Diagnosis of Pendred syndrome
Pendred syndrome Diagnosis: Book Excerpts
Diagnostic Tests for Pendred syndrome: Online Medical Books
16 MEDICAL BOOKS ONLINE!
Review excerpts from medical books online, free, without registration,
for more information about diagnostis of Pendred syndrome.
DEAFNESS:
Ask the following questions:
(Algorithmic Diagnosis of Symptoms and Signs)
- Is it unilateral or bilateral? Unilateral deafness may be due to local conditions such as wax, a foreign body, otitis media, or ruptured drum, or it may be due to neurologic conditions such as Ménière's disease, acoustic neuroma, or multiple sclerosis. Bilateral deafness is more likely due to otosclerosis, acoustic trauma, presbyacusis, or drug toxicity.
- Are there abnormalities on otoscopic examination of the ear? It is very important to do a thorough examination of the ear, as one may find wax, foreign body, otitis media, cholesteatoma, or ruptured drum.
- Is there associated vertigo? The presence of vertigo should make one think of Ménière's disease or some neurologic condition such as acoustic neuroma, multiple sclerosis, or basilar artery insufficiency.
- What are the results of the Rinne test? Normally, the Rinne test should show a 2 to 1 ratio of air to bone hearing. In otosclerosis, the ratio approaches 1 to 1, but in sensory neural deafness the ratio is preserved at 2 to 1. In unilateral deafness, the Weber test is helpful. This will lateralize to the affected ear if the problem is a conductive deafness, and it will lateralize to the good ear if the problem is a sensory neural deafness.
DIAGNOSTIC WORKUP
Audiometry and caloric testing or electronystagmography should be done in almost all cases in which the ear examination is normal. It is probably wise to consult an otolaryngologist at this point. Tympanography will be helpful in diagnosing subtle cases of serous otitis media. X-rays of the mastoids, petrous bones, and internal auditory canal should be done for chronic otitis media, cholesteatoma, and acoustic neuroma. If an acoustic neuroma is suspected, however, an MRI of the brain and auditory canals must be done. If basilar artery insufficiency is suspected, four-vessel cerebral angiography should be done. Magnetic resonance angiography is an excellent noninvasive alternative for diagnosing vertebral-basilar artery disease. If multiple sclerosis is suspected, MRI of the brain, BSEP and VEP studies, and a spinal tap for spinal fluid analysis may be done.
Rather than perform these tests, the most cost-effective approach would be to refer the patient to a neurologist if other focal neurologic findings are evident.
» READ BOOK EXCERPT ONLINE »
Source: Algorithmic Diagnosis of Symptoms and Signs, 2003
TINNITUS AND DEAFNESS:
Approach to the Diagnosis
(Differential Diagnosis in Primary Care)
When a patient complains of tinnitus and deafness, a good occupational history is essential. Gradual onset of unilateral deafness should be considered an acoustic neuroma until proven otherwise. The combination of other symptoms and signs is the key to a clinical diagnosis. Thus tinnitus, deafness, and vertigo suggest Ménière disease. Almost total unilateral deafness (sudden in onset in a diabetic) suggests diabetic neuritis. A similar episode can occur in syphilis, but vertigo is also often present. Tinnitus and vertigo following a head injury suggest either traumatic myringitis, labyrinthitis, or postconcussion syndrome. If there is total deafness with the tinnitus and vertigo, a basilar skull fracture should be considered. Tinnitus and headache suggest migraine.
Diagnostic studies that should be done in all cases are audiograms, caloric tests, and x-rays of the skull, petrous bones, and mastoids. If an acoustic neuroma is suspected, tomography of the petrous bones, a CT scan or MRI, and basilar myelography may be indicated. Syphilis and multiple sclerosis require a spinal tap to assist in diagnosis. Angiography and EEGs may be required in selected cases.
» READ BOOK EXCERPT ONLINE »
Source: Differential Diagnosis in Primary Care, 2007
Hearing Loss and Deafness:
Clinical Features and Diagnosis
(The Diagnostic Approach to Symptoms and Signs in Pediatrics)
Conductive Hearing Loss
External Auditory Canal Disorders
Atresia of External Auditory Canal
Absenceof meatus under tragus signifies presence of external auditory canalatresia. External ear is usually small and deformed.CT should be performed to identifyother abnormalities, especially in middle ear, and to help in evaluationof possible surgical repair. Impacted Cerumen
Impacted cerumen (earwax) in external canalis common cause of conductive hearing loss. Hearing returns to normalafter its removal.
Otitis Externa
Inflammationof external auditory canal with discharge and swelling causes obstructionand diminished sound transmission. Hearing returns to normal afterinflammation subsides.See Chap.16, Earache. Exostosis
Exostoses(bone overgrowths) may be found in external auditory canal or middleear but are uncommon in pediatric population.Usually bilateral and close to tympanicmembrane.Although diagnosis is usually clinical,CT may be useful in defining their extent. Masses
Foreignbodies (e.g., cotton balls, erasers, beads, and other small objects)that obstruct external canal can cause decreased hearing. Readilyseen by otoscopy.Polyps are reddish or purplish massesthat bleed easily. Can arise from external canal and tympanic membraneor protrude from middle ear into canal through perforation in membrane.Often associated with cholesteatoma. Excisional biopsy is diagnostic.Neoplasms arising from external auditorycanal are rare in pediatric population but include neurofibromas,eosinophilic granulomas, and rhabdomyosarcomas. CT shows locationand extent of lesion. Histologic diagnosis is definitive. Middle Ear Disorders
Acute and Chronic Otitis Media and Otitis Media with Effusion
Most commoncauses of conductive hearing loss in children are acute and chronicotitis media and otitis media with effusion.See Chap.16, Earache. Tympanic Membrane Perforation
Most common causes of tympanic membrane perforationare acute otitis media and head trauma. The latter causes conductivehearing loss by accumulation of blood in external canal or middleear or by disruption of ossicular chain. Perforation is seen byotoscopy.
Hemotympanum
Direct blowto ear or basilar skull fracture may cause hemotympanum.Tympanic membrane appears red or purplebecause of blood in middle ear space. Other findings that may beseen with basilar skull fracture include ecchymoses behind ear oraround eyes, and CSF drainage from nose or ears.CT helps determine extent of injury. Tympanosclerosis
Characterizedby whitish plaques in tympanic membrane and nodular deposits insubmucosal layers of middle ear. If deposits of calcium and phosphatecrystals involve ossicles, conductive loss can occur.Predisposing factors are chronic otitismedia and tympanostomy tube placement. Ossicular Chain Defect, Disruption, or Fixation
Should besuspected in cases of conductive hearing loss when external auditorycanal and middle ear appear normal on exam.History of head trauma suggests ossiculardisruption.CT of temporal bone shows ossicularchain and any abnormalities of otic capsule. Cholesteatoma and Other Middle Ear Masses
Cholesteatomausually appears as whitish mass in middle ear. Other middle earmasses are discussed by Bellet et al. (1992).Conductive hearing loss, tinnitus,ear fullness, or facial nerve palsy can indicate presence of middleear mass, regardless of whether it is visible by otoscopy.CT is initial imaging exam for middleear masses. Sensorineural Hearing Loss
Sensorineural Hearing Loss without Associated Abnormalities
In the past these disorders were usuallydistinguished from each other by mode of genetic transmission, ageof onset, severity of hearing loss, and type of audiogram (Gorlinet al., 1995). Recently, several genes for hearing loss have beenmapped to different chromosomes, permitting specific diagnosis (Willems,2000).
Sensorineural Hearing Loss with Associated Abnormalities
Several syndromes may be associated withsensorineural hearing loss: Hurler, Hunter, Cockayne, Alport, Klippel-Feil,Wildervanck, Waardenburg, Usher, Pendred, Jervell and Lange-Nielsen,and branchio-oto-renal.
Chromosomal Disorders
Although trisomies 13, 18, 21, and 22 maybe associated with sensorineural hearing loss, conductive loss dueto otitis media with effusion is more common.
Inner Ear Malformations
The following malformations can usually bediagnosed by CT, although sometimes MRI may be necessary.
Labyrinthine Aplasia
Michel malformation consists of aplasia ofcochlea, vestibule, and semicircular canals.
Common Cavity Malformation
Exists when there is single labyrinthinecavity without cochlea or semicircular canals.
Cochlear Malformations
Most commoncochlear malformation observed with imaging studies is Mondini malformation.Axial CT shows single cochlear cavitywith normal cochlear basal turn.Has been reported in many syndromes:DiGeorge, Goldenhar, Pendred, Waardenburg, and CHARGE association.Pseudo-Mondini malformation is presenceof a cochlear vestige that communicates directly with vestibulewithout intervening bony cochlear basal turn.With cochlear aplasia, nidus of scleroticbone replaces cochlea. Large Vestibular Aqueduct
Both the vestibular aqueduct and endolymphsac are enlarged in this malformation Although hearing loss is progressive,it is often fluctuating. Head trauma may result in sudden, irreversible,profound sensorineural hearing loss.
Prematurity
Mechanism of hearing loss in premature infantswithout any other predisposing factor is unknown.
Hypoxic-Ischemic Encephalopathy
Perinatal asphyxia, including birth trauma,may result in hypoxic-ischemic encephalopathy and hearing loss.
Bilirubin Encephalopathy (Kernicterus)
Usuallycauses bilateral high-frequency hearing loss. Possible mechanismsinclude damage to cochlear nuclei and auditory pathways in brain.See Chap.3, Alteration in Consciousness. Infection
Congenitalinfection with rubella, cytomegalovirus, herpes simplex virus, toxoplasmosis,or syphilis (see Chap. 36, Jaundice)sometimes produces hearing loss and deafness.Although acute and chronic otitis mediacause conductive hearing loss, it is postulated that inflammatorymediators or toxins pass from middle ear to inner ear through roundwindow membrane to cause sensorineural hearing loss.Bacterial meningitis and encephalitiscan cause sensorineural hearing loss that can range from mild toprofound. Trauma
Loud noiseof sufficient duration and intensity can destroy organ of Cortiand its associated neural connections in base of cochlea.Tinnitus almost always occurs in noise-inducedhearing loss.Direct trauma including temporal bonefractures and penetrating wounds may disrupt bony and membranouslabyrinth to cause sensorineural hearing loss. CT is imaging procedureof choice. Drugs
Drugs takenduring pregnancy that may cause hearing loss in neonates includequinine, chloroquine, and isotretinoin.Aminoglycosides (streptomycin, kanamycin,gentamicin, amikacin, neomycin), loop diuretics (furosemide, ethacrynicacid), and cisplatin can cause sensorineural loss in infants andchildren. Perilymph Fistula
Abnormalleak of perilymph (cerebrospinal fluid) into middle ear or mastoidair cell system is caused by defects in temporal bone, particularlyin region of stapes footplate or round window.Defects may be congenital or acquired(secondary to trauma of the temporal bone). They are associatedwith sudden fluctuating or progressive sensorineural hearing lossand can predispose to recurrent meningitis. Vertigo also may occurbut is rare.Injection of intrathecal radioisotopeor dye with subsequent nuclear scintigraphy or CT, respectively,often identifies site of leak. See Chap.41, Nasal Discharge. Neoplasm
Some neoplasticdiseases (e.g., leukemia and neuroblastoma) can invade temporal boneand damage cochlea or auditory pathways.Acoustic neuroma, a benign tumor ofeighth cranial nerve, can cause sensorineural hearing loss, tinnitus,vertigo, and facial nerve paralysis. Presence of bilateral tumorssignifies neurofibromatosis.Posterior fossa tumors in area of cerebellopontineangle (e.g., meningioma) can cause hearing loss, tinnitus and ataxia.CT and MRI can locate and define extent of tumor. Histologic diagnosisis definitive. Ménière Disease
Sensorineural fluctuating hearing loss, tinnitus,and vertigo characterize Ménière disease.
Unknown
There are a number of cases of hearing lossin which the etiology is unknown.
Mixed Hearing Loss
In children with sensorineural hearing loss,presence of acute otitis media or otitis with effusion may produceconductive hearing loss.
Diagnostic Approach
Auditoryand language findings listed in Table26.1 are indications for possible hearing loss or deafness.Suspected hearing loss should be investigatedto determine the type, severity, and cause.Any child with suspected hearing lossshould be referred for audiologic evaluation. Speech and languageassessment is often necessary. Neurologic and otolaryngologic consultationmay be required, depending on suspected problem.
» READ BOOK EXCERPT ONLINE »
Source: The Diagnostic Approach to Symptoms and Signs in Pediatrics, 2006
TINNITUS AND DEAFNESS:
Approach to the Diagnosis
(Differential Diagnosis in Primary Care)
When a patient complains of tinnitus and deafness, a good occupational
history is essential. Gradual onset of unilateral deafness should be
considered an acoustic neuroma until proven otherwise. The combination of
other symptoms and signs is the key to a clinical diagnosis. Thus tinnitus,
deafness, and vertigo suggest Ménière disease. Almost total
unilateral deafness (sudden in onset in a diabetic) suggests diabetic
neuritis. A similar episode can occur in syphilis, but vertigo is also often
present. Tinnitus and vertigo following a head injury suggest traumatic
myringitis, labyrinthitis, or postconcussion syndrome. If there is total
deafness with the tinnitus and vertigo, a basilar skull fracture should be
considered. Tinnitus and headache suggest migraine.
Diagnostic studies that should be done in all cases are audiograms, caloric
tests, and x-rays of the skull, petrous bones, and mastoids. If an acoustic
neuroma is suspected, tomography of the petrous bones, a CT scan or magnetic
resonance imaging (MRI), and basilar myelography may be indicated. Syphilis
and multiple sclerosis require a spinal tap to assist in diagnosis.
Angiography and EEGs may be required in selected cases.
» READ BOOK EXCERPT ONLINE »
Source: Differential Diagnosis in Primary Care, 2007
Whenever you go to a hospital or clinic for a major procedure or diagnostic test, one of the many forms you are given to sign is an "informed...
Germs are a fact of life and catching an infectious disease like a cold may seem inevitable. But there are simple ways to protect yourself against...
Sexual contact can sometimes result in problems. An unwanted pregnancy or sexually transmitted diseases may be some of those consequences. But by...
Sleep is necessary to feel refreshed, but now we know sleep actually impacts the way the body functions. Sleeping poorly can affect how often you get...
See full list of 4 related videos
» Next page:
Signs of Pendred syndrome
Rate This Website
What do you think about the features of this website?
Take our user survey and have your say:
Website User Survey
Medical Tools & Articles:
Next articles:
Tools & Services:
Medical Articles:
Forums & Message Boards
- Ask or answer a question at the Boards:
