Rosen & Barkin's 5-Minute Emergency Medicine Consult (443 page)

• McCollough M, Sharieff GQ. Abdominal pain in children.
  Pediatr Clin North Am
  . 2006;53(1):107–137.
  
• Park JJ, Wolff BG, Tollefson MK, et al. Meckel diverticulum: The Mayo Clinic experience with 1476 patients (1950–2002).
  Ann Surg
  . 2005;241:529–533.
  
• Sagar J, Kumar V, Shah DK. Meckel’s diverticulum: A systematic review.
  J R Soc Med
  . 2006;99(10):501–505.
  
• Sharma RK, Jain VK. Emergency surgery for Meckel diverticulum.
  World J Emerg Surg
  . 2008;3:27.
  
• Zani A, Eaton S, Rees CM, et al. Incidentally detected Meckel diverticulum: To resect or not to resect?
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See Also (Topic, Algorithm, Electronic Media Element)

• Abdominal Pain
  
• Appendicitis
  
• Bowel Obstruction
  
• Diverticulitis
  
• Intussusceptions
  

CODES

751.0 Meckel’s diverticulum

BASICS

• Disease of the inner ear
  
• Classically unilateral ear involvement (may be bilateral in up to 40% of cases)
  
• Characterized by recurrent spontaneous and episodic vertigo, sensorineural hearing loss, “roaring” tinnitus, and aural fullness
  
• Estimated incidence about 15/100,000 in US
  
• Slight female > male (1.3:1)
  
• Positive family history up to 20%
  
• May develop at any age
  
  • Peak incidence is age 40–60 yr.
    
• Affects more Whites of Northern European descent than Africans or Blacks
  
• A benign disease without cure
  
• Can be associated with significant morbidity
  

• Idiopathic
  
• Endolymphatic hydrops: Blockage of the endolymphatic sac and duct leading to endolymphatic outflow obstruction and increased hydraulic pressure within the endolymphatic system:
  
  • Increased pressure causes a break in the membrane that separates the perilymph (potassium [K]-poor extracellular fluid) and the endolymph (K-rich intracellular fluid)
    
  • The resultant chemical mixture bathes the vestibular nerve receptors, leading to a depolarization blockade and transient loss of function
    
• May be associated with structural abnormalities such as atrophy of the sac, hypoplasia of the vestibular aqueduct, narrowing of the endolymphatic duct, forwardly located lateral sinus causing compression, and obstruction of the endolymphatic sac
  
• Autoimmune processes suggested as an etiology, with immune complex deposition in endolymphatic sac and autoantibodies directed against endolymphatic sac
  
• Thought to have a genetic predisposition, leading to earlier age of onset and more severe symptoms
  
• Other proposed mechanisms are subclinical viral infection causing hydrops many decades later, and ischemia of the endolymphatic sac and the inner ear
  
• Need to differentiate Ménière syndrome from other disease processes that interfere with normal production or resorption of endolymph (e.g., thyroid disease, inner ear inflammation due to syphilis, medication)
  

DIAGNOSIS

• Diagnosis based upon clinical symptoms and neurotologic evaluation
  
• Definitive diagnosis currently can only be made postmortem, though MRI holds potential for definitive diagnosis
  
• Diagnostic criteria (1995 American Academy of Otolaryngology guidelines):
  
  • At least 2 episodes of spontaneous and episodic vertigo, ≥20 min
    
  • At least 1 episode of hearing loss documented by audiogram
    
  • Tinnitus or aural fullness in the affected ear
    
  • Certain Ménière disease: Definite disease with histopathologic confirmation
    
  • Definite Ménière disease: 2 or more definitive episodes of vertigo with hearing loss, plus tinnitus, aural fullness, or both
    
  • Probable Ménière disease: Only 1 definitive episode of vertigo and the other symptoms and signs
    
  • Possible Ménière disease: Definitive vertigo with no associated hearing loss or hearing loss with nondefinitive disequilibrium
    

• Classical tetrad of symptoms:
  
  • Vertigo
    
  • Hearing loss
    
  • Tinnitus
    
  • Aural fullness
    
• Vertiginous attacks lasting minutes to hours, often associated with nausea and vomiting (96.2%)
  
• Sensorineural hearing loss is typically fluctuating and progressive
  
  • Low frequencies are affected more severely than high frequencies (87.7%)
    
  • Can result in permanent hearing loss at all frequencies
    
• Tinnitus is typically low pitch
  
• Aural fullness is described as pressure, discomfort, fullness sensation in unilateral ear
  
• Attacks reach maximum intensity within minutes, slowly subside over hours
  
• After the acute attack, patients generally feel tired, unsteady, and nauseated for hours to days
  
• Between episodes, some patients are completely symptom free
  
• Sudden, unexplained falls without loss of consciousness or associated vertigo may also occur
  
• Constellation of symptoms can vary from patient to patient
  
  • Auditory and vestibular symptoms may not be present simultaneously or in the same pattern, particularly in the early phases of disease
    
• Close clustering of attacks may occur
  

• Exam results vary, depending upon the phase of disease
  
• During acute attack, patients are often in significant distress, diaphoretic, and pale
  
• Vital signs may show elevated blood pressure, pulse, and respiration
  
• Horizontal nystagmus
  
• Impaired hearing
  
• Pneumo-otoscopy may elicit symptoms or cause nystagmus
  
• Weber tuning fork test usually lateralizes away from the affected ear
  
• Rinne test usually indicates better air than bone conduction
  
• Positive Romberg test, with instability, especially when eyes are closed
  
• Must exclude central CNS lesion, peripheral pathology in ear (ruptured tympanic membrane, cholesteatoma, cerumen impaction, etc.)
  

• Complete history and neurologic exam
  
• Patients with central vertigo or focal neurologic findings require neuroimaging
  
• Focal findings include new unilateral hearing loss, usually with tinnitus
  

When indicated:

• CBC
  
• Sedimentation rate
  
• Thyroid function
  
• Fasting lipid profiles
  
• Fasting blood glucose, hemoglobin A1c
  
• Treponemal antibody-absorption test
  
• Chemistry panel
  
• Urinalysis for proteinuria or hematuria
  

• MRI with intratympanic gadolinium and views of internal auditory canal (typically outpatient)
  
• CT scan of temporal bone
  
• Standard lateral mastoid radiographs
  

• Audiometric assessment
  
• Bithermal caloric testing
  
• Transtympanic electrocochleography
  
• Electronystagmography
  

• Otologic:
  
  • Chronic suppurative otitis media
    
  • Benign positional vertigo
    
  • Acoustic neuroma
    
  • Vestibular neuronitis
    
  • Vestibular paroxysmia
    
  • Otosclerosis
    
  • Otic capsule dysplasia
    
  • Perilymphatic fistula
    
  • Labyrinthitis
    
• Systemic:
  
  • Vertebrobasilar insufficiency
    
  • Stroke and transient ischemic attack
    
  • Basilar artery thrombosis
    
  • Intracranial hemorrhage
    
  • Head trauma
    
  • CNS lesions (tumors)
    
  • Epilepsy
    
  • Multiple sclerosis
    
  • Paget disease
    
  • Diabetes
    
  • Concussive syndrome
    
  • Pseudotumor cerebri
    
  • Complex or vestibular migraine
    
  • Thyroid dysfunction
    
  • Drugs/medications
    
  • Autoimmune disorders (e.g., systemic lupus erythematosus)
    
  • Viral meningitis/encephalitis
    
  • Lyme disease
    
  • Neurosyphilis
    
  • Electrolyte imbalance
    
  • Panic attacks
    

TREATMENT