Kasr-Al-Aini School of Medicine CAIRO UNIVERSITY, EGYPT
Tinnitus? Dysacusis?? Mohamed Ibrahim ShabanaProf. of Audiological medicine Cairo University
“…only my ears whistle and buzz continuouslyday and night. I can say I am living a wretched life.” Ludwig Von Beethoven - 1801
The scream of the Nature by Edvard Munch Der Schrei der Natur
Paracuses and Hyperacusis Neurophysiological models
Paracuses• Disturbance in auditory perception (other than loss of hearing sensitivity)• Musicians are more sensitive to detecting it, people infrequently complain about it (unable to recognize, confuse, mildly irritating..)• Hyperacusis is the most clinically encountered type
Frequency-related phenomena• Diplacusis: – Double hearing (sound will have a different tone in each ear) – Meniere’s disease? First to disappear on treatment? – Cochlear otosclerosis, fenestration operations – Potassium iodide medication, chloroform inhalation
Diplacusis• Damage to the fine tuning mechanism of the organ of corti (outer hair cell dysfunction?)• Lower intelligibility of speech, the benefits of hearing aids are debatable• PTA, speech discrimination, otoacoustic emissions• Diplacusimetry, psychoacoustic tuning curves
Sound localization dysfunction• Intensity and phase difference of sounds are important for sound directionalization• Time difference, the role of the auricles• Dysstereoacusis: – Can be seen frequently in patients with supra tentorial lesions (central dysfunction) – Can be the presenting symptom in vestibular shwannoma
Intensity-related phenomena• Paracusis Willisii: – Frequently mentioned with otosclerosis – But it is a general feature of conductive hearing loss – Patient’s can hear better in noisy environment – People tend to raise their voices in noisy environment?
Hyperacusis• Unusual tolerance to ordinary environmental sounds (Vernon, 1987)• Consistently exaggerated or inappropriate responses to sounds that are neither threatening nor uncomfortably loud to a typical person (Klein et al, 1990)• It is abnormally strong reaction to sound occurring within the auditory pathways, but it involves limbic system (emotional reaction), Sympathetic, reticular formation (arousal and alerting), and pre-forntal area (awareness and cognition) (Jastreboff&Hazell 2004)
Other terms• Loudness recruitment: – Abnormal growth of loudness due to cochlear hearing loss, and in particular OHCs dysfunction (mechanism?) – Sounds of moderate intensity perceived as uncommonly loud (ABLB, SISI score?) – Reduced dynamic range, steeper than usual input output function on the Cochlear basilar membrane – Great spread of excitation of the basilar membrane.
Other terms• Phonophobia: (fear is the dominant emotion) – Emphasises the emotional impact of the sensitivity to sounds, used more in neurological literature – Phonophobia/photophobia accompanying migraine attacks – Misophonia: A term to describe disliking of sound without the phobic element (Jestreboff, 2003)
Other terms• Noise sensitivity in psychiatric disorders: – Startle reflex in post traumatic stress disorders – The association of noise sensitivity and depression – Improvement of hyperacusis after treatment of depression in tinnitus patients?
Hyperacusis and tinnitus• 9 % point prevalence (Andersson, 2002)• 40-60% in patients attending tinnitus clinic• In patients with primarily hyperacusis complaint, tinnitus estimates varies between 86% (Anari et al, 1999) and 21% (Andersson et al, 2002)• Hyperacusis as a precursor to the development of tinnitus
Severe hyperacusis• 4-5% of population have severe tinnitus• 40% of these have significant hyperacusis• Severe hyperacusis : 2% – Jastreboff, 2000 – Baguley and Andersson, 2007
Medical conditions ass. With hyperacusis• Peripheral: Bell’s palsy, Ramzy Hunt syndrome, Post stapedectomy, perilymph fistula• Central:Migraine, Depression, Post-traumatic stress, Head injury, Lyme disease, Williams syndrome, Autism
Neurophysiological models and mechanisms• Hyperactivity of the auditory nerve (Moore, 1995)• 5-HT (Marriage and Barnes, 1995)• Endogenous opioid peptides ( Sahley et al, 1996 )• Auditory efferent dysfunction• Plastic change leading to increased central auditory gain
Serotonin ( 5-HT)• First recognized as a powerful vasoconstrictor and isolated by Page (1948)• 5 Hydroxytryptamine (5-HT)• Naturally produced in the pineal gland, and its precursor (amino acid Tryptophan) is rich in bananas, milk, Turkey, plums• 90% of Serotonin in the body is in the intestine
5-HT• One role of 5-HT, is as a neurotransmitter, regulating various functions like sleep, memory and learning, temperature regulation, mood, appetite, behaviour, cardiovascular function, muscle contraction, endocrine regulation and depression.• 5-HT released at synaptic clefts in the brain regulate protein binding and change electrical state of the cell, either stimulatory or inhibitory
5-HT and depression ( The molecule of happiness)• Low serotonin levels are believed to be the cause of many cases of mild to severe depression which can lead to symptoms such as anxiety, apathy, fear, feelings of worthlessness, insomnia and fatigue. The most concrete evidence for the connection between serotonin and depression is the decreased concentrations of serotonin metabolites in the cerebrospinal fluid and brain tissues of depressed people
Serotonin ( 5-HT )• Serotonergic fibres and terminal endings found throughout central auditory pathway (Raphe Neucli) through the medulla, pons and midbrain• Postulated role of modulating sound perception or determination of significance – ( Thompson et al, 1994, Simpson and Barnes, 2000 )
Marriage and Barnes (1995) The Journal of Laryngology and Otology October 1995, Vol. 109, pp. 915-921 Neurological conditions associated with hyperacusis: (a) Migraine (Solomon et al, 1992).• (b) Depression (Carmen, 1973).• (c) Pyridoxine deficiency (Oppe, 1992).• (d) Benzodiazepine dependence (Lader, 1984).• (e) Musicogenic epilepsy (case study by Fujinawa et al, 1977).
Neurological conditions associated with Hyperacusis• (f) Tay-Sachs disease or gangliosidosis type 2• (Gordon et al, 1988; Gascon et al, 1992).• (g) Post-traumatic stress disorder.• (h) Chronic/post-viral fatigue syndrome (CFS/ PVFS) or myalgic encephalomyelitis (ME) (Behan and Bakheit, 1991; Merry, 1991).
Hypothesis• Many conditions associated with hyperacusis, especially Migraine and tinnitus (probably accounts for 90% of cases of hyperacusis), are strongly related to dysfunction in 5-HT metabolism, probably reduction of 5-HT activity in the forebrain
Problems with 5-HT hypothesis• Non-specific ( Phillips and Carr, 1998 ) – A Cochrane review has found no evidence of the its effects on tinnitus treatment – Interest in the states, under investigation
Plasticity in central auditory system• Plasticity first proposed by Ramon y Cajal( 1852 - 1934 )The ability of the brain to re-organize itself• Caused by – Reorganization following an insult (sensory deprivation as an example) – Adaptation and change of functions
The role of sensory deprivation• Tonotopic organization through the auditory system means that certain frequency areas on the basilar membrane supplies certain regions in the central auditory system with afferent signals• Damage to the cochlea, resulting in SNHL will lead to loss of afferent information leaving this specific area (frequency region)
Sensory deprivation theory• Corresponding areas in the central auditory system become starved (deprived) of sensory stimulation• This might lead to: – Increased level of spontaneous activity – Plastic rearrangement of neurones leading to abnormal firing patterns• This can be perceived as tinnitus and hyperacusis
Recent PET scan findings Seng-Ha Oh (2010)• Pre and post cochlear implantation in pre lingual and post lingual hearing loss• PET looks at auditory cortical metabolism• Wider pre-operative hypometabolism of the auditory cortex is an indication of BETTER speech abilities post implantation• The more the duration of deafness the LESS the extent of hypometabolism in the auditory cortex
Final thoughts• Hyperacusis is a specific term and should not be confused with other phenomena• The theories of causation are still not proven, though strong associations with cochlear damage, tinnitus and migraine should provide a connection to the pathophysiological mechanisms of these conditions
• Tinnitus -“The perception of sound in the absence of external stimuli.”• Tinnere – means “ringing” in Latin• Includes Buzzing, roaring, clicking, pulsatile sounds
Prevalence1- The hearing threshold is considered the single most important factor affecting the prevalence of tinnitus2- Age: because it is associated with HL, 12.1% in 60-69 year olds compared to 4.7 % in 20-29 year Olds. Heller (2003) 3-Not sex dependent? In groups over age 65, there is a slight tendency for tinnitus to be more prevalent in men over women (Heller 2003)4- Race Caucasians report tinnitus more than do African-Americans, 37
Tinnitus• May be perceived as unilateral or bilateral• Originating in the ears or around the head• First or only symptom of a disease process or auditory/psychological annoyance
Classification• Objective tinnitus – sound produced by paraauditory structures which may be heard by an examiner• Subjective tinnitus – sound is only perceived by the patient (most common)
Tinnitus• Pulsatile tinnitus – matches pulse or a rushing sound – Possible vascular etiology – Either objective or subjective – Increased or turbulent bloodflow through paraauditory structures
Evaluation - History• Infection• Trauma• Noise exposure• Medication usage• Medical history• Hearing loss• Vertigo• Pain• Family history• Impact on patient
Evaluation – Physical Exam• Complete head & neck exam• General physical exam• Otoscopy (glomus tympanicum, dehiscent jugular bulb)• Search for audible bruit in pulsatile tinnitus – Auscultate over orbit, mastoid process, skull, neck, heart using bell and diaphragm of stethoscope – Toynbee tube to auscultate EAC
Evaluation – Physical Exam• Light exercise to increase pulsatile tinnitus• Light pressure on the neck (decreases venous hum)• Valsalva maneuver (decrease venous hum)• Turning the head (decrease venous hum)
Evaluation - Audiometry• Vascular or palatomyoclonus induced tinnitus – graph of compliance vs. time• Patulous Eustachian tube – changes in compliance with respiration• Asymmetric sensorineural hearing loss or speech discrimination, unilateral tinnitus suggests possible acoustic neuroma - MRI
Laboratory studies• As indicated by history and physical exam• Possibilities include: – Hematocrit – FTA absorption test – Blood chemistries – Thyroid studies – Lipid battery
Imaging• Pulsatile tinnitus• Reviewed by Weissman and Hirsch (2000)• Contrast enhanced CT of temporal bones, skull base, brain, calvaria as first-line study• Sismanis and Smoker (1994) recommended CT for retrotympanic mass, MRI/MRA if normal otoscopy
• 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
Glomus TympanicumFrom: Weissman JL, Hirsch BE. Imaging of tinnitus: a review.Radiology 2000;216:343.
Glomus TympanicumFrom: Weissman JL, Hirsch BE. Imaging of tinnitus: a review.Radiology 2000;216:343.
Imaging• Glomus jugulare – Erosion of osseous jugular fossa – Enhance with contrast, may not be able to differentiate jugular vein and tumor – Enhance with T1-weighted MRI with gadolinium and on T2-weighted images – Characteristic “salt and pepper” appearance on MRI
Glomus jugulareFrom: Weissman JL, Hirsch BE. Imaging of tinnitus: a review.Radiology 2000;216:344.
Glomus jugulare “salt and pepper appearance”From: Weissman JL, Hirsch BE. Imaging of tinnitus: a review.Radiology 2000;216:344.
Imaging• Arteriovenous malformations – readily apparent on contrasted CT and MRI• Normal otoscopic exam and pulsatile tinnitus may be dural arteriovenous fistula – Often invisible on contrasted CT and MRI/MRA – Angiography may be only diagnostic test
Imagining• Shin et al (2000) – MRI/MRA initially if subjective pulsatile tinnitus – Angiography if objective with audible bruit in order to identify dural arteriovenous fistula
Imaging• Other contrast enhanced CT diagnoses• Aberrant carotid artery• Dehiscent carotid artery• Dehiscent jugular bulb• Persistent stapedial artery – Soft tissue on promontory – Enlargement of facial nerve canal – Absence of foramen spinosum
Persistent Stapedial ArteryFrom: Araujo MF et al. Radiology quiz case I: persistent stapedial artery. ArchOtolaryngol Head Neck Surg 2002;128:456.
Imaging• Acoustic Neuroma – Unilateral tinnitus, asymmetric sensorineural hearing loss or speech descrimination scores – T1-weighted MRI with gadolinium enhancement of CP angle is study of choice – Thin section T2-weighted MRI of temporal bones and IACs may be acceptable screening test
Acoustic NeuromaFrom: Weissman JL, Hirsch BE. Imaging of tinnitus: areview. Radiology 2000;216:348.
Acoustic NeuromaFrom: Weissman JL, Hirsch BE. Imaging of tinnitus: a review.Radiology 2000;216:348.
BIH – Empty SellaSismanis A, Smoker W. Pulsatile tinnitus: recent advances indiagnosis. Laryngoscope 1994;104:685.
Treatments• Multiple treatments • Reassurance• Avoidance of dietary • White noise from radio stimulants: coffee, tea, or home masking cola, etc. machine• Smoking cessation• Avoid medications known to cause tinnitus
Treatments - Medicines• Many medications have been researched for the treatment of tinnitus: – Intravenous lidocaine suppresses tinnitus but is impractical to use clinically – Tocainide is oral analog which is ineffective – Carbamazepine ineffective and may cause bone marrow suppression
Treatments - Medicines• Alprazolam (Xanax) – Johnson et al (1993) found 76% of 17 patients had reduction in the loudness of their tinnitus using both a tinnitus synthesizer and VAS (dose 0.5mg-1.5 mg/day) – Dependence problem, long-term use is not recommended
Treatments - Medicines• Nortriptyline and amitriptyline – May have some benefit – Dobie et al reported on 92 patients – 67% nortriptlyine benefit, 40%placebo• Ginko biloba – Extract at doses of 120-160mg per day – Shown to be effective in some trials and not in others – Needs further study
Treatments• Hearing aids – amplification of background noise can decrease tinnitus• Maskers – produce sound to mask tinnitus• Tinnitus instrument – combination of hearing aid and masker• Noise generator as a part of TRT
Treatments• Tinnitus Retraining Therapy – Based on neurophysiologic model – Combination of masking with low level broadband noise for several hours per day and counseling to achieve habituation of the reaction to tinnitus and perception of the tinnitus itself
Treatments• Electrical stimulation of the cochlea – Transcutaneous, round window, promontory stimulation have all been tried – Direct current can cause permanent damage – Steenersen and Cronin have used transcutaneous stimulation of the auricle and tragus decreasing tinnitus in 53% of 500 patients
Treatments• Cochlear implants – Have shown some promise in relief of tinnitus – Ito and Sakakihara (1994) reported that in 26 patients implanted who had tinnitus 77% reported either tinnitus was abolished or suppressed, 8% reported worsening
Treatments• Surgery – Used for treatment of arteriovenous malformations, glomus tumors, otosclerosis, acoustic neuroma – Some authors have reported success with cochlear nerve section in patients who have intractable tinnitus and have failed all other treatments, this is not widely accepted
A Trial of Low Level LaserTherapy for Reduction of Tinnitus Symptoms
Treatments• Biofeedback• Hypnosis• Magnetic stimulation• Acupuncture• Conflicting reports of benefit
Repetitive Transcranial Magnetic stimulation• RationaleTinnitus is associated with increase neuronal activity, increase synchronicity, re- organization in Aud. Cortex
Repetitive Transcranial Magnetic stimulation• Targeted modulation of aud. Cortex ?? New therapy• TMS is a non invasive electro-magnetic tool to stimulate the primary motor cortex. Repetitive stimulation produce neuro-stimulation of specific regions potentially involved in the patho-physiology of tinnitus. So the treatment called rep. trans-cranial Magnetic stimulation rTMS.
Conclusions• Tinnitus is a common problem with an extensive differential• Need to identify medical process if involved• Pulsatile/Nonpulsatile is important distinction• Research into mechanism and treatments is needed to better help our patients