Altered Cervical Vestibular-Evoked Myogenic Potential in Children with Attention Deficit and Hyperactivity Disorder

Abstract

Objective: Emerging evidence suggests that children with attention deficit and hyperactivity disorder (ADHD) present more difficulties in standing and walking balance than typically developing children. Most of previous studies have assessed these functions using postural and sensory organization tests showing differences in balance performance between control and ADHD children. However, to date, it is unknown whether these balance alterations are accompanied with vestibular dysfunction. The principal aim of this study is to evaluate vestibular otolith function in ADHD and matched control children.

Methods: We assessed vestibular otolith function in children with ADHD and controls using the subjective visual vertical (SVV) bucket test and cervical vestibular-evoked myogenic potentials (cVEMPs). In addition, gait and balance were evaluated using the dynamic gait index (DGI) and computerized posturography.

Results: Non-significant differences between groups were obtained in SVV evaluation. DGI results show lower scores for overall test performance in children with ADHD (p < 0.001), while computerized postural recordings showed significant differences for the limit of stability between groups (p = 0.02). cVEMPs in response to 500 Hz tone bursts presented at 100 dB were absent or reduced in children with ADHD, as revealed by differences in P1 and N1 peak-to-peak amplitudes between groups (p < 0.01).

Conclusion: These findings suggest that vestibular brainstem reflexes are altered in a subset of children with ADHD. We propose to include cVEMP reflexes in the clinical evaluation of ADHD patients.

Keywords: VEMP; attention deficit and hyperactivity disorder; balance; gait; otolith function; subjective visual vertical.

Figure 1

Similar subjective visual vertical (SVV) perception in controls (n = 13) and attention deficit and hyperactivity disorder (ADHD) children (n = 13). Box-plots showing the median and interquartile range for six attempts in each group. Non-significant differences were observed, revealing similar abilities in both groups for SVV perception.

Figure 2

Attention deficit and hyperactivity disorder (ADHD) children have reduced total dynamic gait index (DGI) score compared to controls. Mann–Whitney, p = 0.0004. Box-plots showing the median and interquartile range for total DGI score in both groups.

Figure 3

Attention deficit and hyperactivity disorder (ADHD) children have significant reduced limits of stability (LOS) area compared to control children. Box-plots showing the median and interquartile range for LOS in both groups.

Figure 4

Bilateral cervical vestibular-evoked myogenic potential (cVEMP) amplitudes are reduced in the group of attention deficit and hyperactivity disorder (ADHD) children. Significant differences were obtained comparing left and right cVEMPs obtained with 500 Hz tones at 100 dB.

Figure 5

There are no differences in cervical vestibular-evoked myogenic potential (cVEMP) P1 latencies between the group of attention deficit and hyperactivity disorder (ADHD) and control children. Box-plots showing the median and interquartile range for P1 latencies in both groups. Left and right cVEMPs were obtained with 500 Hz tones at 100 dB.

Figure 6

Individual cervical vestibular-evoked myogenic potential (cVEMP) amplitudes allow separation of a subset of attention deficit and hyperactivity disorder (ADHD) children. Orange squares and black circles represent individual right and left cVEMP amplitudes in ADHD and control children, respectively. Note that a criterion of left cVEMP amplitude <150 μV and right cVEMP amplitude <100 μV permits identification of ADHD children with 100% specificity and 84.6% sensitivity. The orange symbol at (0,0) with a red cross represents the three ADHD cases with absent cVEMP responses.

Figure 7

Significant correlation between the individual average of bilateral cervical vestibular-evoked myogenic potential (cVEMP) amplitudes and behavioral sensory processing measure (SPM) score. Orange squares and black circles represent the individual average of bilateral cVEMP amplitudes in attention deficit and hyperactivity disorder (ADHD) (n = 13) and control children (n = 13), respectively. Note that there is an overlap in children controls with 19 points in the SPM score and near 150 μV in cVEMP amplitude. A significant negative correlation was obtained (Spearman, p < 0.001), linear regression equation: f(x) = 34.52 − 0.07 × x.