This probably heterogeneous disorder is characterized by recurrent brief episodic attacks of vertigo occurring without warning and resolving spontaneously in otherwise healthy children
A. At least 5 attacks fulfilling criterion B
B. Multiple episodes of severe vertigo, occurring without warning and resolving spontaneously after minutes to hours
C. Normal neurological examination; audiometric and vestibular functions between attacks
D. Normal electroencephalogram
Often associated with nystagmus or vomiting; unilateral throbbing headache may occur in some attacks
A diagnosis of BPVC is one of exclusion, and, therefore, the most important characteristic is the absence of signs and symptoms that suggest another cause. With this in mind, the child does not experience any associated alterations of consciousness, neurological changes, headache, or cochlear symptoms during the entire attack. The child also demonstrates a complete, and typically rapid, recovery with return to normal function.
A family history of migraine is both contributory and common in the child with BPVC with reports suggesting that this finding can be as high as 43 % . As in migraine, children with BPVC will often report a history of motion intolerance most frequently manifested as “car sickness.” In recent literature, there is a suggestion that creatine kinase levels are elevated in BPVC and its measurement may help in the diagnosis . However, this has not become standard clinical practice. Given the overlap in the clinical presentation between BPVC and epileptic vertigo, EEG is often added to a complete neurologic exam and should be normal in the setting of BPVC.
The age of onset of BPVC is variable and reports in the literature range from 18 months to 12 years. However, it most frequently occurs prior to 4 years of age and is uncommon after 8 years . On average, the episodes may occur every 4–6 weeks, with the intervals ranging from once a week to every 6 months. Typically, the frequency of attacks decreases with age. Similar to migraine, BPVC has a higher prevalence in females .
The pathophysiology of BPVC is as yet unproven; however, there is presumed overlap with the underlying pathophysiology for migraine. More specifically, vertigo in the setting of migraine is theorized to result from vascular alterations that produce a transient hypoxia of the vestibular nuclei and the vestibular pathways .
4.5 Peripheral Vestibular Testing in BPVC
While the original report by Basser suggested peripheral vestibular dysfunction based on findings of moderate to complete canal paresis in response to a caloric stimulus, evidence of peripheral dysfunction in the setting of BPVC has not been found by others [13, 21, 22]. As a result, in the presence of a history consistent with BPVC and a normal, complete neuro-otologic exam, ancillary vestibular end-organ testing (e.g., horizontal canal response to caloric or rotational testing and saccular response by vestibular evoked myogenic testing) may not be necessary at the outset. If additional symptoms evolve or if the pattern of episodes differs from the expected natural history of BPVC, peripheral vestibular testing should be considered. Despite the absence of peripheral vestibular loss, a subtle delay in gross motor development has been noted . In addition, some reports suggest that behavioral difficulties, anxiety, depressive, and hyperactivity symptoms are more common in children with BPVC .
4.6 Diagnostic Imaging
Most clinicians would suggest that imaging (typically magnetic resonance imaging (MRI)) is unnecessary in the presence of a convincing history for BPVC. The challenge in managing these children is that families often remain concerned about serious central nervous system causes, such as a brain tumor. It is often difficult to reassure them definitively in the absence of confirmatory imaging. Our experience is that frequently these children will have already undergone imaging ordered by their primary care physician prior to being seen in consultation. If the vertigo does not improve on an expected timeline or additional symptoms evolve, MRI should be considered to exclude a central cause.
4.7 Natural History
Beyond making the diagnosis, the role of the clinician is to inform and reassure parents of the benign nature of this condition that in most cases does not require specific treatment. BPVC has a favorable outlook, and long-term follow-up studies have shown complete resolution along a variety of timelines . A history of BPVC is associated with an increased risk of developing more classic migraine later on in life. In the literature, risk estimates range from 13 to 21 %. These estimates include the development of both classic migraine and other associated symptoms such as cyclic vomiting, recurrent abdominal pain, scotomata, and photophobia [17, 24].
As outlined above, the primary treatment of BPVC primarily relates to reassuring the family of the benign, self-limiting nature of the disease. Once this is understood, most families are happy to cope with the individual episodes and do not request any additional treatment. Beyond reassurance, a conservative treatment, if deemed necessary, would include eliminating factors that trigger a crisis, similar to migraine. Parents may be able to identify such triggers including poor or irregular sleep, intake of certain foods, and stress. In the uncommon situation where attacks are frequent and disabling, a pharmacological approach can be entertained. In children, this typically begins with magnesium replacement followed by prophylactic medications, in keeping with the pharmacological management of more classic migraine. Vestibular suppressants and abortive migraine medications are not helpful in the setting of BPVC because of the short duration of symptoms. In general, the threshold for pharmacological treatment in children is higher than in adults, and in the setting of BPVC, most clinicians find pharmacological treatment unnecessary. If the attacks of vertigo are so severe or frequent to warrant pharmacologic treatment, the clinician may wish to reconsider the diagnosis of BPVC and expand the diagnostic work-up.
4.9 Associated Conditions
Included in section 1.3.3 in the International Classification of Headaches under the umbrella of “Childhood periodic syndromes that are common precursors of migraine” is abdominal migraine. This condition is characterized by recurrent episodic attacks of vomiting, intense nausea associated with pallor and lethargy, as well as midline, moderate to severe intensity abdominal pain. These attacks last 1–72 h with normality between episodes .
In addition to abdominal migraine, although not formally defined in the International Classification of Headaches, many authors suggest that benign paroxysmal torticollis of infancy is a migraine-related disorder [25, 26]. It is clinically characterized as a self-limiting condition, in which the child typically wakes in the morning with direction-varying head tilt lasting anywhere from a few hours to many days, with nighttime relief. Symptoms present typically within the first few months of life and resolve by age 3–4 years. Recently, paroxysmal torticollis, like BPVC, has been associated with gross and fine motor delay . Children with abdominal migraine or benign paroxysmal torticollis of infancy may go on to develop BPVC and/or more classic migraine.
4.10 Other Diagnoses in the Differential
While there is a lengthy differential for the presentation of vertigo in children, those diagnoses that mimic BPVC are few. The following discussion will be limited to those conditions that are most frequently confused with BPVC.