drug or intoxicant use is important, as is a family history of migraine Age of the patient is especially useful—benign paroxysmal vertigo is unusual after age years, whereas Ménière disease is unusual before age 10 years The physical examination focuses on the middle ear and on neurologic and vestibular testing Visualization of the external ear canal may reveal cerumen impaction, foreign body, or zoster lesions (Ramsay Hunt syndrome) Perforation or distortion of the tympanic membrane should be noted A pneumatic bulb will enable the examiner to see whether abrupt changes in the middle ear pressure trigger an episode of vertigo, a suggestion that a perilymphatic fistula may be present (Hennebert sign) The neurologic examination must be complete, focusing closely on the auditory, vestibular, and cerebellar systems Both vestibular and cerebellar disorders may present with an unsteady gait If there is a unilateral lesion, the child will fall toward the side of the lesion The two may at times be distinguishable by the nature of the nystagmus (described below) If cerebellar dysfunction is present, the patient may have dysmetria and ataxia All cases of suspected vestibular or cerebellar dysfunction require close follow-up evaluation because of the risk of a posterior fossa mass Nystagmus is a highly specific sign for both central and peripheral vertiginous disorders A patient complaining of dizziness with vertigo may not have nystagmus at the time that he or she is examined Tests to elicit positional vertigo and nystagmus can therefore be helpful in identifying and even distinguishing central and peripheral vestibular dysfunction, particularly if the tests elicit or increase the patient’s complaint Nystagmus should be sought in all positions of gaze and with changes in head position The Nylen–Hallpike test can be used to elicit nystagmus if not apparent on initial examination It is performed by moving a child rapidly from a sitting to a supine position with the head 45 degrees below the edge of the examining table and turned 45 degrees to one side Nystagmus and a vertiginous sensation may result as the vestibular system is stressed Certain features of nystagmus may be helpful in distinguishing central from peripheral vestibular dysfunction In central dysfunction, for example, onset of nystagmus is immediate; in peripheral vestibular disorders, it is delayed Central lesions are characterized by nystagmus with the fast component toward the affected side and reversal of the fast component when changing from right to left lateral gaze Peripheral vestibular disorders are characterized by a “jerk” nystagmus with the slow component toward the affected side Finally, visual fixation does not affect nystagmus from central causes, but tends to dampen peripheral nystagmus FIGURE 24.1 Approach to the child with true vertigo CT, computed tomography; TM, tympanic membrane; CNS, central nervous system The cold caloric response tests for integrity of the peripheral vestibular system Slow and careful irrigation of either 100 mL of tap water 7°C below body temperature or 10 mL of ice water into the external ear canal through a soft plastic tube, with the child lying about 60 degrees recumbent, should induce a slow movement of the eyes toward the stimulus and a fast movement away Instillation of warm water (44°C) will cause an inverse reaction Vestibular damage will suppress the response on the affected side Absence of nystagmus indicates absence of peripheral vestibular function The test is contraindicated if the tympanic membrane is perforated Ancillary Tests Laboratory investigations have a limited role in the evaluation of vertigo Useful initial tests include complete blood count, serum glucose, and an electrocardiogram Together, these may help identify patients with pseudovertiginous conditions caused by anemia, hypoglycemia, and rhythm abnormalities Further laboratory testing may reveal diabetes or renal failure, both of which have been associated with vertigo Toxicologic testing including specific anticonvulsant levels and an ethanol level, if indicated, may be helpful A lumbar puncture is indicated in cases of suspected meningitis or encephalitis, but imaging may be required to rule out obstructive hydrocephalus from a posterior fossa mass if there are cerebellar signs Radiologic imaging of the central nervous system, preferably by MRI for adequate visualization of the posterior fossa and brainstem, is indicated in cases of chronic and recurrent vertigo to exclude mass lesions Children with vertigo and an underlying bleeding diathesis or a predisposition toward ischemic stroke (i.e., sickle cell disease) may also need an emergent cranial CT or MRI Posttraumatic vertigo, especially when accompanied by hearing loss or facial nerve paralysis, is best assessed by CT that includes adequate images of the temporal bone Some children with true vertigo will require referral for more extensive testing An EEG is indicated when vertigo accompanies loss of consciousness or other manifestations of a seizure Audiometry is indicated when vertigo accompanies otalgia, hearing loss, or tinnitus Specialized testing for nystagmus, including electronystagmography, which measures eye movements at rest and at extremes of gaze, can separate central from peripheral vestibular disorders It may be combined with caloric and positional testing MANAGEMENT Most causes of vertigo remit spontaneously without therapy, but specific disorders require treatment Suppurative labyrinthitis, for example, is treated with antibiotics if a bacterial etiology is suspected An erosive cholesteatoma requires surgical removal Anticonvulsants may diminish vestibular and vestibulogenic seizures Motion sickness may respond to simple behavioral changes (e.g., encouraging children to look out the window) Subspecialist consultation is indicated in certain situations Neurosurgical evaluation after trauma may be indicated in cases of suspected basilar skull fracture Suspected perilymphatic fistula, cholesteatoma, traumatic rupture of tympanic membrane, or complicated otitis media may merit otorhinolaryngologic evaluation Neurologists may be helpful in cases of suspected seizure or migraine FIGURE 24.2 Approach to the child with pseudovertigo EKG, electrocardiogram Children with severe or recurrent attacks of vertigo may require treatment with specific medications The antihistamines dimenhydrinate (12.5 to 25 mg orally every to hours, maximum dose 75 mg per day for ages to years and 25 to 50 mg every to hours for ages to 12 years, maximum dose 150 mg per day) and meclizine (12.5 to 25 mg orally every 12 hours in children older than 12 years of age) may be helpful Concomitant use of a benzodiazepine such as diazepam (0.1 to 0.3 mg/kg/day orally divided every to hours, maximum 10 mg per dose) as a sedative may be necessary in severe cases Pseudovertigo Pseudovertigo ( Fig 24.2 ) refers to a broad array of symptoms such as lightheadedness, presyncope, intoxication, ataxia, visual disturbances, unsteadiness, stress, anxiety, and fear Uniformly absent are a sense of rotation and ocular nystagmus Underlying causes are numerous; several of the most common causes are listed in Table 24.3 (see also discussions of syncope in Chapter 76 Syncope ) Careful consideration of the patient’s age, gender, detailed