“Triple Cross” of the Hypoglossal Nerve and its Microsurgical Impact to Entrapment Disorders

Abstract

Objective: Cadaveric dissections were performed to review the intracranial and extracranial course of the hypoglossal nerve. The neurological significance of a newly defined “triple cross” of the hypoglossal nerve is discussed. Materials and Methods: 10 cadaveric heads (left and right; 20 sides) were dissected using microsurgical techniques. Results: In the cisternal segment of hypoglossal nerve, the diameter of the rostral trunk amounted to 155-680 μm (mean 435 μm), and the caudal trunk to 210-820 μm (mean 482 μm). The roots formed three trunks in 20% of the hypoglossal nerves and two trunks in the rest. As a first cross, the anterior medullary segment of the vertebral artery crossed the hypoglossal nerve roots in 14 of 20 sides (70%). As a rare variation, the vertebral artery extended medial to the nerve (25%) or between its roots (5%). The second cross was found between the descendens hypoglossus and the occipital artery (75%), sternocleidomastoid artery and vein complex (15%) and external carotid artery (10%). The third cross was shown in the submandibular triangle between the lingual hypoglossus and its drainage vein; vena committans nervus hypoglossus. Conclusion: Throughout its way, the hypoglossal nerve passes over vascular structures in three crossing points which may serve as a probable cause of hypoglossal nerve entrapment disorders.

Hypoglossal nerve - triple cross - cross-compression - entrapment disorders - microsurgical anatomy

References

• 1 Gibo H, Marinkovic S, Nikodijevic I, Stimec B, Erdem A. The blood supply of the hypoglossal nerve: the microsurgical anatomy of its cisternal segment.  Surg Neurol. 1997;  48 85-91
• 2 Ballotta E, Da Giau G, Renon L, Narne S, Saladini M, Abbruzzese E, Meneghetti G. Cranial and cervical nerve injuries after carotid endarterectomy: a prospective study.  Surgery. 1999;  125 85-91
• 3 Meziti L, Iffenecker C, Fuerxer F, Benoudiba F, Comoy J, Lacroix C, Doyon D. XII cranial nerve pseudoneurinoma due to spontaneous transformation of an aneurysm of the vertebral artery.  J Neuroradiol. 1998;  25 307-311
• 4 Rollnik JD, Sindern E, Mosler F, Spring B, Malin JP. Isolated peripheral hypoglossal palsy caused by a kinking of the left vertebral artery (hypoglossal vertebral entrapment syndrome).  Eur Neurol. 1996;  36 324-325
• 5 Salvi F, Mascalchi M, Plasmati R, Tugnoli V, De Grandis D. Hypoglossal vertebral entrapment syndrome.  Muscle Nerve. 1999;  22 288-289
• 6 Yousry I, Moriggl B, Schmid UD, Wiesman M, Fesl G, Bruckmann H, Naidich TP, Yousry TA. Detailed anatomy of the intracranial segment of the hypoglossal nerve: neurovascular relationships and landmarks on magnetic resonance imaging sequences.  J Neurosurg. 2002;  96 1113-1122
• 7 Lang J. About a very rare variation of the course and width of the vertebral arteries and the hypoglossal nerve.  Acta Neurochir (Wien). 1990;  106 73-77
• 8 Morini A, Rozza L, Manera V, Buganza M, Tranquillini E, Orrico D. Isolated hypoglossal nerve palsy due to an anomalous vertebral artery course: report of two cases.  Ital J Neurol Sci. 1998;  19 379-382
• 9 Wen HT, Rhoton Jr AL, Katsuta T, de Oliveira E. Microsurgical anatomy of the traanscondylar, supracondylar and paracondylar extensions of the far-lateral approach.  J Neurosurg. 1997;  87 555-585
• 10 Aldoori M, Baird NR. Local neurological complication during carotid endarterectomy.  J Cardiovasc Surg. 1988;  29 432-436
• 11 Bejjani G, Sullivan B, Lopez ES, Abello J, Wright D, Jurjus A, Sekhar L. Surgical anatomy of the infratemporal fossa: the styloid diagram revisited.  Neurosurgery. 1998;  43 842-853
• 12 Forsell C, Kitzing P, Berqvist D. Cranial nerve injuries after carotid artery surgery. A prospective study of 663 operations.  Eur J Vasc Endovasc. 1995;  10 445-459
• 13 Maniglia A, Han P. Cranial nerve injuries following carotid endarterectomy: an analysis of 336 procedures.  Head & Neck. 1991;  13 121-124
• 14 O’Rahilly R, Muller F. The early development of the hypoglossal nerve and occipital somites in staged human embryos.  Am J Anat. 1984;  169 237-257
• 15 Nathan H, Levy J. The course and relations of the hypoglossal nerve and the occipital artery.  Am J Otolaryngol. 1982;  3 128-132
• 16 Hans SS, Shah S, Hans B. Carotid endarterectomy for high plaques.  Am J Surg. 1989;  157 431-435
• 17 Imparato A, Bracco A, Kim GE, Bergmann L. The hypoglossal nerve in carotid arterial reconstructions.  Stroke. 1972;  3 576-578
• 18 Radonic V, Baric D, Giuino L, Buca A, Sapunar D, Marovic A. Surgical treatment of kinked internal carotid artery.  J Cardiovasc Surg (Torino). 1998;  39 557-563
• 19 Scotti G, Melancon D, Olivier A. Hypoglossal paralysis due to compression by a tortuous internal carotid artery in the neck.  Neuroradiology. 1978;  17 263-265
• 20 Takase K, Kohyama Y, Ueda S. Surgical management of peripheral hypoglossal nerve palsy caused by abnormal external carotid artery.  No Shinkei Geka. 1983;  11 1313-1318
• 21 Bademci G, Batay F, Tascioglu AO. Non-traumatic elevation techniques of the hypoglossal nerve during carotid endarterectomy: a cadaveric study.  Minim Invas Neurosurg. 2005;  48 108-112
• 22 Kim DD, Caccamese JF, Ord RA. Variations in the course of the hypoglossal nerve: a case report and literature review.  Int J Oral Maxillofac Surg. 2003;  32 568-570
• 23 Bademci G, Batay F, Vural E, Avci E, Al-Mefty O, Yasargil MG. Microsurgical anatomical landmarks associated with high bifurcation carotid artery surgery and related to hypoglossal nerve.  Cerebrovasc Dis. 2005;  19 404-406
• 24 Shangkuan H, Xinghai W, Shizhen Z, Zengxing W, Shiying J, Jiasong G. Morphologic studies of the venous drainage of the tongue.  Surg Radiol Anat. 1998;  20 89-92
• 25 Skandalakis J, Gray S, Rowe J. Surgical anatomy of the submandibular triangle.  Am Surg. 1979;  590-596

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