Vestibular system dysfunction in patients after mild traumatic brain injury

Introduction. In the literature there are some discrepancies concerning the occurrence of vertigo and disequilibrium, as well as the type of vestibular dysfunction in patients after mild traumatic brain injury (MTBI). Objective. The aim of the study was to assess the type of vestibular system dysfunction in MTBI patients after injury at baseline and 6-month follow-up. Materials and method. From a group of 188 patients with vertigo/dizziness and balance instability after MTBI, prospective analysis in 50 patients with abnormal videonystagmography (VNG) were conducted. Anamnesis, otoneurological examination, self-assessed Dizziness Handicap Inventory (DHI) and VNG test were carried in each patient twice – at baseline and after 6 months. Results. A significant improvement in the DHI total score (9.8 points, p<0.001) and in the subscales was found after 6 months. At baseline, VNG test showed the peripheral vestibular system dysfunction in 19 cases (38%), central vestibular dysfunction in 20 patients (40%) and mixed vestibular dysfunction in 11 cases (44%). After 6 months, the VNG records normalization was observed in 19 patients (38%), an improvement was significantly more frequently related to peripheral disorders, compared to central ones (p<0.001). Conclusions. In patients after mild traumatic brain injury, about one-fourth of them had vestibular system dysfunction with the same frequency of peripheral, central and mixed lesions in videonystagmography. Subjective post-traumatic symptoms and vestibular system dysfunction in patients after MTBI decrease after 6-month follow-up. However, more than half of patients still have abnormal VNG results, which indicate dysfunction of the central vestibular system.