Ears Flashcards
(152 cards)
1
Q
which parts of the external ear partially cover opening of ear canal (prevent foreign body entrance)?
A
Tragus and conchal cartilage
2
Q
what is the function of ear Hair and isthmus narrowing?
A
inhibit entry of contaminants.
3
Q
what are the properties of cerumen (earwax) and their purpose?
A
It is acidic, which helps to inhibit the growth of bacteria and fungi.
Its hydrophobic properties repel water, preventing the ear canal from becoming too moist, which could otherwise lead to infections.
Additionally, its sticky nature allows it to trap dust, debris, and small particles, preventing them from reaching the eardrum.
4
Q
which portion of ear canal is bony and which is cartilaginous?
A
the inner 2/3 is bony while the outer 1/3 is cartilaginous.
5
Q
what produces furuncle or pustule in otitis externa?
A
folliculitis of hair follicle
6
Q
what is the most common bacteria that causes otitis externa?
A
Pseudomonas aeruginosa and Staphylococcus aureus
However, it can also be caused by fungal infections (eg. Candida Albicans)
7
Q
what bacterial skin infection of the outer layer can affect the concha and ear canal if it spreads there and what bacteria causes it?
A
Erysipelas
group A Streptococcus
8
Q
what is otitis externa?
A
Otitis externa, commonly known as “swimmer’s ear,” is an inflammation of the ear canal.
9
Q
what are the clinical symptoms of otitis externa?
A
Clinical Features: The infection typically presents with:
Erythema: Redness of the skin lining the external ear canal. [redness of eardrum]
Edema: Swelling due to inflammation, which can narrow the ear canal.
Pus and Skin Debris: Discharge is common in otitis externa, which may contain pus and flakes of skin debris from the infected and inflamed skin within the ear canal.
Pain: The ear canal is sensitive and inflammation can lead to significant pain, which can be exacerbated by moving the ear or jaw.
Lymphadenopathy: The infection can cause the regional lymph nodes (often in the neck or near the ear) to become swollen and tender.
[cellulitis-infection of skin]
[otorrhea-discharge from ear]
[pruritus]
10
Q
what is a furuncle?
A
A furuncle, commonly known as a boil, is a deep folliculitis, or infection of a hair follicle. It is typically caused by bacterial infection, most commonly by Staphylococcus aureus. When a furuncle occurs in the ear canal, it can almost completely occlude the meatus (the external opening of the ear canal), leading to pain and other symptoms.
11
Q
which health condition are risk factors for otitis externa more common in?
A
Risk Factors:
The condition is more common in individuals with a weakened immune system, diabetes, and swimmers due to increased exposure to moisture.
12
Q
what are the risk factors for otitis externa?
A
Swimming (Water Exposure):
Excess moisture from activities like swimming can lead to skin maceration (softening and breaking down of the skin) and disrupt the protective skin-cerumen (earwax) barrier.
Microflora Changes:
The ear canal’s normal flora may shift towards predominantly gram-negative bacteria following prolonged moisture exposure, increasing infection risk.
Trauma:
Trauma from excessive ear cleaning or aggressive scratching can strip away the protective cerumen and create abrasions through which bacteria or fungi may infect deeper tissues.
Foreign Bodies:
Items such as cotton swabs or tissue paper can partially disintegrate inside the ear canal, leading to severe skin reactions and possible infection.
Ear Canal Occlusion:
Devices that occlude the ear canal, like hearing aids, earphones, or diving caps, can create a moist environment conducive to infection.
Allergic Contact Dermatitis:
Allergies to materials in earrings or chemicals found in cosmetics or shampoos can cause inflammation of the ear canal.
Dermatologic Conditions:
Skin conditions such as psoriasis and atopic dermatitis can predispose individuals to develop otitis externa.
Radiation Therapy:
It can lead to ischemic changes in the ear canal, altering normal cerumen production and the natural migration of epithelial cells, making the ear more susceptible to infection.
13
Q
how does otitis externa develop?
A
Breakdown of Skin-Cerumen Barrier: The skin lining the ear canal has a protective layer of cerumen (earwax), which has antimicrobial properties and forms a barrier against water and pathogens. Disruption of this layer, often due to moisture (as in swimmers), trauma from scratching or cleaning, or skin conditions like eczema, can initiate otitis externa.
Inflammation and Edema: Once the barrier is compromised, bacteria or fungi can invade, leading to inflammation. This results in swelling (edema) and narrowing of the ear canal.
Pruritus and Obstruction: The inflammation is irritating and causes itching (pruritus), which leads individuals to scratch the ear, causing further damage to the skin and exacerbating the condition. The swelling can also lead to partial or complete obstruction of the ear canal, trapping any fluid or debris and creating an environment conducive to infection.
Altered Cerumen: The normal acidic pH and protective properties of cerumen are altered. This, combined with the impaired migration of the epithelial cells that line the ear canal due to inflammation, can lead to an increase in the pH, making the environment more alkaline.
Ideal Environment for Pathogens: The combination of a warm, moist, and alkaline environment in the ear canal provides an ideal breeding ground for pathogens.
14
Q
what is otomycosis and how does it present clinically?
A
This is a fungal infection of the ear canal, often caused by Aspergillus or Candida species.
Aspergillus: Typically presents as a fine, dark coating within the ear canal.
Candida: May present as a whitish, sebum-like substance in the ear canal.
15
Q
how do you differentiate mild, moderate, or severe otitis externa?
A
Severity Grading:
Mild External Otitis: Characterized by minor discomfort, itching, and minimal swelling of the ear canal.
Moderate External Otitis: Involves more pain and itching, with the ear canal partially blocked by swelling.
Severe External Otitis: Presents with intense pain, complete occlusion of the ear canal, and may be accompanied by redness around the ear (periauricular erythema), swollen lymph nodes (lymphadenopathy), and fever.
16
Q
what are 2 complications of acute otitis externa?
A
Periauricular cellulitis and Malignant external otitis
17
Q
what is an infection of the skin around the ear (auricle), characterized by redness (erythema), swelling (edema), and warmth.
Pain is generally mild, and systemic symptoms, such as fever or malaise, are typically absent.
usually does not spread far beyond the local site of infection?
A
Periauricular Cellulitis
18
Q
what is a severe and potentially life-threatening infection that extends from the external ear canal to the base of the skull, particularly affecting the temporal bone and the soft tissues of the temporal region.
The infection is often caused by Pseudomonas aeruginosa, though Methicillin-Resistant Staphylococcus aureus (MRSA) has also been reported.
It is more common among older individuals, diabetics, or those with compromised immune systems?
A
Malignant External Otitis (Necrotizing Otitis Externa or Skull Base Osteomyelitis)
19
Q
what is the main bacteria that causes Malignant External Otitis (Necrotizing Otitis Externa or Skull Base Osteomyelitis)?
A
Pseudomonas aeruginosa
20
Q
what is a sign of poor prognosis in acute otitis externa complications?
A
If cranial nerves are involved, resulting in palsies, it’s a poor prognostic sign.
21
Q
what lab findings are revealed in acute otitis externa complications?
A
Laboratory findings often reveal a markedly elevated erythrocyte sedimentation rate (ESR), indicating inflammation.
22
Q
what are some clinical presentations of acute otitis externa complications?
A
Patients typically present with severe ear pain (otalgia) and discharge from the ear (otorrhea).
A classic sign is granulation tissue at the junction of the bony and cartilaginous parts of the ear canal floor.
There may be edema and erythema around the ear, along with actual skin necrosis within the ear canal.
23
Q
what is a classic sign of acute otitis externa complications?
A
A classic sign is granulation tissue at the junction of the bony and cartilaginous parts of the ear canal floor.
24
Q
what imaging modality is used in acute otitis externa complications?
A
Imaging with CT (computed tomography) or MRI (magnetic resonance imaging) can provide detailed views of the extent of the infection and any bone involvement.
25
what is cholesteatoma?
A cholesteatoma is an abnormal, noncancerous skin growth that can develop in the middle section of the ear, behind the eardrum. It is typically caused by repeated infection or a poorly functioning Eustachian tube that does not equalize ear pressure properly and causes the eardrum to retract ( forming a pocket or cyst that fills with old skin cells and other debris. Over time, this cyst can grow and may become infected). Cholesteatoma can also occur as a birth defect (thought to arise from embryonic epithelial remnants in the middle ear), though this is less common.
Over time, a cholesteatoma can expand and erode through the delicate structures within the temporal bone, which houses the middle and inner ear.
This erosive process can lead to the destruction of the ossicles (tiny bones necessary for sound conduction), the inner ear, and can even affect the facial nerve which traverses the middle ear.
These are more common and usually occur as a result of chronic ear infections or eustachian tube dysfunction.
They can also form after a perforation of the tympanic membrane, which may occur due to chronic otitis media, trauma, or previous ear surgeries.
With the perforation, skin cells from the outer layer of the eardrum and external ear canal can migrate into the middle ear and form a cholesteatoma.
26
how do you confirm an ear infection is fungal in nature?
It doesn't respond to topical antibiotics
27
what's the difference between diffuse otitis externa and localized otitis externa?
Diffuse affects the entire ear canal, more severe pain, more systemic symptoms like fever or malaise, and hearing loss may be more pronounced
localized involve a localized area in ear canal often the hair follicle, presents as furuncle/boil in ear canal while rest of ear canal looks normal.
28
what also form after a perforation of the tympanic membrane, which may occur due to chronic otitis media, trauma, or previous ear surgeries?
Cholesteatoma
29
what is the classic sign of cholesteatoma and what causes it?
The classic sign of a cholesteatoma is a painless ear discharge, which is often chronic and foul-smelling. The discharge occurs due to the accumulation and breakdown of skin cells and other debris from the cholesteatoma.
30
If there is an associated infection, abscess formation, or mastoiditis (infection of the mastoid bone) with cholesteatoma, pain will be present. Why might these conditions be difficult to treat when cholesteatoma is present?
because the cholesteatoma may impede adequate blood supply, making it difficult for antibiotics to reach the infected area effectively.
31
what kind of hearing loss is typical in cholesteatoma? conductive or sensorineural?
Hearing loss in cases of cholesteatoma is typically conductive, meaning that sound waves are not efficiently conducted through the outer and middle ear to the inner ear.
This can be due to obstruction from the cholesteatoma itself or from the destruction of the ossicles (the small bones in the middle ear that transmit sound vibrations).
32
what causes conductive hearing loss in cholesteatoma?
This can be due to obstruction from the cholesteatoma itself or from the destruction of the ossicles (the small bones in the middle ear that transmit sound vibrations).
33
what does vertigo indicate in cholesteatoma?
Vertigo is less common but can be very concerning when it occurs. It indicates that the cholesteatoma has created a fistula, which is an abnormal connection into the labyrinth (inner ear structures responsible for balance). This can lead to balance disturbances and dizziness.
34
what are some neurologic complications from cholesteatoma?
Neurologic Complications:
Facial Nerve Palsy: The facial nerve runs through the middle ear, and a cholesteatoma can exert pressure on this nerve, leading to paralysis of the facial muscles.
Sigmoid Sinus Thrombosis: A serious complication where the cholesteatoma causes a blood clot in the sigmoid sinus, a major blood vessel within the skull.
Epidural Abscess: An accumulation of pus between the tough outer membrane of the central nervous system (the dura mater) and the skull.
Meningitis: The most serious complication, which is an infection of the membranes covering the brain and spinal cord.
35
what is the most serious complication of cholesteatoma?
Meningitis: The most serious complication, which is an infection of the membranes covering the brain and spinal cord.
36
what's the most important factor in the development of otitis media?
dysfunction of eustachian tube
37
what is acute otitis media?
Acute otitis media (AOM) is an infection of the middle ear, which is the air-filled space behind the eardrum that contains the tiny vibrating bones of the ear. It's common in children and often happens after a child has had a cold for a few days.
38
what normally precedes acute otitis media in a child?
a cold for a few days
39
which ear infection is most common in children?
acute otitis media
40
what are the most common bacterial causes of acute otitis media?
It's typically caused by bacteria, and the most common bacterial pathogens are Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis. Viruses can also contribute to the infection, either alone or as part of a co-infection with bacteria.
41
what are risk factors associated with Acute otitis media?
Risk Factors for AOM include:
Tobacco Smoke Exposure: Children exposed to tobacco smoke may have increased colonization of S. pneumoniae in their nasopharynx, which can lead to more frequent and severe infections.
Young Age: Children between 6 and 16 months old are at a higher risk due to their still-developing immune system and less functional Eustachian tubes.
Anatomical Variations: Children with Down syndrome or Pierre Robin sequence may have anatomical differences that affect the function of the Eustachian tube, leading to fluid build-up and infection.
Lack of Immunizations: Immunizations help protect against certain pathogens that can cause AOM. A lack of immunizations means the child's immune system may not be primed to fight off these pathogens.
Lack of Breastfeeding: Breastfeeding provides important antibodies, like IgA, that help protect infants from infections. A lack of breastfeeding can increase the risk of colonization with pathogens.
Daycare Attendance: Children who attend daycare are exposed to more infectious agents due to overcrowding and greater exposure to other children who may be ill.
42
why is tobacco smoke exposure in children a risk factor for acute otitis media?
Tobacco Smoke Exposure: Children exposed to tobacco smoke may have increased colonization of S. pneumoniae in their nasopharynx, which can lead to more frequent and severe infections.
43
which bacterial growth does tobacco smoke exposure encourage in children leading to AOM?
Streptococcus Pneumoniae
44
what is the function of eustachian tube?
The Eustachian tube connects the middle ear to the back of the throat and serves to equalize air pressure and drain fluid from the middle ear.
Fluid can accumulate behind the eardrum, and negative pressure can develop in the middle ear, leading to a conducive environment for bacterial or viral growth.
45
why is otitis media more common in children than adults?
In children, the Eustachian tube is shorter, narrower, and more horizontally positioned than in adults, which makes it more challenging for the tube to function properly. These anatomical differences contribute to the higher incidence of otitis media in children compared to adults.
46
what role does the soft palate muscle play related to the eustachian tube and how does this relate to children getting more frequent acute otitis media infections than adults?
The muscles of the soft palate play a role in the opening and closing of the Eustachian tube. In young children, the relative position of the muscle sling that opens the Eustachian tube is not as effective, leading to less frequent and less efficient opening.
47
what is a characteristic finding in otitis media with effusion (OME), where fluid is present in the middle ear without signs or symptoms of an acute infection?
air-fluid level
48
what does the appearance of air-fluid level in middle ear look like?
Translucent Above the Line: The upper part of the tympanic membrane appears more clear or translucent when air is above the fluid level in the middle ear. This indicates that there is still some air present in the middle ear space.
Opaque Below the Line: Below this line, the tympanic membrane looks cloudy or opaque due to the presence of fluid, which can vary from serous (clear fluid) to purulent (pus) depending on the nature and severity of the infection or inflammation.
The line that demarcates the separation between the air and fluid is a horizontal line that can be seen during an examination with an otoscope. It is an indication that there is a difference in the density of the middle ear contents — air above and fluid below. You may also see bulging tympanic membrane.
49
what are some complications of acute otitis media?
Vestibular Dysfunction: When fluid builds up in the middle ear for a prolonged period, it can affect the inner ear where the balance apparatus is located, leading to balance problems or vertigo.
Perforation of the Tympanic Membrane (TM): The pressure from the fluid accumulation in the middle ear can lead to a rupture of the eardrum. This can provide temporary pain relief as the pressure decreases, but also leads to discharge from the ear (otorrhea).
Conductive Hearing Loss: The fluid in the middle ear can interfere with the transmission of sound to the inner ear, leading to a temporary reduction in hearing.
Mastoiditis/Mastoid Abscess: The infection can spread to the mastoid cells, which are air spaces in the bone behind the ear, leading to mastoiditis or the formation of an abscess.
Effect on Cranial Nerve VIII: While mastoiditis can affect the nearby cranial nerve VIII (vestibulocochlear nerve), resulting in hearing problems, sensorineural hearing loss due to AOM is quite rare.
Severe Infection/Spread: In some cases, the infection can spread beyond the middle ear to other parts of the body, which can lead to very serious complications such as meningitis (inflammation of the membranes around the brain and spinal cord), brain abscesses, sepsis (a widespread infection in the bloodstream), high fever, and febrile seizures.
50
what is one of the causes of otorrhea in acute otitis media?
Perforation of the Tympanic Membrane (TM): The pressure from the fluid accumulation in the middle ear can lead to a rupture of the eardrum. This can provide temporary pain relief as the pressure decreases, but also leads to discharge from the ear (otorrhea).
51
what is mastoiditis?
Mastoiditis/Mastoid Abscess: The infection from acute otitis media can spread to the mastoid cells, which are air spaces in the bone behind the ear, leading to mastoiditis or the formation of an abscess.
52
what are some complications of mastoiditis?
Lateral Sinus Thrombosis:
This condition occurs when the infection leads to a clot within the lateral sinus (a large vein within the brain).
Symptoms may include spiking fevers, headache, neck stiffness or pain (meningeal signs), swelling and tenderness over the mastoid bone, discharge from the ear (otorrhea), ear pain (otalgia), and potential issues with cranial nerves IX (glossopharyngeal), X (vagus), and XI (spinal accessory).
Bezold Abscess:
This type of abscess occurs when the infection spreads from the mastoid bone to the surrounding neck muscles, particularly the sternocleidomastoid muscle.
It may present as a painful, swollen area in the neck.
Subperiosteal Abscess:
An abscess that forms beneath the periosteum, the layer covering the mastoid bone.
This can push the outer ear (pinna) forward and outward.
Facial Nerve Palsy (CN VII):
The facial nerve (cranial nerve VII), which passes through the middle ear and mastoid bone, can be affected by the infection or pressure from an abscess, leading to weakness or paralysis of the muscles on one side of the face.
Sensorineural Hearing Loss and Labyrinthitis (CN VIII):
Inflammation or infection that affects the inner ear (labyrinth) can cause vestibular symptoms such as vertigo (labyrinthitis) and sensorineural hearing loss, involving cranial nerve VIII (vestibulocochlear).
Meningitis:
Infection can spread to the meninges, the protective membranes covering the brain and spinal cord, leading to meningitis, a potentially life-threatening condition.
Temporal Lobe Abscess:
An abscess in the temporal lobe of the brain can occur if the infection spreads through the inner ear or via bone erosion.
Epidural/Subdural Abscess:
These abscesses form between the skull and the dura mater, or between the dura mater and the arachnoid mater, respectively. They can exert pressure on the brain and require urgent treatment.
Cerebellar Abscess:
An abscess in the cerebellum, the part of the brain responsible for coordinating movement, can cause problems with balance, coordination, and other cerebellar functions.
53
what is a type of abscess that occurs when the infection spreads from the mastoid bone to the surrounding neck muscles, particularly the sternocleidomastoid muscle.
It may present as a painful, swollen area in the neck?
Bezold abscess
If the infection spreads further, it can lead to necrotizing fasciitis, which is a severe, rapidly progressing infection that results in the death of the soft tissue.
54
what type of abscess pushes the outer ear forward and outward?
Subperiosteal Abscess:
An abscess that forms beneath the periosteum, the layer covering the mastoid bone.
This can push the outer ear (pinna) forward and outward.
55
which cranial nerve passes through the middle ear and mastoid bone and can be affected by mastoiditis what abnormal effect does it cause when affected?
Facial Nerve Palsy (CN VII):
The facial nerve (cranial nerve VII), which passes through the middle ear and mastoid bone, can be affected by the infection or pressure from an abscess, leading to weakness or paralysis of the muscles on one side of the face.
56
What is the mastoid antrum and where is it located?
The mastoid antrum is an air-filled cavity located in the temporal bone behind the middle ear. It is connected to the middle ear via a short passageway known as the aditus ad antrum.
57
What is the function of the mastoid antrum?
The mastoid antrum serves as a resonating chamber for sound and also helps to protect the delicate structures of the middle ear. Additionally, it is part of the system of air spaces that helps to equalize air pressure within the middle ear.
58
What is the tegmen mastoideum and its significance?
The tegmen mastoideum is the superior wall or roof of the mastoid antrum. It extends anteriorly as the tegmen tympani and forms a barrier that protects the brain from infections that may originate in the mastoid antrum.
59
How do the mastoid antrum and the mastoid air cells relate to each other?
The mastoid antrum intercommunicates peripherally with the mastoid air cells, which are multiple, variably-sized air spaces extending throughout the mastoid process. These air cells provide additional air volume and surface area to assist with the functions of the mastoid antrum.
60
What imaging technique is used to assess the mastoid antrum and air cells?
A CT (computed tomography) scan is commonly used to assess the mastoid antrum and air cells, as it provides detailed images of the bone structures and can help identify any abnormalities or infections.
61
How is mastoiditis related to the mastoid antrum?
Mastoiditis is an infection that can develop when bacteria from a middle ear infection spread into the mastoid antrum and the surrounding mastoid air cells, causing inflammation and potentially leading to serious complications if not treated promptly.
62
what is Tinnitus?
Tinnitus is the perception of noise or ringing in the ears when no external sound is present. It is a symptom, not a disease itself, and can manifest in various ways. It may be perceived as coming from within one or both ears, from inside the head, or from an external distance.
63
what is a common type of tinnitus that's not usually considered a serious medical periblem? continuous or intermittent
intermittent tinnitus
64
what is the difference between pulsatile and non-pulsatile tinnitus?
Non-pulsatile tinnitus is a constant noise that does not beat in time with the person's pulse. It is the most common type and is often associated with hearing loss.
Pulsatile tinnitus is less common and is characterized by a pulsing sound that typically beats in time with the heart. It is often caused by altered blood flow or increased blood turbulence near the ear.
65
which type of tinnitus is the most common type and often associated with hearing loss? pulsatile or non-pulsatile
non-pulsatile
66
what is the cause of pulsatile tinnitus?
It is often caused by altered blood flow or increased blood turbulence near the ear.
67
why is pulsatile tinnitus more concerning and require medical evaluation?
Pulsatile tinnitus is more concerning because it may indicate a vascular disorder or conditions that affect the blood vessels, such as high blood pressure, an aneurysm, or a tumor. It requires thorough medical evaluation to identify any underlying conditions.
68
what is a phenomenon where an individual perceives sound that does not come from an external source. It is often described as a ringing, buzzing, hissing, or whistling sound in the ears or head?
subjective tinnitus
The sound is subjective, meaning it can only be heard by the patient.
69
what are the main causes of subjective tinnitus?
Main Causes:
Acoustic Trauma: Exposure to loud noise can cause noise-induced sensorineural hearing loss, leading to tinnitus.
Presbycusis: Age-related hearing loss is another common cause of tinnitus.
Meniere’s Disease: A disorder characterized by episodes of vertigo, hearing loss, and tinnitus, associated with abnormal fluid pressures in the inner ear.
Ototoxic Drugs: Certain medications can damage the inner ear and result in tinnitus.
70
what are the 3 components of meniere's disease?
Meniere’s Disease: A disorder characterized by episodes of vertigo, hearing loss, and tinnitus, associated with abnormal fluid pressures in the inner ear.
71
what is the proposed theory behind subjective tinnitus?
The loss of normal auditory input to the brain may lead to changes in neural activity within the auditory cortex. This can result in the brain interpreting the increased neural activity as sound when there is none, leading to tinnitus.
72
what are some other causes of subjective tinnitus besides the proposed theory?
Other Potential Causes:
Demyelination: Conditions such as multiple sclerosis (MS) or vitamin B12 deficiency can affect the myelin sheath of nerve fibers, including those of CN VIII.
Otosclerosis: An abnormal bone growth in the middle ear that can cause hearing loss.
Vestibular Schwannoma: Also known as acoustic neuroma, is a benign tumor that can press on the auditory nerve.
Ear Wax Buildup: Can block the ear canal and contribute to hearing loss and tinnitus.
Cochlear Cell Damage: Caused by various factors such as ischemia, noise trauma, age, or vitamin A deficiency.
Fatty Deposits in the Inner Ear: Can alter the function of the inner ear structures.
Toxic Reactions: Some medications can have toxic effects on the inner ear.
Temporomandibular Joint Dysfunction: TMJ disorders can affect the muscles and nerves close to the ear, leading to tinnitus.
Psychogenic Causes: Tinnitus is sometimes associated with conditions like fibromyalgia, depression, or anxiety, although the exact mechanisms are not clear.
73
what is An abnormal bone growth in the middle ear that can cause hearing loss?
Otosclerosis
74
what is Also known as acoustic neuroma, is a benign tumor that can press on the auditory nerve?
Vestibular Schwannoma
75
what are some causes of demyelination?
Conditions such as multiple sclerosis (MS) or vitamin B12 deficiency can affect the myelin sheath of nerve fibers, including those of CN VIII.
76
what causes meniere's disease?
In Meniere’s disease, the inner ear experiences abnormal fluctuations of endolymph pressure, known as endolymphatic hydrops. This can lead to periodic episodes of tinnitus, hearing loss, and vertigo. Over time, these fluctuations can lead to the degradation of the hair cells in the cochlea, which are critical for hearing.
77
what is objective tinnitus?
Objective tinnitus is a type of tinnitus that, unlike the more common subjective tinnitus, can be heard by both the patient and the examiner. It is caused by an actual physical sound generated within the patient's body, often near the middle ear.
78
what are the 2 main category of causes for objective tinnitus?
Blood Vessel-Related Causes
Muscle-Related Causes
79
what are blood vessel related causes of objective tinnitus?
Normal Vessels with Increased or Turbulent Flow: Conditions that increase blood flow, such as exercise or pregnancy, can sometimes make normal blood flow audible. Turbulent blood flow caused by narrowed or kinked blood vessels (often due to atherosclerosis) can also create noise that may be heard as tinnitus.
Abnormal Vessels: Vascular malformations, such as arteriovenous malformations (AVMs) or tumors that involve blood vessels like paragangliomas (e.g., glomus tumors), can produce audible noises as blood flows through them. These sounds are typically pulsatile and may sync with the patient's heartbeat.
80
what causes turbulent blood flow in objective tinnitus?
Turbulent blood flow caused by narrowed or kinked blood vessels (often due to atherosclerosis) can also create noise that may be heard as tinnitus.
81
what conditions can increase blood flow causing objective tinnitus?
exercise or pregnancy
82
what often causes narrowed or kinked blood vessels?
atherosclerosis
83
which vascular malformation or blood vessel tumors can cause audible noise as blood flows through them and are normally pulsatile and in sync with patient's heartbeat?
arteriovenous malformation (AVMs)
paragangliomas (eg. glomus tumor)
84
what are some muscle related causes of objective tinnitus?
Myoclonus or Spasms of Palatal Muscles: Rapid, rhythmic contractions of the muscles in the soft palate can produce clicking or snapping sounds.
Muscles in the Middle Ear: The stapedius and tensor tympani muscles in the middle ear can also spasm or twitch, resulting in a clicking sound. This can be voluntary or involuntary and may be triggered by various factors, including stress or other muscle spasm disorders.
85
which two muscles in middle ear can spasm and cause clicking sound in objective tinnitus?
stapedius and tensor tympani muscles.
86
which type of tinnitus is more common, subjective or objective?
subjective
87
what are some differentials for tinnitus?
Drug-Induced Tinnitus:
Certain medications, including salicylates (like aspirin), aminoglycoside antibiotics, loop diuretics, and chemotherapy drugs like cisplatin, can cause tinnitus.
With salicylates, there can also be accompanying hearing loss.
Aminoglycosides are known for their potential to cause not only tinnitus but also bilateral vestibular loss, leading to symptoms such as dizziness and a sense of disequilibrium.
Meniere’s Disease:
This is an inner ear disorder characterized by episodes of unilateral (one-sided) hearing loss, tinnitus, ear fullness, and severe vertigo.
The hearing loss in Meniere's disease often starts as fluctuating but can become permanent, particularly affecting low-frequency sounds.
Presbycusis:
Presbycusis is age-related hearing loss that typically starts with the high-frequency sounds.
It often runs in families and is a common cause of hearing difficulties in older adults.
Objective Tinnitus:
Objective tinnitus is a rare form of tinnitus that can be heard by an examiner with a stethoscope. It can be caused by physical sources of sound within the body, such as arteriovenous malformations, turbulent blood flow near the carotid artery or jugular vein, vascular tumors, or muscle spasms (myoclonus) in the palatal muscles, tensor tympani, or stapedius muscles.
It is usually unilateral and can manifest as pulsatile or non-pulsatile. Sounds like bruits, clicking, and venous hums may be observed on a physical exam.
88
what are some drugs that can cause tinnitus?
Certain medications, including salicylates (like aspirin), aminoglycoside antibiotics, loop diuretics, and chemotherapy drugs like cisplatin, can cause tinnitus.
89
which drug can cause both tinnitus and hearing loss?
With salicylates, there can also be accompanying hearing loss.
90
which drug can cause both tinnitus and bilateral vestibular loss?
Aminoglycosides are known for their potential to cause not only tinnitus but also bilateral vestibular loss, leading to symptoms such as dizziness and a sense of disequilibrium.
91
which hearing disorder an inner ear disorder characterized by episodes of unilateral (one-sided) hearing loss, tinnitus, ear fullness, and severe vertigo?
meniere's disease
92
which hearing disorder primarily affects low frequency sounds?
meniere's disease
The hearing loss in Meniere's disease often starts as fluctuating but can become permanent, particularly affecting low-frequency sounds.
93
what is an age-related hearing loss that typically starts with the high-frequency sounds.
It often runs in families and is a common cause of hearing difficulties in older adults?
Presbycusis
94
is objective tinnitus unilateral or bilateral?
unilateral
95
what are some red flags associated with tinnitus that indicate a more serious underlying condition?
Sudden Onset Pulsatile Tinnitus:
This can indicate vascular abnormalities, such as carotid artery dissection, arteriovenous malformations, or high blood pressure.
Tinnitus with Significant Neurological
Symptoms/Signs:
If tinnitus is accompanied by symptoms such as facial weakness, it might be a sign of a stroke or Bell's palsy.
Tinnitus Associated with Severe Vertigo:
This could signify Meniere's disease or a vestibular disorder like vestibular neuritis or labyrinthitis.
Tinnitus Secondary to Head Trauma:
Following a head injury, tinnitus can be a sign of traumatic brain injury, skull fracture, or blood vessel damage.
Tinnitus with Unexplained Sudden Hearing Loss:
Sudden hearing loss may be a sign of labyrinthine infarction (stroke of the inner ear) or acoustic neuroma, among other possible etiologies.
96
what is vertigo and what are its 2 forms?
Vertigo is a specific type of dizziness that is characterized by the sensation of spinning or movement. [false sensation of movement]. It can be divided into two categories based on the perception of movement:
Objective or External Vertigo
Subjective or Internal Vertigo
97
what is the sensation that the environment around the person is spinning or moving. It often results from a disturbance in the balance organs of the inner ear (the vestibular system), which can be caused by conditions such as benign paroxysmal positional vertigo (BPPV), Meniere's disease, or vestibular neuritis?
Objective or External Vertigo
98
what are some common causes of objective or external vertigo?
benign paroxysmal positional vertigo (BPPV), Meniere's disease, or vestibular neuritis.
99
what refers to the feeling that one is moving or spinning when no actual movement is occurring. It can be due to neurological issues affecting the brain's centers that process balance and spatial orientation?
Subjective or Internal Vertigo
100
what causes subjective or internal vertigo?
It can be due to neurological issues affecting the brain's centers that process balance and spatial orientation.
101
what is dizziness?
sensation of disturbed or impaired spatial orientation without a false or distorted sense of motion. “a feeling of being light-headed, ‘swimmy’ or giddy”. It's a broader term and have various causes, from dehydration to cardiovascular issues.
102
what is unstableness?
feeling about to lose balance/fall or being unstable while seated, standing, or walking without a particular directional preference.
can result from many factors, including muscular weakness, joint problems, or neurological conditions.
103
what is Benign Paroxysmal Positional Vertigo (BPPV) and what causes it?
Benign Paroxysmal Positional Vertigo (BPPV):
BPPV is caused by calcium deposits or debris that become dislodged and enter the posterior semicircular canal of the inner ear.
This can lead to short, frequent, and often intense episodes of vertigo that are usually triggered by changes in head position.
104
which conditions involve inflammation of the inner ear (labyrinthitis) or the vestibular nerve (vestibular neuritis), often due to a viral infection.
They can cause sudden onset of vertigo, possibly accompanied by hearing loss?
Acute Labyrinthitis and Vestibular Neuritis
105
which one has vertigo accompanied by hearing loss? Acute Labyrinthitis or Vestibular Neuritis
Labyrinthitis
106
what is the Herpes Zoster Oticus (Ramsay Hunt Syndrome)?
Herpes Zoster Oticus (Ramsay Hunt Syndrome):
This syndrome is caused by the reactivation of the Varicella-zoster virus (which causes chickenpox and shingles) in the geniculate ganglion.
It results in inflammation of the vestibulocochlear nerve (cranial nerve VIII), and often the facial nerve (cranial nerve VII) is also involved, which can lead to facial paralysis in addition to vertigo.
107
which cranial nerves are inflamed in Herpes Zoster Oticus (Ramsay Hunt Syndrome)?
vestibulocochlear nerve (cranial nerve VIII), and often the facial nerve (cranial nerve VII) is also involved, which can lead to facial paralysis in addition to vertigo.
108
how does cholesteatoma cause vertigo?
Cholesteatomas:
Though less common, cholesteatomas can cause vertigo by eroding into structures of the inner ear and disrupting normal function.
109
what are some causes for peripheral vertigo?
Benign Paroxysmal Positional Vertigo (BPPV):
BPPV is caused by calcium deposits or debris that become dislodged and enter the posterior semicircular canal of the inner ear.
This can lead to short, frequent, and often intense episodes of vertigo that are usually triggered by changes in head position.
Ménière’s Disease:
This condition is characterized by increased pressure of the endolymph fluid within the inner ear.
Symptoms include episodic vertigo, fluctuating hearing loss, tinnitus (ringing in the ears), and a sensation of aural fullness.
Acute Labyrinthitis and Vestibular Neuritis:
These conditions involve inflammation of the inner ear (labyrinthitis) or the vestibular nerve (vestibular neuritis), often due to a viral infection.
They can cause sudden onset of vertigo, possibly accompanied by hearing loss (more common in labyrinthitis).
Herpes Zoster Oticus (Ramsay Hunt Syndrome):
This syndrome is caused by the reactivation of the Varicella-zoster virus (which causes chickenpox and shingles) in the geniculate ganglion.
It results in inflammation of the vestibulocochlear nerve (cranial nerve VIII), and often the facial nerve (cranial nerve VII) is also involved, which can lead to facial paralysis in addition to vertigo.
Cholesteatomas:
Though less common, cholesteatomas can cause vertigo by eroding into structures of the inner ear and disrupting normal function.
110
what are some causes of central vertigo?
Ischemic/Hemorrhagic Strokes:
These occur when there is a disruption of blood flow (ischemic) or bleeding (hemorrhagic) within the cerebellum or vertebrobasilar systems, which can affect balance and spatial orientation.
Tumors in Cerebellopontine Angle:
This region is where the cerebellum and pons are located, and tumors here, such as brainstem glioma, medulloblastoma, or vestibular schwannoma, can cause symptoms of vertigo by disrupting the function of the brainstem and associated structures.
Migraine (Vestibular Migraine):
Vestibular migraines can lead to episodes of vertigo that may or may not be associated with the classic headache of a migraine.
Multiple Sclerosis:
MS can cause lesions in the brain and spinal cord that affect the pathways responsible for balance and spatial orientation, leading to both peripheral and central vertigo.
Medication-Induced:
Certain medications, like phenytoin (used to treat seizures) and salicylates (found in aspirin and other pain relievers), can affect the central nervous system and lead to vertigo.
Psychological Disorders:
Conditions such as mood disorders, anxiety, and somatization can manifest with somatic symptoms, including dizziness and vertigo, which are mediated by central nervous system pathways.
111
what is the difference between peripheral and central vertigo?
peripheral vertigo involves horizontal movement, problems arise from inner ear
central vertigo involves multidirectional movement, problem arise from CNS especially the brainstem or cerebellum.
112
which condition can cause both peripheral and central vertigo?
multiple sclerosis
113
which medications affect the CNS and can lead to vertigo?
Certain medications, like phenytoin (used to treat seizures) and salicylates (found in aspirin and other pain relievers), can affect the central nervous system and lead to vertigo.
114
which vertigo is more serous and requires more comprehensive evaluation and treatment? central or peripheral
central vertigo
115
what other conditions produce similar symptoms as meniere's disease?
Symptoms similar to those of Meniere's disease can be caused by other conditions affecting metabolic, neurological, or vascular aspects of health, including thyroid disorders, diabetes, various central nervous system diseases, autoimmune diseases, and infections like neurosyphilis.
116
what is endolymphatic hydrops?
(excessive build-up of the endolymph fluid) with distortion and distention of the membranous, endolymph-containing portions of the labyrinthine system.
117
what makes up the Labyrinthine System?
Labyrinthine System: The labyrinth is made up of the cochlea (responsible for hearing) and the vestibular system (responsible for balance).
118
what is the most disruptive symptom of menieres disease?
Episodic Vertigo:
This is often the most disruptive symptom of Meniere's disease. The vertigo is described as a spinning or rocking sensation and can be severe enough to cause nausea and vomiting. These episodes can last from 20 minutes to as long as 24 hours.
119
what type of hearing loss does meniere's disease produce? sensorineural or conductive?
Sensorineural Hearing Loss:
Hearing loss in Meniere's disease typically starts at low frequencies and is fluctuating, meaning it can get better or worse over time. Eventually, over a period of years (8-10yrs), the hearing loss can progress to affect all frequencies and become permanent.
120
what pitch is normally associated with tinnitus in meniere's disease and what does the sound resemble?
Tinnitus associated with Meniere's disease is typically low-pitched and may be likened to the sound of the ocean in a seashell or the humming of machinery.
121
what is conductive hearing loss?
Conductive Hearing Loss: This occurs when there is a problem conducting sound waves anywhere along the route through the outer ear, tympanic membrane (eardrum), or middle ear (ossicles). Conductive hearing loss usually involves a reduction in sound level or the ability to hear faint sounds.
122
what causes conductive hearing loss?
Common causes include earwax build-up, fluid in the middle ear from colds or allergies, ear infections, perforated eardrum, benign tumors, and malformation of outer ear, ear canal, or middle ear structures.
123
what is sensorineural hearing loss?
Sensorineural Hearing Loss (SNHL): This type of hearing loss occurs when there is damage to the inner ear (cochlea) or to the nerve pathways from the inner ear to the brain. Most of the time, SNHL cannot be medically or surgically corrected. It is the most common type of permanent hearing loss.
124
what is the most common type of permanent hearing loss?
sensorineural hearing loss
125
what causes sensorineural hearing loss?
SNHL can result from aging, exposure to loud noise, injury, disease, certain drugs, birth defects, or genetics.
126
what is mixed hearing loss?
Mixed Hearing Loss: This is when both conductive hearing loss and sensorineural hearing loss are present. That is, there may be damage in the outer or middle ear and in the inner ear (cochlea) or auditory nerve.
127
what's an example of mixed hearing loss?
For example, someone with a long-standing sensorineural hearing loss might experience a conductive hearing loss resulting from earwax accumulation, leading to mixed hearing loss.
128
What is considered normal hearing in terms of decibel levels?
Normal hearing is defined as having hearing thresholds of 0 to 25 decibels (dB).
which means the quietest sounds that people can hear are between 0 and 25 dB.
129
What difficulties might individuals with mild hearing loss experience?
Individuals with mild hearing loss may have difficulty understanding words when there is a lot of background noise.
130
what is mild hearing loss range?
Hearing loss in the range of 26 to 40 dB.
131
what is moderate hearing loss range?
Hearing loss between 40 to 69 dB.
People often need to ask others to repeat themselves during conversations, especially if there is background noise.
132
what is severe hearing loss range?
Hearing loss between 70 to 94 dB.
Individuals with severe hearing loss cannot hear most conversations unless they are using a hearing aid. They may rely on lip reading and louder volumes for better comprehension.
133
what is profound hearing loss range?
Inability to hear sounds below 95 dB.
People with profound hearing loss may not hear anything except extremely loud sounds and often communicate using sign language.
134
at which decibel stage do you definitely need hearing aid or else you can't hear?
Severe Hearing Loss:
Hearing loss between 70 to 94 dB.
Individuals with severe hearing loss cannot hear most conversations unless they are using a hearing aid. They may rely on lip reading and louder volumes for better comprehension.
135
what are some causes of conductive hearing loss?
Obstruction (Cerumen Impaction):
Accumulation of earwax (cerumen) can block the external auditory canal, preventing sound from reaching the eardrum.
Mass Loading (Middle Ear Effusion):
Fluid in the middle ear from infections (like otitis media with effusion) adds mass to the middle ear system, which impedes the movement of the ossicles and decreases the efficiency of sound conduction.
Stiffness (Otosclerosis):
Otosclerosis involves abnormal bone growth around the stapes (one of the ossicles in the middle ear), which can fixate it and prevent it from vibrating normally in response to sound waves.
Discontinuity (Ossicular Disruption):
This occurs when there is a break or dislocation in the ossicular chain (the small bones in the middle ear), such as from trauma, which interrupts the transmission of sound.
Common Causes in Adults:
Adults often experience conductive hearing loss due to cerumen impaction or because of eustachian tube dysfunction, which can occur with an upper respiratory tract infection. The eustachian tube helps equalize pressure in the middle ear; when it's not functioning properly, it can affect hearing.
Persistent Conductive Losses:
Chronic ear infections can cause persistent effusions and structural damage to the ear, leading to long-term conductive hearing loss.
Trauma to the ear or temporal bone can also result in conductive hearing loss if it damages the ossicular chain or tympanic membrane.
Otosclerosis can also cause progressive conductive hearing loss if not treated, often requiring surgical intervention.
136
what is sensorineural hearing loss?
Sensorineural hearing loss (SNHL) is a type of hearing loss in which the root cause is located in the vestibulocochlear nerve (Cranial nerve VIII), the inner ear, or central processing centers of the brain.
137
what are some causes of sensorineural hearing loss?
Cochlear Deterioration: This involves the loss of sensory hair cells within the organ of Corti, which is the sensory organ of hearing within the cochlea. These cells convert sound vibrations into electrical signals sent to the brain. Their damage leads to hearing impairment.
Age-Related Changes (Presbycusis): This is the most common form of sensorineural hearing loss, which is a gradual process predominantly affecting the high-frequency hearing. This form of hearing loss increases with advancing age due to the natural degeneration of auditory structures.
Exposure to Loud Noise: This can cause acoustic trauma leading to the damage of hair cells.
Head Trauma: Physical injury to the head can damage the inner ear, auditory nerve, or the brain areas responsible for processing sound.
Systemic Diseases: Certain illnesses like autoimmune diseases, diabetes, and circulatory disorders can affect the cochlea or the auditory nerve.
Lesions in Auditory Pathways: This may include acoustic neuromas (benign tumors on the auditory nerve), which can press on and damage the nerve. Other possible issues could involve the auditory nuclei in the brainstem, the ascending auditory tracts, or the auditory cortex. Conditions such as multiple myeloma and auditory neuropathy also fall into this category, where the damage may occur at any point along the central auditory pathway.
138
what is the most common form of sensorineural hearing loss?
Age-Related Changes (Presbycusis): This is the most common form of sensorineural hearing loss, which is a gradual process predominantly affecting the high-frequency hearing. This form of hearing loss increases with advancing age due to the natural degeneration of auditory structures.
139
what are some systemic diseases that causes sensorineural hearing loss?
Diabetic Vasculopathy and Cochlear Ischemia:
Diabetes can cause damage to blood vessels throughout the body, including those in the inner ear, through a process known as vasculopathy.
This can lead to cochlear ischemia, where the blood supply to the cochlea is reduced, impairing its function and potentially causing hearing loss.
Anemia, White Blood Cell Dyscrasia, and Hearing Loss:
Anemia, characterized by a lack of healthy red blood cells, can lead to decreased oxygenation of tissues, including those in the auditory system.
White blood cell dyscrasias, disorders affecting white blood cells, can result in similar issues due to micro blockages in the vasculature of the inner ear or by increased susceptibility to infections that can affect hearing.
Thyroid Disorders (Hyperthyroidism and Hypothyroidism):
Both excessive and insufficient thyroid hormone levels can affect hearing.
Hyperthyroidism and hypothyroidism can lead to changes in the composition and pressure of endolymph fluid in the inner ear, potentially causing hearing problems.
Syphilis and Hearing Loss:
Syphilis is an infectious disease that can have numerous systemic effects, including on the auditory system.
It can cause sensorineural hearing loss, either through direct infection of the inner ear structures or as a result of the body's immune response to the infection.
140
how does diabetes cause hearing loss?
Diabetes can cause damage to blood vessels throughout the body, including those in the inner ear, through a process known as vasculopathy.
This can lead to cochlear ischemia, where the blood supply to the cochlea is reduced, impairing its function and potentially causing hearing loss.
141
how does anemia and white blood cell dyscrasia cause hearing loss?
Anemia, characterized by a lack of healthy red blood cells, can lead to decreased oxygenation of tissues, including those in the auditory system.
White blood cell dyscrasias, disorders affecting white blood cells, can result in similar issues due to micro blockages in the vasculature of the inner ear or by increased susceptibility to infections that can affect hearing.
142
what is dyscrasia?
a disordered state
143
what is meant by ototoxic drugs?
Ototoxic drugs are substances that can cause temporary or permanent damage to the inner ear or vestibulocochlear nerve, resulting in hearing loss, tinnitus, or balance disorders.
144
what are some examples of ototoxic drugs?
Aminoglycosides (e.g., gentamycin, tobramycin, amikacin, neomycin):
These antibiotics can damage the hair cells in the cochlea, leading to hearing loss, which is often irreversible. They can also affect the vestibular system, causing balance issues.
Antibiotics (e.g., erythromycin and tetracycline):
These can also be ototoxic, particularly when used in high doses or for extended periods. Erythromycin can cause temporary hearing loss, while tetracycline can affect calcium metabolism, leading to inner ear problems.
Chemotherapeutic Agents (e.g., cisplatin):
Cisplatin is well-known for its ototoxic potential. It can damage the cochlear hair cells and lead to permanent hearing loss.
High-Dose Aspirin:
Aspirin can cause reversible tinnitus and hearing loss, usually when taken in high doses. The effects are typically temporary and resolve after discontinuing the drug.
Phosphodiesterase 5 Inhibitors (e.g., sildenafil):
These medications, commonly used for erectile dysfunction, have been associated with sudden hearing loss in some cases.
Antimalarial Drugs (e.g., quinine):
Quinine and related drugs can cause tinnitus, hearing impairment, and in some cases, a degree of irreversible hearing loss.
Heavy Metals (e.g., lead, mercury, arsenic):
Exposure to these metals can lead to toxic effects on the auditory system as well as the central nervous system, causing hearing loss and balance problems.
145
what are examples of aminoglycosides?
Aminoglycosides (e.g., gentamycin, tobramycin, amikacin, neomycin)
146
which antibiotic can affect calcium metabolism, leading to inner ear problems?
tetracycline
147
which antibiotic causes temporary hearing loss?
erythromycin
148
which drug can cause reversible tinnitus and hearing loss, usually when taken in high doses. The effects are typically temporary and resolve after discontinuing the drug?
aspirin
149
which chemotherapy agent is well-known for its ototoxic potential. It can damage the cochlear hair cells and lead to permanent hearing loss?
cisplatin
150
which medications, commonly used for erectile dysfunction, have been associated with sudden hearing loss in some cases?
Phosphodiesterase 5 Inhibitors (e.g., sildenafil)
151
which antimalarial drugs can cause tinnitus, hearing impairment, and in some cases, a degree of irreversible hearing loss?
quinine
152
exposure to what type of heavy metal can lead to toxic effects on the auditory system as well as the central nervous system, causing hearing loss and balance problems?
lead, mercury, arsenic
