gh-frequency sounds (consonants at 3 \200\2234kHz are needed for speech dis- crimination). Hearing is most aff ected in the presence of background noise. Hearing aids are the usual treatment. See pure tone audiograms on p541 ( \201 g 2). Tips on communicating with those who are hard of hearing \200 Decrease background noise. Use of an induction loop system ( eg a wire around the TV room) achieves this for those with suitably adapted aids (with a sw itch, ie the T setting; NB: some new aids are too small for these). 550 UK prevalence: 10% \200 Is your hearing reduced? \200 Do people \200\230mumble \200\231? \200 Do you keep sayi ng \200\234What? \200\235 \200 Do you misunderstand names? \200 Is your TV volume \200\230too loud \200\231? \200 Are noisy rooms a problem? s e s a e s i d T N E Use short sentences. Be on the same level as the person you are addressing. \200 Ensure t hat light falls on your face. Unilateral sensorineural deafness Think of acoustic neuroma. 1 Stroke; sarcoidosis; 81 Takayasu \200\231s arteritis; Chlamydia pneumoniae; immune comple xes; autoantibodies to inner ear proteins; anticardiolipin (aCL) antibodies; cellular immun e defects. 82 2 Middle ear implants: Surgical implantation of auditory devices is a rapidly growing area in the rehabilita- tion of deafness. They should be viewed as an alternative to conventional hearing aids for individuals who are either unable to wear hearing aids or reject them for any reason. 83 551 Classi \201 cation of deafness Conductive deafness There is impaired sound transmission vi a the exter- nal canal and middle ear ossicles to the foot of the stapes through a va- riet y of causes. External canal obstruction (wax, pus, debris, foreign body, developmental anom alies); drum perforation (trauma, barotrauma, infec- tion); problems with the ossicular cha in (otosclerosis, infection, trauma); and inadequate Eustachian tube ventilation of the mid dle ear (eg with eff usion secondary to nasopharyngeal carcinoma) all result in conductive deafness. Sensorineural deafness results from defects central to the oval window in the coc hlea (sensory), cochlear nerve (neural) or, rarely, more central path- ways. Ototoxic drugs (eg streptomycin, vancomycin, gentamicin, chloroquine and hydroxychloroquine, vinca alkalo ids), postinfective (meningitis, measles, mumps, \202 u, herpes, syphilis), cochlear vasc ular disease, M ni re \200\231s (p554), trauma, and presbyacusis are all sensorineural. R are causes: Acoustic neu- roma, B12 de \201 ciency, multiple sclerosis, secondary carcinom a in the brain. s e s a e s i d T N E Choosing an aid: head-to-head speech vs cross-talk (amid noise) Amplifying speech is a majo r factor to take into account when choosing an aid: get help from independent experts as di gital technologies are constant- ly improving. We know that speech is best heard when liste ning binaurally. The bene \201 ts of directional microphones in hearing aids are also well docu- mented in lab settings. If it is necessary to \201 t 2 aids, should they both be d irectional (symmetrical directional \201 tting)? Yes, if the speech comes from in front o f the listener (head-to-head) and the noise sources are located to the side of or surround the listener. When speech is located to the side of the listener, use of directional proces sing on the ear adjacent to the speaker is likely to reduce speech audibility and thus degr ade speech understand- ing. 84 NB: hearing aids with directional microphones cannot be \201 tted entirely within the ear canal, and so are more noticeable that smaller aids. Also , aids that \201 t in the canal may give better results with the telephone. \200 Managin g sudden sensorineural deafness: a summary \200 Get expert ENT help. \200 Look for causes : WR; ANA; INR; TSH; blood glucose; cholesterol; ESR; FBC; LFT; viral titres; audiology; ev oked response audiometry CXR; Mantoux; MRI; pANCA; lymph node and nasopharyngeal biopsy for malignancy/TB culture. \200 Imaging: gadolinium MRI; CT. \200 Audiometry and auditory brainstem evoked responses . \200 High-dose steroids are no more eff ective when combined with antivirals. One starti ng regimen is prednisolone 80mg/24h PO for 4 days tapered over 8 days.85 Intratympanic dexa methasone may have a salvage role. The bounds of \200\230normal \200\231 hearing Both frequency (Hz) and sound pressure (deci bels, dB) are important for the detection of sound by the human ear, though the relationshi p between the two is also important. Sound frequencies between 500 and 4000Hz are the most important for speech interpretation. Severe sensorineural deafness is de \201 ned as >100 \200\223120dB loss; signi \201 cant hearing loss is considered as >35dB loss. Remember tha t decibels are a logarithmic scale, and that the range from 0 to 120dBs actually represents a million times relative increase in sound pressure. Another unit for the sound pressure ( \211\210 \200\230volume \200\231 in common par- lance) is the dyne/cm2, which is not a log arithmic scale. At high intensity ( \200\206130dB), sound can also be a painful stimulus, showing an intere sting (and variable) threshold relationship between useful information from special senses and painful stimuli (also present in the eye). Tinnitus Tinnitus (Latin tinnire, meaning to ring) is a sensation of non-verbal sound not d ue to stimuli outside the body. Age of onset is 50 \200\22360yrs (peak). Ringing, hissing, or buzzing suggests an inner ear or central cause. Popping or click- ing suggests problems in the external or middle ear, or the palate. Pulsatile sounds (somatosounds) may re \202 ect anxiety, benign intracranial hyperten- sion, vascular causes: glomus tumors ( \201 g 1 ), carotid body tumors, carotid stenosis, arterio venous malformations, aneurysms, hyperten sion,86 and high- output cardiac states (Paget \200\231s, hyperthyroidism).87 Central tinni tus Most people get tinnitus, but automatically suppress it. If this suppression fails, tin nitus is intrusive and is perceived as a threat. Tinnitus training (below) reduces this thr eat. 4 areas are of concern: altered central processing; spontaneous otoacoustic emissions; crosstalk between adjacent nerve \201 bres from myelin damage after trauma, and, very im portantly audi- tory \200\223limbic interactions, esp. the nucleus accumbens (mediates nega tive emo- tions, see functional MRI data). 88 It is likely that feedback connections from l imbic regions block the tinnitus signal from reaching auditory cortex. 89 Diag- nosing subj ective idiopathic tinnitus (SIT) depends on excluding: 1 Local causes, eg hearing loss; pre sbyacusis; noise-induced; head injury; otosclerosis/ post-stapedectomy; M ni re \200\231s . 2 General: Cardiovascular: BP \200\200, Hb \200\201, heart fail- ure. 3 Drugs: Aspirin; l oop diuretics; aminoglycosides, quinine, alcohol excess. Assess psychological associations (eg redundancy, divorce, retirement). The patient History: Character (constant? pulsatile?) ; alleviating/exacer- bating factors; otalgia; social surroundings (tinnitus is worse if is olated or depressed); drugs. Impact: does it disturbs sleep? Associations: deafness (preval ence rises to up to 100% in noise-induced trauma, 80% in severe deaf- ness, and 70% in Schw annomas).90 Signs: Otoscopy to detect drum mobility (patulous Eustachian tube or myoclonus of tensor tympani) and middle ear disease; hearing/tuning fork tests. BP & pulse. Tests: Au diometry (with mask- ing), tympanogram (+stapedial re \202 ex thresholds). \200\207In uni lateral tinnitus do MRI to exclude acoustic neuroma (p553; 10% present this way). Hb; lipid s; ?WR.et al \202\221 Take time to explain tinnitus. Do tests to exclude acoustic neuroma (MRI) and transmitted noise (eg glomus tympanic- um tumors, \201 g 1). Treat the treatabl e; sup- port and reassure to help remodel symptoms. Positive attitudes help; avoid saying \200\234it \200\231s untreatable; nothing can be done \200\235. Treat the whole person, not just a malfunctioning ear. \200 Aids: If hearing loss >35dB, a hearing aid that improves perception of background noise makes tinnitus less apparent. Masking with background white noise is no longer advised. \200 Psychological support is vital; therapists use tinnitus retraining therapy (TRT makes tinnitus less intrusive, by sound therapy, and dispelling un founded beliefs/fears). Cognitive therapy (p374) and patient groups help. \200 Music, mas sage and other media may have a role.91 \200 Drugs: None are standard. Melatonin ( 3mg at night, p404) may help, eg if sleep disturbance is bad; 92 hypnotics are addictive. Betahis tine only helps if M n i re \200\231s is the cause. Baclofen (10mg/12h PO up to 30mg/12h over 3wks) may also help. Anticonvulsants, eg carbamazepine, aren \200\231t much better tha n placebos but with side eff ects (in 18%). A meta-analysis of \200\230near or total eradi cation of tinnitus annoyance \200\231 showed no eff ect of anticonvulsants. 93 \200 Intra tympanic dexamethasone + oral alprazolam helped 76% (less for SIT of long duration) in one randomized study.94 N=107 \200 Surgery: Has little role. Destructive techniques are rarel y justi \201 ed. 552 prevalence: 25%; tinnitus.org.uk s e s a e s i d T N E Anterior Fig 1. Glomus tympanicum tum- our: note red anterior mass and a small \202 uid m eniscus around it. Rory Herdman FRCS. 553 Acoustic neuroma These are typically indolent, histologically benign subarachnoid tumors th at cause problems by local pressure, and then behave as space-occupying lesions. They are m isnomers as they usually arise from the sup erior vestibu- lar nerve schwann cell layer, he nce the name vestibular schwannoma. The patient: Progressive ipsilateral tinnitus sensor ineural deafness (cochlear nerve compression). Big tumors may give ipsilateral cerebellar s igns or ICP \200\200 signs. Giddiness is common; vertigo rare. Trigeminal compression above the tumor may give a numb face. Nearby cranial nerves at risk: (V, VI, VII). Tests: MRI. \200\207Do MRI in all those with unilateral tinnitus/deafness. \201\231 \201\231 : Me- nin gioma. Surgery: (diffi cult, and often not needed, eg if elderly);95 there are many methods with various ways of preserving hearing and the facial nerve (eg continuous intraoperative monit oring of evoked electromyograms).96 Gamma knife surgery is one good way to \200\201 neuroma volume. Follow-up: MRI detects expansion. Noise and the dangers of excessive noise Our waking and sleeping lives are bathed in seas of noise. Let \200\231s attend to our cur rent soundscape: in my case, Sussex rain not quite drowned out by a string quartet and a ph one ringing. For many it will be the unending roar of traffi c, sirens, aircraft, urban str ife, car alarms, and the shouts of the angry pursuing the drunk, maybe all occluded by MP3 ear- phones. What is the eff ect of all this noise?97 \200 Pain (rape alarms hurt) \200 Hearing fatigue tinnitus \200 Presbyacusis/hearing loss \200 Fatigue, somatization1 03 \200 Feelings of helplessness, \201 g 1 Hyperacusis (auditory discomfort at 20 \200 \22334dB) Peripheral causes: facial nerve palsy; myasthenia; tympanoplasty. Central: MS; AV malformations; work as a musician; migraine; pervasive refusal syndrome (unable to move/sp eak, closed eyes, tics, grimacing, hyperacusis hyperaesthesia). Management: earplugs. Vi broacoustic disease (VAD) is a whole-body pathology (+loss of cilia) that develops in those exposed to \200\200infrasound (0 \200\22320Hz) or deep noise (cabin crew, pilots, disc-jo ckeys). VAD causes abnormal growth of extracellular matrices (collagen & elastin) in blood vessels, pericardium, 106 trachea, and lung ( \201 brosis). Avoiding noise-induced hearing loss Attend to sense, symbol, soma, and soundscape.103 Turn the volume down. Avoid cities! Listen to nightingal \201\201s; abide by health and safety rules; don \200\231t build hous es near railways or runways;107 wear ear muff s; support urban plans that address noise. Re frame auditory- somatic experience and address feelings of vulnerability, and defenseless- ness. 103 Examining the nightingale \200\231s code:1 \201\201 As a medical student, John Ke ats had a troubling time walking the noisy wards of Guy \200\231s Hospital, which were fore ver on the edge of chaos (p397): \200\230here, where men sit and hear each other groan \200\231 he reframed, for all time, the white noise and chaos of our lives into the sublime . Each midnight we must repeat this trick so that we can hear ourselves think, by trumping the groans of the sick by the nightingales of the mind. s e s a e s i d T N E Fig 1. Noise causing helplessness. \200 Sleep disturbance and all its consequences98,99 \200 School problems ( \200\201reading ability)100 \200 Cardiac output \200\201;101 MI r isk \200\200; hypertension102 \200 Neuroendocrine issues & CD4 cells & IgG \200\201104 \200 Poor memory, depression, even suicide105 Call \200\231d him soft names in many a mus d rhyme, \201\201 Darkling I listen; and, for many a time, I have been half in love with easeful Death, Now more than ever seems it rich to die, To cease upon the midnight with no pain, While tho u art pouring forth thy soul abroad Ode to a Nightingale To take into the air my quiet breath; In such an ecstasy! Vertigo: the illusion of movement Vertigo can be ghastly. Find out if there other fea- ture s: feeling unreal, panicky, loss of memory. 554 \200 Causes (often multifactorial) Peripheral \200 M ni re \200\231s disease \200 Benign p ositional Vestibular (peripheral) vertigo is often severe, and may be accompanied by nausea, vomiting , hearing loss, tinnitus, and nystagmus (usually hori- zontal). Hearing loss and tinnitus a re less common in central vertigo (it is usually less severe). Nys- tagmus may be horizonta l or vertical with central vertigo, and may be diff erent in each eye (eg the abducting eye in MS). Is the symptom vestibular? \200\234I \200\231m dizzy \200\235 is am- biguous. Eli cit the illusion! Ask \200\234Did you or the world seem to spin (like getting off a playgr ound roundabout?) \200\235 or \200\234Which way are things going? \200\235 Those with vert igo often know without hesitation; if not, this is a cue to pursue other causes (light- hea dedness a \200\230sense of collapse \200\231 can be vascular, ocular, musculoskeletal, metabolic, or claustro- phobic). \200\207Ask about duration of vertigo: seconds to minutes \211\210 BPPV; 30mins to 30h \211\210 M ni re \200\231s or migraine; 30h to a week \211\210 acute vestibular failure. Examination/tests Assess CNS & ears (esp. middle ear). T est cranial nerves, cerebellar function & re \202 exes. Assess: nystagmus, gait, Romberg \200\231s test (+ve if balance is worse when eyes are shut, implying defective joint positi on sense or vestibular input) and Unterberger \200\231s (march up and down on the spot with arms stretched out in front and eyes closed; +ve if >45 turn in \211 50 steps).108 Do p rovocation tests (Hallpike test, BOX). If equivocal, do audi ometry electro nystagmograp hy; brainstem auditory evoked responses; calorimetry (the only way to test each labyrinth1 separately; irrigate each canal with water 7 C above and below body T : is nystagmus indu ced?); CT; MRI. M ni re \200\231s disease Dilatation of the endolymphatic spaces2 of the membra- nous labyrinth causes vertigo for 12h with prostration, nausea/vomiting a feeli ng of fullness in the ear; uni- or bilateral tinnitus sensorineural deaf- ness (eg \202 uctuating). Attacks occur in clusters (<20/month). Cause: A mys- tery! \200 : Electr ocochleography; endolymphatic space MRI. \201\227: Prochlorperazine as Buccastem 3mg/8h PO (1st-line if vomiting) or betahistine 16mg/8h PO or chlortalidone may help. 109 \200\223 111 Surgical approaches, eg endolymphatic shunts, seem logical, but robust evidence (using sham surgery for controls) is lack- ing. Labyrinthectomy may stop vertigo but causes total ipsilateral deafness; vestibular neurectomy spares hearing. Day-case instillation of ototox ic drugs (gentamicin via a grommet) has been tried and can avoid deafness. Acute vestibular failure follows a febrile illness in adults, eg in winter (eg herpes simplex virus type 1) . Sudden vertigo, vomiting, and prostration are exacerbated by head movement. \201\227: Tr y cyclizine 50mg/8h PO. Improvement occurs in days, though full recovery occurs within 2 \200\2233 weeks (longer if elderly). Methylprednisolone may also help, but valaciclovir doe s not. 112 It is impossible to distinguish from \200\230viral labyrinthitis \200\231 and s o this term is best avoided. Vertigo due to incomplete vestibular compensation After inner ear injury the brain adapts to the altered sensory input and the perception of vertigo fade s over days to weeks \200\224or never happens. Relapses in compensation (de- compensation) in response to new physical or emotional stresses also occurs. 1 The cochlea ( \201 g 1, p 534) and the semicircular canals are called the labyrinth as its shape reminds us of the la byrinth built by Daedalus to imprison the Minotaur ( bull, man, who ate 7 virgins/yr). Like Daedalus, we are all prone to build structures such as books that seem designed for o thers to get lost in. 2 Also called endolymphatic hydrops. Endolymph is the \202 uid in t he scala media ( \201 g 3, p535) that is of a similar make-up to intracellular \202 uid. Perilymph is similar to CSF in composition, and is the \202 uid in the scala tympani and the scala vestibuli of the cochlea, that communicate at its apex via the helicotrema. (postural) vertigo (BPV) Vestibular failure \200 Labyrinthitis \200 Cholesteatoma Central \200 Acoustic neurom a \200 Multiple sclerosis \200 Head injury \200 Inner ear syphilis \200 Vertebrobas ilar insuffi ciency Drugs (central/ototoxic) \200 Gentamicin (neuronitis) \200 Diuretics \200 Co-trimoxaz ole \200 Metronidazole s e s a e s i d T N E 555 Benign positional vertigo Attacks of sudden rotational vertigo lasting >30sec are provoked by head- turning. It is common after head injury. Other otological symptoms are rare. Patho genesis: Displacement of otoconia (=otoliths, ie calcium carbonate par- ticles displaced fr om cells within in the endolymph) in semicircular canals. Causes: Idiopathic, middle-ear di sease, head injury, otosclerosis, spontaneous labyrinthine degeneration; postviral illness; stapes surgery (perilymph leak113). Diagnosis: Establish important negatives: \200\207no persistent vertigo \200\207no speech, visual, motor, or sensory problems \200\207no tinni tus, headache, ataxia, facial numb- ness, or dysphagia \200\207no vertical nystagmus. Hall pike test: 1 Treatment: Usually self-limiting in months; if persistent, try: \200 Vestibu lar ha- bituation exercises (BOX 2). \200 Reassurance \200 \200\201Alcohol intake may h elp \200 Drugs: histamine analogs (betahistine); vestibular sedatives (prochlorperazine); antidepressants \200 Epley maneuvers ( \201 g 1) \200 Last resort: posterior semicirc u- lar canal denervation or obliteration (deafness may follow). s e s a e s i d T N E Cawthorne Cooksey exercises for vestibular rehabilitation 1 In bed: Eye movements, slow, th en quick; up and down;from side to side then focusing on \201 nger moving from 1 meter to 30cm away from the face. Then head movements at \201 rst slow, then quick, later with eyes closed bending forward and backward; turning from side to side. 2 Sitting. Eye movemen ts and head movements as above, then: Shoulder shrugging and circling \200 Bending forward and picking up objects from the groun d 3 Standing: Eye, head and shoulder movements as before, then: Changing from sitting to standing position with eyes open and shut \200 Throwing a small b all from hand to hand (above eye level) \200 Throwing a ball from hand to hand under knee \200 Changing from sitting to standing and turning around in between 4 Moving about: With eyes closed then open; ball games. Fig 1. Otoconia reposit - ioning with Epley head maneuvers.114 The ENT Dr/physiother- apist procures 4 se- quential head move- in ments with rest each for position 30sec. The aim is to reposition otoconia away from the sensi- tive posterior canals. This works in 80% (a 2 nd go may help). 1 The Hallpike maneuver rotates the posterior semicircular canal in the plane of gravity. E xplain/reas- sure, and say \200\234Keep your eyes open and look straight ahead \200\235. W hile supine, the head is held between the examiner \200\231s hands, turned 30 \200\22340 to one side and then rapidly lowered 30 below the couch \200\231s level. Ask the patient if they feel dizzy and look for nystagmus. If +ve, there is vertigo and rotary nystagmus to wards the undermost ear, after a latent period of 5 \200\22310sec. This lasts <1min (adapta tion). On sitting, there is more vertigo ( nystagmus). If any of these features are absent (no latency, no symptoms, and persisting nystagmus), seek a central cause.