Diseases of the Inner Ear
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Diseases of the Inner Ear

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Questions and Answers

What is the primary clinical test for diagnosing BPPV?

The Dix-Hallpike maneuver.

List two characteristics of nystagmus observed in BPPV.

Torsional with vertical component and transient.

Name the maneuver that aims to reposition displaced otoliths in BPPV treatment.

Epley’s maneuver.

What is a common symptom experienced during an attack of Meniere's disease?

<p>Episodic vertigo.</p> Signup and view all the answers

How long do episodes of vertigo typically last in Meniere's disease?

<p>30 minutes to 4 hours.</p> Signup and view all the answers

Describe the pathophysiological cause of Meniere's disease.

<p>Fluid accumulation in the membranous labyrinth, leading to distension.</p> Signup and view all the answers

What are two common symptoms that follow an attack of Meniere's disease?

<p>Nausea and fatigue.</p> Signup and view all the answers

What is a rare treatment option for persistent BPPV cases?

<p>Surgery on the posterior semicircular canal.</p> Signup and view all the answers

What type of hearing loss is characteristic of early stage Meniere’s disease?

<p>Sensorineural hearing loss affecting lower frequencies.</p> Signup and view all the answers

What symptoms may precede an attack of Meniere’s disease?

<p>Tinnitus and a feeling of fullness or pressure in the affected ear.</p> Signup and view all the answers

What is the primary long-term treatment for managing Meniere’s disease symptoms?

<p>Betahistine and diuretics along with lifestyle modifications.</p> Signup and view all the answers

What is a definitive treatment option for unilateral Meniere’s disease in patients with serviceable hearing?

<p>Vestibular nerve section.</p> Signup and view all the answers

What viral infection is most commonly associated with vestibular neuritis?

<p>Herpes simplex virus type one (HSV-1).</p> Signup and view all the answers

What is a key feature of the vertigo experienced in vestibular neuritis?

<p>Acute spontaneous vertigo aggravated by head movement.</p> Signup and view all the answers

In the acute phase of Meniere's disease, what vestibular sedative is commonly used?

<p>Cinnarizine.</p> Signup and view all the answers

What diagnostic method is used to confirm the presence of sensorineural hearing loss in Meniere's disease?

<p>Cochleography and audiogram.</p> Signup and view all the answers

What are the two main components of the inner ear, and their primary functions?

<p>The cochlea, which is concerned with hearing, and the vestibular apparatus, which is responsible for equilibrium.</p> Signup and view all the answers

Name the three semicircular canals in the inner ear.

<p>Lateral semicircular canal, anterior semicircular canal, and posterior semicircular canal.</p> Signup and view all the answers

What structure is responsible for the transmission of sound waves into the inner ear?

<p>The stapes in the oval window.</p> Signup and view all the answers

What is the role of the cochlear duct in the inner ear?

<p>The cochlear duct houses the organ of Corti, which contains hair cells responsible for converting sound vibrations into neural signals.</p> Signup and view all the answers

Identify the nerves associated with the inner ear.

<p>The vestibulocochlear nerve [VIII] and the facial nerve [VII].</p> Signup and view all the answers

Which part of the inner ear is primarily concerned with balance?

<p>The vestibular apparatus.</p> Signup and view all the answers

What is the function of the tectorial membrane in the cochlea?

<p>The tectorial membrane interacts with hair cells to transduce sound vibrations into electrical signals.</p> Signup and view all the answers

What separates the scala vestibuli from the cochlear duct?

<p>The vestibular membrane.</p> Signup and view all the answers

Where does the vestibular aqueduct lead, and what is its function?

<p>It leads to the inner ear and helps maintain pressure balance, facilitating fluid communication.</p> Signup and view all the answers

What role do outer hair cells play in the cochlea?

<p>Outer hair cells amplify and refine sound vibrations that enter the cochlea.</p> Signup and view all the answers

What is the significance of the positive Unterberger test in diagnosing vestibular neuritis?

<p>A positive Unterberger test indicates rotational movement towards the side of the lesion, helping to identify dysfunction in the affected labyrinth.</p> Signup and view all the answers

How does vestibular neuritis typically manifest during an acute attack?

<p>During an acute attack, vestibular neuritis presents with nystagmus that is horizontal and directed towards the unaffected side.</p> Signup and view all the answers

What type of hearing loss is associated with longitudinal fractures of the temporal bone?

<p>Longitudinal fractures typically result in conductive hearing loss due to ossicular dislocation and possible tympanic membrane rupture.</p> Signup and view all the answers

Which treatment options are recommended for managing vestibular neuritis during an acute attack?

<p>Corticosteroids, antiviral drugs, and vestibular sedative medications like plochloroperazine are recommended.</p> Signup and view all the answers

What are the potential complications associated with transverse fractures of the temporal bone?

<p>Transverse fractures can lead to sensorineural hearing loss and facial palsy in up to 50% of cases.</p> Signup and view all the answers

Describe the characteristic movement of a patient with vestibular neuritis when attempting the Unterberger test.

<p>Patients with vestibular neuritis typically rotate towards the affected side when performing the Unterberger test.</p> Signup and view all the answers

What is the difference between the effects of longitudinal and transverse fractures on the labyrinth?

<p>Longitudinal fractures usually spare the labyrinth, while transverse fractures often involve it, leading to more severe symptoms.</p> Signup and view all the answers

What clinical signs may indicate a ruptured tympanic membrane following a longitudinal fracture?

<p>Signs can include bleeding from the ear, hearing loss, and CSF otorrhea if the membrane is disrupted.</p> Signup and view all the answers

What is the role of steroids in hearing loss treatment?

<p>Steroids relieve edema through their anti-inflammatory effects, particularly aiding individuals with moderate degree hearing loss.</p> Signup and view all the answers

How does carbogen inhalation benefit cochlear health?

<p>Inhalation of carbogen, a mixture of 5% CO2 and 95% O2, enhances cochlear blood flow and provides better oxygenation.</p> Signup and view all the answers

What factors lead to a poor prognosis in patients with sudden hearing loss?

<p>Poor prognostic factors include old age, profound deafness, presence of vertigo, vascular risk factors, and delayed treatment.</p> Signup and view all the answers

Describe the sensory type of presbycusis pathology.

<p>Sensory type presbycusis involves the degeneration of the organ of Corti, starting at the basal coil and progressing towards the apex, affecting higher frequencies first.</p> Signup and view all the answers

What characterizes the neural type of hearing loss pathology?

<p>Neural type hearing loss features degeneration of the spiral ganglion from the basal coil to the apex, causing poor speech discrimination despite pure tone loss.</p> Signup and view all the answers

What are the clinical features of presbycusis?

<p>Clinical features include slowly progressive, symmetric SNHL in individuals over 60, with difficulties in hearing amid background noise and poor speech understanding.</p> Signup and view all the answers

Explain the metabolic type of presbycusis and its audiometric characteristics.

<p>Metabolic type presbycusis involves atrophy of the stria vascularis with a flat pure tone audiogram and good speech discrimination.</p> Signup and view all the answers

Why is early treatment considered a good prognostic factor in sudden hearing loss?

<p>Early treatment can significantly enhance recovery chances, particularly within the first month post onset of hearing loss.</p> Signup and view all the answers

What condition is characterized by episodic vertigo triggered by specific head movements?

<p>Benign Paroxysmal Positional Vertigo (BPPV)</p> Signup and view all the answers

What is the primary pathophysiological cause of BPPV?

<p>Canalolithiasis theory, where otoliths detach and enter the posterior semicircular canal.</p> Signup and view all the answers

What are the characteristic symptoms of vestibular neuritis?

<p>Vertigo, often severe, and imbalance without hearing loss.</p> Signup and view all the answers

How long do attacks of vertigo last in individuals with BPPV?

<p>The attacks last only for seconds.</p> Signup and view all the answers

What are the three main symptoms of inner ear diseases?

<p>Deafness, vertigo, and tinnitus.</p> Signup and view all the answers

What is the main cause of vestibular neuritis?

<p>A viral infection, most commonly caused by herpes simplex virus type one.</p> Signup and view all the answers

What is a common acute treatment for Meniere's disease?

<p>Vestibular sedatives, such as cinnarizine.</p> Signup and view all the answers

How do episodes of hearing loss change as Meniere's disease progresses?

<p>Hearing loss transitions from fluctuating to permanent over time.</p> Signup and view all the answers

What symptom often precedes an attack of Meniere's disease?

<p>Tinnitus and a feeling of fullness or pressure in the affected ear.</p> Signup and view all the answers

What is the purpose of gentamicin treatment in Meniere's disease?

<p>To selectively damage vestibular cells to alleviate symptoms.</p> Signup and view all the answers

What is one long-term management strategy for Meniere's disease?

<p>Avoidance of caffeine and salt.</p> Signup and view all the answers

What characterizes the vertigo experienced during vestibular neuritis?

<p>It is acute spontaneous vertigo aggravated by head movement.</p> Signup and view all the answers

What is a surgical treatment option for unilateral Meniere's disease?

<p>Endolymphatic sac surgery.</p> Signup and view all the answers

What is the primary symptom experienced by patients with vestibular neuritis?

<p>Patients typically experience vertigo and imbalance.</p> Signup and view all the answers

How does a longitudinal fracture of the temporal bone affect hearing?

<p>It typically results in conductive deafness due to ossicular dislocation.</p> Signup and view all the answers

What kind of nystagmus is observed during an acute attack of vestibular neuritis?

<p>Horizontal nystagmus that beats towards the unaffected side.</p> Signup and view all the answers

What indicates a positive Unterberger stepping test?

<p>Rotational movement greater than 30° towards the affected side.</p> Signup and view all the answers

What is the common treatment approach during an acute attack of vestibular neuritis?

<p>The use of vestibular sedative drugs and corticosteroids.</p> Signup and view all the answers

What symptom can result from a transverse fracture of the temporal bone?

<p>Sensorineural hearing loss and profound vertigo.</p> Signup and view all the answers

What clinical sign may occur if the tympanic membrane is disrupted?

<p>Battle’s sign, which is ecchymosis in the post-auricular area.</p> Signup and view all the answers

Which types of traumas commonly lead to traumatic inner ear diseases?

<p>Road traffic accidents and blunt trauma to the skull.</p> Signup and view all the answers

What is the primary treatment for hemotympanum?

<p>Conservative treatment usually suffices, resolving within 3-4 weeks.</p> Signup and view all the answers

How long does it typically take for a tympanic membrane perforation to heal?

<p>It usually heals within 3 months.</p> Signup and view all the answers

What is recommended for immediate facial nerve paralysis treatment?

<p>Surgical exploration with an attempt to repair the nerve is recommended.</p> Signup and view all the answers

What are two key treatments for a CSF leak?

<p>Medical treatment includes bed rest and lumbar drain, while surgical closure is considered if persistent for over 10 days.</p> Signup and view all the answers

What characterizes noise-induced hearing loss (NIHL)?

<p>NIHL results from chronic exposure to noisy environments and can lead to temporary or permanent hearing loss.</p> Signup and view all the answers

What frequency range is most damaging for sensorineural hearing loss due to noise?

<p>Frequencies between 2,000–3,000 Hz cause more SNHL than lower or higher frequencies.</p> Signup and view all the answers

What audiometric finding is characteristic of early stage noise-induced hearing loss?

<p>A typical notch at 4000 Hz is observed in both air and bone conduction.</p> Signup and view all the answers

What are common clinical features of noise-induced hearing loss?

<p>Symptoms include shouting to communicate and experiencing aural fullness or tinnitus.</p> Signup and view all the answers

What precautionary measures should workers in noisy environments take to prevent noise-induced hearing loss (NIHL)?

<p>Workers should have annual audiograms and use ear protectors like ear plugs or earmuffs.</p> Signup and view all the answers

What is the mainstay treatment for sudden sensorineural hearing loss (SSNHL)?

<p>Corticosteroid therapy is the primary treatment for SSNHL.</p> Signup and view all the answers

List two common associated symptoms of sudden sensorineural hearing loss.

<p>Tinnitus and temporary spells of vertigo are common symptoms.</p> Signup and view all the answers

What could be the underlying etiological factors speculated for idiopathic SSNHL?

<p>Speculated factors include viral infections, vascular issues, and rupture of cochlear membranes.</p> Signup and view all the answers

What laboratory tests might be ordered to investigate suspected causes of SSNHL?

<p>Tests may include CBC, ESR, tests for syphilis, diabetes, and lipid profiles.</p> Signup and view all the answers

Why is Gadolinium-enhanced MRI indicated for patients with SSNHL?

<p>It is indicated when there is suspicion of acoustic neuroma.</p> Signup and view all the answers

What is the recommended initial dosage of prednisolone for treating sudden hearing loss?

<p>The initial dosage is 40–60 mg in the morning for one week.</p> Signup and view all the answers

How does noise exposure above 85 dB impact hearing health in factory workers?

<p>It puts workers at risk for noise-induced hearing loss (NIHL).</p> Signup and view all the answers

Study Notes

Diseases of the Inner Ear

  • The inner ear consists of the cochlea (hearing) and the vestibular apparatus (balance).
  • Benign Paroxysmal Positional Vertigo (BPPV) is a common cause of vertigo.
    • It is caused by displaced otoliths (ear stones) in the semicircular canals.
    • Dix-Hallpike maneuver is used to diagnose BPPV.
      • The patient is rapidly moved from a sitting to a supine position with their head hanging off the edge of the bed.
      • A positive test results in vertigo and nystagmus (jerky eye movements).
    • Treatment for BPPV includes Epley's maneuver (a series of head movements), vestibular exercises, and rarely surgery.
  • Meniere's Disease is an inner ear disorder characterized by episodic vertigo, hearing loss, tinnitus, and a feeling of fullness in the ear.
    • The cause is thought to be endolymphatic hydrops (fluid buildup in the inner ear).
    • Clinical features include:
      • Vertigo lasting 30 minutes to 4 hours.
      • Sensorineural hearing loss (affecting lower frequencies in the early stages) that fluctuates.
      • Tinnitus and a feeling of fullness in the ear.
    • Treatment includes:
      • Vestibular sedatives like cinnarizine.
      • Long-term medications such as betahistine and diuretics.
      • Lifestyle modifications like avoiding caffeine and salt.
      • Medical ablation therapy (using gentamicin to damage vestibular cells) for severe cases.
      • Endolymphatic sac surgery or vestibular nerve section for some patients.

Vestibular Neuritis

  • Aetiology is thought to be viral, with herpes simplex virus type 1 being a likely culprit.
  • Clinical Presentation:
    • Acute vertigo associated with nausea and vomiting.
    • Symptoms are aggravated by head movements and minimized by keeping the head still.
    • Hearing is normal, but there may be balance issues that persist for months.
  • Diagnosis is clinical.
  • Treatment includes corticosteroids, antiviral drugs, and vestibular sedatives.

Traumatic Inner Ear Disease

  • Occurs due to temporal bone fractures, commonly caused by RTA or blunt trauma to the skull.
  • Fracture Types:
    • Longitudinal fractures (80-90%) are less likely to directly involve the labyrinth.
    • Transverse fractures (10-20%) are more likely to involve the labyrinth and lead to sensorineural hearing loss.
  • Longitudinal fracture often causes conductive hearing loss due to ossicular dislocation, bleeding into the middle ear, or tympanic membrane rupture.
  • Transverse fracture frequently leads to sensorineural hearing loss, vertigo, and facial palsy.
  • Treatment may include steroids to reduce edema, supportive measures, and antivirals.
  • Affects more than one-third of people over 75.
  • Predisposing factors include genetics, chronic noise exposure, vascular risk factors, ototoxicity, and diet.
  • Four pathological types have been identified:
    • Sensory: Degeneration of the organ of Corti.
    • Neural: Degeneration of the spiral ganglion.
    • Striatal or metabolic: Atrophy of the stria vascularis.
    • Cochlear conductive: Stiffening of the basilar membrane.
  • Clinical features include:
    • Gradual, symmetrical hearing loss.
    • Difficulty hearing in noisy environments.
    • Poor speech discrimination.
    • There is no specific treatment, but hearing aids can help.

Anatomy of the Inner Ear

  • Consists of three semicircular canals, the utricle, and the saccule

Inner Ear Diseases

  • Symptoms: Deafness (sensorineural hearing loss or SNHL), vertigo, and tinnitus
  • Causes: Can be peripheral (e.g., labyrinth) or central
  • Types of Vertigos:
    • Benign Paroxysmal Positional Vertigo (BPPV)
    • Meniere's Disease (Endolymphatic Hydropis)
    • Vestibular Neuritis
    • Labyrinthitis

Benign Paroxysmal Positional Vertigo (BPPV)

  • Characterized by episodic vertigo triggered by head movement
  • Pathophysiology: Canalolithiasis theory - otoliths (calcium carbonate particles) detach from the utricle and enter the posterior semicircular canal during head movement, causing vertigo
  • Clinical features:
    • Vertigo lasting seconds
    • Triggered by specific head movements (e.g., turning in bed, looking up)
    • No hearing loss, tinnitus, or other neurological symptoms

Meniere's Disease

  • Characteristics:
    • Fluctuating sensorineural hearing loss (affects lower frequencies early on)
    • Tinnitus and a feeling of fullness or pressure in the ear
    • Hearing loss and tinnitus become permanent over time
    • Usually unilateral initially, but can become bilateral
  • Diagnosis:
    • Audiogram showing low frequency SNHL
    • Treatment:
      • Acute phase: Vestibular sedatives (e.g., cinnarizine, pyride)
      • Long term: Betahistine, diuretics, avoiding caffeine and salt, reassurance
  • Medical ablation therapy: Gentamicin administered through the tympanic membrane to damage vestibular cells
  • Surgical Options:
    • Endolymphatic sac surgery
    • Vestibular nerve section

Vestibular Neuritis

  • Viral infection of the vestibular nerve
  • Aetiology: Likely caused by viral infection, supported by polymerase chain reaction (PCR) detection of viral DNA
  • Clinical presentations:
    • Acute spontaneous vertigo, nausea, vomiting
    • Aggravated by head movement
    • Improved by keeping the head still and closing the eyes
    • During walking, the patient tends to fall to the side of the affected labyrinth
  • Features:
    • Symptoms subside over days, but residual imbalance can last for months
    • Hearing is normal
    • Nystagmus (horizontal towards the unaffected side)
    • Positive Unterberger test
  • Diagnosis: Clinical, no neurological signs
  • Treatment: Corticosteroids with antiviral drugs, vestibular sedative during acute attacks, rest

Traumatic Inner Ear Disease (Temporal Bone Fractures)

  • Occurs in 20% of skull base fractures
  • Aetiology: Road traffic accidents (RTA), blunt trauma to the lateral surface of the skull
  • Classification:
    • Longitudinal fractures (80-90%)
    • Transverse fractures (10-20%)

Longitudinal Fractures

  • Often spare the labyrinth
  • Fracture involves the external meatus and the roof of the middle ear
  • Hearing loss: Conductive deafness due to ossicular dislocation, bleeding into the middle ear cleft (haemotympanum), tympanic membrane rupture
  • Facial palsy: Uncommon
  • Other symptoms: Bleeding from the ear, CSF otorrhea if tympanic membrane is disrupted, Battle's sign

Transverse Fractures

  • Usually involve the labyrinth, leading to sensorineural hearing loss and profound vertigo
  • Vertigo usually settles over time as central compensation occurs
  • Facial palsy occurs in 50% of cases

Treatment of Temporal Bone Fractures

  • Haemotympanum: Conservative treatment, resolves within 3-4 weeks
  • Tympanic membrane perforation: Usually heals within 3 months, myringoplasty if it persists
  • Facial nerve paralysis: Immediate paralysis treated surgically, delayed treated conservatively
  • CSF leak: Medical treatment (bed rest, head elevation, stool softener, lumbar drain, antibiotics), surgical defect closure if it persists for more than 10 days

Acoustic Trauma

  • Caused by sudden loud sounds (e.g., explosions)
  • Effects:
    • Sensorineural hearing loss (SNHL, most common)
    • Conductive hearing loss due to tympanic membrane rupture or damage to the middle ear

Noise-Induced Hearing Loss (NIHL)

  • A major cause of preventable SNHL
  • Follows chronic exposure to less intense sounds than acoustic trauma
  • Types:
    • Temporary threshold shift (recovers within minutes to weeks)
    • Permanent threshold shift (hearing loss becomes permanent)
  • Factors affecting noise trauma:
    • Frequency (2,000-3,000 Hz most damaging)
    • Intensity and Duration (higher intensity requires less exposure time)
    • Continuous vs Interrupted noise (continuous is more harmful)
    • Susceptibility (some individuals are genetically susceptible)
    • Pre-existing ear disease
  • Pathology: Damages hair cells, starting at the basal turn of the cochlea, outer hair cells affected first
  • Clinical features:
    • Shouting at work
    • Aural fullness, tinnitus, muffled hearing after work
  • Pure Tone Audiogram (PTA):
    • Early stage: Notch at 4,000 Hz, usually symmetrical
    • Late stage: Notch deepens and widens to involve lower and higher frequencies, including speech frequencies

Prophylaxis for NIHL

  • Pre-employment and annual audiograms
  • Ear protectors (earplugs or earmuffs)
  • Rehabilitation for existing NIHL

Sudden Sensorineural Hearing Loss (SSNHL)

  • Develops over hours or days, hearing loss may be partial or complete
  • Mostly unilateral, but can affect both ears
  • Associated symptoms: Tinnitus, temporary vertigo
  • Etiology: Idiopathic in 85-90% of cases, speculated causes include viral, vascular, rupture of cochlear membranes
  • Causes that need to be ruled out: Upper respiratory infections (URI), acoustic neuroma
  • Investigations:
    • Laboratory tests: CBC, ESR, tests for syphilis, diabetes, hypothyroidism, blood disorders, lipid profiles, vestibular tests
    • Gadolinium-enhanced MRI for acoustic neuroma
    • Exploratory tympanotomy for suspected perilymph fistula
  • Treatment: Empirical, as cause is often unclear
  • Mainstay treatment: Corticosteroid therapy
  • Other therapies: Vasodilators, diuretics, anticoagulants, thrombolytic agents
  • Key elements of treatment: Bed rest, steroid therapy (Prednisolone 40-60 mg in a morning dose for 1 week, tapered over 3 weeks)

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Inner Ear Diseases PDF

Description

Explore the common diseases affecting the inner ear, including Benign Paroxysmal Positional Vertigo (BPPV) and Meniere's Disease. Learn about their causes, symptoms, and diagnostic methods such as the Dix-Hallpike maneuver. This quiz will test your knowledge on the treatment options and clinical features of these inner ear disorders.

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