Vestibulopathies in Childhood

Transcription

1 Vestibulopathies in Childhood Raquel Mezzalira Introduction Until a short time ago, vestibulopathies were considered as diseases of the adult or the elderly. However, children are also under the risk of vestibular diseases. Nevertheless, the diagnosis of vestibulopathies in childhood is not easy because signs and symptoms are subjective and children are not able to characterize them. Manifestations of these diseases in the child have some peculiarities and the child is examined in a way that is different from adults. It is not easy to obtain from the child or the parents the necessary description about the symptoms related to body balance, and many cases of vestibular syndromes are misdiagnosed as malaise, epilepsy or gastrointestinal disorders. Therefore, when a child is presented with loss of balance it is important to keep in mind that some vestibular condition can be present. Children under one year of age are better off in the cradle, because they have a larger area of contact when lying down, supplying larger proprioceptive information. They present the pending head s phenomenon in an attempt of finding a position to relieve the dizziness. They have constant and unexplained nausea and vomiting, and may have nystagmus when they cry. Between one and seven years of age, the child has episodes of sudden paleness, falls without becoming unconscious, have a fast recovery, nausea, sudoresis, crying, headache, kinetosis, abdominal pains and bumps into other people or objects ( child had an awkward behavior ). The falls are a symptom of great importance, being the main reason for mothers to seek medical service. Night terror and night enuresis are a result of the dizziness caused by the privation of visual information. Difficulties appear during games and playing with toys and lead to social isolation. A school age child (7-11 years old) is already able to report characteristics of dizziness, headache and associated hearing symptoms. They are usually restless, because they try to find a comfortable and safe position, which generates concentration difficulty and dispersion of attention, and these children lag behind in school. There are some predisposing factors that interfere with the vestibular function as infectious diseases during pregnancy, use of ototoxic drugs, maternal migraine, anoxia at birth, middle ear infections and cranial traumatisms.

2 290 V IAPO MANUAL OF PEDIATRIC OTORHINOLARYNGOLOGY Vestibular evaluation in childhood Every child thought to have vestibular dysfunction should be thoroughly investigated. The otoneurological evaluation of the dizzy child is of great importance because it can reveal a brain tumor in 3% of the cases. The evaluation can be carried out in any child, provided it has been adapted for its age. The study starts by taking the history, obtaining as much information about the child as possible from the parents and other relatives, in order to characterize the dizziness and associated symptoms. The information about remaining conscious is very important, helping to differentiate between central and peripheral diseases. Data about the pregnancy, birth and early childhood, as well as the family history should be investigated. The physical examination should begin with an otoscopy to eliminate the possibility of middle ear infections. In an older child, the neurological exam can be accomplished as in the adult, including pairs of cranial nerves, cerebellum, evaluation of static and dynamic balance and presence of spontaneous nystagmus. In the newly born and in very small children it is only possible to evaluate the primitive reflexes that are useful to evaluate the neurological development, but can be altered when there is any condition related to the vestibular function or to balance. The electronystagmography test is extremely important in the clinical evaluation of vertigo during childhood. In older children, around five years of age, the caloric testing can already be performed as well as the pendulum tracking test, which can be performed in any age. The caloric testing evaluates the function of the peripheral organ and the pendulum test evaluates the state of vestibular compensation. Usually starting at five years of age, children can also have oculomotricity tested, obtaining information on the central vestibular pathways of brain steam and cerebral cortex. The normal values for children, however, are different from those in adults, probably due to the degree of the central nervous system maturity and a great deal of caution in the data analysis is advisable. The computerized dynamic posturography is a test that studies the balance through labyrinthine, visual and somatosensorial integration. It can be used to diagnose vestibulopathies and to evaluate its treatment. In clinical practice, a vestibulopathy can be diagnosed in almost all childhood cases by associating the data obtained in the history and the results of the otoneurological evaluation (that always includes hearing evaluation). A neurological evaluation including an electroencephalogram, CSF punction and imaging should be performed when any condition of the central vestibular system is suspected. Computerized tomography and magnetic resonance imaging can also be carried out in the research of inner ear malformations. Serology testing is used when there is a possibility of infectious diseases affecting the vestibular pathways (syphilis, toxoplasmosis, measles, cytomegalovirus, herpes and HIV). Other tests can also be requested as thyroid function, carbohydrate metabolism and autoimmune studies.

3 V IAPO MANUAL OF PEDIATRIC OTORHINOLARYNGOLOGY 291 Vestibular diseases in childhood All the diseases that affect the adult vestibular system can also affect the child. Comments will be made here about those that are more frequent or exclusive of childhood. Peripheral vestibulopathies are the most frequent and are characterized by episodic and paroxysmal dizziness with associated neurovegetative and hearing symptoms, with no conscience loss. The affection of the middle ear, either due to pressure alterations or otitis leading to labyrinthitis, is the main cause and a careful otoscopy is fundamental. The paroxysmal torticollis occurs in less than 1 year of age. The head has a characteristic bending to one side and there is a light rotation of the body to the contralateral side, with neurovegetative symptoms but without any sign of pain. The crisis may last from minutes to days and the nystagmus can be present during the crisis or not. The most probable cause is vascular, because it is believed that torticollis precedes the benign paroxysmal vertigo of childhood. The vestibular, neurological and orthopedic exams are normal and the resolution tends to be spontaneous with age. The benign paroxysmal vertigo of the childhood is the second most common cause of vestibulopathy in the childhood. Along with the affections of the middle ear it comprises more than 50% of the diagnoses of infantile dizziness. It affects children from 4 to 6 years of age and has as characteristic sudden and fleeting dizziness episode, with neurovegetative symptoms, without hearing symptoms and without loss of conscience associated. Headache may be present or not. The most probable cause is a transitory vasoconstriction in the vertebrobasilar territory with ischemia of the vestibular nuclei and it is therefore considered as a precursor of migraine. The neurological exam is normal (it provides differential diagnosis with epilepsy). The vestibular evaluation results may be normal or show labyrinth hypoactivity. It is a self-limited disease. It is believed that the paroxysmal torticollis, the benign paroxysmal vertigo of childhood and the migraine are phases of a same disease because they are caused by a vasoconstriction-vasodilatation mechanism in the vertebrobasilar system. Other causes of vestibulopathies in childhood are kinetosis, Ménière s disease, vestibular neuronitis, benign paroxysmal postural vertigo, ototoxicity, and metabolic vestibulopathies, Grisel s syndrome, labyrinth concussion, temporal fractures, perilymphatic fistula, labyrinth malformations (dysplasias), and Alport, Waardenburg, von Recklinghausen, Pendred, Refsum s and Usher syndromes. The central vestibulopathies affect the vestibular pathways starting in the brainstem and are characterized by persistent imbalance. Walking disturbances, diplopia, visual blurring, headache and loss of conscience are present. The causes are use of psychotropic drugs, Addison s disease, ophthalmologic causes, anemia, syncopes, hypoglycemia, stroke, psychic alterations, cranioencephalic traumatism, epilepsy, neoplasia, Arnold Chiari, degenerative diseases and infections, HIV and migraine. It is important to stress that posterior fossa tumors have a higher incidence in childhood than in adulthood and disturbance in balance may be one of the initial manifestations.

4 292 V IAPO MANUAL OF PEDIATRIC OTORHINOLARYNGOLOGY Treatment of childhood vestibulopathies The treatment of childhood vestibulopathies should be the most conservative as possible. The cause should be established in order to prescribe a specific treatment for each disease. A very important point is the adaptation of the diet with low ingestion of tyramine, sugar, salt, caffeine, chocolate and xanthines. Physical activities should be stimulated. If drugs are necessary, the choice should be made based on the lowest rate of side effects, for the shortest time and in the lowest possible dose. Vertigo in the child is usually not as intense as in the adult. Some medications can be useful in the treatment of the acute crisis: Dimenhydrinate: o Orally or IM: 1-5 mg/kg/dose qid (maximum 300 mg/d) Metoclopramide: o Orally or IM: 0.5 mg/kg/day tid (maximum 15 mg/day) Child younger than 6 years: up to 0.1 mg/kg/dose Bromopride: o Orally or IM: mg/kg/day Diazepam: o IV/IM: : mg/kg/dose o Orally: mg/kg/dose (maximum 0.6 mg/kg/dose) Clonazepam: o Orally: mg/kg/day tid (maximum 20 mg) On the other hand, the maintenance treatment can also include: Ginkgo biloba (first choice): o 1-2 drops/kg/dose tid, orally Calcium channel blockers: second choice orally, o Cinnarizine: 1 drop/kg o Flunarizine: 5 mg/day, useful also for migraine prophylaxis However, the chosen treatment for childhood vestibulopathies is vestibular rehabilitation that includes a series of repeated movements of the head, neck and eyes with the objective of stimulating the labyrinth compensation. As the cerebral plasticity is quite active during childhood, the child responds very well to this treatment and can obtain relief not just for the dizziness but also for the headache and the kinetosis. Besides, vestibular rehabilitation can make the child to return to his/her environment, making him/her able to accomplish all the activities of a healthy childhood. There are some cases of rehabilitation failures that can be explained by a secondary gain with dizziness, non-compensated metabolic factors and by the presence of a central condition. Conclusion The child does not refer being dizzy, but his/her attitude indicate so. Thus, regardless of either the history or the physical exam, a dizziness condition should be throughly investigated because it may be an indication of a disease that can interfere with child s health and development.

5 Recommended readings V IAPO MANUAL OF PEDIATRIC OTORHINOLARYNGOLOGY Medeiros IRT, Bittar RSM, Pedalini MEB, Lorenzi MC, Kii MA, Formigoni LG. Evaluation of the treatment of vestibular disorders in children with computerized dynamic posturography: preliminary results. J Pediatr (Rio J); 79(4):337-42, Toupet M. Vertigine chez l`enfant. Encycl Med Chir (Paris France). Oto-rhinolaryngologie B-10, 1995, 12p. 3. Uneri A, Turkdogan D. Arch Dis Child; 88(6):510-1, 2003.

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