The use of a neck brace does not influence visual vertical perception

• Main Authors: Martha Funabashi, Natya N.L. Silva, Luciana M. Watanabe, Taiza E.G Santos-Pontelli, José Fernando Colafêmina, Antonio A.O. Carneiro, Osvaldo M. Takayanagui
• Format: Article
• Language: English
• Published: Academia Brasileira de Neurologia (ABNEURO) 2011-06-01
• Series: Arquivos de Neuro-Psiquiatria
• Subjects: percepção visual; propriocepção; sáculo; utrículo
• Online Access: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0004-282X2011000400019&lng=en&tlng=en

Subjective visual vertical (SVV) evaluates the individual's capacity to determine the vertical orientation. Using a neck brace (NB) allow volunteers' heads fixation to reduce cephalic tilt during the exam, preventing compensatory ocular torsion and erroneous influence on SVV result. OBJECTIVE: To analyze the influence of somatosensory inputs caused by a NB on the SVV. METHOD: Thirty healthy volunteers performed static and dynamic SVV: six measures with and six without the NB. RESULTS: The mean values for static SVV were -0.075º±1.15º without NB and -0.372º±1.21º with NB. For dynamic SVV in clockwise direction were 1.73º±2.31º without NB and 1.53º±1.80º with NB. For dynamic SVV in counterclockwise direction was -1.50º±2.44º without NB and -1.11º±2.46º with NB. Differences between measurements with and without the NB were not statistically significant. CONCLUSION: Although the neck has many sensory receptors, the use of a NB does not provide sufficient afferent input to change healthy subjects' perception of visual verticality.