.) in facial muscles similar to the R1 disynaptic blink reflex response, but not followed by an R2 blink reflex component 46. Thus in addition to replacing the facial neurons at peripheral synapses, these hypoglossal nerves contribute to a trigemino-hypoglossal reflex. The aim of this work was to study the type of reflex activities which can be elicited in both facial and tongue muscles by electrical stimulation of cutaneous (supraorbital nerve) or mucosal (lingual nerve) trigeminal (V) afferents in normal subjects. The results show that although stimulation of cutaneous V1 afferents elicits the well-known double component (R1–R2) blink reflex response in the orbicularis oculi muscles, it does not produce any detectable reflex response in the genioglossus muscle, even during experimental paradigms designed to facilitate the reflex activity. Conversely, stimulation of mucosal V3 afferents can elicit a single reflex response of the R1 type in the genioglossus muscle but not in the orbicularis oculi muscles, even during experimental paradigms designed to facilitate the reflex activity. These data are discussed in terms of two similar but separate circuits for the R1 responses of cutaneous (blink reflex) and mucosal (tongue reflex) origins. They suggest that in patients with hypoglossal-facial (XII–VII) nerve anastomosis, the short-latency trigemino-`hypoglossal-facial' reflex of the R1 blink reflex type observed in facial muscles following supraorbital nerve stimulation could be due to changes in synaptic effectiveness of the central connectivity within the principal trigeminal nucleus where both cutaneous and mucosal trigeminal afferents project.

Hypoglossal-Facial Nerve Anastomosis: Patients’ Self-Assessment of Facial Function

Objectives: In a retrospective study, we tried to evaluate the recovery of facial function as well as the resulting discomfort and the role of priming tongue movements in voluntary facial movement after hypoglossal-facial nerve anastomosis (HFA) predominantly from the point of view of concerned patients. Patients and Methods: Our analysis was based upon a questionnaire, which was returned by 27 patients who had undergone HFA. Twenty-four of the 27 patients (89%) could be re-examined at our department where postoperative facial function was evaluated by the investigators using the nerve grading system as described by House and Brackmann. Results: The mean time interval between HFA and first voluntary movements as estimated by the patients was 5.5 months (range: 3–18). The patients’ main complaints consisted of mimic deficit (41%), dysphagia (26%), eye symptoms (22%), oral incontinence (19%), synkinesis (15%) and speech problems (11%). Twenty-one patients (78%) reported to perform facial training regularly. Priming tongue movements could be evaluated as necessary for voluntary facial function in 25 patients (92.5%). As a result of re-examination, a statistically significant correlation (p < 0.05) between the grade of facial nerve function and the time interval from onset of the facial palsy to HFA was evident. Conclusions: Despite the fact that HFA seems to be a good option for mimic rehabilitation in cases in which a direct nerve repair is not possible, there are some special functional and aesthetic deficits after reinnervation which can be minimized by surgical modifications or other additional therapeutic options.

Hypoglossal-Facial Anastomosis in Complete Unilateral Facial Palsy

Hypoglossal-facial nerve anastomosis is a popular technique for the treatment of unilateral complete facial palsy when restoration of the continuity of the facial nerve by grafting or repair is not possible. Thirteen cases of complete facial palsy treated with hypoglossal-facial nerve anastomosis between 1984 and 1995 are reviewed. In 11 patients good facial symmetry at rest was restored. All patients achieved voluntary facial movements to varying degrees by learned changes in placement of the tongue. Hemi-atrophy of the tongue was eventually noted in all cases, being marked in 2. However, no patient described subjective difficulty with speech or swallowing. Twelve of the 13 patients expressed satisfaction with the outcome of the procedure.

Delayed hypoglossal-facial nerve suture after predegeneration of the peripheral facial nerve stump improves the innervation of mimetic musculature by hypoglossal motoneurons.

Surgical reconstruction of the facial nerve is common clinical practice following destruction of the intracranial facial nerve. Delayed hypoglossal-facial anastomosis (HFA) is the procedure of choice, although the effect of delay on outcome remains unclear. To study the effect of delayed anastomosis on reinnervation, we sutured the proximal stump of a freshly transected hypoglossal nerve of Wistar rats to the distal stump of the ipsilateral facial nerve, which had been transected 7-56 days earlier. Animals that had received HFA without delay served as the control group. Forty days after HFA, horseradish peroxidase (HRP) was injected into the whisker pad; 2 days later, the animals were killed. Reinnervation was assessed by determining the proportion of labeled neuronal cell bodies in the brainstem. The control group had 68% reinnervation of these muscles by hypoglossal neurons and had 32% reinnervation by facial neurons. When the distal facial nerve had been allowed to degenerate for 7 days before HFA, reinnervation of the hypoglossal nerve decreased to 54%, and reinnervation by the facial nerve increased to 46%. However, after a delay of 10-56 days, the hypoglossal fraction increased and stabilized at 77%, and the facial motoneuron fraction decreased to 23%. The presence of new neuromuscular junctions was confirmed by HRP labeling of motor end plates in vivo and by electromyography. We conclude that, under the conditions of hypoglossal-facial crossed nerve suture, the predegeneration of the distal stump of a transected facial nerve enhances the reinnervation of facial muscles by hypoglossal axonal sprouts.

Hypoglossal-facial nerve side-to-end anastomosis for preservation of hypoglossal function: Results of delayed treatment with a new technique: Sawamura Y, Abe H. J Neurosurg 86:203, 1997

Hypoglossal-facial nerve side-to-end anastomosis for preservation of hypoglossal function: Results of delayed treatment with a new technique: Sawamura Y, Abe H. J Neurosurg 86:203, 1997