We aimed to study the neurovascular relationships between the anterior inferior
cerebellar artery (AICA) and the abducens nerve to help determine the
pathogenesis of abducens nerve palsy which can be caused by arterial compression.
Twenty-two cadaveric brains (44 hemispheres) were investigated after
injected of coloured latex in to the arterial system. The anterior inferior
cerebellar artery originated as a single branch in 75%, duplicate in 22.7%, and
triplicate in 2.3% of the hemispheres. Abducens nerves were located between
the AICAs in all hemispheres when the AICA duplicated or triplicated. Additionally,
we noted that the AICA or its main branches pierced the abducens
nerve in five hemispheres (11.4%). The anatomy of the AICA and its relationship
with the abducens nerve is very important for diagnosis and treatment.
(Folia Morphol 2010; 69, 4: 201-203

Bilecenoglu, B.

Esmer, A.F.

Karahan, S.T.

Sen, T.

Tuccar, E.

Uz, A.

English

Via Medica Journals

Folia Morphol. Vol. 69, No. 4, pp. 201–203Copyright © 2010 Via MedicaISSN 0015–5659www.fm.viamedica.plO R I G I N A L   A R T I C L E201Address for correspondence: A.F. Esmer, MD, Ankara University, Faculty of Medicine, Department of Anatomy, Morfoloji binasl, 06100,Sihhiye, Ankara, Turkey, tel: +903123105001, fax: +903123105001, e-mail: alife76@yahoo.comINTRODUCTIONVascular disorders, infections, tumours, diabe-tes mellitus, and traumas are the most commoncauses of abducens nerve palsy, occasionally accom-panied with other cranial nerve disorders, especiallyregarding facial and trigeminal nerves. The reasonfor isolated abducens nerve palsy could be the re-sult of vascular disorders such as aneurysms or vas-cular compression in the root exit zone [4, 6, 11,13]. The anterior inferior cerebellar artery (AICA) isclosely related to the abducens nerve. In this studywe aimed to describe this relationship and discussits clinical significance.MATERIAL AND METHODSTwenty-two human cadaveric brains were usedin this study. Basilar and internal carotid arteries wereseparately cannulated and injected with colouredlatex. The brains were embalmed in 10% formalinsolution after injection. The dissections were per-formed using a surgical microscope (Opmi 99; CarlZeiss, Gottingen, Germany). The origin of the AICAfrom the basilar artery and the relationship with theabducens nerve were investigated.RESULTSThe AICA was present in each of the 44 hemi-spheres. All of the AICAs originated from the basi-lar artery (BA), usually from its lower parts. It origi-nated as a single artery in 33 hemispheres (75%),duplicate (two arteries) in 11 hemispheres (22.7%),and triplicate (three arteries) in 1 hemisphere(2.3%). The AICAs bifurcated into two mainbranches as rostral and caudal trunks in singletrunks, which were present in 33 hemispheres. TheAICAs or their branches were in contact with theNeurovascular relationship between abducensnerve and anterior inferior cerebellar arteryA.F. Esmer1, T. Sen1, B. Bilecenoglu2, E. Tuccar1, A. Uz1, S.T. Karahan11Ankara University, Faculty of Medicine, Department of Anatomy, Ankara, Turkey2Ufuk University, Faculty of Medicine, Department of Anatomy, Ankara, Turkey[Received 1 September 2010; Accepted 13 October 2010]We aimed to study the neurovascular relationships between the anterior infe-rior cerebellar artery (AICA) and the abducens nerve to help determine thepathogenesis of abducens nerve palsy which can be caused by arterial com-pression. Twenty-two cadaveric brains (44 hemispheres) were investigated af-ter injected of coloured latex in to the arterial system. The anterior inferiorcerebellar artery originated as a single branch in 75%, duplicate in 22.7%, andtriplicate in 2.3% of the hemispheres. Abducens nerves were located betweenthe AICAs in all hemispheres when the AICA duplicated or triplicated. Addi-tionally, we noted that the AICA or its main branches pierced the abducensnerve in five hemispheres (11.4%). The anatomy of the AICA and its relation-ship with the abducens nerve is very important for diagnosis and treatment.(Folia Morphol 2010; 69, 4: 201–203)Key words: abducens nerve palsy, neuroanatomy, vascularcompression202Folia Morphol., 2010, Vol. 69, No. 4abducens nerve in all hemispheres. The AICAswhich originated as a single trunk from the basi-lar artery coursed at the dorsal aspect of the ab-ducens nerve in 24 hemispheres (72.7%) and ex-tended to the ventral aspect in 9 hemispheres(27.3%). The abducens nerve was located betweenthe AICAs in the hemispheres in which the AICAswere duplicated.The abducens nerve was penetrated by the up-per branch of the triplicated AICA (Fig. 1). We ob-served that the AICA or its main branches piercedthe abducens nerve in five hemispheres (11.4%), in-cluding the triplicated one.DISCUSSIONMartin et al. [8] observed single AICA 72%, du-plicated AICA 26%, and triplicated AICA 2% in allcases in their study. Marinkovic et al. [7] also foundsingle AICA 64.28% and duplicated AICA 35.71% inall the cases in their study, but they did not noteany triplicated AICA. Our results are similar to thoseof these researchers. In our series, triplicated AICAwas seen in 2.3% of cases. This was in contrast tothe findings of Yasargil [17] who noted 20% of theAICAs originated as triplicate.Arterial penetration of the abducens nerve hasbeen mentioned in literature [7, 14, 15]. WhileNathan et al. [12] and Yasargil [17] described it asa rare phenomenon, Marinkovic et al. [7] showedthat the AICA penetrated 25% of the abducensnerves. According to our results, penetration of theabducens nerve by AICA was neither a very rare sit-uation, as described by Nathan et al. [12] andYasargil [17], nor a common situation as mentionedin the study by Marinkovic et al. [7]. In our study,the AICA or its main branches contacted either thedorsal or ventral aspect of the abducens nerve in allhemispheres. We believe that these relationshipswith the AICA and abducens nerve may be a poten-tial cause of abducens nerve palsies. Abducens nervepalsies usually accompany other cranial nerve issuesand can be caused by various factors like ischaemia,haemorrhage, aneurysm, trauma, tumour, arterio-venous malformation, and postoperative complica-tion [1–3, 6, 9, 10, 13, 15]. Isolated abducens nervepalsy is a rare situation. This situation generally re-sults from arterial disorders, especially vascular com-pression, and in some cases the aetiology is unclear[3, 6, 10, 11, 13]. Most studies indicate isolatedabducens nerve palsies as a result of basilar or ver-Figure 1. Anterior aspect of the brainstem with the vertebrobasilar system. Duplicated anterior inferior cerebellar artery (AICA) at the leftand triplicated AICA at the right. Right abducens nerve pinched by AICA; black arrowheads — triplicate originated AICA; white arrow-heads — duplicate originated AICA; B — basilar artery; III — oculomotor nerve; IV — trochlear nerve; V — trigeminal nerve; VI —abducens nerve, black arrows: different divisions of the abducens nerve separated by AICA.203A.F. Esmer et al., Anterior inferior cerebellar artery and abducens nervetebral arteries disorders [3–5, 11, 16, 18]. We thinkthat the close relationship with the AICA and ab-ducens nerve must be evaluated during diagnosisand treatment of isolated abducens nerve palsies,and this must be kept in mind especially in caseswith penetration of the abducens nerve by the AICAor its branches when the aetiology is unclear.CONCLUSIONSIsolated abducens nerve palsy is a rare conditionwhich is a potential result of vascular disorders inthe root exit zone. Different treatment options areavailable for cranial nerve pathologies, but if thesepathologies are related to vascular disorders, phar-macological treatment may be ineffective. In theseconditions, surgical procedures such as microvascu-lar decompression could be a good option. AICA orits main branches are closely related with the ab-ducens nerve and these could be a potential causeof abducens nerve pathologies such as palsies orpareses. Due to this, the anatomy of the AICA andits relationship with the abducens nerve is very im-portant for diagnosis and treatment. We believe thatthis anatomical study will be helpful to comprehendthe clinico-anatomical correlations.REFERENCES1. Berlit P (1991) Isolated and combined pareses of cra-nial nerves III, IV and VI. A retrospective study of412 patients. J Neurol Sci, 103: 10–15.2. Choudhari KA (2005) Isolated abducent nerve palsy af-ter microvascular decompression for trigeminal neu-ralgia: case report. Neurosurgery, 57: E13–E17.3. De Ridder D, Menovsky T (2007) Neurovascular com-pression of the abducent nerve causing abducent pal-sy treated by microvascular decompression. Case re-port. J Neurosurg, 107: 1231–1234.4. Goldenberg-Cohen N, Miller NR (2004) Noninvasiveneuroimaging of basilar artery dolichoectasia in a pa-tient with an isolated abducens nerve paresis. Am JOphthalmol, 137: 365–367.5. Lin JY, Lin SY, Wu JI, Wang IH (2006) Optic neuropathyand sixth cranial nerve palsy caused by compressionfrom a dolichoectatic basilar artery. J Neuroophthal-mol, 26: 190–1901.6. Mamata Y, Muro I, Matsumae M, Komiya T, Toyama H,Tsugane R, Sato O (1998) Magnetic resonance cister-nography for visualization of intracisternal fine struc-tures. J Neurosurg, 88: 670–678.7. Marinković SV, Gibo H, Stimec B (1994) The neurovas-cular relationships and the blood supply of the abdu-cent nerve: surgical anatomy of its cisternal segment.Neurosurgery, 34: 1017–1026.8. Martin RG, Grant JL, Peace DA, Theiss C, Rhoton AL Jr(1980) Microsurgical relationships of the anterior infe-rior cerebellar artery and the facial-vestibulocochlearnerve complex. Neurosurgery, 6: 483–507.9. Miller NR (1996) The ocular motor nerves. Curr OpinNeurol, 9: 21–25.10. Moster ML, Savino PJ, Sergott RC, Bosley TM, Schatz NJ(1984) Isolated sixth-nerve palsies in younger adults.Arch Ophthalmol, 102: 1328–1330.11. Narai H, Manabe Y, Deguchi K, Iwatsuki K, Sakai K, Abe K(2000) Isolated abducens nerve palsy caused by vascu-lar compression. Neurology, 55: 453–454.12. Nathan H, Ouaknine G, Kosary IZ (1974) The abducensnerve. Anatomical variations in its course. J Neurosurg,41: 561–566.13. Ohtsuka K, Sone A, Igarashi Y, Akiba H, Sakata M (1996)Vascular compressive abducens nerve palsy disclosedby magnetic resonance imaging. Am J Ophthalmol, 122:416–419.14. Rhoton AL (1980) Anatomy of saccular aneurysms. SurgNeurol, 14: 59–66.15. Rush JA, Younge BR (1981) Paralysis of cranial nervesIII, IV, and VI. Cause and prognosis in 1000 cases. ArchOphthalmol, 99: 76–79.16. Smoker WRK, Corbett JJ, Gentry LR, Keyes WD, Price MJ,McKusker S (1986) High resolution computed tomo-graphy of the basilar artery: 2. Vertebrobasilar doli-choectasia: clinical pathologic correlation and review.Am J Neuroradiol, 7: 61–72.17. Yasargil MG ed. (1987) Intracranial arteries. Microneuro-surgery. Vol. I. Thieme Medical Publishers Inc: New York.18. Zhu Y, Thulborn K, Curnyn K, Goodwin J (2005) Sixthcranial nerve palsy caused by compression from a doli-choectatic vertebral artery. J Neuroophthalmol, 25:134–135.

Neurovascular relationship between abducens nerve and anterior inferior cerebellar artery

https://journals.viamedica.pl/folia_morphologica/article/download/15853/12491

Neurovascular relationship between abducens nerve and anterior inferior cerebellar artery

Abstract

Similar works

Full text

Available Versions

Via Medica Journals