Benign paroxysmal vertigo of childhood: A review of the literature

Abstract

Childrens’ complaints of headache and dizziness merit careful evaluation to differentially diagnose a vestibular disorder. Children can manifest with a syndrome mimicking certain classic signs and symptoms of adult vestibular disorders, such as benign paroxysmal positional vertigo, usually associated with aging. Benign paroxysmal vertigo of childhood in which migraine is a key manifestation along with sudden onset of dizziness, is a rare peripheral vestibular disorder in children that is commonly overlooked or misdiagnosed. This review covers the historical development of the diagnosis, evaluation and treatment approaches of benign paroxysmal vertigo of childhood.

Childrens’ complaints of dizziness merit careful evaluation in the diagnosis of a vestibular disorder (1). First, a differential diagnosis of vestibular problems in children must take into account their general level of maturation, especially the development of postural control (2,3). Second, although both children and adults may be affected by the same disorders, the signs and symptoms are not identical (4). Third, children may have less facility in describing (articulating) their symptoms (5,6). Finally, children require different approaches to testing where fear- and age-appropriate needs are considered, and the results of these tests must be adjusted for a younger population to be fully reliable (1,3,7). This is a review of the literature on benign paroxysmal vertigo of childhood (BPVC), a peripheral vestibular disorder reputedly similar to benign paroxysmal positional vertigo (BPPV) in adults.

BPPV is a vestibular disorder seen in adults over the age of 50 years (8–10). It is a commonly overlooked and misdiagnosed disorder associated with aging (10–13). First described by Barany in 1920 (14), BPPV is characterized by recurring acute attacks of vertigo of short duration, usually provoked by changes in head position. BPPV is known by a variety of names, such as ‘positional nystagmus of the benign paroxysmal type’ (15) and ‘benign recurrent vertigo’ (9). These names refer to the importance of sudden changes in head-on-body positioning that provoke episodic and reversible symptoms (16). Other names, such as ‘cupulolithiasis’ (16) and ‘canalithiasis’ (17) allude to the cause of BPPV (16).

BPPV in children was first reported in 1964 by Basser (18) who observed the condition in 17 children (both boys and girls) under the age of four years. Symptoms included sudden episodic sensations of spinning (vertigo) without hearing loss or tinnitus, loss of balance and staggering, expressions of fear, pallor, diaphoresis and occasional vomiting. These episodes would reoccur several times a month for several years, often disappearing by age eight (18). Although the cause was unclear, vascular disturbances affecting the posterior arterial circulation of the brain seemed to be implicated (18).

After a sufficient number of other BPPV cases in children had been reported throughout the 1970s and 1980s, the syndrome ‘benign paroxysmal vertigo of childhood’ was classified (19,20). However, some researchers dispute the notion of BPPV in children, claiming that it has not been reported in children under the age of 11 (21), and that episodic vertigo in children is most likely related to migraine and should be treated as a migrainous disorder (12,21,22), or considered a complex (a combination of BPPV and migraine) (23).

Supporters of the diagnosis of BPVC consider it a relatively rare peripheral vestibular disorder that is commonly misdiagnosed or overlooked (7,22) and whose clinical picture is similar to adult BPPV but with several additional distinctive features. In both BPPV (adult) and BPVC, the short duration of the attack, latent period before the onset of vertigo, fatigability of the signs and symptoms, kind of nystagmus and periods of exacerbation-remission have rendered this disorder a peripheral end-organ disturbance (3,5,6). While sudden onset of spinning (paroxysmal vertigo) may occur in many peripheral vestibular disorders, it is the absence of hearing loss (1,24), and the positional disequilibrium and positional nystagmus (16) that seem to help differentiate both adult and child positional vertigo from other manifestations of dizziness and vertigo of vestibular origin. Vertigo attacks are precipitated by a relatively rapid change in head posture, with a latency of a few seconds between the shift and the onset (16). Vertigo can begin within 1 s to 40 s after being in a provoking position, and both nystagmus and vertigo fluctuate with intensity until symptoms abate, often within 60 s (12). Treatment includes positional provocation and repositioning (3), and no permanent labyrinthine deficits result (25). The reversibility of symptoms (ie, the response of symptoms to change in position of the head and body) is pivotal in differentiating between a peripheral and a central vestibular lesion (20,26). Autonomic signs such as nausea, vomiting, pallor and diaphoresis also occur with varied expression (3,5). A child may not complain of dizziness (1) but rather the autonomic signs, and may express fear. Parents may notice unusual awkwardness, clumsiness or poor balance (27).

ETIOLOGY AND PATHOPHYSIOLOGY

Although the exact cause of BPPV (and its alleged childhood variant, BPVC) is unknown, clinicians concur that the vestibular disturbances could be caused by diffuse damage to the vestibular neuroepithelium (28). Symptoms could result from either freely-floating particles of cellular debris (eg, calcium crystals from the otoconia) in the semicircular canals or particles of otoconia that break off from the utricle, and are displaced and settle into the cupula (3,17,29). Schuknecht (17) first described this as ‘cupulolithiasis’ or ‘canalolithiasis’, stating that the posterior semicircular canal was the primary site of debris, although deposits have also been seen in the superior and lateral canals histological sections of the temporal bones (11). The existence of debris in the vestibular system is suggestive of either degenerative effects associated with aging or trauma (3,6).

Support for the migraine thesis underlying BPVC is the dearth of cellular debris in anatomical specimens of paediatric temporal bones (11). Bachor et al (11) observed deposits in 121 temporal bones of children between the ages of newborn and 10 years, and found that deposits occurred much less frequently in the paediatric bones (11). Ischemia can also be restricted to the utricle’s otoconia (22), giving further credence to the cause being of vascular origin.

The theory that BPVC is really childhood migraine is a compelling one. Migraine headache occurs in children of all ages and has been reported in children as young as 18 months (30). Bille (30) observed 8993 school children between the ages of seven and 15 and found that 4% presented with migraine. Similarly, Russell and Abu-Arafeh (22) surveyed 2165 school-age children and 314 of the children responded with at least one episode of dizziness in the previous year. Fifty-seven of these respondents had three attacks either related to migraine or to unexplained causes. However, 47% of these 57 children presented with isolated symptoms of benign paroxysmal vertigo.

Many children with initial vertigo and suspected BPVC go on to develop migraine (20,22,23,31–34). Child migraine is different from adult ‘classical’ migraine (19) in that the most intense symptom (and common complaint) is usually gastrointestinal upset and fever rather than headache or visual disturbances (31). Also, children’s migraine attacks are often more frequent, of shorter duration (lasting less than 2 h) (35), may not be experienced as throbbing (35), and may present with a less clearly defined pattern of prodromal expression. Bilateral head pain is common, as opposed to the unilateral headache of classic migraine in adults (34,36,37).

Vertigo is relatively common in basilar artery migraine. Lapin and Golden (38) observed 30 cases of basilar artery migraine in children in which 48% had vertigo and 86% had a positive family history of migrainous headache. Vasospasm occurs in some intracranial vessels with migraine, but there is controversy regarding its role in producing vestibular symptoms (39). Vestibular symptoms associated with migraine include imbalance and motion intolerance occurring with headache, rather than a preceding aura, and abnormal central processing of vestibular input rather than vasospasm (although damage can be great with extensive, severe ischemia).

Finally, there is controversy surrounding the pathophysiology of vertigo and associated hearing loss in migraine. Episodic vasospasm can lead to hypoperfusion of the inner ear and subsequent damage (13). In summary, migraine should not be considered only a ‘central’ phenomenon, but rather a condition that selectively targets the peripheral vestibular system, making a clear distinction between BPVC and child migraine complex (10,13).

DIFFERENTIAL DIAGNOSIS

A thorough evaluation is needed to obtain a definitive diagnosis of peripheral BPVC or migraine. Vertigo commonly presents in a number of diagnostic categories including whiplash, basal artery migraine, seizures, infection, labyrinthine concussion and other traumatic head injuries (22,40), and ocular or ophthalmological disorders (41). The vestibular system is anatomically developed and responsive at birth, but matures along with other senses in the first seven to 10 years of life (2). The evaluation must take into account the developmental stage of all the anatomical relationships of the ear and vestibular system (Eustachian tube, temporo-mandibular joint, facial nerve, oculomotor nerves and ocular pathways, etc) (42,43), as well as the maturation of postural control (2,3). Vestibular disorders due to either congenital anomalies or trauma may result in postural head tilt, delayed postural control and incoordination (3,43–45).

The subjective interview should include a profile of development, including any anatomical or developmental anomalies or congenital abnormalities (1,46,47). A history of ‘TORCH’ (toxoplasmosis, other infections, rubella, cytomegalovirus infection and herpes simplex) infections are often associated with labyrinthitis (6,47), cardiorespiratory disease and head trauma, and a family history of vertigo, migraine, hearing loss, demyelinating disease or seizures (6,47). A history of torticollis, either traumatic or paroxysmal, should be checked as well (22). Psychological factors must also be assessed (47).

Establishing the pattern – episodic, acute (‘paroxysmal’) onset vertigo, provoked by changes of head position and with the presence of rotary upbeating nystagmus, and the absence of tinnitus or hearing loss – is essential. If nystagmus is absent through examination, the problem may not be vestibular (6). However, paroxysmal peripheral nystagmus is seen with acute labyrinthitis, stapedectomy and per-ilymphatic fistula (1,47).

Paroxysmal vertigo with hearing loss, for example, is usually due to infection, labyrinthitis or Meniere’s disease (uncommon in children) (1,47). Paroxysmal vertigo without hearing loss can also be caused by respiratory infections and otitis media. If the vertigo occurs without hearing loss but with loss of postural control, the cause may be basilar artery migraine (1). Unremitting vertigo or dizziness with neurological signs usually signals a central lesion, tumour or degenerative disorder (1).

One common cause of benign paroxysmal vertigo in the child without associated hearing loss is closed head injury (1,40,48), with accompanying headache, nausea, vomiting, and visual disturbances. Damage to the otolith membrane (cupulolithiasis), detachment of otoconia, or floating debris (canalolithiasis) (S Whitney, personal communication) can occur after closed head trauma. Labyrinthine dysfunction secondary to fracture, brain stem contusion and peri-lymphatic fistula can occur. Postconcussion syndrome can include sensations of swimming, light-headedness, dizziness, floating, rocking and disorientation (13). Vertigo also occurs in post-traumatic epilepsy (49).

Brain stem injury from head trauma is rarely a cause of isolated vestibular symptoms (13). Biaural, often simultaneous (50) caloric irrigation helps to test for symmetry of vestibular function. Caloric testing also helps to determine the prognosis of head trauma victims, particularly if there is brain stem involvement. Persons in coma do not produce normal tonic (cold-opposite nystagmus, warm-same [COWS]) deviations of the eyes. The absence of tonic nystagmus is a poor prognostic sign of recovery (13).

Computed tomography scans and x-rays of the petrous portion of the temporal bone are ordered if clinical examination is inconclusive or suspicious of head trauma or tumour. x-rays and scans of the temporal bones, audiograms and electroencephalograms should all be normal in BPVC (4).

Objective clinical testing for vestibular dysfunction is not as well standardized in children as it is in adults. Additionally, it is more difficult to perform, requiring modified approaches to reduce fear and to obtain reasonably reliable recordings (6). Games and role playing are needed to maintain attention and gaze. Parents may have to be present to decrease fear and anxiety, and smaller children, or those under three years of age, may actually have to sit on their parents laps to be tested in special equipment such as the rotational chair (6). The testing environment must not be overly colourful or busy, although a picture of a child undergoing the same type of testing may be helpful (6,7).

An objective vestibular examination involves both indirect and direct measures of vestibular function. Testing static visual acuity can include a review of cranial nerves, especially optic, oculomotor and auditory nerves, and vestibulo-ocular reflex testing, usually through playful games like peek-a-boo and gaze fixation and gaze shifts (7). Dynamic visual acuity, also an indirect measure of vestibular function, commonly includes the head-shaking nystagmus test in which a child can say “no” as fast as he or she can (7). Frenzel lenses can be added for older children (6,7).

Weber Rhinne tests, coordination (finger-to-nose) as well as gross motor (hop, skip, jump) tests with eyes open and closed serve as quick screens (47). Specific (Hallpike-Dix positioning maneuver with or without Frenzel lenses [ICS Medical, USA]) (7,15) and nonspecific (Fukuda stepping) tests may help clarify a vestibular involvement without the use of special equipment (7,12,47). Peabody and Oseretsky-Bruninks tests are also useful in clarifying the diagnosis.

A majority of normal children demonstrate normal vestibular responses to caloric and rotational stimuli by the age of two months (3). While caloric testing is the ‘gold standard’ of adult vestibular testing (7), children’s inattentiveness, lack of experience, fear and incomplete development of some components of ocular motor system make caloric testing challenging (3). Warm water is recommended over cold, or using air instead of water, with shorter durations of irrigations (3,7,50).

Electronystagmography helps to establish the existence and pattern of spontaneous nystagmus (4), smooth pursuit, saccades and optokinetic nystagmus (7,50). Normal results should indicate a low velocity and amplitude positional nystagmus and mild, postcaloric directional preponderance in the same direction as nystagmus during the attack in the head-hanging position (40,47). Darkened environments can help the clinician observe spontaneous nystagmus in infants and young children (7). Rotary chair testing is generally well tolerated and can help provide additional quantitative data (6,7).

Although balance assessment in children is considered a vital component of a developmental evaluation (1,3), no studies have directly compared clinical postural control tests with quantitative vestibular testing in children (2). Platform posturography can be adapted for children using the Pediatric Clinical Test of Sensory Integration for Balance (P-CTSIB) in children over six years (2,7). The P-CTSIB is an improvement over the tiltboard in discriminating individual sensory inputs (2). Depending on the level of developmental maturation, a child might be relying more on the visual system for balance between the ages of four months and two years, and only begin to integrate vestibular and somatosensory information between the ages of seven and 10 years (2,51).

TREATMENT

Treatment of children with BPVC is remarkably absent in the literature. While ample treatment for childhood migraine can be found through drugs and behavioural therapy(4,5,24,37,52,53), nonpharmacological or behavioural treatments (54) are absent. Additionally, little is known about health care utilization in childhood migraine (55). In one study sampling 3580 children, 95 of whom had migraine (2.7%), 58% of parents took the children to see a physician, but follow-up rehabilitation services were not tracked (55).

Although extensive protocols for rehabilitation of adult BPPV, such as the University of Michigan Vestibular Rehabilitation Program (56), are well-outlined, controlled protocols on children are not available. While protocols exist on training balance in children, few have acceptable reliability and validity (2).

Further research in this area would help to confirm or refute the general consensus that BPVC and childhood migraine are distinct clinical entities, and establish reliable protocols for decreasing child symptoms of vertigo and regaining function.