The purpose of investigation is to assess the levels of metabolic factors (hydroxyvitamin D, homocysteine) between patients with vestibular dysfunction of peripheral origin (BPPV) and central origin (vestibular migraine). Also we will analyse another factors (such as anxiety and depression) and optimize therapeuthical approach accordingly with the data.

Dizziness causes up to 2 to 15% of primary neurological complaints. In some patients who have undergone acute vertigo, postural instability, persistent postural perceptual vertigo (PPPV) develops, while in other similar cases occurs full recovery. So, it is necessary to search for neurophysiological, metabolic and psychophysiological factors and associated premorbid conditions that affect the outcome of neurovestibular compensation.

The case-control study will include 2 groups of patients suffering from vertigo of central and peripherial etiology. First group is recruited with patients were diagnosed with peripherial vestibular disorders, such as benign paroxysmal positional vertigo (BPPV), Meniere disease, vestibular neuritis. The proposal number of subjects in the first group is about forty. The second group will consist of forty patients with central vestibular disfunction: vestibular migraine, central positional vertigo etc. The inclusion of patient with persistent postural perceptual dizziness is discussed. Patients will be tested for hydroxyvitamin D and homocysteine in serum using an enzyme-linked immunosorbent assay (ELISA). The perception of the severity of disability was assessed using the Dizziness scale Handicap Inventory (DHI). All patients will undergo psychological test, including tas-26 scale, Beck's Depression Inventory, Spielberg-Hanin'sscale. Statistical analysis was carried out with the Statistical Analysis System (SAS) package. The relationships will be assessed using the chi squared test and logistic regression. The level of significance is set at p < 0.05. The methods for small samples (Mann-Whitney U ) will be used. It is presumed that differences in vitamin D levels beetween two groups will be considerable.

Inclusion Criteria:

• Written informed consent of participation in the study;
• Age:over 18 years old
• complaints of dizziness and insteadiness

Exclusion Criteria:

• Severe cognitive impairment (dementia)
• Severe depression
• Syncopal paroxysms
• Epileptic seizures
• Orthostatic hypotension
• Severe arrhythmia, unstable angina pectoris, acute myocardial infarction
• Pregnancy 8. Alcoholism, substance abuse and drug addiction
• Organic liver and kidney diseases with the development of functional disorders.
• Anemia (hemoglobin <10.5 g / dl for women and <11.5 g / dl for men)
• Active oncological process
• Demyelinating and neurodegenerative diseases.

patients from clinic with damage of peripheral and central origin

I give my consent to provide actual study protocol. However, It is impossible to provide stastistical documents and primary patient's documentation (It is forbidden by Local Ethic Committee of Sechenov University)