Isolated Unilateral Hypoglossal Nerve Palsy Due to Vertebral Artery Dissection

Abstract

The hypoglossal nerve (CN XII) is the motor nerve of the tongue. Isolated hypoglossal nerve paralysis is uncommon. Vascular, inflammatory, traumatic, or space-occupying lesions can affect the CN XII anywhere in its course, from the nucleus in the caudal medulla, through the intracranial extramedullary portion of the nerve, across the hypoglossal canal, or into its extracranial termination. [1][2][3][4] The rootlets cross the premedullary cistern superior to the vertebral artery and exit the skull base through the hypoglossal canal. 1,3 This close relationship can cause compression of rootlets intracranially when there is vertebrobasilar pathology or anatomic variants of the vertebral artery resulting in paralysis of the nerve. [3][4][5] The rootlets join to form one or two trunks before piercing through the dura. 1,2 The nerve then descends almost vertically to a point corresponding with the angle of the mandible. In the neck it is deeply seated beneath the internal carotid artery, internal jugular vein, and vagus nerve. Lower in the neck the nerve emerges superficially just below the digastric muscle. 2Case Report A woman, 20 years old, presented to the emergency room with sudden onset of slurring of speech, lasting for about an hour. This was preceded by a two week period of neck pain. The patient took acetaminophen and ibuprofen with limited relief. There was no history of trauma, nausea, vomiting, headache, blurring of vision, double vision, or dysphagia; however, she felt dizzy five seconds before the symptoms appeared. On examination, the patient was normotensive, dysarthric, and afebrile. She scored a 2 on the NIH stroke scale. The dysarthria was due to difficulty in tongue movement. She could not repeat "Methodist Episcopal," "Huckleberry Finn," and "Fifty-Fifty," but she was able to repeat We report the case of a patient with unilateral tongue weakness secondary to an isolated lower motor neuron hypoglossal nerve palsy that was caused by a right vertebral artery dissection in the lower neck. The patient had a boggy tongue with a deviation to the right side but an otherwise normal neurological examination. Magnetic resonance angiography showed a narrow lumen of the right vertebral artery in the neck. After initially treating the patient with aspirin in the emergency room and later with warfarin for three months, there was complete recanalization of the right vertebral artery. Only one other case of vertebral artery dissection and twelfth nerve palsy has been reported before.Keywords: Dysarthria; Hypoglossal nerve; Lateral medullary syndrome; Tongue weakness; Vertebral artery dissection CM&R 2012 : 3 (August) 128Hypoglossal nerve palsy "Mama" and "Tip-Top". She had a boggy tongue that was enlarged on the left side which led to difficulty in movement.Her tongue deviated to the right side on protrusion. With consent, a picture of the tongue movement was obtained (figure 1). The remaining cranial nerve examination as well as the rest of her neurological examination was unremarkable.A laboratory evaluation wi...

Ultrasound of the Hypoglossal Nerve in the Neck: Visualization and Initial Clinical Experience with Patients

“…There are also reports of carotid and vertebral artery dissections leading to hypoglossal nerve injury. [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] In a large case series of hypoglossal nerve palsies, the site of the lesion could not be localized in 6%. 9 In the radiologic diagnostic work-up, a segmental imaging approach is advised.…”

Skull base osteomyelitis presenting with an isolated hypoglossal nerve palsy

“…Most cases of hypoglossal nerve palsy occur with other neurological or systemic signs. Reported cases of truly isolated palsy are due to cancer1—which is the most common cause2—carotid artery aneurysms,3 vertebral artery dissection,4 cervical osteophytosis,5 calcified persistent hypoglossal artery,6 synovial cysts,7 vasculitides/rheumatological diseases,2 dental disease,8 trauma9 and following transoral intubation10 among others.…”

Persistent Isolated Unilateral Hypoglossal Nerve Palsy

“…The hypoglossal nerve is the motor nerve responsible for movement of the tongue muscles playing an important role in articulation of speech [4]. Isolated hypoglossal nerve damage presents less frequently then isolated damage to cranial nerves III, IV, VI, and is a rare finding in clinical practice [5].…”