[The significance of electrophysiologic examinations in vestibular schwannomas diagnosis].

UNLABELLED: The most important for the diagnosis of vestibular schwannoma is MRI technic, which allows assessing its size and shape. The gold diagnostic standard includes also PTA, SD and ABR, nystagmography with calorics and VEMP. Nystagmography with calorics reflects the status of superior vestibular nerve. The sensitivity of calorics amounts to 61-87%. VEMPs reflect the status of interior vestibular nerve; its sensitivity is about 80%. The greatest diagnostic sensitivity shows ABR method, which is estimated for about 96-99%.

AIM: analysis of PTA, ABR, VEMP and calorics results in smaller G1(≤10mm) and greater G2 (>11mm) tumors, and assessement of influence of the size of the tumor for auditory and vestibular function. MATHERIAL: PTA, ABR, VEMP and calorics results performed in 33 patients with CPA tumors.

RESULTS

CPA tumors originate from inferior vestibular nerve in most cases; there is no statistical PTA differences in G1 and G2 groups; sensitivity of calorics (G1 53%, G2 95%), and ABR (G1 75%, G2 100%) depend on tumor size and tumor size has significant influence on results of both of these methods; sensitivity of VEMPs is similar in G1 and G2 groups (83% and 89%).

CONCLUSIONS

there is no strict correlation between tumor origin and calorics and ABR results; greatest sensitivity in our material show VEMP, what is probably results of frequent tumors origin from inferior vestibular nerve.