Head shaking is useful for both identifying the nystagmus, and assisting in converting cupulolithiasis to canalolithiasis for horizontal canal BPPV.  Both variants (geotrophic and apogeotrophic), nystagmus will beat towards non-affected side (Galgon, 2012).



Technique:  Pitch head forward 30 degrees, and move head sideways in a sinusodial fashion at approximately 3 hertz for 15 seconds.  This technique was effective in converting apogeotropic variant to geotropic variant in 19/51 patients (Oh et al., 2009).