LIMITATIONS OF VESTIBULAR REHABILITATION THERAPY USING DYNAMIC COMPUTERIZED POSTUROGRAPHY IN PATIENTS WITH CENTRAL VESTIBULAR SYNDROME

Objectives. To evaluate the importance of computerized dynamic posturography in vestibular rehabilitation (VR) of patients with central vestibular syndrome. Methods. The study included 30 patients with central vestibular syndrome with mean age (± SD) = 72.96 ± 11.97 which benefi ted from VR on a posturography platform between 2012-2014. All patients were evaluated using sensory integration tests. The parameters studied were: Romberg coeffi cient, statokinesigram (SKG), maximum amplitude of the degree of deviation in anterior-posterior and medial-lateral planes, SKG and the time interval of the rehabilitation program. Results. All of the analyzed parameters showed statistically signifi cant results (p <0.05). The anterior-posterior and medio-lateral balance improved signifi cantly at the end of the vestibular rehabilitation program and the parameters decreased to values close to normal. Conclusions. For patients with central vestibular syndrome, the vestibular rehabilitation improves postural stability and quality of life by reducing the risk of falls.


INTRODUCTION
Computerized Dynamic Posturography gives an objective assessment of the overall balance of the patient and also highlights what system uses each subject for maintaining posture. (1) Vestibular rehabilitation on a posturography platform is achieved by the selecting games runned in different sequences, depending on the condition that causes impaired balance and aims at the recovery of the vestibular function. (2,3) The purpose of this study was to determine the value of vestibular rehabilitation performed using a posturography platform in patients with central vestibular defi cit.

MATERIAL AND METHODS
The study included 30 patients with central vestibular syndrome who received vestibular rehabilitation using platform posturography between 2012-2014. The patients who participated in this study signed an informed consent form and all patients have completed the whole vestibular rehabilitation program. The study included patients diagnosed with central vestibular defi cit and who have never benefi ted from vestibular rehabilitation on platform posturography. We excluded the patients who refused inclusion in the study, those with associated neurological disorders (dementia, Parkinson's, etc.), psychiatric disorders, visual disturbances, patients treated with neuroleptics, sedatives, antiepileptics, antidepressants, drugs or alcohol abuse, patients with severe orthopedic dysfunction and arthrosis of the ankle, hip and knee.

STUDY PROTOCOL
For this research we took into account the results obtained from patients that were tested with eyes open (EO) and eyes closed (EC) on foam platform. Subjects were evaluated using sensory integration tests. We used Posturographic Synapsys System (version 3.0, SYNAPSYS, Marseille, France). The evaluation of patients was performed before and after the eight sessions of vestibular rehabilitation. The tests consisted of two trials each of 20 seconds. The VR program consisted of games included in the software used by the posturographic system. Each session began with a test reference, which helped monitor the patient's evolution throughout the rehabilitation. The same game benchmark was used for each session separately and for each patient included in the study. Four game groups were included in the rehabilitation session: Stabilization, Weight shift, Weight bearing and Postural control.(3)

STATISTICAL ANALYSIS
To evaluate the success of VR therapy on posturography platform, we created two groups of patients, according to their performance: improved and stationary. For these two groups we defi ned limit values for each parameter included in our research, both for eyes open and eyes closed condition on foam platform. These are shown in Table 1. The collected data were analyzed using the software StataIC 11 (StataCorp. 2009. Stata: Release 11 Statistical Software. College Station, TX, USA). The data were expressed as a percentage, frequency, mean, standard deviation, depending on the situation. T test (Student) was used for the eva-luation of quantitative differences in the calculation of media. The level of statistical signifi cance was set at 0.05.

RESULTS
The study was conducted on a group of 30 patients with central vestibular syndrome, consisting of 19 women (63.3%) and 11 men (36.67%); 13 cases from rural areas (43.33%) and 17 cases from urban areas (56.67%). The average age of was 72.9 years ± 11.97 SD (aged between 37 and 90 years).

CHART 1. Distribution of cases according to etiology
For the patients included in this study 20% were diagnosed with vestibular omissions, 10% with multiple sclerosis and 7% of with vestibular migraine. In 63% of these cases, the cause for the central vestibular defi cit was unknown, they showed demyelination and areas of cerebral atrophy on the brain MRI.
The statistical analysis of the associated risk factors, revealed mostly cervical spondylosis in 15 cases (50%). The second risk factor was essential hypertension with 14 cases (46.67%), followed by diabetes with 10 cases (33.33%), carotid atheromatosis and dyslipidemia with 8 cases each representing 26.67%. The remaining patients in the study were diagnosed with stroke in 3 cases accounting for 10%. All parameters studied showed statistically signifi cant results (p <0.05). (Table 2) Romberg coeffi cient, statokinesigram (SKG), maximum amplitude of the degree of deviation in anterior/posterior and medial/lateral planes, SKG and the time interval of the rehabilitation program RQ1 and RQ2: Romberg coeffi cient before and after RV; SKG1 and SKG2 foam EO: statokinesigram with eyes open before and after VR on foam platform; AP1 and AP2 foam EO: maximum amplitude of the degree of deviation with eyes open in the anterior-posterior plane before and after VR on foam platform; ML1 and ML2 foam EO: maximum amplitude of the degree of deviation with eyes open in medio-lateral plane before and after VR on foam platform; SKG1 and SKG2 foam EC: statokinesig-ram with eyes closed before and after VR on foam platform; AP1 and AP2 foam EC: maximum amplitude of the degree of deviation with eyes closed in the anterior-posterior plane before and after VR on foam platform; ML1 and ML2 foam EC: maximum amplitude of the degree of deviation with eyes closed in medio-lateral plane before and after VR on foam platform; SKG1 and SKG2 before and after rehabilitation program: statokinesigram of the reference game before and after vestibular rehabilitation process; T1 and T2 before and after rehabilitation program: the time interval (seconds) of the reference game before and after vestibular rehabilitation process.

Statistical analysis of statokinesigram (cm 2 ) and time (seconds) of the reference game before and after the vestibular rehabilitation process
The time interval of the reference game is reduced signifi cantly (p <0.05) after VR, from a mean of 25.03 ± 9,37 s before VR to an average of 20.03 ± 7,11 s after VR. The average difference is 5 (p <0.0001; Student t-test; IC 95% is 3.37 to 6.63). In terms of the SKG obtained in the reference game after VR, there was a signifi cant decrease (p <0.05) from an average of 32.53 ± 12,49 cm 2 before VR to an average of 24.56 ± 10,59 cm 2 after VR. The average difference is 7.96 (p <0.0001; Student t-test; IC 95% is 5.56 to 10.36). All parameters studied showed highly statistically signifi cant results (p <0.05) at the end of the 8 sessions of vestibular rehabilitation.

DISCUSSION
Final evaluations showed that from the group of 30 patients with central vestibular syndrome who benefi ted from vestibular rehabilitation on posturography platform, only 12 patients showed a signifi cant improvement in evolution (40%) and 14 patients (46.67%) had a stationary evolution. Most satisfactory results were recorded in 4 cases (13.33%), where the evolution of the subjects was very good at the completion of the fi rst meeting of vestibular rehabilitation. In only 13.33% of the cases full recovery of vestibular function was achieved. The recovery capacity depends very much on the vestibular function defi cit of the affected vestibular organ. Patients with central vestibular syndromes, may have the adaptation and compensation functions affected or they can have a progressive disease. Thus, improving postural control is often more diffi cult than in patients with peripheral vestibular syndrome. There are studies showing that by controlled and monitored rehabilitation programs we can obtain a high level of recovery in comparison with the cases that remain untreated. (4, 5) Aging and/or associated risk factors such as diabetes, hypertension, and stroke, infl uence balance and posture by increasing instability and the risk of falls and for that reason improvement of postural control is made more diffi cult. (6,7) For patients diagnosed with central vestibular defi cit, vestibular rehabilitation on posturography platform involves improving postural stability and quality of life by reducing the risk of falls, improvement of neuromuscular coordination and decrease of anxiety due to vestibular disease. (8,9) The fi nal results ob- Statistical analysis of the statokinesigram and the time interval of the reference game before and after the RV were found to be signifi cant (p<0.0001) in terms of assessing therapeutic success of RV in patients included in the study.

CONCLUSIONS
A proper posture is essential for the effective functioning of the human body. In patients with central vestibular syndrome, vestibular rehabilitation implies improving postural stability and quality of life by reducing the risk of falls. Successful treatment by vestibular rehabilitation requires active patient cooperation and participation inducing a positive psychological effect with an impact on self confi dence and improving physical condition, thus improving quality of life. Vestibular rehabilitation programs on platform posturography in patients with central vestibular defi cit encompasses all these advantages and allows evaluation and monitoring of medium and long-term performance.