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.

MATERIAL AND METHODS: 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.