British Journal of Radiology 74 (2001),669-670 © 2001 The British Institute of Radiology
Pulsatile tinnitus
P Corr, MBChB, FRCR
and
L Tsheole-Marishane, MBChB
Department of Radiology, Wentworth Hospital, University of Natal, Private Bag 7, Congella, 4013 Durban, South Africa
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Introduction
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A 49-year-old male presented with a 6-month history of persistent and pulsatile tinnitus in the left ear. Clinical and otoscopic examinations were normal. The patient was noted to be hypertensive. There was no hearing deficit on audiometry.
Contrast enhanced CT was performed (Figure 1
) followed by MRI. A T2 weighted image through the petrous bone is shown (Figure 2). What is the diagnosis?
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Answer
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Contrast enhanced CT through the petrous bones demonstrated an ectactic basilar artery. The brain stem appeared normal. T2 weighted MRI through the same region showed that the basilar artery was compressing the left seventh and eighth cranial nerves as they entered the left internal auditory meatus. A time-of-flight MR angiogram (Figure 3) confirmed dolichoectasia of the basilar artery. The patient was treated for hypertension and there has been a decrease in the tinnitus.
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Figure 3. Time-of-flight MR angiogram in the sagittal plane confirms dolichoectasia of the basilar artery.
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Pulsatile tinnitus is the perception of a rhythmical noise that is synchronous with the patient's heartbeat [1]. Although uncommon, it can be an extremely debilitating symptom. Pulsatile tinnitus is usually the result of blood flow turbulence in vessels close to the seventh and eighth cranial nerves or inner ear [1]. The causes are important to identify and include vascular tumours such as paragangliomas, especially glomus tympanicum and jugulare tumours, vascular anomalies, Paget's disease and an idiopathic group [2, 3]. Common vascular causes include an aberrant internal carotid artery, a high jugular vein bulb, a jugular diverticulum, dehiscent jugular bulb, dural arteriovenous fistula, internal carotid artery aneurysm and stenosis, as well as vertebrobasilar arterial dissection [2–4]. Dolichoectasia is defined as fusiform dilatation of an artery. It is distinct from aneurysmal dilatation and particularly affects the basilar artery [5]. Dolichoectasia is more common in elderly males, especially if they are hypertensive, and is often incidentally detected on CT [5]. However, MRI and MR angiography are the imaging investigations of choice in these patients. Dolichoectasia of the basilar artery can cause compression of the cochlear nerve at the internal auditory meatus, resulting in pulsatile tinnitus. More commonly, the anterior inferior cerebellar artery and vein cause compression ofthe cochlear nerve [3]. Microvascular decompression appears to reduce the tinnitus [3]. Dolichoectasia of the basilar artery is the cause of vertebrobasilar stroke from embolisation in 48% of patients, as well as the cause of facial and trigeminal neuralgia from seventh and fifth cranial nerve compression by the dilated artery in 39% of patients [5, 6].
Received for publication August 18, 2000.
Revision received September 28, 2000.
Accepted for publication October 5, 2000.
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References
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Sanchez TG, Santoro PP, Torres de Medeiros IR, Bittar RS, Bento RF. Magnetic resonance angiography in pulsatile tinitus: role of normal variations. Int J Tinnitus 1998;4:122–6.
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Zimmerman RA, Gibby WA, Carmody RF, editors. Neuroimaging. Clinical and physical principles. Berlin: Springer, 2000.
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Weissman JL, Hirsch BE. Imaging of tinnitus: a review. Radiology 2000;216:342–9.[Abstract/Free Full Text]
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Yokota M, Ito T, Hosoya T, Suzuki Y, Aoyagi M. Sudden onset tinnitus associated with arterial dissection of the vertebrobasilar system. Acta Otolaryngol Suppl 2000;542:29–33.[Medline]
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Levine RL, Turski PA, Grist TM. Basilar artery dolichoectasia. Review of the literature and six patients studied with magnetic resonance angiography. J Neuroimaging 1995;5:164–70.[Medline]
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Nuti D, Passero S, Di Girolamo S. Bilateral vestibular loss in vertebrobasilar dolichoectasia. J Vestib Res 1996;6:85–91.[Medline]
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