Application Of Modified Dynamic Gait Index On Gait Assessment To People With Vestibular Disorders

Background and objectivesThe vestibular system functions to maintain body balance and to coordinate head and body movements.Dysfunction of the vestibular system can lead to disequilibrium that manifests as ataxic gait and postural instability.The most commonly used methods of vestibular function tests in clinical practice are static detection based on vestibular function,which cannot display the dynamic information of gait in patients with vestibular dysfunction,and the dynamic information can better reflect the actual state of vestibular function.Gait can reflect the dynamic performance of the overall balance function.The control of gait depends to a large extent on the information obtained by the vestibule.Therefore,gait measurement is of great significance for assessing the balance function and diagnosis and treatment of patients with clinical vestibular dysfunction.The Dynamic Gait Index(DGI)is a relatively effective clinical gait measure that has been validated for use in patients with vestibular disorders.The modified version of the DGI(M-DGI)is based on the original DGI.Unlike DGI,M-DGI not only has more detailed test instructions and scoring rules,but also has independent scoring options for each task.M-DGI focuses on postural stability during walking activities to facilitate and effectively measure gait performance in patients with vestibular dysfunction.The purpose of this study was to further verify the reliability,consistency and validity of M-DGI in gait assessment of patients with vestibular disorders,making it is an effective indicator of dynamic gait in patients with vestibular disorders.DesignAn interventional study.ParticipantsParticipants were 45 patients with vestibular disorders and 30 healthy subjects.MethodsBefore the test,75 subjects underwent unified neurological examination and three vestibular function tests:caloric test(CT),video head impulse test(vHIT)and vestibular evoked myogenic potential(VEMP).According to the above auxiliary examination results and diagnostic criteria of vestibular disease,45 patients with vestibular dysfunction were divided into Vestibular Neuritis(VN),Meniere's Disease(MD),Vestibular Migraine(VM),and Benign Paroxysmal Positional Vertigo(BPPV)four diseases.Then raters followed the M-DGI implementation instructions to set and identify the evaluator and the location of each obstacle.According to the mission requirements specified by M-DGI,gait detection in various scenarios was performed,including Gait on Level Surface,Change in gait speed,Gait with horizontal head turns,Gait with vertical head turns,Gait and pivot turn,Step over obstacle,step around obstacles and Stairs eight gait tasks.The overall test process was:Four raters simultaneously scored two M-DGI tasks for the 75 subjects,and the two tests were completed with an interval of two hours in-between.After completing the first M-DGI test,45 patients with vestibular dysfunction were evaluated on the Dizziness Handicap Inventory(DHI)Scale.After completing the second M-DGI test,45 patients with vestibular dysfunction were tested for the Timed Up and Go test(TUG).Reliability of total M-DGI scores was assessed using intraclass correlation(ICC).Reliability of individual M-DGI item scores weas calculated using Percentage Agreement and Kappa Statistics.Consistency between M-DGI score for each task and total score was evaluated using Cronbach's alpha.Correlation between M-DGI and published DHI and TUG was assessed using Spearman's rank order correlation coefficient,and further to evaluate the validity of M-DGI.ResultsInterrater and intrarater reliability of the total M-DGI scores were reflected by ICC of 0.99 and 0.97.The Kappa values of intrarater reliability of individual M-DGI item scores ranged from good(K=0.64)to excellent(K=0.86),and the percentage(%)agreement ranged from medium(77.22%)to excellent(87.77%);the Kappa values of interrater reliability of individual M-DGI item scores ranged from medium(K=0.40)to excellent(K=1.00),and the percentage(%)agreement ranged from poor(31.1%)to excellent(100%).Consistency between M-DGI score for each task and total score was 0.9975.Spearman's rank order correlation coefficient of the M-DGI score with the DHI and the TUG was 0.72 and 0.65,respectively.ConclusionsThrough the analysis of the research data,it is concluded that the scores of individual M-DGI item and total M-DGI are good to excellent reliability;the scores of individual M-DGI item and total M-DGI has excellent consistency;there is excellent correlation between the M-DGI scale and DHI and TUG tests,that is,M-DGI has excellent effectiveness for gait assessment of patients with vestibular dysfunction.In summary,the M-DGI has good reliability,consistency and validity for use as a clinical gait indicator for patients with vestibular dysfunction,reflecting the patient's dynamic balance.