Achados à prova calórica e canal semicircular acometido na vertigem posicional paroxística benigna

Abstract

OBJETIVO: Caracterizar os achados da prova calórica em pacientes com vertigem posicional paroxística benigna, segundo o canal semicircular comprometido. MÉTODOS: Foram analisados 1033 prontuários de pacientes submetidos à pesquisa de nistagmo posicional e de posicionamento e à eletronistagmografia. Os achados da prova calórica, de acordo com os canais semicirculares acometidos, foram submetidos à análise estatística. RESULTADOS: No comprometimento de canal posterior, houve prevalência de normorreflexia (p<0,0001); hiporreflexia prevaleceu sobre hiper-reflexia (p<0,0001) e preponderância direcional (p<0,0001), e hiper-reflexia prevaleceu sobre preponderância direcional (p<0,0001). No comprometimento de canal lateral, normorreflexia prevaleceu sobre hiporreflexia (p<0,0001) e hiper-reflexia (p<0,0001); hiporreflexia tendeu a prevalecer sobre hiper-reflexia (p=0,0771), e preponderância direcional não ocorreu. No comprometimento de canal anterior, normorreflexia prevaleceu sobre hiporreflexia (p<0,0001); hiper-reflexia e preponderância direcional não ocorreram. CONCLUSÃO: Na prova calórica de pacientes com vertigem posicional paroxística benigna, normorreflexia, hiporreflexia, hiper-reflexia ou preponderância direcional do nistagmo pós-calórico ocorrem em ordem decrescente de prevalência, quando há comprometimento do canal posterior; normorreflexia prevalece sobre hiporreflexia ou hiper-reflexia e hiporreflexia tende a prevalecer sobre hiper-reflexia, no comprometimento do canal lateral; normorreflexia prevalece sobre hiporreflexia, no comprometimento do canal anterior.PURPOSE: To characterize caloric test results in benign paroxysmal positional vertigo patients, according to the damaged semicircular canal. METHODS: The data of 1033 patients submitted to Dix-Hallpike testing, positional nystagmus and electronystagmography were analyzed. Caloric test results were compared to the damaged semicircular canals and were submitted to statistical analysis. RESULTS: In cases with posterior canal damage, there was prevalence of normal responses compared to abnormal results (p<0.0001); hypo activity was more prevalent than hyperactivity (p<0.0001) and directional preponderance (p<0.0001), and hyperactivity more prevalent than directional preponderance (p<0.0001). In cases with lateral canal damage, normal responses were more prevalent than hypo activity (p<0.0001) and hyperactivity (p<0.0001); there was a tendency of prevalence of hypo activity over hyperactivity (p=0.0771), and directional preponderance was not observed. In cases with anterior canal damage, normal responses were more prevalent than hypo activity (p<0.0001); hyperactivity and directional preponderance were not observed. CONCLUSION: In the caloric test of benign positional paroxysmal vertigo patients, normal responses, hypo activity, hyperactivity or directional preponderance of post-caloric nystagmus occur in decreasing order of prevalence when the posterior canal is damaged; normal responses are more prevalent than hypoactive or hyperactive caloric responses, and there is a tendency of prevalence of hypoactive over hyperactive caloric responses when the lateral canal is damaged; normal responses are more prevalent than hypoactive caloric responses when the anterior canal is damaged.