|Year : 2020 | Volume
| Issue : 1 | Page : 34-36
Facial baroparesis in a 12-year-old boy
Santosh Kumar Swain, Nishtha Anand
Department of Otorhinolaryngology, IMS and SUM Hospital, Siksha “O” Anusandhan University (Deemed to be), Bhubaneswar, Odisha, India
|Date of Submission||06-Apr-2020|
|Date of Acceptance||06-Oct-2020|
|Date of Web Publication||23-Dec-2020|
Prof. Santosh Kumar Swain
Department of Otorhinolaryngology, IMS and SUM Hospital, Siksha “O” Anusandhan University (Deemed to be), Bhubaneswar, Odisha
Source of Support: None, Conflict of Interest: None
Facial baroparesis is an extremely uncommon clinical entity that occurs due to the middle ear barotrauma. It is rarely reported in the medical literature which can happen among persons who ascend to high altitude in flight or by scuba diving. The overpressure in the middle ear space due to eustachian tube dysfunction may cause exertion of the high pressure over the facial nerve through dehiscence of the horizontal segment of the facial nerve leading to facial nerve paralysis. Clinical history plays a vital role in diagnosis and also sometimes imaging helps confirm this rare cause of facial nerve paralysis. Here, we report a case of a 12-year-old boy who experiences unilateral facial nerve paralysis upon ascent to altitude on a flight with relieves from symptoms shortly after the descent.
Keywords: Eustachian tube dysfunction, facial baroparesis, middle ear barotrauma
|How to cite this article:|
Swain SK, Anand N. Facial baroparesis in a 12-year-old boy. Muller J Med Sci Res 2020;11:34-6
| Introduction|| |
Facial baroparesis or barotraumatic facial paralysis is a transient ischemic neuropraxia of the facial nerve that occurs due to eustachian dysfunction during the change of atmospheric pressure. It is often found among pilots or divers due to the development of the high pressure in the middle ear cavity. This occurs due to the impaired function of the Eustachian tube More Details. There are certain conditions that narrow the lumen of the eustachian tube such as edema, increased viscosity of the mucus coating of the tubal mucosal membrane, or impairment of the tube to open. The facial nerve passes through the temporal bone through the Fallopian canal More Details. This fallopian canal is a complicated bony pathway that is affected by the pressure changes. The development of the high pressure in the tympanic segment of the facial nerve may cause temporary ischemic neuropraxia which is thought to be the cause of the facial nerve palsy. The facial nerve palsy can be relieved by equalizing the pressure in the middle ear cavity through the nasopharynx through the eustachian tube. We report a case of baroparesis in a 12-year-old boy who developed transient facial nerve paralysis while traveling on a commercial flight.
| Case Report|| |
A 12-year-old boy with his parents attended the outpatient department of the otorhinolaryngology with complaints of right-side facial weakness for 3 days. He had a history of travel with his parent through a flight where he developed facial weakness. He had increased sensation of pressure in his ears during the ascent of the flight but failed to relieve even after doing yawning or chewing gum or Valsalva as per the advice of the flight attendant. During maximum elevation, he felt a tingling sensation on the right side of the face and felt numbness over the face along with mild headache. The flight attendant helped him with mid-air emergency service. The child vitals such as blood pressure, pulse rate, and respiratory rate were within normal limits. During the descent of the flight, he felt a little comfortable and leading to near-complete resolution of the symptoms. However, the facial weakness on the right side persisted, so he attended our outpatient department. He had a history of upper respiratory tract infection along with nasal congestion and cough for 3 weeks before the flight. Examinations of the ear and nose were unremarkable. All the cranial nerves were normal except facial asymmetry with Grade II House Brackmann's facial nerve paralysis on the right side [Figure 1]. The sensory and motor coordination with reflexes was within normal limits. Noncontrast computed tomography (CT) scan of the head, CT angiography of the head and neck, and magnetic resonance imaging (MRI) with and without the contrast of his head and neck were done. CT scan of the temporal bone showed dehiscence at the tympanic segment of the facial nerve [Figure 2]. Routine laboratory blood tests were also within normal limits. The child was treated with nasal decongestants and antihistamines for upper respiratory tract infections. The facial weakness was completely subsided after 1 week of treatment.
|Figure 2: Computed tomography scan of the temporal bone showing dehiscence at the tympanic segment of the facial nerve|
Click here to view
| Discussion|| |
Facial baroparesis is the seventh cranial nerve paralysis due to transient hypoxemia of the facial nerve secondary to raised pressure in the middle ear space. Facial baroparesis is a rare clinical entity that usually occurs due to dysfunction of the eustachian tube leading to overpressure at the middle ear. There are a few isolated cases of facial baroparesis reported in the medical literature. The pathophysiology for facial baroparesis can be explained by the anatomical course of the seventh cranial nerve. The facial nerve exits from the brainstem at the pontomedullary junction and passes through the cerebellopontine angle before entering into the petrous part of the temporal bone through the internal auditory canal. Then, it travels through the facial canal or fallopian canal, which is divided into three segments such as the labyrinthine segment, the tympanic segment, and the mastoid segment. After traversing the fallopian canal, the facial nerve exits the skull through the stylomastoid foramen and then enters into the parotid gland and divides into five terminal branches which innervate the muscles of facial expression. The widely accepted explanation for facial nerve baroparesis is ischemic neuropraxia found at the tympanic segment of the facial nerve. The tympanic segment of the facial nerve passes through the middle ear space just medial to the incus. In this place, the facial nerve and middle ear are separated by a very thin layer of the bone. One study reveals spontaneous dehiscence of the tympanic segment of the fallopian canal and was found on CT scan in up to around 55% of the normal population, leading to direct communication between the middle ear space and the facial nerve. The middle ear cavity is an enclosed air-filled space. In the middle ear cavity with an intact tympanic membrane, the only way for pressure equalization through the nasopharynx is through the eustachian tube. If there is eustachian tube dysfunction, it can be difficult to equalize the middle ear pressure with ambient pressure. At a cruising altitude of 35,000 feet, the cabin pressure is reduced to be as high as 266 cm of water, a pressure which can easily overcome the capillary hydrostatic pressure. Hence, an increase in middle ear pressure is transmitted directly to the tympanic segment of the facial nerve, resulting in temporary ischemic neuropraxia. In this case, all the symptoms are resolved shortly after the equalization of the middle ear space and ambient pressure.
If somebody with eustachian dysfunction will fly too high altitude, he or she may suffer from fullness in the ear, otalgia, vertigo, facial nerve palsy, and even rupture of the tympanic membrane and bleeding. These symptoms may be disappeared swiftly on the descent. The patients are usually asymptomatic before and after the flight. Clinical examinations often show a bulged tympanic membrane at the affected side. Neurological examination or cranial nerve examination confirms the facial nerve paralysis. A hearing assessment is often done to assess cochlear functions. A vestibular examination may be associated with abnormal vestibular tests. Pure-tone audiometry is usually done to find the degree and type of hearing loss. Tympanometry often shows a Type C curve. CT scan of the temporal bone is useful to assess the bony wall of the fallopian canal. MRI can be done to assess the brain and soft tissue of the facial nerve. In our case, pure-tone audiometry showed normal hearing, whereas the tympanometry curve was Type C. Congenital dehiscence of the facial nerve canal of the temporal bone is often seen at the tympanic segment where neuropraxia occurs due to middle ear barotrauma leading to facial baroparesis. In this case, CT temporal bone was showing dehiscence at the tympanic segment of the fallopian canal, and the overpressure of the middle ear exerted on the dehiscent part of the facial nerve leading to facial baroparesis.
This facial baroparesis can be prevented using nasal decongestant drops such as xylometazoline in both nostrils before aviation to high altitude. The patient was also instructed for doing Valsalva after boarding in the flight. After the development of the facial baroparesis, the patient is also treated with topical nasal decongestant and Valsalva or Toynbee maneuver for getting a patent eustachian tube. These treatments usually relieve the facial baroparesis after equalization of the middle ear pressure. In the case of long-standing facial baroparesis, immediate myringotomy with grommet insertion is helpful to relieve symptoms. Endoscopic balloon dilation of the eustachian tube may be considered in certain persistent cases of facial baroparesis for making the eustachian tube functional.
Transient facial baroparesis is a rare complication of the barotrauma in-flight travelers. It is also an underreported clinical entity. We should encourage the reporting of more cases for better understanding and management of facial baroparesis.
| Conclusion|| |
Facial baroparesis is a rare clinical entity and usually seen among air travelers or pilots and divers. It is often a temporary clinical manifestation. The most accepted pathogenic mechanism for this facial palsy is ischemic neuropraxia of the facial nerve. Clinicians must consider this diagnosis when a patient presents with facial weakness with a history of flying. Accurate history taking, typically the history of flying or underwater diving, will to a diagnosis of facial baroparesis. The clinical symptoms are usually resolved after the equalization of the middle ear and ambient pressures.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
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Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2]