Illustrating cases of horizontal head-shaking nystagmus (HSN) in posterior canal benign paroxysmal positional vertigo (PC-BPPV).

<p><strong>Supplementary video 1. </strong>Illustrating case&nbsp;of<strong> </strong>horizontal head-shaking nystagmus (HSN) in left&nbsp;posterior canal benign paroxysmal positional vertigo (PC-BPPV).</p> <p><strong>Supplementary video 2. </strong>Illustrating case&nbsp;of pure downbeat head-shaking nystagmus (HSN) in right&nbsp;posterior canal benign paroxysmal positional vertigo (PC-BPPV).</p> <p><strong>Supplementary video 3. </strong>Illustrating case&nbsp;of torsional downbeat head-shaking nystagmus (HSN) in right posterior canal benign paroxysmal positional vertigo (PC-BPPV).</p>