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Hypoglossal Nerve Palsy

Cranial Nerve Palsy XII Hypoglossal

Hypoglossal nerve palsy is an uncommon neurological deficit characterized by unilateral weakness and/or atrophy of the tongue that may arise due to trauma, iatrogenic causes (eg. surgery), infections, vascular malformations, or tumors. The clinical examination is the principal method by which hypoglossal nerve palsy can be detected, but imaging studies, either computed tomography or magnetic resonance imaging, must be used to identify the exact site of the lesion and the underlying cause.


The hypoglossal nerve, also known as the XII cranial nerve, arises from the medulla oblongata, carriers only motor fibers and supplies the muscles of the tongue [1] [2]. Its travel, from the point of origin to the tissue it innervates, is quite long and is generally divided into five segments - medullary, cisternal (intracranial), skull base, nasopharyngeal/oropharyngeal and carotid [1] [2]. Many pathologies have been described in the literature when it comes to the damage of the hypoglossal nerve in any of the mentioned segments, and it is estimated that tumors, such as nasopharyngeal carcinomas, gliomas, acoustic neuromas, chordomas, and metastases, are responsible for the majority of cases [2] [3] [4]. Other known causes include trauma [3], surgery-induced (examples being endotracheal intubation, cervical spine surgery, etc.) [5] [6] [7], and vascular changes (ischemia or hemorrhage) [1]. Signs and symptoms of hypoglossal nerve palsy are highly distinctive, the main feature being a unilateral weakness of the tongue [1]. In addition, the tongue may deviate toward the side of the damaged nerve (if the lesion is located inferior to the hypoglossal nerve nucleus) or contralaterally in the case of a supranuclear lesion [1]. Weakness is often accompanied by atrophy of the tongue, as well as fasciculations [1]. Furthermore, a number of patients might suffer from impaired speech (dysarthria) and swallowing difficulties (dysphagia), which may be severely debilitating [1] [3] [5] [6].

Cervical Lymphadenopathy
  • The patient's oropharyngeal and laryngeal examination was unremarkable with no cervical lymphadenopathy. He had normal laboratory investigations and cerebrospinal fluid examination.[ncbi.nlm.nih.gov]
  • There was no cervical lymphadenopathy, facial asymmetry and no external scars of the neck or scalp. Cranial nerves I–XI were intact generally except for some decreased sensation in the distribution of the right lingual nerve.[nature.com]
Streptococcal Infection
  • Anti-streptolysin O titre was increased to 1280 suggesting a preceding streptococcal infection. Magnetic resonance imaging of the brain did not show any intracranial or extracranial abnormality. She had a partial improvement at 3 months.[ncbi.nlm.nih.gov]
Fasciculation of the Tongue
  • […] of the tongue at rest, tongue flaccidity, or the inability to move the tongue rapidly from side to side or vertically.[medigoo.com]
  • The fasciculation of the tongue still bothered her as she was a teacher but swallowing was no longer a problem. However, she experiences occasional gagging sensation.[nature.com]
  • Lesions of the hypoglossal nerve Paralysis, atrophy and fasciculations of the tongue on the ipsilateral side (with nuclear or infranuclear lesions) Mild weakness of the tongue on the contralateral side (with supranuclear lesions) The "central" supranuclear[derangedphysiology.com]
  • Nuclear or infranuclear lesions produce paralysis, atrophy, and fasciculations of the tongue on the involved side. Supranuclear lesions produce mild to moderate contralateral weakness that may be transient.[ncbi.nlm.nih.gov]
Hemiatrophy of the Tongue
  • Hemiatrophy of the tongue with fatty displacement was demonstrated by means of T1-weighted magnetic resonance imaging.[ncbi.nlm.nih.gov]
  • Intraoral examination of the patient revealed hemiatrophy of the tongue, on the right side, and the inability to completely deviate the tongue toward the left side of the mouth on protrusion.[anatomybox.com]
Hemiatrophy of the Tongue
  • Hemiatrophy of the tongue with fatty displacement was demonstrated by means of T1-weighted magnetic resonance imaging.[ncbi.nlm.nih.gov]
  • Intraoral examination of the patient revealed hemiatrophy of the tongue, on the right side, and the inability to completely deviate the tongue toward the left side of the mouth on protrusion.[anatomybox.com]
  • Every possible prophylactic measure should be taken (eg, sedating the patient during oral or dental procedures, aggressive preoperative management of general and local periodontal chronic infections, avoiding prolonged perioperative neck hyperextention[ncbi.nlm.nih.gov]
  • KEYWORDS: CT; MRI; atlanto-occipital joint; hypoglossal nerve palsy; osteophyte[ncbi.nlm.nih.gov]
  • Hypoglossal palsy secondary to atlanto-occipital osteophytes has been previously described in single-case reports. 9 , 10 In our 2 patients with hypoglossal palsy secondary to C1-occipital osteophytes, osteophyte encroachment and secondary hypoglossal[ajnr.org]
Tongue Muscle Weakness
  • Distinguishing between extrinsic and intrinsic tongue muscle weakness in unilateral hypoglossal palsy. Neurology. 1984; 34 :1367–68. [ PubMed : 6541310 ] Rubinstein MK. Cranial mononeuropathy as the first sign of intracranial metastases.[ncbi.nlm.nih.gov]


To make the diagnosis of a hypoglossal nerve palsy, the physician is obliged to perform a detailed physical examination and obtain a thorough patient history that should reveal any preexisting disorders or events that could predispose the patient to this neurological deficit. The unilateral weakness of the tongue can be readily observed during a properly conducted neurological exam and the assessment of cranial nerves. To test the hypoglossal nerve, the patient is asked to protrude his tongue, when the deviation (and possibly atrophy or fasciculations) to one side is apparent [3] [5] [6] [7]. In order to identify the underlying cause, however, a more detailed investigation is warranted, with imaging studies being the cornerstone. Computed tomography (CT) and magnetic resonance imaging (MRI) are both recommended for the evaluation of hypoglossal nerve palsy. CT is able to visualize the skeletal structures in greater detail, while soft-tissues are better defined using MRI, particularly when gadolinium is employed as a contrast [1]. In fact, either CT or MR angiography are of great value in the diagnosis of vascular insults [2].

  • When the neuropathy occurred, the patient was in a mildly active stage of ulcerative colitis. We concluded that the mononeuritis observed in the present case was likely an extraintestinal manifestation of ulcerative colitis.[ncbi.nlm.nih.gov]


  • This complication suggests that over embolization with Onyx-18 in the treatment of hypoglossal canal DAVFs should be avoided, and transvenous embolization may be safer.[ncbi.nlm.nih.gov]
  • Following treatment with intravenous antibiotics for 6 weeks, symptoms resolved.[ncbi.nlm.nih.gov]
  • Dentists who might at times see patients with isolated hypoglossal nerve palsy should be aware of the significance of its oral manifestation, and they should be able to perform differential diagnosis of patients with the condition who appear for treatment[ncbi.nlm.nih.gov]
  • The patient refused treatment and so has been managed conservatively for more than five years, and he remains well.[ncbi.nlm.nih.gov]
  • He made a good recovery without treatment. English literature search revealed very few cases of idiopathic, transient, unilateral hypoglossal nerve palsy. 2014 BMJ Publishing Group Ltd.[ncbi.nlm.nih.gov]


  • There was uncertainty around prognosis at onset due to the rarity of this condition.[ncbi.nlm.nih.gov]
  • Although the aetiological importance and ominous prognosis of neoplasia has been emphasized by others, our study suggests that an isolated hypoglossal nerve palsy may be benign and idiopathic.[link.springer.com]
  • Keywords: Hypoglossal nerve ; Paralysis ; Prognosis 1. Combarros O, Alvarez de Arcaya A, Berciano J. Isolated unilateral hypoglossal nerve palsy: Nine cases. J Neurol 1998;245:98–100. 2. Lee SS, Wang SJ, Fuh JL, Liu HC.[synapse.koreamed.org]
  • Hypoglossal nerve palsy following intubation might have a favourable prognosis as long as continuity of the nerve sheath is maintained. Authors User assignment Assign yourself or invite other person as author.[infona.pl]
  • The prognosis for recovery seems better in secondary nerve palsy than in immediate palsy. It is therefore important to note the chronology of appearance of the deficit as this may have medico-legal consequences.[em-consulte.com]


  • Neuroradiological examinations and other investigations for etiology of hypoglossal nerve palsy and urticaria were normal. We suggest that all patients with hypoglossal palsy must be carefully evaluated for atypical findings and etiologies.[ncbi.nlm.nih.gov]
  • Results: Major etiologic categories included: postoperative (29.3%), idiopathic (15.1%), primary neoplastic (14.2%), metastatic malignancy (13.0%), inflammatory (7.3%), radiation (6.1%), and traumatic (4.1%).[mayoclinic.pure.elsevier.com]
  • The diagnosis is frequently missed by the anesthesia care team in the recovery room due to the delayed symptomatic onset and often requires neurology and otolaryngology evaluations to exclude serious etiologies.[ncbi.nlm.nih.gov]
  • It also represents a diagnostic challenge in every day clinical practice due to its diverse etiologies.[jneuro.com]
  • Multiple different etiologies have been proposed for the development of hypoglossal nerve palsy associated with anesthesia.[practicalneurology.com]


  • Home Online First Current Issue Past Issues Journal Home FIND ISSUES Current Issue ARTICLE & MULTIMEDIA Most Accessed Articles Clinical Epidemiology Workshop Series Supplements Videos FOR AUTHORS Guide for Author Reviewer List BOPA Online Submission ABOUT[hkmj.org]
  • Maria alle Fonti” Medical Center, Salice Terme, Pavia, Italy d San Rossore Hospital, Pisa, Italy e Unit of Maxillo-Facial Surgery, Department of Health Sciences, San Paolo Hospital, University of Milan, Milan, Italy f Department of Biometry and Clinical Epidemiology[functionalneurology.com]
  • Epidemiology In 2007, the Moebius Syndrome Foundation estimated that there were at the time a total of approximately 2,000 cases of Moebius Syndrome worldwide [6] .[physio-pedia.com]
Sex distribution
Age distribution


  • The relevant literature is reviewed and different hypotheses concerning the pathophysiological mechanisms of nerve damage are discussed. Copyright 2002 S. Karger AG, Basel[ncbi.nlm.nih.gov]
  • We reviewed the pathophysiological causes of hypoglossal nerve injury and discuss the associated clinical and procedural characteristics of affected patients.[ncbi.nlm.nih.gov]
  • This case strongly suggests that surgical intervention is effective for this pathophysiology.[surgicalneurologyint.com]
  • There is a scarcity of literature in recognizing HNPs following trauma and a lack of pathophysiological understanding to both a delayed presentation and to resolution versus persistence.[jcvjs.com]
  • PATHOPHYSIOLOGY The hypoglossal nerve originates from the hypoglossal nuclei in the medulla at the inferior aspect of the fourth ventricle. 8,9 It then exits the skull base from the hypoglossal canal in close association with CN IX, X, and XI and medial[practicalneurology.com]


  • Therefore, in order to prevent this complication, we must perform mask ventilation and direct laryngoscopy carefully. Head and neck manipulation should be gentle during anesthesia for shoulder surgery.[ncbi.nlm.nih.gov]
  • Currently, there are no specific preventive or therapeutic recommendations. We found 69 cases of HNP after procedural airway management reported in the literature from 1926 to 2013.[ncbi.nlm.nih.gov]
  • Treatments focus on maintaining function and prevention of abnormal airway-related swallowing events.[ncbi.nlm.nih.gov]
  • […] possible prophylactic measure should be taken (eg, sedating the patient during oral or dental procedures, aggressive preoperative management of general and local periodontal chronic infections, avoiding prolonged perioperative neck hyperextention) to prevent[ncbi.nlm.nih.gov]
  • Understanding radiological patterns of tongue denervation is important to prevent misinterpretation. Close evaluation of the skull base is critical as hypoglossal palsies resulting from pathology here are often overlooked.[ncbi.nlm.nih.gov]



  1. Thompson EO, Smoker WR. Hypoglossal nerve palsy: a segmental approach. Radiographics. 1994;14(5):939-958.
  2. Boban M, Brinar VV, Habek M, Rados M. Isolated hypoglossal nerve palsy: a diagnostic challenge. Eur Neurol. 2007;58:177-181.
  3. Loro WA, Owens B. Unilateral Hypoglossal Nerve Injury in a Collegiate Wrestler: A Case Report. J Athl Train. 2009;44(5):534-537.
  4. Hui AC, Tsui IW, Chan DP. Hypoglossal nerve palsy. Hong Kong Med J. 2009;15(3):234.
  5. Yasuda T, Togawa D, Hasegawa T, et al. Hypoglossal Nerve Palsy as a Complication of an Anterior Approach for Cervical Spine Surgery. Asian Spine J. 2015;9(2):295-298.
  6. Al-Benna S. Right hypoglossal nerve paralysis after tracheal intubation for aesthetic breast surgery. Saudi J Anaesth. 2013;7(3):341-343.
  7. Shah AC, Barnes C, Spiekerman CF, Bollag LA. Hypoglossal Nerve Palsy After Airway Management for General Anesthesia: An Analysis of 69 Patients. Anesth Analg. 2015;120(1):105-120.

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Last updated: 2018-06-21 23:54