Menieres; Malignant OM; Mastoiditis Flashcards
(20 cards)
Describe the pathophysiology of Menieres disease [1]
Ménière’s disease is associated with the excessive buildup of endolymph in the labyrinth of the inner ear, causing a higher pressure than normal and disrupting the sensory signals. This increased pressure of the endolymph is called **endolymphatic hydrops. **
TOM TIP: Remember the typical triad of symptoms in Ménière’s disease, as this is commonly tested in exams. What are they? [3]
What are other presenting features?
TOM TIP: Remember the typical triad of symptoms in Ménière’s disease, as this is commonly tested in exams:
* Hearing loss
* Vertigo - Vertigo is usually the prominent symptom
* Tinnitus
A sensation of aural fullness or pressure is now recognised as being common
other features include nystagmus and a positive Romberg test
episodes last minutes to hours
typically symptoms are unilateral but bilateral symptoms may develop after a number of years
Describe the natural history of Menieres [2]
Natural history
symptoms resolve in the majority of patients after 5-10 years
the majority of patients will be left with a degree of hearing loss
psychological distress is common
Describe the typical presentation of case of Menieres [+]
The typical patient is 40-50 years old, presenting with unilateral episodes of vertigo, hearing loss, and tinnitus.
Vertigo in Ménière’s disease comes in episodes. These last for 20 minutes to several hours before settling.
- These episodes can come in clusters over several weeks, followed by prolonged periods (often months) without vertigo symptoms.
- Vertigo is NOT triggered by movement or posture.
Tinnitus initially occurs with episodes of vertigo before eventually becoming more permanent.
- It is usually unilateral.
What is a ‘drop attack’ in Menieres? [1]
Unexplained falls (“drop attacks”) without loss of consciousness
Acute tx [2] and prophylactic tx [1] of Menieres?
For acute attacks, short-term options for managing symptoms include:
* Prochlorperazine
* Antihistamines (e.g., cyclizine, cinnarizine and promethazine)
Prophylaxis is with:
* Betahistine
Describe who you see malignant otitis externa in? [1]
What is the most common infective organism? [1]
Describe the pathophysiology [2]
Uncommon type of otitis externa that is found in immunocompromised individuals (90% cases found in diabetics)
- Infective organism is usually Pseudomonas aeruginosa
Infection commences in the soft tissues of the external auditory meatus, then progresses to involve the soft tissues and into the bony ear canal
- Progresses to temporal bone osteomyelitis
Pulsenotes:
- Malignant otitis externa is a serious condition where infection spreads from the external auditory canal to the skull base.
What are the key features of Malingant ottitis externa? [4]
- Diabetes (90%) or immunosuppression (illness or treatment related)
- Severe, unrelenting, deep-seated otalgia
- Temporal headaches
- Purulent otorrhea
- Possibly dysphagia, hoarseness, and/or facial nerve dysfunction
Tx for malignant otitis externa? [1]
Intravenous antibiotics that cover pseudomonal infections
Malignant otitis externa can lead to damage to which cranial nerve? [1]
Cranial Nerve Involvement: The most common complication, often starting with the facial nerve (cranial nerve VII), leading to facial palsy. Other cranial nerves such as IX, X, XI, and XII may also be affected.
Describe what is meant by mastoiditis [2]
Mastoiditis is inflammation of the mastoid antrum and the lining of the mastoid air cells
- mastoid process is the area of bone formed of the petrous temporal and occipital bones which is present posterior and inferior to the external auditory meatus
Describe the pathophysiology of mastoiditis [+]
The mastoid bone is made up of air spaces within the occipital and petrous temporal bones which are lined with a mucosa and are interconnected.
- These are called the mastoid air cells. They communicate directly with the cavity of the middle ear and so pus collecting in the middle ear (acute otitis media) can enter the mastoid air cells.
This can also occur as a result of a cholesteatoma developing
- The cholesteatoma results in excessive collection of keratin and sloughed cells building up in the mastoid air cells and middle ear.
- The resulting collection can become infected and subsequently spread throughout the air cells.
Once infection enters the air cells it gains an advantage against the immune system and mastoid osteomyelitis rapidly develops leading to sepsis, erythema and swelling over the mastoid process.
The main pathogens linked with otitis media and mastoiditis are:
[1] is most common in young children prior to vaccination.
[2] are the most common in children of school age.
[2] are the most common pathogens in adults.
[1] can be a less common cause in adults, usually in diabetic patients.
Haemophilus influenzae is most common in young children prior to vaccination.
Streptococcus pyogenes and Streptococcus pneumoniae are the most common in children of school age.
Streptococcus pneumoniae and Staphylococcus aureus are the most common pathogens in adults.
**Pseudomonas aeruginosa **can be a less common cause in adults, usually in diabetic patients.
Key features of mastoiditis? [+]
The key features usually found in the history are:
* Recent or concurrent acute otitis media in around 50% of cases.
* Deep otalgia on the affected side in nearly all cases.
* Recent loss of hearing (progressive) on affected side.
* Generally unwell with young children often not eating or drinking as normal.
* Seizures and symptoms of intracranial infection are rarely the presenting symptoms.
Features of mastoiditis on exam? [4]
They key findings on examination are:
Fever.
Usually bulging tympanic membrane with clear fluid level or perforation with purulent discharge from the ear.
Erythema and swelling over mastoid process behind the ear in up to 75% of cases.
Mastoid tenderness.
Cervical lymphadenopathy on affected side.
Ix for mastoiditis?
The key investigations required are CT or MRI imagining of the head. Ideally both would be performed, especially when planning surgical management.
* CT scanning is quick and will demonstrate the extent of mastoid air cell opacification. A CT scan with contrast can also identify intracranial infection and the extent of this.
* MRI imaging is better for identifying intracranial infection and will give better detail of the soft tissues but struggles to see the bone in as much detail.
Mx for mastoiditis? [+]
The mainstay of management is early intravenous antibiotics
- ceftriaxone: have good bone penetration
The operative options for treating mastoiditis are:
Myringotomy and grommet insertion in addition to antibiotics to help infection drain via the middle ear.
Mastoidectomy to drill out the mastoid bone and allow the infection to drain. This can be accomplished in two ways:
* A cortical mastoidectomy is performed through a skin incision behind the ear and involves removing the mastoid without entering the ear canal.
* A radical mastoidectomy involves both removing the mastoid and removing the walls of the auditory canal and clearing the contents of the middle ear. This has a significant risk of affecting hearing compared to a cortical mastoidectomy.
Describe the different types of hearing loss see in mastoiditis [2]
Conductive hearing loss
- can be due to a middle ear effusion from co-existing acute otitis media or due to infection causing destruction of the ossicles.
Sensorineural hearing loss and vertigo can occur if the inner ear is affected by progressive mastoid destruction.
Mastoiditis:
The most serious complication is erosion of the mastoid into the cranial vault. This can result in any of:
[3]
The most serious complication is erosion of the mastoid into the cranial vault. This can result in any of:
Meningitis.
Formation of a subdural empyema.
Intracerebral abscess formation.
