Isolated Abducens Nerve Palsy as Manifestation of Diffuse Intracranial Dolichoectasia

An 83-year-old man presented with a 1-year history of abducens palsy. Brain MRA revealed arterial dolichoectasia of most cerebral vessels, including the basilar, internal carotid, and middle cerebral arteries. Abducens nerve palsy as a sole manifestation of diffuse intracranial dolichoectasia is unusual but may occur in diffuse intracranial dolichoectasia.

Photo Essay Section Editors: Melissa W. Ko, MD Dean M. Cestari, MD Isolated Abducens Nerve Palsy as Manifestation of Diffuse Intracranial Dolichoectasia Jose I. Benavides, MD, Adalgisa Corona, MD, Johanna I. Aguilera, MD, Jose M. Paliza, MD FIG. 1. Diffuse intracranial arterial dolichoectasia seen in a 3D magnetic resonance angiography reconstruction. Abstract: An 83-year-old man presented with a 1-year history of abducens palsy. Brain MRA revealed arterial dolichoectasia of most cerebral vessels, including the basilar, internal carotid, and middle cerebral arteries. Abducens nerve palsy as a sole manifestation of diffuse intracranial dolichoectasia is unusual but may occur in diffuse intracranial dolichoectasia. Journal of Neuro-Ophthalmology 2020;40:107-109 doi: 10.1097/WNO.0000000000000783 © 2019 by North American Neuro-Ophthalmology Society Department of Neuro Ophthalmology (JIB, AC, JIA), Dr. Elias Santana Hospital, Santo Domingo, Dominican Republic; and Diagnostica SA (JMP), Santo Domingo, Dominican Republic. The authors report no conflicts of interest. Address correspondence to Jose I. Benavides, MD, Dr. Elias Santana Hospital, Department of Neuro Ophthalmology, 501 Prolongacion Duarte Street, Los Alcarrizos, Santo Domingo 10801, Dominican Republic; Email: [e-mail] Benavides et al: J Neuro-Ophthalmol 2020; 40: 107-109 A n 83-year-old man presented for evaluation with a 1year history of persistent esotropia without diplopia or progressive bilateral visual loss. During the evaluation, a 60prism-diopter esotropia and a complete abduction limitation of the right eye were identified. The pupils were symmetrical and reactive. Best-corrected visual acuities were 20/200 in both eyes. Forced duction testing was negative for restriction. No history of trauma was present. There was no history of hypertension or diabetes mellitus. Other findings included bilateral symmetrical opaque cataracts. Funduscopic examination was normal. No other neurologic signs were identified. Laboratory tests were negative for diabetes, dyslipidemia, or syphilis. Blood pressure was within a normal range. A brain magnetic resonance angiography (MRA) scan was ordered during the patient's first visit since he had presented a nonimproving abduction deficit. The patient 107 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. Photo Essay FIG. 2. T1 axial (A) and T1 coronal (B) MRI with contrast demonstrate the significant dilation of the basilar artery, middle cerebral arteries, and the cavernous carotid arteries. returned to the office to review his MRA 2 weeks later without clinical improvement. The MRA revealed significant dilation of the large intracranial arteries (Fig. 1). These vessels included basilar artery (10.4-mm diameter), supraclinoid carotids (9.5-mm diameter each), and middle cerebral arteries (10.2-mm diameter each). Bilateral aneurysmal dilation of the internal carotid arteries was noted in the cavernous sinuses (15.2-mm diameter each) (Fig. 2). These vessels also had notable tortuosity and elongation along their course; this indented the supratentorial and infratentorial parenchyma. Given the imaging findings, it is likely that the elongated basilar artery was compressing the right sixth nerve (Fig. 3). The patient was referred to neurosurgery for further evaluation; however, no additional contact could be made with him following this referral. Intracranial arterial dolichoectasia (IADE) is an unusual vascular condition of aneurysmal dilation, elongation, and tortuosity of a cerebral arterial segment. Vertebrobasilar dolichoectasia is the most frequent manifestation (1). However, involvement of multiple cerebral vessels ($2 main vessels) is a much less common form of presentation for IADE-often called diffuse intracranial dolichoectasia (2). Local weakening of the arterial tunica media in IADE is strongly related to aging, while elevated systolic blood pressure, diabetes mellitus, and dyslipidemia have lesser degrees of association (3). Diffuse intracranial dolichoectasia has been labeled as a systemic arterial vasculopathy, with aortic aneurysms more likely to be present simultaneously and associated with a higher aneurysm-related death and worse neurological function than is seen in patients with vertebrobasilar dolichoectasia (2). The clinical course of IADE can be asymptomatic or may present with symptoms related to ischemic or 108 hemorrhagic stroke, brainstem compression, cranial nerve compression, or hydrocephalus (4). Vascular compression of cranial nerves in these cases usually manifests as trigeminal neuralgia or hemifacial spasm (5); these were absent in our patient. Few cases of isolated abducens palsy as a manifestation of IADE have been reported (6). A unilateral abducens palsy as a sole manifestation of IADE is unusual but may occur in this disorder. FIG. 3. Proximity of the enlarged basilar artery to the pontomedullary junction in T1 sagittal MRI with contrast. Benavides et al: J Neuro-Ophthalmol 2020; 40: 107-109 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. Photo Essay STATEMENT OF AUTHORSHIP Category 1: a. conception and design: J. I. Benavides, A. Corona, J. I. Aguilera, and J. M. Paliza; b. acquisition of data: J. I. Benavides, A. Corona, J. I. Aguilera, and J. M. Paliza; c. analysis and interpretation of data: J. I. Benavides, A. Corona, J. I. Aguilera, and J. M. Paliza. Category 2: a. drafting the manuscript: J. I. Benavides, A. Corona, J. I. Aguilera, and J. M. Paliza; b. revising it for intellectual content: J. I. Benavides, A. Corona, J. I. Aguilera, and J. M. Paliza. Category 3: a. final approval of the completed manuscript: J. I. Benavides, A. Corona, J. I. Aguilera, and J. M. Paliza. REFERENCES 1. Del Brutto VJ, Ortiz JG, Biller J. Intracranial arterial dolichoectasia. Front Neurol. 2017;8:344. Benavides et al: J Neuro-Ophthalmol 2020; 40: 107-109 2. Brinjikji W, Nasr DM, Flemming KD, Rouchaud A, Cloft HJ, Lanzino G, Kallmes DF. Clinical and imaging characteristics of diffuse intracranial dolichoectasia. Am J Neuroradiology. 2017;38:915-922. 3. Zhai FF, Yan S, Li ML, Han F, Wang Q, Zhou LX, Ni J, Yao M, Zhang SY, Cui LY, Jin ZY, Zhu YC. Intracranial arterial dolichoectasia and stenosis risk factors and relation to cerebral small vessel disease. Stroke. 2018;49:1135-1140. 4. Wolters FJ, Rinkel GJ, Vergouwen MD. Clinical course and treatment of vertebrobasilar dolichoectasia: a systematic review of the literature. J Neurol Res. 2013;35:131-137. 5. Pico F, Labreuche J, Amarenco P. Pathophysiology, presentation, prognosis, and management of intracranial arterial dolichoectasia. Lancet Neurol. 2015;14:833-845. 6. Pham T, Wesolowski J, Trobe JD. Sixth cranial nerve palsy and ipsilateral trigeminal neuralgia caused by vertebrobasilar dolichoectasia. Am J Ophthalmol Case Rep. 2018;10:229- 232. 109 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited.