Serious device-related complications for hypoglossal nerve stimulators are rare, but surgeons should implement a prompt and systematic approach to quickly troubleshoot a non-functioning device.

Records were queried at a single academic tertiary referral centre between January 2019 and June 2021.

The authors present four cases of non-functioning hypoglossal nerve stimulator devices: one case in which migration of the stimulation lead required a revision implantation, one in which the implantable pulse generator was found to be non-functional intra-operatively, one case of an intramuscular sensory lead tract causing pain and one case of implantable pulse generator failure that was probably triggered by implantable cardiac device discharge. In this study, computed tomography imaging was critical to the diagnosis for the first and third cases.

Given the limited complication reporting available for hypoglossal nerve stimulators, these cases highlight management and unique imaging findings. The authors present an algorithm to work-up non-functioning hypoglossal nerve stimulator devices.

This paper aimed to: retrospectively analyse single-centre results in terms of surgical success, respiratory outcomes and adverse events after short-term follow up in obstructive sleep apnoea patients treated with upper airway stimulation; and evaluate the correlation between pre-operative drug-induced sleep endoscopy findings and surgical success.

A retrospective descriptive cohort study was conducted, including a consecutive series of obstructive sleep apnoea patients undergoing implantation of an upper airway stimulation system.

Forty-four patients were included. The total median Apnoea–Hypopnea Index and oxygen desaturation index significantly decreased from 37.6 to 8.3 events per hour (p < 0.001) and from 37.1 to 15.9 events per hour (p < 0.001), respectively. The surgical success rate was 88.6 per cent, and did not significantly differ between patients with or without complete collapse at the retropalatal level (p = 0.784). The most common therapy-related adverse event reported was (temporary) stimulation-related discomfort.

Upper airway stimulation is an effective and safe treatment in obstructive sleep apnoea patients with continuous positive airway pressure intolerance or failure. There was no significant difference in surgical outcome between patients with tongue base collapse with or without complete anteroposterior collapse at the level of the palate.

To evaluate VIIth–XIIth cranial nerve (hypoglossal–facial nerve) anastomosis results by age.

A total of 34 patients who attended a follow-up visit in 2016, aged 20–63 years, were enrolled. The House–Brackmann facial nerve function grading system and the Facial Clinimetric Evaluation scale were applied.

Regarding post-anastomosis facial nerve function, in the group aged 40 years or less, 14 patients (78 per cent) had House–Brackmann grade III and 4 patients (22 per cent) had House–Brackmann grade IV facial nerve function post-anastomosis. In the group aged over 40 years, nine patients (56 per cent) had House–Brackmann grade III and seven patients (44 per cent) had House–Brackmann grade IV facial nerve function post-anastomosis. There was a statistically significant difference between the two groups in mean facial movement domain scores (p = 0.02). Analysis between age and facial movement score in all 34 patients demonstrated a moderate negative correlation (Pearson correlation coefficient: −0.38) and statistical significance (p = 0.02).

Facial reanimation yielded better results in younger than in older patients.

Unilateral total facial palsy is a debilitating condition that can affect an individual's physical, social and emotional wellbeing. When this occurs bilaterally, the severity of impact is extreme, with significant cosmetic disfigurement and functional morbidity. A variety of facial reanimation techniques have been used for unilateral facial weakness of varying House–Brackmann grades, and these are also applicable in bilateral cases. In bilateral cases, it is difficult to gauge successful improvement in comparison to the contralateral side, which also is afflicted.

This paper presents our experience with a bilateral facial paralysis patient who had a complex otological history. The patient, who presented with bilateral debilitating grade VI facial palsy, achieved a good result from bilateral facial reanimation with sequential hypoglossal–facial anastomosis. This is considered a reasonable option in cases of bilateral facial paralysis.

A pneumocele occurs when an aerated cranial cavity pathologically expands; a pneumatocele occurs when air extends from an aerated cavity into adjacent soft tissues forming a secondary cavity. Both pathologies are extremely rare with relation to the mastoid. This paper describes a case of a mastoid pneumocele that caused hypoglossal nerve palsy and an intracranial pneumatocele.

A 46-year-old man presented, following minor head trauma, with hypoglossal nerve palsy secondary to a fracture through the hypoglossal canal. The fracture occurred as a result of a diffuse temporal bone pneumocele involving bone on both sides of the hypoglossal canal. Further slow expansion of the mastoid pneumocele led to a secondary middle fossa pneumatocele. The patient refused treatment and so has been managed conservatively for more than five years, and he remains well.

While most patients with otogenic pneumatoceles have presented acutely in extremis secondary to tension pneumocephalus, our patient has remained largely asymptomatic. Aetiology, clinical features and management options of temporal bone pneumoceles and otogenic pneumatoceles are reviewed.

Variant anatomy of the hypoglossal nerve is very rare. We report an unusual intra-operative finding of an aberrant branch of the hypoglossal nerve, encountered during a facial reanimation procedure.

A 50-year-old man was referred to the head and neck surgery department by the neurosurgeons for hypoglossal-facial nerve anastomosis to treat his facial paralysis, which had occurred following the removal of an intracranial neoplasm. During surgery, we identified an aberrant branch of the hypoglossal nerve, which took a more ventral and superior course in the carotid triangle, prior to entering the base of the tongue. Following further dissection, we found the main trunk of the ‘true’ hypoglossal nerve. Several interconnecting strands were seen in the proximal aspect of both the aberrant branch and the main trunk of the hypoglossal nerve. These interconnecting fibres appeared to have tethered the main trunk into an abnormal anatomical position.

As far as we can ascertain, this is the first report of an aberrant branch of the hypoglossal nerve. Although this variant would appear to be extremely rare, surgeons must consider all variations of this nerve during head and neck procedures, in order to minimise iatrogenic complications.

Paragangliomas are rare tumours arising from the paraganglia of the autonomic nervous system.

We present a case of a paraganglioma arising from the hypoglossal nerve and producing an unusual clinical picture at presentation.

We supply radiological evidence of a paraganglioma originating from the hypoglossal nerve, and thus extend the evidence base for this rare site of origin. Our patient presented as an emergency with long tract neurological symptoms and progressive brainstem involvement. This presentation is not characteristic of paragangliomas in general, which usually have an indolent growth pattern and often demonstrate benign symptoms for a number of years prior to diagnosis. The location of a hypoglossal paraganglioma differs significantly from more common paragangliomas described in the neck and skull base, and this should inform the surgical approach undertaken.

This study aimed to evaluate retrospectively the results of experience with end-to-end anastomosis of cranial nerves VII and XII, performed due to transection of the facial nerve during acoustic neuroma removal.

We assessed the facial reanimation results of 33 patients whose facial nerves had been transected during acoustic neuroma excision via a retrosigmoid approach, between 1985 and 2006, and who underwent end-to-end hypoglossofacial anastomosis. We compared the facial nerve functions of patients receiving short term (two to three years) and long term (more than three years) follow up, and we assessed any complications of the anastomosis.

A House–Brackmann grade III facial function was achieved in 46.2 and 86.4 per cent of the patients in the short and long term, respectively. House–Brackmann grade IV facial function was achieved in 53.8 and 13.6 per cent of the patients in the short and long term, respectively. There was a statistically significant difference between the facial recovery results, comparing the short and long term follow-up periods (p = 0.03). Disarticulation was the most common complication, seen in 19 (57.6 per cent) patients; numbness of the tongue was the next commonest (10 (30.3 per cent) patients). None of the patients developed dysphagia.

Despite such morbidities as disarticulation and tongue numbness, end-to-end hypoglossofacial anastomosis is still an effective procedure for the surgical rehabilitation of static and dynamic facial nerve functions. Significant improvement in facial nerve function can occur more than three years post-operatively.