|Ahead of print publication
Bilateral optic neuropathy due to dolichoectasia of internal carotid Arteries
Sahil Gupta, Shalesh Rohatgi, Furqan Khan, Satish Nirhale, Prajwal Rao, Pravin Naphade, Dhaval Dave, Prashant Dubey, Advait Gitay
Department of Neurology, Dr. D. Y. Patil Medical College, Hospital and Research Centre, Dr. D. Y. Patil Vidyapeeth, Pune, Maharashtra, India
|Date of Submission||03-Aug-2021|
|Date of Decision||07-Aug-2021|
|Date of Acceptance||24-Oct-2021|
Department of Neurology, Dr. D. Y. Patil Medical College, Hospital and Research Centre, Dr. D. Y. Patil Vidyapeeth, Pimpri, Pune - 411 018, Maharashtra
Source of Support: None, Conflict of Interest: None
Intracranial arterial dolichoectasia is a disorder of cerebral vasculature characterized by abnormal elongation, tortuosity, and dilatation of the cerebral arteries. The posterior circulation is more frequently affected than the anterior circulation. Dolichoectasia of internal carotid arteries (ICAs) presenting with binasal hemianopia is rare. We report a case report of a 48-year-old male who presented with a history of binasal hemianopia. Magnetic resonance (MR) imaging of the brain with MR angiography showed bilateral dolichoectasia of ICAs compressing bilateral optic nerve and optic chiasm. Diagnosis of bilateral optic neuropathy due to dolichoectasia of ICAs was made after thorough investigation and ruling out of other possible etiologies of bilateral optic neuropathy. Dolichoectasia is a rare cause of bilateral optic neuropathy and should be suspected in patients who present with gradually progressive visual field loss with onset in the nasal field.
Keywords: Dolichoectasia, internal carotid artery, optic neuropathy
|How to cite this URL:|
Gupta S, Rohatgi S, Khan F, Nirhale S, Rao P, Naphade P, Dave D, Dubey P, Gitay A. Bilateral optic neuropathy due to dolichoectasia of internal carotid Arteries. Med J DY Patil Vidyapeeth [Epub ahead of print] [cited 2022 Dec 7]. Available from: https://www.mjdrdypv.org/preprintarticle.asp?id=339389
| Introduction|| |
The term dolichoectasia springs from Greek words, “dolichos” meaning elongation, and “ectasia” meaning dilatation. Dolichoectasia of the intracerebral vessels is a rare disorder affecting the large arteries of the brain. The vertebrobasilar system is more often affected than the internal carotid arteries (ICAs). Neurological deficits may occur secondary to local compression, embolization, or thrombotic occlusion. Neuro-ophthalmic manifestations are most often caused by compression of nearby structures and include cranial nerve palsies, optic neuropathy, chiasmal syndromes, hemifacial spasms, trigeminal neuralgia, and ocular tilt. We report a case of bilateral optic neuropathy caused by direct compression of bilateral optic nerves and optic chiasm by dolichoectasia of bilateral intracranial ICAs.
| Case Report|| |
A 48-year-old male presented with complaints of diminution of vision in his left eye for 1 year, which was insidious in onset, and initially involved the nasal side of the left visual field and gradually progressed to involve all quadrants of the visual field. After 6 months from the onset of symptoms, he developed diminution of vision in his right eye, which involved the nasal side of the visual field. There was no history of painful eye movements, headache, orbital pain, or double vision. There was no history of any motor weakness or sensory complaints. His bladder and bowel function were normal. There was no history of any preceding viral illness and no symptoms suggesting autoimmune etiology. There was no history of weight loss, drug intake, alcohol, toxin, or radiation exposure. The patient was a known hypertensive for 4 years, nondiabetic, and had no other symptoms apart from diminished vision.
On ocular examination, the confrontation test showed nasal visual field defect in the right eye and constricted vision in all fields in the left eye. Only perception of light was present in the left eye. Eye movements as well as other cranial nerve examinations were normal. Fundus examination revealed pale optic discs in both the eyes with clear optic disc margins [Figure 1]. Motor and sensory examinations were normal. There were no neurocutaneous markers or skeletal and spinal deformities. Examination of the gastrointestinal, cardiovascular, and respiratory systems was normal.
Perimetry (Humphrey visual field test) done 6 months after the onset of symptoms revealed nasal hemianopia in the left eye and normal visual field in the right eye [Figure 2]a. Repeat perimetry done at 1 year revealed nasal hemianopia in the right eye and complete visual field loss in the left eye [Figure 2]b. Optical coherence tomography [Figure 3] showed retinal nerve fiber layer thinning in both the eyes suggestive of optic atrophy which was more in the left eye.
|Figure 2: (a) Perimetry done at 6 months from the onset, showing nasal hemianopia in the left eye, and a normal visual field in the right eye. (b) Repeat perimetry at 1 year, showing nasal hemianopia in the right eye, and complete visual field loss|
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|Figure 3: Optical coherence tomography showing retinal nerve fiber layer thinning in both the eyes suggestive of bilateral optic atrophy|
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Visual-evoked potentials study showed absent potential in the left eye and prolonged latency with decreased P100 amplitude in the right eye. All laboratory parameters were within the normal range. Vasculitic profile (ANA by IFA, p-ANCA, c-ANCA, RA factor, erythrocyte sedimentation rate, and C-reactive protein), viral serology (human immunodeficiency virus, hepatitis B, and hepatitis C), anti-aquaporin-4 antibodies, anti-MOG antibodies, and cerebrospinal fluid oligoclonal bands were negative.
Magnetic resonance imaging (MRI) of the brain and orbit (plain and contrast) and MR angiogram were done which revealed ectatic bilateral ICAs compressing the bilateral optic nerves along with optic chiasm [illustrated in [Figure 4] and [Figure 5]. Contrast-enhanced computed tomography of the abdomen did not reveal abdominal aneurysms or polycystic kidneys. On the basis of the above clinical and radiological presentations, diagnosis of bilateral optic neuropathy secondary to dolichoectatic compression of optic nerves by ectatic bilateral ICAs was made. Our patient was given the option of surgical decompression in view of the preserved right temporal visual field, but he denied surgical intervention and was lost to follow-up.
|Figure 4: Gadolinium-enhanced T1-weighted magnetic resonance imaging brain showing bilateral dolichoectatic internal carotid arteries (red arrow) indenting cisternal segment of optic nerve bilaterally (blue arrows) and optic chiasma bilaterally (yellow arrow)|
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|Figure 5: Magnetic resonance angiography showing bilateral dolichoectatic internal carotid arteries (red arrows) and dolichoectatic basilar artery (blue arrow)|
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| Discussion|| |
Intracranial arterial dolichoectasia is an unusual arteriopathy defined by the presence of at least one ectatic or enlarged artery in the cerebral vasculature. In dolichoectatic vessels, the underlying pathogenesis is the involvement of tunica media of the arterial wall due to disruption of the internal elastic lamina, atrophy of the muscle layer, and hyalinization of connective tissue leading to abnormal dilation of the affected blood vessel. Both the anterior and posterior cerebral circulations can be affected. The basilar artery is the most commonly affected vessel that can present with posterior circulation stroke, symptoms due to cranial nerves involvement such as a hemifacial spasm, trigeminal neuralgia, and brainstem compression, arterial rupture and bleeding, and obstructive hydrocephalus.
Anterior circulation dolichoectasia is a rare presentation and can present with a vast range of symptoms such as ischemic changes, hemorrhage, and compressive effects such as cranial nerve palsies, optic neuropathy, chiasmal syndromes, nystagmus, and ocular tilt.
In a series by Purvin et al., 10 patients with intracranial dolichoectasia were identified. The carotid artery involvement was seen in seven patients and the basilar artery in three. Four patients presented with unilateral optic neuropathy, one with bilateral optic neuropathy, three with chiasmal syndrome, and two with optic tract syndrome. Patterns of visual loss were variable depending on the site of compression. The most common pattern seen in patients with optic neuropathy was nasal field loss. Seven patients had a dolichoectatic ICA, causing compression of one optic nerve in four, of both optic nerves in one, and of the chiasm in two. Three patients had a dolichoectatic basilar artery, compressing optic chiasm in one, and optic tract in two cases. One patient experienced a progressive visual loss that prompted a surgical intervention. Other patients were followed up from 7 months to 10 years. During the follow-up, six patients remained stable and three showed progression. Of the three, the change was small in one and mild-to-moderate in one. Improvement of vision was seen in one patient who had surgical intervention.
For most patients, conservative management is appropriate. In patients who present with rapidly progressive visual loss, surgical intervention is effective in reversing the visual loss and preventing further deterioration.
Our patient had sequential involvement of bilateral optic nerve which clinically manifested as binasal hemianopia due to the compression of bilateral optic nerves and optic chiasma by the dolichoectatic bilateral ICAs, it is a rare manifestation of intracranial anterior circulation dolichoectasia. At the time of presentation to our hospital, the patient had no vision in the left eye and had a nasal hemifield defect in the right eye. Patients with such presentation if detected early, timely intervened can yield reversal in vision loss and prevent permanent disability.
| Conclusion|| |
ICAs dolichoectasia causing bilateral optic neuropathy is a rare presentation. MRI of the brain with angiography is the diagnostic modality of choice. A heightened awareness of this disorder is essential since early detection and timely intervention can cause a reversal in vision loss and prevent permanent disability.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient (s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
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Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]