* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Tinnitus: What You Need to Know
Survey
Document related concepts
Cognitive neuroscience wikipedia , lookup
Blood–brain barrier wikipedia , lookup
Neurophilosophy wikipedia , lookup
Limbic system wikipedia , lookup
Human brain wikipedia , lookup
Metastability in the brain wikipedia , lookup
Time perception wikipedia , lookup
Neuroplasticity wikipedia , lookup
Syncope (medicine) wikipedia , lookup
Persistent vegetative state wikipedia , lookup
Intracranial pressure wikipedia , lookup
Cognitive neuroscience of music wikipedia , lookup
Functional magnetic resonance imaging wikipedia , lookup
Transcript
Tinnitus:WhatYouNeedtoKnow Author Contact: Jeremy Nguyen, MD. Associate Professor of Radiology at Tulane University Medical Center . Email: [email protected]. EnriquePalaciosMD,FACR;JeremyNguyenMD;LorenaGarzaMD; SarahCasIlloMD;JuanS.GomezMD;MandyWeidenhaKMD SCHOOL OF MEDICINE IntroducIon Department of Radiology, Tulane University School of Medicine, New Orleans, LA Jugular Fossa Dehiscence Pulsatile Tinnitus due to Vascular Anomalies Tinnitus is the perception of sound in proximity to the head, in the absence of a corresponding external acoustic stimulus. This entity is a disorder with a prevalence of 10% -15% and is more common in men. Tinnitus sounds like ringing, hissing, static, pulsing, buzzing, clicking or whistling. The majority of cases are related to auditory issues however, it is not the auditory issue itself, but the generated BRAIN REACTIONS. Most of the auditory pathology is associated with the cilia, which are responsible for high frequency transmission. The brain will try to compensate with a mechanism known as “Homeostatic plasticity”, which suggests that brain reactions are the culprit for tinnitus rather than the inner ear. A Persistent Stapedial Artery A C C B B Figure 12. Persistent Stapedial Artery. CT. (A) -Axial showing absent right-sided foramen Spinosum (yellow circle) and normal left foramen Spinosum (yellow arrow). (B) -Coronal demonstrating small tympanic mass adjacent to the tympanic portion of the right facial nerve canal corresponding to the Persistent Stapedial Artery (red arrow). Angiogram (C) showing intratympanic aberrant vessel through the Stapes giving rise to the middle Meningeal artery. (blue arrow). D Figure 3. Angiograms. A revealing atherosclerotic stenosis of the Internal Carotid Artery. B demonstrating Fibromuscular dysplasia of the vertebral artery with beaded appearance. C showing Internal Carotid Artery aneurysms. ( arrows). Figure 7. Jugular Fossa Dehiscence. CT. (A) -Coronal; MR post contrast. (B) and (C) -Axial and (D) MR Venogram revealing an intratympanic mass corresponding to a Jugular bulb within the Jugular Fossa (arrows). tumor among others.4 protrude into the middle ear cavity.7,8 Ø The persistent stapedial artery is an uncommon congenital vascular anomaly that may present as a pulsatile middle ear mass or that may appear as an Ø Pulsatile tinnitus may result from non-laminar blood flow caused by increased Ø Dehiscent jugular bulbs results from the absence of the sigmoid plate that incidental finding. This entity is usually associated normally lies between the middle ear and a high riding jugular bulb. A high with an aberrant ICA. The presence of a persistent blood flow or a reduced vascular cross sectional area. This entity may occur in jugular bulb can erode inner ear structures creating a jugular bulb related stapedial artery may be recognized with plain conjunction with various diseases, such as arteriovenous malformation, high inner ear dehiscence This dehiscent, allows the wall of the jugular bulb to jugular bulb, dural arterio-venous fistula, intracranial hypertension, skull base radiography, CT, or angiography. 6,12 Arteriovenous Fistula Basilar Artery Dolichoectasia OBJECTIVETINNITUS • From identifiable intracranial causes and within the base of the skull. A Figure 4. Spontaneous Arteriovenous Fistula. Digital Angiographic exam. (A), (B ) and (C). Lateral views. MR Venogram. (D), revealing abnormal arteriovenous communication at the level of the Dural sigmoid sinuses. (arrows). A C B Figure 13. Idiopathic Intracranial Hypertension. MR. (A) –Axial and (B) -Sagittal of the orbits demonstrating papilledema manifested by dilation of the sheath of the optic nerve (yellow arrow) and protrusion of the head of the optic nerve (red arrow). MR Venogram (C) revealing stenosis of the bilateral transverse sinuses at the junction of the sigmoid sinuses. (blue arrows). Figure 8. Basilar Artery Dolichoectasia. CT (A) -Axial (B) -Coronal revealing a markedly enlarged internal acoustic canal (red arrows). (C). Antero posterior Angiogram revealing an ectatic basilar artery within the left internal acoustic canal (yellow arrow). Ø Acquired Arteriovenous fistula (AVF) is commonly associated with hearing loss and tinnitus. Dural AVF is reported as the most common cause of pulsatile tinnitus and may result from an abnormal connection between the meningeal veins and meningeal arteries. Common locations of Dural AVF include lateral, sigmoid and cavernous sinuses.4 D Ø Dolichoectasia is a marked elongation, dilatation and tortuosity of a blood vessel. The incidence of intracranial dolichoectasia ranges from 0.06% to 5.8%, with vertebrobasilar involvement being the most common segment affected.9 D Ø Idiopathic Intracranial Hypertension is a disorder characterized by symptoms of elevated intracranial pressure such as papilledema, headaches, and vision loss. Usually has cerebrospinal fluid composition within reference range and no other cause of intracranial hypertension showed by neuroimaging.13. Frequent in obese young females using oral contraceptives pills. D C Osteodystrophies Carotid Aneurysm • Patients with tinnitus exhibit increased connectivity between the extraauditory regions including the basal ganglia, brainstem, nucleus accumbens, cerebellum, parahippocampus, right prefrontal and parietal cortex. • These areas also exhibit increased connectivity: primary auditory cortex, left prefrontal region, bilateral occipital lobes and left fusiform gyrus. • There is variation amongst cortical and subcortical connectivity in patients with tinnitus, hence why other areas get affected including attention, memory and emotions. C B A Resting-state Functional Magnetic Resonance Imaging (fMRI) of the Auditory Network Connectivity in Tinnitus Patients 2. Bolus-tracking measures cerebral blood volume, making use of external contrast agents (Belliveau et al. 1991). 3. Spin-tagging assesses cerebral blood flow, using arterial blood for intrinsic contrast (Detre et al. 1992). Idiopathic Intracranial Hypertension B -Definition: § fMRI study of the brain without explicit task performed by the patient. § Measuring the low frequency spontaneous fluctuation in the BOLD signal. -Multiple resting state networks (RSN) have been patterned: § Networks contain areas of functional connectivity. *Spatially-distinct brain regions that are simultaneously active. § Thought to reflect functional system supporting core perceptual and cognitive process. Thulborn 2006). v OBJETIVE TINNITUS: if it is perceived from an identifiable cause within the cranial vault. v SUBJECTIVE TINNITUS: when it is perceived without an internal or external source. Resting State (RS) fMRI Functional Magnetic Resonance Imaging (fMRI) -Functional magnetic resonance imaging (fMRI) is a noninvasive imaging technique to measure and localize specific functions of the human brain. -Functional areas: • Regions of the human brain that govern motor, sensory, language or memory functions. -Brain function is assessed indirectly by detection of local hemodynamic changes in capillaries and draining veins. -fMRI measurements can be accomplished with different techniques: 1. Blood oxygenation level dependent (BOLD) fMRI is the most frequently used in human brain (Thulborn et al. 1996; Thulborn 1998; B B A ClassificaIon Dr. Juan Gomez is a visiting student from Colombia S.A.. Dr. Mandy Weidenhaft, Dr. Enrique Palacios and Dr. Jeremy B. Nguyen are faculty members at the Department of Radiology at Tulane University Medical Center. Dr. Lorena Garaza is a Second year medical student at Tulane University School of medicine in New Orleans, LA. Special thanks to Donald Olivares, Digital Imaging Specialist, for assistance with poster design and printing. Blood Oxygen Level Dependent -fMRI -The BOLD-technique mainly utilizes the different magnetic properties of oxygenated (oxyHb) and deoxygenated (deoxy-Hb) hemoglobin to generate the image. § Deoxy-Hb: Paramagnetic substance with large magnetic susceptibility effect, producing local field inhomogeneities resulting in signal decrease. § Oxy-Hb: Diamagnetic substance with small magnetic susceptibility effect, does not interfere significantly with the external magnetic field. -Neuronal activity in functional area can be detected as a BOLD signal influenced by the following factors: • Metabolite byproduct • Cerebral blood flow (CBF) • Cerebral blood volume (CBV) • Cerebral metabolic rate of oxygen (CMRO) • Blood oxygenation (balance of oxy-Hb and deoxy-Hb) Auditory Resting-State Network Connectivity in Tinnitus: A Functional MRI Study. Multi Institutional Project. PLoS ONE | www.plosone.org 1 May 2012 Volume 7 | Issue 5 | e36222. Subjective Tinnitus and Neuroplasticity • Originally it was believed that tinnitus only had an auditory etiology, however there is now evidence that the limbic system has an effect over subjective tinnitus. • Based on Functional Imaging and Electrophysiology, tinnitus is now categorized as a “Problem within the Brain Pathways” with increased interaction between the auditory and limbic systems. Anna Seydell-Greenwald, Erika P. Raven, Amber M. Leaver, Ted K. Turesky and Josef P. Rauschecker. DWI, fMRI of Auditory and Auditory-Limbic Connectivity in Tinnitus: Preliminary Evidence and Methodological Challenges; Volume 20. 2014. Resting State for Subjective Tinnitus C Default mode – blue Limbic - green Acoustic - red Visual – orange Attention and task - purple Vascular Loop Compression B A Paragangliomas A Ø Paragangliomas are neuroendocrine tumors arising from extraadrenal autonomic paraganglia derived from the embryonic neural crest and usually secret catecholamines.3 q Glomus Tympanicum A neoplasm arising from the paraganglia situated in the vicinity of the medial promontory wall of the middle ear.3 A B Otosclerosis Figure 5. Carotid Aneurysm. CT. (A) -Axial and (B) -Coronal demonstrating bone defect corresponding to an aneurysm of the proximal intrapetrosal portion of the Internal Carotid artery (red arrows). (C). Digital Angiogram ( yellow arrow). Ø Aneurysms are segmental dilations of a blood vessel. Based on anatomical classification, aneurysms are categorized as true or false (pseudo) aneurysms. True aneurysms involve all layers of the arterial wall (intima, media and adventicia). In pseudoaneurysms, the wall of the blood vessel is ruptured and blood leaks into surrounding tissues. Common risk factor reported for a true aneurysm is atherosclerosis and for a false aneurysm is trauma.5 . C 10 Figure 9. Otosclerosis. CT. (A) and (B) -Axial demonstrating an otosclerotic focus at the right oval window / fissula ante fenestram (arrows). CT. (C) -Axial showing postsurgical changes with stapes prosthesis in place at the oval window. C Superior Semicircular Canal Dehiscence C D Figure 14. Vascular Loop Compression. MR. (A) and (B) –Axial, (C) Coronal; MR Angiogram -Coronal showing vascular loop of the distal left vertebral artery at the left cerebellopontine angle compressing the left Facial nerve (arrows). Figure 15. BOLD imaging of primary auditory cortex (red arrow) adjacent to a cavernoma (yellow arrows). C Figure 1. Glomus Tympanicum. CT. (A) -Axial, (B) -Coronal; MR post contrast. (C) -Coronal revealing an enhanced soft tissue mass in the hypotympanum of the left middle ear (arrows). C q Glomus Jugulare A A A Figure 2. Glomus Jugulare. MR post contrast. (A) -Axial, B. -Coronal demonstrating an inhomogeneous enhancing soft tissue mass in the left jugular fossa (red arrows). CT. (C) -Axial revealing an enlarged jugular fossa with irregular erosions (yellow arrow) . C B C Figure 6. Aberrant / Ectopic Internal Carotid Artery (ICA). CT. (A ) and (B) -Axial; Angiographic examination (C) revealing developmental dehiscence of the carotid canal with an ectopic ICA within the tympanic cavity (arrows). B Ø An aberrant ICA is a variant of the carotid artery and represents a collateral pathway resulting from involution of the normal cervical portion (first embryonic segment) of ICA. Characteristic angiographic findings of aberrant ICA include lateral extension of the ICA well beyond the vestibular line of Lapayowker. CT is considered one of the most reliable ways to diagnose an aberrant ICA.6 B Ø In superior semicircular canal dehiscence syndrome, the middle fossa and superior semicircular canal communicate abnormally resulting in deficient vestibular function. Symptoms may include conductive hearing loss, vertigo and tinnitus.11 Figure 10. Superior Semicircular Canal Dehiscence. CT. (A) -Coronal and 3D reconstruction (B). Demonstrates dehiscence of the superior semicircular canal (red arrows). CT. (C) and (D); 3D reconstruction (E). Revealed normal examination within the superior semicircular canal (yellow arrow). • B • • Tinnitus without an identifiable intracranial or external source. References 1. 2. 3. 4. Lanting CP, de Kleine E, Langers DRM, van Dijk P (2014) Unilateral Tinnitus: Changes in Connectivity and Response Lateralization Measured with fMRI. PLoS ONE 9(10): e110704. doi:10.1371/ journal.pone.0110704 http://127.0.0.1:8081/plosone/article? id=info:doi/10.1371/journal.pone.0110704 BOLD-fMRI study of auditory cortex in patients with tinnitus MAO Chun-li, CHEN Xian-ming, CHEN Zi-qian, YE Youqiang2, LUO Ping. Department of Otorhinolaryngology Head and Neck Surgery, Fuzhou General Hospital of People’s, Liberation Army, Fuzhou 350025, China Journal of Otology 2010 Vol. 5 No. 1 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. C D E Schmidt et al., Burton et al., 2002. Maudoux et al., 2012. Kim et al., 2012 Many of the supposed anatomic changes associated with tinnitus are frequently encountered in asymptomatic patients. Correlation between imaging findings and the clinical picture is usually in discordance. Resting State fMRI offered some evidence of involvement of non-auditory functional areas. • Figure 16. BOLD imaging shows activated areas : - Medial geniculate ganglion (MGL). - Inferior colliculus (IC). - Some cranial nerves (CN). A Figure 18. • Strong relationship in patients with tinnitus (solid lines). • Less solid relationships (dotted lines). Conclusions Ø Vascular compression syndrome describe a clinical entity characterized by compression of one of the cranial nerves by a vessel and may result in vascular perfusion reduction, focal demyelination and axonal hyperactivity.14,15 SUBJECTIVE TINNITUS B A neoplasm arising from the paraganglia situated in the vicinity of the jugular bulb. May involve Cranial Nerves: IX, X, XI.3 Ø P r o g r e s s i v e h e a r i n g l o s s characterized by abnormal bone remodeling in the otic capsule and multifocal areas of sclerosis within the endochondral temporal bone. Symptoms may include hypoacusis, conductive hearing loss and tinnitus. A Aberrant - Ectopic Carotid Artery A B B 19. Figure 17. Extensive activation of non-auditory regions in a patient with bilateral tinnitus in response to stimuli to left ear. 20. Langguth B, Kreuzer PM, Kleinjung T, et al. Tinnitus: causes an clinical management. Lancet Neurol. 2013;12(9):920-30. Shargordosky J, Curhan GC, Farwell WR. Prevalence and characterirstics of tinnitus among US adults. Am J Med 2010;123:711. DeLellis RA, Lloyd RV, Heitz PU, Eng C. (Eds), Pathology and Genetics of Tumours of the Endocrine Organs. WHO Classification of Tumours, IARC press, Lyon, France 2004. Kim S, Byun J, Park M, Pulsatile Tinnitus with a Dural Arterio-Venous Fistula. Diagnosed by Computed Tomography-Angiography. Korean J Audiol 2013;17:133-137 Garg K, Rockman CB, Lee V, et al. Presentation and management of carotid artery aneurysms and pseudoaneurysms. J Vasc Surg 2012; 55:1618. Roll JD, Urban MA, Larson TC et-al. Bilateral aberrant internal carotid arteries with bilateral persistent stapedial arteries and bilateral duplicated internal carotid arteries. AJNR Am J Neuroradiol. 2003;24 (4): 762-5 Krishnan A, Mattox DE, Fountain AJ et-al. CT arteriography and venography in pulsatile tinnitus: preliminary results. Am J Neuroradiol. 2006;27 (8): 1635-8. Park J.J,Shen A,Loberg C, et al. The relationship between jugular bulb position and jugular bulb related inner ear dehiscence: a retrospective analysis. Am J Otolaryngol. 2015;36(3):347-51 Siddiqui A, Chew NS, Miszkiel K. Vertebrobasilar dolichoectasia: a rare cause of obstructive hydrocephalus: case report. Br J Radiol. 2008;81 (964): e123-6. Schrauwen I, Ealy M, Huentelman MJ, et al. A Genome-wide Analysis Identifies Genetic Variants in the RELN Gene Associated with Otosclerosis. Am. J. Hum. Genet. 2009;84 (3): 328–38. Yew A, Zarinkhou G, Spasic M, et al. Characteristics and Management of Superior Semicircular Canal Dehiscence. Neurol Surg B Skull Base. 2012; 73(6): 365–370. Silbergleit R, Quint DJ, Mehta BA, Patel SC, Metes JJ, Noujaim SE. The persistent stapedial artery. AJNR Am J Neuroradiol 2000;21:572–577 Biousse V, Bruce BB, Newman NJ. Update on the pathophysiology and management of idiopathic intracranial hypertension. J Neurol Neurosurg Psychiatry 2012; 83:488. Gultekin S, Celik H, Akpek S; et al. Vascular loops at the cerebellopontine angle: is there a correlation with tinnitus?. Am J Neuroradiol. 2008;29(9):1746-9. Janetta PJ. Neurovascular cross-compression in patients with hyperactive dysfunction of the eighth cranial nerve. Surg Forum 1975;26:467–69 Meikle MB. The interaction of central and peripheral mechanisms in tinnitus [M]. In: Vemon JA. Moller RA, Mechanism of tinnitus. Boston: Allyn and Bacon, 1995, 18-20. Mahlke C, Wallhausser-Franke E. Evidence for tinnitus-related plasticity in the auditory and limbic system, demonstrated by arg3.1 and c-fos immunocyto chemistry [J]. Hear Res, 2004195. (1-2): 17-34. Melcher JR, Sigalovsky IS, Guinan JJ Jr, et al. Lateralized tinnitus studied with functional magnetic resonance imaging: abnormal inferior colliculus activation. J Neurophysiol. 2000, 83(2): 1058-72. Arnold W, Bartenstein P, Oestreicher E, et al. Focal metabolic activation in the predominant left auditory cortex in patients suffering from tinnitus: a PET study with [18F] deoxyglucose. ORL J Otorhinolaryngol Relat Spec, 1996, 58(4): 15-19 Lockwood AH, Salvi RJ, Coad ML, et al. The functional neuroanatomy of tinnitus: evidence for limbic system links and neural plasticity[J]. Neurology, 1998: 50(1): 114-120.