Volume 5, Issue 4 , Pages 174-176, December 2010
Isolated hypoglossal nerve palsy following open surgery in the beach-chair position under general anesthesia: A case report
Article Outline
Abstract
Hypoglossal nerve palsy frequently occurs with other cranial nerve palsies; an isolated hypoglossal nerve palsy is rare. Most hypoglossal nerve palsies are caused by tumors. However, several reports have shown an association with oropharyngeal manipulation such as intubation, laryngeal mask airway or as a complication of surgery such as carotid endarterectomy, and tooth extraction. When the nerve was injured, a deviation to the affected side, atrophy, and tongue fasciculation could be observed. We treated a patient with isolated hypoglossal nerve palsy after open repair of a fracture of the humerus in the beach-chair position.
Keywords: Complication, Hypoglossal nerve palsy
1. Introduction
Hypoglossal nerve palsy occurs frequently in conjunction with the paralysis of other nerves; however, hypoglossal nerve palsy alone is very rare [1]. Most cases with palsy are caused by tumors in the jugular foramen or the parapharyngeal space [2]. In addition, it may be caused by trauma due to extension of the neck area during surgery [3], surgery on the carotid [4], oropharyngeal manipulation such as intubation or a laryngeal mask airway [5], and tooth extraction [6]. Rarely, case caused by infectious mononucleosis has been reported [7].
The symptoms include: tongue discomfort, dysarthria, and dysphagia. In addition, depending on the cause, headache, deterioration of visual acuity, and ataxia may develop [3], [8]. In cases caused by organic lesions, computed tomography or magnetic resonance imaging is useful for diagnostic purposes [1], [4]. However, in cases without specific findings on radiological testing, paralysis caused by trauma should be considered [5], [8], [9].
We treated a patient with hypoglossal nerve palsy; a 14 years old girl had repair of a fracture of the humerus in the beach-chair position under general anesthesia with transoral intubation for 3
h.
2. Case report
A 14 years old girl was admitted to the emergency room of our hospital for pain of the shoulder joint area after a traffic accident. A fracture of the humerus was identified and she was admitted to the department of orthopedics at our hospital for surgical treatment. Only pain associated with the humerus was reported. There were no other significant physical findings. The medical history was unremarkable. The day after admission the patient was transferred to the operating room, and general anesthesia with transoral intubation was performed without any difficulties. The patient was in the beach-chair posture used for surgery on the shoulder joint area. In this position, the patient is in approximately a 45° angle from the surface turned 30° toward the opposite side of the lesion. The operation time was approximately 3h, and after the patient awoke from anesthesia, extubation was performed without any difficulties. The patient was transferred to the recovery room, and upon recovery, the patient was transferred to a hospital ward.
In the morning, the next day after surgery, the patient reported discomfort while moving her tongue and a slight difficulty with articulation. An otorhinolarygology consultation was obtained. The physical examination showed that the tongue was deviated to the left when the tongue was protruded to the front, and while moving the tongue to the left side, poor movement was detected; in addition, folding due to atrophy of the left side of the tongue was detected (Fig. 1A). These findings suggested loss of the left hypoglossal nerve function. Evaluation of all cranial nerves followed and no other abnormalities were detected.
Fig. 1.
(A) External photograph of 5 days after surgery. The tongue was deviated to the left side on protrusion, demonstrating a lack of function of the left hypoglossal nerve. (B) External photograph 6 months later; normal function of the hypoglossal nerve without other neurological problems. The symptoms were completely resolved.
To determine the cause of the abnormal findings, cervical computed tomography, cerebral magnetic resonance imaging, general blood tests, blood testing for viral infections, electroencephalography, and carotid doppler testing were performed. There were no results suggestive of a cause for the abnormality. In addition, a neurology consultation was obtained and the paralysis was thought to be idiopathic. Based on the above results, we suspected an isolated hypoglossal nerve palsy, and similar to the treatment of Bell's palsy, oral steroids (methyl-prednisolone) were administered. The dose was 60mg per day for 4 days, and subsequently, a tapering dose of 40mg per day for 2 days, 30mg per day for one day, 20mg per day for 1 day, and 10mg per day for 2 days, over a total of 10 days. The symptoms improved 6 days after initiating the steroid treatment. The patient was followed monthly after discharge, for three months. The articulation disorder improved gradually. Six months later, the deviation of the tongue was no longer present (Fig. 1B).
3. Discussion
The hypoglossal nerve is the 12th cranial nerve; it is involved in the control of tongue movement [1]. The nerve travels through the hypoglossal nerve canal, leaves the cranium and descends between the internal jugular vein and the internal carotid artery [3]. It is located on the surface of arteries in the area beneath the angle of the mandible, progresses to the area above the greater horn of hyoid bone, and enters the floor of the mouth [10]. Thus, it supplies the motor nerves of the intrinsic and extrinsic muscles of the tongue [10]. In addition, by branching after the merging of the cervical nerves C2 and C3, with the hypoglossal nerve, it forms the ansa hypoglossi and the ansa cervicalis and thus controls the muscles in the neck area [10]. Because the pathway the nerve travels is long, the hypoglossal nerve is divided into six areas including: the supranuclear segment, medullary segment, cisternal segment, skull base segment, nasopharyngeal/oropharyngeal carotid space segment, and the hypoglossal segment [11]. Therefore, symptoms associated with a given disorder develop depending on the segment affected, and the results of radiological tests can be slightly different [11], [12].
Hypoglossal nerve palsy usually occurs in conjunction with other cranial nerve abnormalities [1]. Primarily, it is caused by space occupying lesions of the internal or external cranium [2], [12], metastatic diseases involving the skull base [2], and iatrogenic causes after neck or shoulder surgery [3], [9]. Although rare, other causes include paralysis after radiation therapy [2], aneurysm of the external carotid artery [4], oropharyngeal manipulation such as intubation and laryngeal mask airway [5], tooth extraction [6], infectious disease [7], and subluxation of the atlanto-occipital joint [13].
The symptoms associated with hypoglossal nerve palsy are characteristically a deviation of the tongue, progressive and unilateral tongue atrophy, spasm of the tongue, dysphagia, phonation and articulation disorders [1]. Depending on the etiology, paraplegia, muscle weakness, muscle atrophy, and nystagmus may also be present [3], [8], [9], [13]. For a diagnosis, based on the presence of typical symptoms, it is useful to perform general blood tests, autoimmunity testing, viral serum tests, and radiological tests such as CT and MRI to determine the cause [1], [4], [7], [8].
The causes that are relevant to the case reported here include the following. First, the possibility of compression of the hypoglossal nerve by the angle of mandible, while turning the neck toward the opposite side, of the side undergoing surgery, during orthopedic surgery in the beach-chair position. Second, paralysis might have developed by compression of the side of the tongue muscles by the blade of the laryngoscope during transoral intubation, under direct laryngoscopy, during general anesthesia. Third, injury could have occurred during excessive extension of the neck; if the nerve was immobilized by compression of the cricoid cartilage caused by the cuff of the tube after transoral intubation. Such possibilities might have induced neuropraxia that blocked nerve conduction locally with the development of edema in the area where the hypoglossal nerve was compressed. Therefore, early and aggressive treatment was essential to prevent further injury of the nerves and to improve prognosis. Steroid treatment likely controlled the edema and suppressed further progression of paralysis.
4. Conclusion
This case illustrates hypoglossal nerve palsy can develop alone. Once all other possible causes were ruled out, the possibility of injury during surgery was considered as the cause.
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PII: S1871-4048(09)00058-6
doi:10.1016/j.pedex.2009.09.005
Published by Elsevier Inc.
Volume 5, Issue 4 , Pages 174-176, December 2010
