The functional head impulse test: Comparing gain and percentage of correct answers

A comparison of the video head impulse test and the functional head impulse test in chronic unilateral vestibular loss

OBJECTIVE

To examine the correlation of video head impulse test, functional head impulse test and Dizziness Handicap Inventory results in patients with chronic unilateral vestibular loss, and to compare the results with healthy controls.

METHODS

Forty-eight patients diagnosed with chronic unilateral vestibular loss and 35 healthy individuals, aged 18-65 years, were included. The video head impulse test, functional head impulse test and Dizziness Handicap Inventory were administered.

RESULTS

A significant positive correlation was found between functional head impulse test and video head impulse test results for the study group in all semicircular canals (p < 0.05). There was no significant correlation between Dizziness Handicap Inventory, functional head impulse test and video head impulse test results (p > 0.05). The functional head impulse test and video head impulse test results of the control group were significantly higher than those of the study group in all semicircular canals planes (p < 0.05).

CONCLUSION

In chronic unilateral vestibular loss patients, with high head accelerations, the functional head impulse test indicates deterioration in vestibulo-ocular reflex functionality. It would be beneficial to include the video head impulse test and functional head impulse test in clinical practice as complementary tests in vestibulo-ocular reflex evaluation.

Role of the functional head impulse test in evaluating vestibulo-ocular reflex abnormalities in individuals with Parkinson's disease

PURPOSE

To assess vestibular-ocular reflex (VOR) function in patients with Parkinson's disease (PD) using a new method called functional head impulse test (fHIT).

STUDY DESIGN

Case-control study.

SETTING

Tertiary medical center.

PARTICIPANTS

Twenty individuals with PD were recruited for PD group, and twenty healthy individuals for the control group. Ages of both groups ranged from 47 to 76 years.

MAIN OUTCOME MEASURES

According to the modified Hoehn-Yahr score, PD group was classified as an early stage with a range of 1-2.5 and a mid-late stage with a range of 3-5. Percentage of correct answers (%CA) was calculated using fHIT for lateral, anterior and posterior semicircular canal (SCC) planes.

RESULTS

PD group had statistically lower fHIT %CA in the right lateral, left lateral, and left posterior SCC planes compared to control group (p < .05). There was no statistical difference between two PD severity groups and functional VOR abnormality.

CONCLUSION

It was concluded that the functional VOR in the right lateral and left lateral and left posterior SCC plane was affected in individuals with PD. Our results show that impaired VOR and reduced dynamic visual acuity should be considered in individuals with PD for vestibular rehabilitation exercises.

A comparison of functional vestibulo-ocular reflex and proprioception in athletes of combat sports and ball sports

Background

The contribution and role of sensory systems in providing postural control may vary depending on the condition or activity. Vestibulo-ocular reflex (VOR) and proprioception might be affected by the type of sport.

Objective

This study aimed to compare athletes engaged in combat sports and ball sports in terms of functional VOR and proprioception.

Design

This study is a cross-sectional, comperative research.

Method

Twenty-four athletes engaged in combat sports and 20 in ball sports were included in the study. Functional examination of VOR in athletes was performed with a novel Functional Head Impulse Test (fHIT). Proprioception analysis was evaluated using Laser Pointer Assisted Angle Reproduction Test (LPA-ART) in 90° shoulder flexion and abduction.

Results

fHIT lateral and posterior % Correct Answer (CA) values and anterior SCC 6000°/s² values of athletes engaged in ball sports were found to be statistically significantly higher than athletes in combat sports (p < 0.05). Except for anterior SCC 4000°/s² value, scores of the ball players in all accelerations and directions were higher than combat sports athletes, although it was not statistically significant. The 90° shoulder flexion and abduction angle deviation values obtained from the LI-ATT were statistically lower in those who played ball sports (p < 0.05).

Conclusions

Participation in sports branches played with the ball is expected to provide gains for athletes who want to reach high-level performance in proprioceptive and vestibular functioning and those with vestibular/proprioceptive pathology. Maintaining clear vision in dynamic sports branches can be improved by training VOR function.

Comparison of children with and without dyslexia using functional head impulse test and pediatric balance scale

Purpose

The aim of this study is to compare functionality of vestibulo-ocular reflex (VOR) responses to evaluate the functional properties of the vestibular system and daily balance performance in children with dyslexia and children with normal development.

Method

Fifteen participants diagnosed with dyslexia were included in the study group (SG), and 15 healthy participants were included in the control group (CG). All groups underwent Functional Head Impulse Test (f-HIT) and Pediatric Balance Scale (PBS). f-HIT was performed with at least 15 head impulses at 4000-5000-6000°/s² randomly to the right and left in the plane of the horizontal semicircular canal (SCC). Statistical analysis was performed using descriptive statistics and the Mann-Whitney U test.

Results

SG percentage values were obtained lower than CG percentage values. Comparisons between the two groups showed that there was a significant difference in all parameters (4000-5000-6000°/s² and total) in the right-side stimulation, there was significant difference for 4,000 s² and total correct answers in the left side. In addition, although there was no significant difference between the groups in terms of the PBS score, the SG scores were lower (p = 0.062).

Conclusions

As a novel test, f-HIT, revealed the difference in functionality of vestibular performance in the dyslexia group. In the dyslexia group, f-HIT may be helpful in evaluating and monitoring the vestibular system.

Evaluation of Vestibular Function in Patients Affected by Obstructive Sleep Apnea Performing Functional Head Impulse Test (fHIT)

PURPOSE

Obstructive sleep apnoea (OSA) is a common disease with significantly related complications. Since a connection between the vestibular nucleus and sleep regulator pathways has been demonstrated, vestibular evaluation in OSA patients was partially studied and none used functional head impulse test (fHIT) for this purpose. This paper aimed at evaluating the vestibular function in patients affected by OSA using fHIT, selecting patients who did not present any other related to cardiovascular, neurological, or metabolic diseases.

PATIENTS AND METHODS

Patients enrolled had a diagnosis of OSA by polysomnography type III and were cataloged according to American Association of Sleep Medicine criteria. Each patient underwent fHIT. Statistical significance was set at 0.05.

RESULTS

A total of 85 patients were enrolled in the study of which 50 had a diagnosis of OSA and were included in the case group, while 35 belonged to the control group. In 88.6% of subjects of the case group was evidenced a vestibular impairment with a substantial difference between the two study groups (p<0.05).

CONCLUSION

The results show that the incidence of vestibular lesions in patients with obstructive sleep apnoea is underestimated and that fHIT can identify these lesions early.

Vestibular Functioning in Children with Neurodevelopmental Disorders Using the Functional Head Impulse Test

Several studies in children with neurodevelopmental disorders (NDDs) including autism spectrum disorders (ASDs), reading impairment, or attention deficit/hyperactive disorder (ADHD) pointed toward a potential dysfunction of the vestibular system, specifically in its complex relationship with the cerebellum. The aim of the present study was to test the functional vestibulo-ocular reflex (VOR) responses in children with NDDs to measure functional performance of the vestibular system. The VOR is specifically involved in this stabilization of the image on the retina during rapid movements of the head. To perform this study, four groups of children with ASD, ADHD, reading impairment, and with neurotypical development (TD) were enrolled (n = 80). We performed the functional head impulse test (fHIT), which measured the percentage of correct responses by asking the child to identify an optotype briefly presented during passive head impulse in each direction of each semicircular canal plane. We observed significantly lower correct answers in children with NDDs compared with those with TD (p < 0.0001). Surprisingly, there was no significant difference between the three groups of children with NDDs. Our study fostered preliminary evidence suggesting altered efficiency of vestibular system in children with NDDs. VOR abnormalities estimated using the fHIT could be used as a proxy of NDD impairments in children, and represent a potential biomarker.