An Update on the Predominant Forms of Vertigo in Children and Their Associated Findings on Balance Function Testing

Introduction

There are many disorders that can cause “dizziness” in the pediatric population. In 1999, Russell and Abu-Arafeh published an epidemiological study showing that in their sample, 15% of school-age children had experienced at least one episode of vertigo in the previous year. In a further effort to describe the prevalence and causes of dizziness in the pediatric population, O’Reilly et al. searched electronic medical records (i.e., ICD-9 codes) of 561,151 inpatient and outpatient visits during a 4-year period. These investigators reported that approximately 1% of this cohort met criteria for presenting with a primary complaint related to balance. Further analysis revealed that 2283 patients (0.4%) received a diagnosis of unspecified dizziness, and of these, 6.2% were diagnosed with a peripheral cause of dizziness while 4.1% were diagnosed with a central cause. The total prevalence of diagnoses related to balance in the records reviewed was determined to be 0.45%. These data serve to highlight the relative rarity of seeking medical attention for symptoms of dizziness and imbalance in young children. Numerous investigators have described the most common disorders causing vertigo and imbalance in children in their clinics. Even though these reports originate from different clinics and regions of the world, there is surprisingly good agreement regarding primary causes of dizziness in the pediatric population. Nevertheless, children experiencing vertigo and imbalance have received less attention in the literature than their adult counterparts. This is most likely due to the difficulty that young children have in describing their symptoms, coupled with challenges that exist for clinicians in working through the differential diagnostic process with children. Despite these limitations, it is now known that the most common disorders in children that cause dizziness manifest themselves as abnormalities on quantitative balance function testing (i.e., rotary chair testing, videonystagmography/electronystagmography, and vestibular evoked myogenic potential [VEMP] testing).

Background

Assessment of vestibular system function in the pediatric population is gaining interest for several reasons. First, determining vestibular system integrity can assist physicians in diagnosing impairment and in defining the most appropriate course of treatment. Second, some children with dizziness and balance problems have serious health issues, and vestibular system assessment can help identify patients whose symptoms may stem from neurologic impairment secondary to intracranial abnormality (e.g., head trauma, brain tumor) versus developmental delay. However, unlike in adults, episodic vertigo occurs rarely in children and may manifest itself in many forms. For example, a child with acute vestibular system impairment may present with many of the same symptoms as adults (e.g., vomiting, nystagmus, hearing loss, ataxia) or may have subtler symptoms such as visual disturbance, motor delay, or headache. As with adults, children with vestibular disorders may also present with loss of vestibular function, which is progressive or chronic, thereby affecting development of postural control. Identifying whether dizziness in a pediatric patient is of vestibular origin requires a team approach, beginning with an assessment by a physician. During this initial visit, a detailed case history should be obtained along with comprehensive neurologic and otologic examinations. Once neurologic impairments are excluded, quantitative balance function testing may help identify both peripheral and central vestibular system deficits.

Despite the fact that dizziness and vertigo occur in children, there are few dizziness clinics that have made a commitment to test this population. One explanation for this is the challenge of extracting clinical and laboratory information from children. According to Wiener-Vacher, children will often not report vertiginous symptoms because of their inability to verbalize the abnormal sensations they are experiencing. Vestibular disorders in young children often are dismissed by professionals and caregivers alike, and the symptoms are consequently attributed to behavioral problems (i.e., finding ways to attract attention) or simply being “clumsy.” Additionally, diseases that affect the vestibular system in adults have a different frequency of occurrence in the pediatric population. For example, benign paroxysmal positional vertigo (BPPV) is generally quoted as the most common form of vertigo in adults. It has been estimated to have a prevalence of 2.4% in the general adult population. In children, BPPV has been reported to occur in up to 6% of those presenting with dizzy concerns. This means that the provider must approach the diagnosis of childhood dizziness and vertigo with a very different background of knowledge. Finally, although there continues to be interest in the development of techniques for assessing the vestibular system in adults, the same energy has not been directed toward adapting these techniques for application to children. One of the pioneers in the assessment of vestibular function in the pediatric population was Dr. David Cyr who worked at the Boys Town Institute. Much of his work in the 1980s focused on adapting existing adult protocols for use with children. Many of these adaptations are still in use today (see Chapter 4 ). Although interest in the assessment of the vestibular system in children has led manufacturers to develop both age-adjusted pupil tracking algorithms and age-appropriate visual targets, the majority of manufacturers at the time of this report do not offer videonystagmography goggles that are appropriately sized for children. Having equipment that allows for accurate assessment of children is critical because many disorders causing dizziness and vertigo in children have a vestibular origin. Although the clinical utility of quantitative balance function testing is well-documented in children, continued research and development in balance assessment techniques will further our understanding of pediatric dizziness and vertigo.

Assessing Dizziness Handicap in Pediatric Patients

It is now standard practice to evaluate the impact that balance disorders have on an individual’s ability to participate in age-appropriate activities and document any restrictions that may be imposed by the impairment. This is referred to in the literature as a patient’s dizziness-related quality of life (DRQoL). There are a number of important reasons to measure patients’ DRQoL. First, these metrics provide the treating clinician with information that can be used to design and guide treatment of a patient’s symptoms. Specifically, a clinician can administer a handicap measure to a patient, provide treatment designed to mitigate the origin of the impairment, and then reassess to determine if there has been any change. Historically, psychometric investigations have been performed describing how much change in the score is needed to be considered significant. Having outcome measures that include the patient’s perception of their symptoms in addition to findings on the vestibular test battery as well as their subsequent response to intervention provides a multidimensional profile of the patient’s symptom status. Secondly, it has been shown that there is often a disparity between a patient’s symptoms and their findings on vestibular function studies. That is, there are no semiobjective measures of vestibular impairment that are strongly predictive of dizziness handicap and/or disability. Lastly, in the current health care environment, evidence-based practice is important to all parties involved, including insurance carriers.

DRQoL has been typically assessed using validated self-report measures. These appraisals are most commonly done in a paper-pencil format, are brief to complete, and are psychometrically robust (i.e., test-retest reliability is high). There are a number of tools that assess DRQoL including the Vertigo Handicap Inventory and the Dizziness Handicap Inventory (DHI). Until recently, there was no single measure of dizziness handicap and/or disability for children. In 2015, the Vanderbilt Pediatric Dizziness Handicap Inventory of Patient Caregivers (DHI-PC) was introduced and validated for use with children aged 5–12 years. Questions on the DHI-PC are written in such a way that they may be answered by the child or their proxy. The DHI-PC form is shown in Fig. 5.1 .

Differential Diagnosis

The differential diagnostic process is more complex in children reporting dizziness or balance problems than in adults for several reasons. First, symptoms of dizziness can manifest differently in children than in adults. Moreover, young children have limited verbal skills and often the clinician must rely on the caregiver’s observations for the case history. Accordingly, determining which pediatric patients should receive vestibular testing can be difficult. In this regard, several investigators have designed structured case histories to be used for the evaluation of vertiginous children. One example set forth by Ravid et al. consists of a set of structured questions coupled with a computer algorithm designed to aid in the differential diagnosis of the dizzy child.

To validate the effectiveness of the questionnaire, the authors performed a retrospective analysis of data collected from all children presenting with dizziness to their clinic over a 2-year period. Responses to the structured questionnaire were compared with the computer algorithm, and both were compared against the final diagnoses in the medical record. The questionnaire-derived diagnoses matched the medical record diagnoses in 92% of the patients, and results of the computer-assisted algorithm were identical to the final diagnoses in the medical record in 84% of patients. Similarly, Niemensivu et al. evaluated a structured case history for the diagnosis of dizziness in children and, following thorough clinical examination and vestibular laboratory testing, found that the most common disorders identified using this approach were otitis media–related vertigo, migraine-associated dizziness, and benign paroxysmal vertigo of childhood (BPVC).

In our experience, using a structured case history coupled with a decision tree has worked well to identify patients who will benefit from vestibular testing. For instance, if the algorithm suggests that the patient may have labyrinthitis, then quantitative testing can be performed to determine whether the child has a peripheral impairment, whether it is unilateral or bilateral, if unilateral how severe, and whether the child is compensating centrally for the impairment. Conversely, if a child presents with chronic dizziness, no hearing loss, and a documented neurologic deficit(s), balance function testing would most likely not be indicated, and other issues would need to be ruled out (e.g., degenerative disease or posterior fossa tumor) using different techniques. This information is useful to both the physician and the pediatric physical therapist when considering management options. This approach also streamlines the differential diagnostic process and affords the physician the ability to be selective in determining which tests will be beneficial in deriving the diagnosis and which will not.

Recently, Pavlou, Whitney, and associates developed and validated the Pediatric Vestibular Symptom Questionnaire (PVSQ). This instrument is designed to identify and quantify subjective vestibular symptoms (e.g., dizziness, imbalance) in children aged 6–17 years. The study also had a secondary component, which described relationships among symptoms in children with vestibular impairment versus dizziness or imbalance secondary to concussion. This instrument can be used not only as an indicator for whether a child requires further assessment to investigate a potential balance impairment, but also as a metric that can be used to evaluate the effectiveness of treatment ( Fig. 5.2 ).

The Most Common Disorders

After otitis media, the two most common conditions reported in the literature causing dizziness/vertigo in children are migraine headache and BPVC. The next most common disorders are trauma and vestibular neuritis. Interestingly, all of these disorders can result in patients who have abnormal findings on balance function testing. This reinforces the importance of having vestibular testing available in the pediatric dizzy clinic. Two recent studies illustrate this argument well. First, a recent report by Szirmai evaluated vestibular function in children (<14 years of age, n = 66) and adolescents (14–18 years of age, n = 79). The author reported that migrainous vertigo (MV) was the most common disorder causing dizziness in this cohort, followed by extravestibular disease (e.g., anxiety, panic disorder) and then labyrinthitis. Only 36% of the patients in this study demonstrated normal vestibular system function. In the group of adolescents, extravestibular disease was the most common cause of vertigo followed by migraine. Only 39% of the adolescents demonstrated normal vestibular results.

A report by Wiener-Vacher reviewed the most common vestibular disorders in over 2000 children over a 14-year period. Patient records were examined retrospectively to determine the most common diagnoses in children presenting with dizziness and vertigo. Consistent with many earlier reports, the most commonly diagnosed vestibular disturbance was MV, which was responsible for nearly 25% of patients. BPVC represented 20% of the diagnoses, and cranial trauma and ophthalmologic disorders each accounted for 10% of the diagnoses. In this cohort, vestibular neuritis (5%) and posterior fossa tumors (<1%) were less often encountered.

Table 5.1 provides a summary of findings from a series of studies each describing the most frequent causes of pediatric dizziness/vertigo that are encountered clinically. Characteristics of these conditions (i.e., pathophysiology and balance function test findings) are described.

Migraine-Associated Vertigo in Children

A number of epidemiologic investigations of dizziness in childhood have been published recently. Pacheva and Ivanov reported their observations from a sample of 2509 pediatric migraine patients who were evaluated in a pediatric neurologic clinic. These investigators reported that migraine variants were responsible for symptoms in 24% of the patients, basilar migraine (BM) was diagnosed in 6% of patients, and BPVC and hemiplegic migraine were responsible for 5% and 4% of diagnoses, respectively.

Teixeira et al. reported findings of patients with migraine equivalents who were evaluated in an outpatient pediatric neurology clinic. Of the 674 pediatric headache patients, 38 (5.6%) had migraine equivalents, and the majority were males. Further review revealed that 15 patients had abdominal migraine, 12 had BPVC, 5 had confusional migraine, 3 had aura without migraine, 2 had paroxysmal torticollis, and 1 patient had cyclic vomiting. A family history of migraine was common.

Marcelli et al. conducted an investigation focusing on BPVC, which is one of the most common pediatric migraine equivalents. It was the authors’ objective to characterize the progression of BPVC by conducting a 10-year longitudinal investigation with a sample of 15 children. These investigators reported that 67% of the patients reported either the onset or worsening of migraine over this interval. Furthermore, the neurootologic assessment was abnormal for 20% of patients during the symptom-free period and was abnormal for 67% of patients during the episode.

Another epidemiologic investigation by Raucci et al. reported their experience assessing vertigo and dizziness in a pediatric emergency department over a 5-year period. They found that dizziness and/or vertigo was the presenting complaint in 616 out of a total of 248,834 visits (or 2.5 dizzy patients per 1000 visits). The most common dizziness disorders were migraine, which accounted for 25% of visits, and BPVC, which accounted for 6% of the diagnoses.

Sommerfleck et al. reported the primary dizziness diagnoses of 206 patients aged 1–18 years (median age: 10 years). These investigators commented that 39% of the sample met criteria for definite vestibular migraine and another 13% satisfied criteria for probable MV. Interestingly, before puberty more boys than girls had migraine diagnoses. Following puberty the sex ratio favored girls. The most common disorder affecting children aged 1–5 years was BPVC. For the group between 6–11 and 12–18 years of age, the most common disorder was vestibular migraine.

The general view is that vestibular migraine coupled with BPVC account for approximately 37% of dizzy/vertiginous diagnoses in pediatric patients. The dizziness is described as moderate to severe in intensity and should be present for at least 5 minutes and no more than 72 hours. In fact, one-third of patients experience dizziness lasting minutes, one-third experience dizziness lasting hours, and one-third experience dizziness lasting days. Approximately 10% of patients experience short-lasting dizziness (seconds). Dizziness may precede or follow the headache, and the dizziness perception may be either spinning or a rocking sensation.

There are a number of “episodic syndromes” that may be migraine variants that can affect pediatric dizzy patients. These syndromes include infantile colic, benign paroxysmal torticollis, benign paroxysmal vertigo, cyclical vomiting syndrome, and abdominal migraine. These are referred to as episodic syndromes because head pain may be completely absent. These variants may occur in isolation or may coexist with other migrainous diagnoses. Furthermore, the prevalence of these syndromes has been reported to range from 2% to 4% of the pediatric dizzy population.

Treatments for vestibular migraine range from sleep hygiene and diet control to prophylactic treatment with medications that include flunarizine, propranolol, metoprolol, topiramate, clonazepam, lamotrigine, nortriptyline, amitriptyline, verapamil, and lomerizine.

As mentioned previously, the most common diagnosis in children with vertigo and dizziness is migraine headache or migraine equivalent, although the temporal relationship of headache and dizziness has been reported to be variable. That is, vertigo may precede, follow, or occur simultaneously with dizziness/vertigo, and often there are accompanying symptoms such as nausea and/or sensory distortions (i.e., sensitivity to light, sound, taste, smell, and motion). The clinical features of migraine in children can be different from those seen in adults. In childhood, migraines often are localized to the frontal or periorbital region, last less than 2 hours and may not manifest themselves as the typical throbbing pain often described by adults. Approximately 20% of children with migraine have associated dizziness. There are three commonly reported migraine variants that can produce abnormal findings on quantitative vestibular system testing : BM, MV, and BPVC. Reports estimate that BM occurs in 3%–19% of children with migraine and usually occurs around age 7 years. Many migraines present with an aura consisting of different sensory sensations (e.g., olfactory, visual, or vestibular). BM has been described in the literature as presenting with an aura consisting of audiovestibular manifestations, such as tinnitus, loss of hearing, acute imbalance, and vertigo. Usually, the neurologic examination in pediatric patients with BM is normal. According to Eggers, only a very small proportion of patients with MV meet criteria for BM.