A typical tympanogram plots compliance If the eardrum is under no positive or negative pressure, it will have it's maximum compliance at 0. On the other hand, if it is under negative or positive pressure, the peak will move to the left or right.
Tympanogram On the test below, the left ear is flat. This indicates that the left ear drum is abnormally stiff
Prevalence The prevalence of congenital deafness in the United States is estimated to be approximately 1:1,000 or 0.1% Approximately 3:1,000 well babies have hearing loss of varying degrees Approximately 6:1,000 combined well and at-risk babies have some degree of hearing loss (HL).
Deafness Acquired deafness associated with age or noise exposure is more common than genetic deafness by roughly two orders of magnitude Autosomal recessive inheritance is the most common form, accounting for more than 75% of all congenital deafness
Types of HL Peripheral HL (outer, inner, middle ear or auditory nerve) 1. Conductive 2. Sensorineural 3. Mixed Central.
Congenital forms of CHL 1. Aural stenosis 2. Atresia 3. Stapes fixation
SNHL A sensorineural HL (SNHL) affects the inner ear (cochlea) or auditory nerve (eighth cranial nerve). Most SNHLs are sensory and restricted to the cochlea and do not result from an abnormality to the auditory nerve. Routine audiometric testing does not differentiate between a sensory loss and a neural loss.
Electrophysiologic measures (brainstem auditory evoked response [BAER] and otoacoustic emissions [OAE]) must be used to differentiate between sensory and neural causes. SNHL cannot be identified on routine physical otoscopic examination.
Mixed HL Abnormalities are identified in the outer or middle ear as well as the inner ear
Congenital Sensorineural Hearing Loss Disorders Craniofacial and Skeletal Disorders — Absence of tibia — Cleidocranial dysostosis — Diastrophic dwarfism — Hand-hearing syndrome — Klippel-Feil — Saddle nose and myopia — Split-hand and foot
Congenital fusion within the cervical spine ( cervical synostosis). Failure of segmentation occurs during weeks 3 to 8 of gestation. Other systems are involved including cardio-vascular (10%), genitourinary (30%) and nervous systems
Klippel-Feil Hearing may be impaired (30%). A classical clinical finding is Synkinesis (20%) or mirror movements. Scoliosis (60%) is common and may have a significant kyphotic element. Sprengel's deformity or congenital elevation of the scapula may be seen in about 30%.
Integumentary and Pigmentary Disorders — Albinism with blue irides — Congenital atopic dermatitis — Ectodermal dysplasia — Keratopachyderma — Lentigines
Integumentary and Pigmentary Disorders — Partial albinism — Piebaldness — Pili torti — Waardenburg syndrome __Onychodystrophy
Albinism with blue irides Clinical features: nystagmus; decreased visual acuity blue-gray to light brown irides white skin; white to golden blonde or red hair Inheritance: autosomal recessive
Ectodermal dysplasia (1) hair anomalies or trichodysplasias (2) dental abnormalities (3) nail abnormalities or onychodysplasias (4) eccrine gland dysfunction or dyshidrosis
Waardenburg syndrome Lateral displacement of the medial canthi combined with dystopia of the lacrimal puncta and blepharophimosis Prominent broad nasal root Hypertrichosis of the medial part of the eyebrows White forelock Heterochromia iridis Deafmutism
Endocrine and Metabolic Disorders — Goiter — Hyperprolinemia I — Iminoglycinuria — Pendred
Pendred syndrome Pendred syndrome is a genetic disorder that causes early hearing loss in children. It also can affect the thyroid gland and sometimes may affect a person's balance. The syndrome is named after Vaughan Pendred, the physician who first described individuals with the disorderthyroid gland
Fanconi anemia syndrome Skin Body Upper limbs Thumbs Radii Hands Gonads Head and face Neck - Sprengel abnormality, short, low hairline, webbed Spine Feet Legs Ears Kidneys Gastrointestinal system Cardiopulmonary system
Goldenhar syndrome a partially formed or totally absent ear (microtia)microtia the chin may be closer to the affected ear one corner of the mouth may be higher than the other benign growths of the eye a missing eye
Treacher Collins External ears that are abnormal to almost completely missing Hearing loss Very small jaw (micrognathia)micrognathia Very large mouth Defect in the lower eyelid called a colobomacoloboma Scalp hair that extends onto cheeks Cleft palate
Craniofacial and Skeletal Disorders Craniofacial and Skeletal Disorders — Achondroplasia — Crouzon syndrome — Marfan syndrome — Pierre Robin — Pyle disease
Crouzon syndrome Craniosynostosis most often of the coronal and lambdoid, and occasionally sagittal sutures Underdeveloped midface with receded cheekbones or exophthalmos (bulging eyes) Ocular Proptosis which is a prominence of the eyes due to very shallow orbits. The patient may have crossed eyes and/or wide-set eyes
Pierre Robin small lower jaw (micrognathia) a tongue which tends to ball up at the back of the mouth and fall back towards the throat (glossoptosis) breathing problems horsehoe-shaped cleft palate may or may not be present
Möbius syndrome Mobius syndrome, a rare genetic disorder characterized by facial paralysis, is caused by the absence or underdevelopment of the 6th and 7th cranial nerves. These nerves control eye movements and facial expression
Alport syndrome Alport syndrome is an inherited form of kidney inflammation (nephritis). It's caused by a mutation in a gene for a protein in connective tissue, called collagen. Risk factors include: End-stage kidney disease in male relatives End-stage kidney disease Family history of Alport syndrome Glomerulonephritis Hearing loss before age 30 Hearing loss Nephritis
Hunter syndrome Hunter syndrome is inherited as an X- linked recessive disease lack of the enzyme iduronate sulfataseenzyme
Hunter syndrome Coarse facial features Large head (macrocephaly)macrocephaly Stiffening of joints Increased hair (hypertrichosis)hypertrichosis Deafness (progressive) Deafness Enlargement of internal organs such as liver and spleen Abnormal retina (back of the eye) Carpal tunnel syndrome
Hurler syndrome severe form may have mental retardation, short stature, stiff joints, speech and hearing impairment, heart disease Autosomal recessive
Otosclerosis Otosclerosis is a disease of the bones of the inner ear. These are labeled the malleus, incus and stapes (2-4) in figure 1, and are also known in aggregate as the "ossicles". The ossicles become knit together into an immovable mass, and do not transmit sound as well as when they are more flexible. Otosclerosis can also affect the other ossicles (malleus and incus) and the otic capsule -- the bone that surrounds the inner ear.