The ear
Rogan J Corbridge in Essential ENT, 2011
The facial nerve (Figure 9.32) is a motor nerve supplying the muscles of the face. Its nucleus is situated in the pons and the nerve emerges in the CPA. It is associated with the nervus intermedius, which carries secretomotor fibres to the salivary glands of the head and neck (except the parotid gland) from the superior salivary nucleus. This nerve also carries the taste fibres from the anterior part of the tongue. The facial nerve enters the internal auditory meatus with the VIII nerve and travels through the petrous temporal bone to emerge on the medial surface of the middle ear. Here, the nerve turns posteriorly, making its first genu, and then turning again, making its second genu, to travel inferiorly through the mastoid bone and exit the skull at the stylomastoid foramen to supply the facial muscles. The nervus inter medius runs with the facial nerve, giving off the greater petrosal nerve and the chorda tympani (which can be seen travelling on the medial portion of the tympanic membrane), which carries taste fibres from the tongue.
Middle Fossa Surgery
John C Watkinson, Raymond W Clarke, Christopher P Aldren, Doris-Eva Bamiou, Raymond W Clarke, Richard M Irving, Haytham Kubba, Shakeel R Saeed in Paediatrics, The Ear, Skull Base, 2018
Inadvertent entry into the inner ear, damage to its blood supply or to the VIIIth nerve, can result in hearing loss, tinnitus or balance disturbance. Weakness of the face may develop and be accompanied by damage to the sensory component of the facial nerve. An extradural haematoma may accumulate and can be limited by suspending the dura to the edges of the craniotomy. CSF leakage is less common than in posterior fossa surgery but, nevertheless, can be equally tedious and dangerous as there is a definite risk of infection or meningitis. There has been much debate regarding the possibility of temporal lobe damage following MF surgery. The risk is in the order of 1 in 50 patients having a single early post-operative seizure following a MF exposure of the IAC.10 Aggarwal et al. 49 described two cases of single ictal events which had the effect of prohibiting the patients from driving for a period of one year. A long-term predisposition to seizures has not been described. Retraction trauma leading to cortical injury, aphasia or hemiparesis has not been described either, but there is some suggestion that temporal lobe function is affected at least temporarily following surgery and may lead to some transient memory loss. There are additional risks in MF transpetrous surgery that include damage to the intrapetrous carotid artery, trigeminal neuropathy and ophthalmoplegia.
Complications of Reconstructive Surgery
Stephen M. Cohn, Matthew O. Dolich in Complications in Surgery and Trauma, 2014
Soft-tissue injuries may affect additional structures of the head and face, which are crucial to function. Because of its course and superficial location, the facial nerve is easily damaged by a number of mechanisms of trauma to the face. Early intervention and repair of such injuries are important to assure the long-term function of the facial muscles. Once significant scarring and muscle atrophy have occurred, return of function is less than optimal. Injuries to the orbital and ocular region may cause substantial long-term complications. Such injuries may include unrecognized injuries to the lacrimal system, corneal abrasions with residual scarring, and orbital malposition or entrapment of the globe or the extraocular muscle with subsequent enophthalmos and diplopia. If recognized early, most of these injuries can be successfully treated with a minimum number of residual long-term complications. Traumatic ectropion is exceedingly difficult to correct if not addressed early. Late repair of such problems is generally less satisfactory because scar formation in such delicate tissues may compromise function. Additional complications may involve neuropraxia to the sensory nerves, especially the infraorbital and inferior alveolar nerve. Proper alignment of fractures in the maxilla and mandible is generally sufficient to help restore function, if the nerve has not been lacerated. With blunt injury, however, chronic pain or complete loss of sensation may yield substantial morbidity.
Objective assessment of eyelid position and tear meniscus in facial nerve palsy
Published in Orbit, 2022
Alicia Galindo-Ferreiro, Victoria Marqués-Fernández, Hortensia Sanchez-Tocino, Silvana A. Schellini
The seventh cranial nerve, called the facial nerve, controls the muscles for facial expression. Bell’s palsy (BP) is an idiopathic, unilateral, acute weakness of the facial muscles in a pattern consistent with peripheral facial nerve dysfunction resulting in blink dysfunction, malposition of the eyelids such as lower lid ectropion, upper lid retraction, decreased tear production, and a defective tear pump lacrimal drainage mechanism.1Concurring with facial nerve palsy (FNP), the altered position of the lids associated with lower lid laxity can commonly lead to exposure keratopathy, dry eye, and tearing.2 However, there are few studies that objectively evaluate eyelid malposition, with quantitative measurements of margin reflex distance to the upper (MRD1) or to the lower (MRD2) lid in patients with FNP.2,3 Additionally, there are no studies that measure these changes over time.
Clinical long-term observation of the keyhole microvascular decompression with local anesthesia on diagnosis and treatment of vestibular paroxysmia
Published in Acta Oto-Laryngologica, 2020
Fang Liu, Chengzhong Wei, Weining Huang
MVD has been widely used as the preferred surgical treatment for NVCC causing TGN, HFS and GPN. However, it is controversial for the application of MVD in the treatment of VP in the case selection, surgical indication, surgical methods, efficacy evaluation and prevention of complications [15]. First, facial nerve is located in the ventromedial, the cochleovestibular nerve located in the dorsolateral side of facial nerve, and the vertebrobasilar artery located in the midline of brainstem in CPA. Therefore, the probability that facial nerve is compressed by responsible vessels will be higher than that of cochleovestibular nerve. Second, despite the report of successes, MVD did not gain overall acceptance and should be reserved for cases with VP who responded but did not tolerate the medical treatment and in whom the affected side could be clearly identified because of the risk of a brainstem infarction due to intra- or post-operative vasospasm [10]. However, trigeminal nerve, facial nerve, glossopharyngeal nerve and cochleaovestibular nerve are all in the same surgical field of CPA. Therefore, the responsible vessels for cochleovestibular nerve and the other nerve roots can be explored, and MVD can be carried out for NVCC at the same time, which will not significantly increase the risks of operation and be easy to be accepted by patients. Therefore, in our study, we selected the patients with coexistent VP and the other NVCC.
Bilateral facial palsy
Published in Acta Oto-Laryngologica, 2019
Junyang Jung, Dong Choon Park, Su Young Jung, Myung Jin Park, Sang Hoon Kim, Seung Geun Yeo
Unilateral facial palsy, first reported in 1830, is relatively uncommon [1]. Although facial palsy does not affect patient longevity, it causes facial asymmetry and loss of function, resulting in mental and emotional stress. Normally, the facial nerve runs through the ostium in the temporal bone, but some facial nerves have an unusual anatomic course. The facial nerve may be easily damaged by middle ear or temporal bone surgery, trauma, or infection because dehiscence of the neural tube is frequent in the upper part of the oval window and the geniculate ganglion part of the dorsal ganglia. In addition, facial nerve paralysis may be secondary to facial nerve tumor or systemic disease. In contrast, congenital anomalies are rarely accompanied by facial palsy. The incidence of each cause of facial palsy varies by region, subject, age, research institute, and researcher. For example, Bell's palsy, the most common type of facial palsy, does not have a specific cause [2]. The incidence rate of facial palsy is about 20–30 per 100,000 persons. Its incidence increases with age, but there are no differences between men and women. In most patients, facial palsy is unilateral and results in incomplete paralysis. Among patients with facial palsy, about 0.3% have bilateral facial palsy. Of these patients, 9% had a previous history of idiopathic facial nerve palsy and 8% had a family history of facial palsy.
Related Knowledge Centers
- Abducens Nerve
- Brainstem
- Facial Canal
- Facial Muscles
- Pons
- Stylomastoid Foramen
- Taste
- Temporal Bone
- Cranial Nerves
- Tongue