tinnitus discuss the causes ,radiological evaluation and findings

8/22/2019 TINNITUS Discuss the Causes ,Radiological Evaluation and Findings

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Discuss the causes ,radiological

evaluation and findings in a 60yr.Old man presenting with

tinnitus.

Presentation by Dr. Omatiga A.Gabriel

Radiology Dept. OAUTHCILE-IFE


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outline

Introduction

Epidermiology

Types Causes

Radiological evaluation

Radiological findings


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introduction

DEFINED as the perception of sound in the

absence of external stimulus

Tinnere means ringing in Latin

The sound include ringing,clicking, buzzing

,whistling all in the absence of any external

stimuli


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epidermiology

40 million affected in the United States

10 million severely affected

Most common in 40-70 year-olds More common in men than women


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types

Pulsatile otherwise called vascular

Non-pulsatile or non vascular

or

Unilateral

Bilateral


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TYPES

OBJECTIVE ; SOUND PRODUCED BY PARA-

AUDITORY STRUCTURES THAT CAN BE HEARED

BY THE EXAMINER

SUBJECTIVE; IN WHICH CASE THE SOUND IS

ONLY HEARED BY THE PATIENT


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CAUSES

Causes of pulsatile tinnituswill include


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Pulsatile Tinnitus Neoplasms (typically vascular in nature)

Glomus tumors or paragangliomas

(chemodectoma,paragangliomas) Glomus tympanicum, glomus jugulare, glomus

jugulotympanicum


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Hemangioma

Facial nerve hemangioma, cavernous

hemangioma

Other less vascular neoplasms

Meningioma, adenoma


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Vascular lesions

Acquired arterial lesions

Atherosclerotic plaque (carotid or intracranial)

Vascular malformations (intracranial, dural;maybe sequel to trauma)

Aneurysm

Carotid artery dissection (spontaneous ortraumatic)


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congenital

Congenital arterial abnormalities

Aberrant internal carotid artery

Persistent stapedial artery


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Jugular bulb abnormality

high position,

diverticulum,

dehiscence , enlargement


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Miscellaneous vascular abnormalities

Fibromuscular dysplasia of carotid artery

Vascular compression of cochlear or auditory

nerve at root entry zone


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Miscellaneous causes

Valvular heart disease (aortic stenosis,

insufficiency)

Benign intracranial hypertension or

pseudotumor cerebri

Hyperdynamic state (eg, anemia, thyrotoxicosis)

Otosclerosis with anastomoses between

haversian

bone and endochondral layer


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Nonpulsatile Tinnitus

Palatal myoclonus

Spasm, fasciculations, or fibrillations of tensor

tympani or stapedius muscles Spontaneous otoacoustic emissions

Patulous eustachian tube


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Drugs that cause tinnitus

Antinflammatories

Antibiotics (aminoglycosides)

Antidepressants (heterocyclines)

Aspirin

Quinine

Loop diuretics

Chemotherapeutic agents (cisplatin,vincristine)


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RADILOGICAL EVALUATION

The approach to radiological evaluation is

teken from the point of the possible etiology

History and physical examination

audiometry are very important


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IMAGING MODALITIES

MAGNETIC RESONANCE IMAGING

MRA

FMRI

GADOLINIUM ENH.MRICOMPUTED TOMOGRAPHIC SCAN

CECT/NCECT/CTA

COVENTIONAL ANGIOGRAPHY

PET SCANS

VASCULAR ULTRASONOGRAPHY


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Pulsatile tinnitus raise the consideration of a

vascular cause, malfomations and other

congenital and acquired causes as enumerate

earlier, Contrast enhanced CT of temporalbones, skull base, brain, calvaria as first-line

study


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CT SCAN

The imaging approach is to start with contrast

enhanced CT SCAN .This shows vascular

anormalies and vascular tumours. It also has

the advantage of demonstrating bony erosionwithin and around the ear cavity,

rcommended for retrotympanic masses

The draw back however is that small lesions

may be missed


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MRI

In otherwise normal otoscopy and an unremarkable CTscan MRI/MRA with its better soft tissue resolution isthe next imaging modality being able to show verysmall lesion and also its non-invasiveness in showing

vascular lesions The draw backs include

non-availability

cost

and the niose which mask the source of tinnitus indynamic brain activity studies

And also its poor delineation of bonyaffectation/invovement


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ANGIOGRAPHY

Conventional angiography was the initial method

of choice for the evaluation of vascular tinnitus ,

but it is has been taken over by the newer

modalities which are less invasive with attendantreduction in the complication.

It demonstrates malformatios ,stenoses, ectopic

vessel It also has the advantage of being used for

interventional procedures


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Glomus tympanicum bone algorithm CT scan

best shows extent of mass

May not be able to see enhancement of small

tumor

Tumor enhances on T1-weighted images with

gadolinium or on T2-weighted images


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IMAGING FINDINGS

Glomus jugulare

Erosion of osseous jugular fossa

Enhances with contrast, may not be able to

differentiate jugular vein and tumor

Enhances with T1-weighted MRI with gadolinium

and on T2-weighted images

Characteristic salt and pepper appearance onMRI


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GLOMUS TYMPANICUM

Glomus tympanicum tumors arise fromGlomus tympanicum tumors range at

presentation from millimeters in diameter

to a mass that fills the middle ear. Thetumor is usually visible otoscopically as a

reddish, pulsatile mass behind an intact

tympanic membrane. Small tumors arebest seen on a thin-section (1-mm) bone

algorithm CT scan


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Glomus tympanicum

The diagnosis is made on bone algorithm scan

Its usually difficult to appreciate enhancement of

small tumors confined to the middle ear on CT

CT shows the anatomic extent clearer than MRI b

MRI shows better tumor enhancment.and the

tumor usually shows as a small entensely

enhancing mass on gadolinium administration

Most tumor arise on the cochlear primontory


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Bone windqw cranial ct and gadolinium enhnced Ti w

MRI showing a mass over the the promontory of the

cochlear and a highly enhancing oval shaped lesionover the signal void promontory

Glomus tympanicum tumors


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Glomus jugulare

Usually arise from the paraganglia of the adventitia ofjugular bulb where the sigmoid sinus become internaljugular vein

Glomus jugulare Erosion of osseous jugular fossa lateral and anterior wall

Occasionally enlarged inferior tympanic canaliculus may be seen

Enhance with contrast, may not be able to differentiate jugularvein and tumor because of their intense enhancement withcontrast on ct

Enhance with T1-weighted MRI with gadolinium and on T2-

weighted images Characteristic salt and pepper appearance on T1W

ENHANCED MRI


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Both glomus jugulare tumor and

jugulotympanicum tumors may grow into the

neck within the lumen of internal jugular vein

to obstruct the vein partially (which maycause slow flow ) or completely


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Glomus jugulare tumor

T1weighted MRI with gadoliniumshowing a large bell shaped enhancing

lesion with areas of flow voids giving

the salt and pepper appearance


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SALT AND PEPPER APPEARANCEOFGLOMUS JUGULARE TUMOR ON

T1W GADOLINIUM ENHANCED MRI


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AV-MALFORMATION

These are congenital lesion

Involving abnormal communication between thevenous and arterial systems which mayinvolveany of the following

Occipital artery and transverse sinus, internalcarotid and vertebral arteries, middle meningealand greater superficial petrosal arteries

Mandible

Brain parenchyma

Dura


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AVMs

Dural AVM or AVF is also the mostfrequent

cause of objective pulsatile tinnitusin the

patient with a normal otoscopic examination

Symptoms usually include Pulsatile tinnitus

Headache

Papilledema

Discoloration of skin or mucosa


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AVMs

The transverse,sigmoid, and cavernoussinuses are the most frequent locations ofdural AVMs

transverse and sigmoid sinus involvementcauses pulsatile tinnitus

Branches of the external carotidartery supplythese dural AVMs; venousdrainage may beextracranial, intracranial,or both all thesefeatures are demonstrated on angiography


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The Other contrast enhanced CT diagnoses

Aberrant carotid artery

Dehiscent carotid artery

Dehiscent jugular bulb

Persistent stapedial artery


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a

T1W MRI of the skull and lateral

view of common carotid angio

showing cluster of small vessels(arrows) in the left occipital

subcutaneous soft tissues.

andshows a dural AVM.

Dural AV -malformation


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Dehiscent jugular vein

Contrast enhanced cranial CT conedview of the internal acoustic meaTus

shows a dehiscent jugular vein (white

arrow) bulging into the middle ear

through a discontinuity

(black arrows) in the cortex of the

jugular tus


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Dissection of internal carotid artery

Difficult to diagnose on CT

Transverse T1-weighted MR images showshyperintense oval shaped mass in the false lumensurrounding the narrowed true lumen of the artery

MR angiography and CT angiography bothdemonstrate the narrowed true lumen of the artery.

Conventional angiography is not necessaryto make the diagnosis.


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Dissection of ICA

Transverse T1-weightedMR images shows

hyperintense oval shaped

mass in the false lumen

surrounding the narrowed

true lumen of the artery


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ATHEROSCLOROTIC VASCULAR

DISEASE

BOTH atherosclerotic vascular disease and

tinnitus increase in prevalence with age

Stenosis is usually seen on conventional angio

The bifurcation of the carotid is the usual site

Fibromuscular dysplasia may also be seen as

segmental narrowing with pre stenotic

dilatation giving a beaded appeaerance


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Radiological evaluation

Carotid angiogram showing stenois of

A segment of the carotid artery

causing tinnitus


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ACOUSTIC NEUROMAS

usually in the cerebellopontine angle,

unilateral

Acoustic Neuroma

Unilateral tinnitus, asymmetric sensorineuralhearing loss or speech descrimination scores

T1-weighted MRI with gadolinium enhancementof CP angle is study of choice

Thin section T2-weighted MRI of temporal bonesand IACs may be acceptable screening test


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Mri of acoustic neuroma

tinnitus discuss the causes ,radiological evaluation and findings

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