“…Given the (1) increased time constants of the HSN and rotatory nystagmus, (2) emergence of the HSN even with a short duration of head-shaking, and (3) good responses to baclofen, we proposed that unstable and asymmetric VSM may be the cause for vertigo and BRV-HSN (2). Apparently, the characteristics of HSN observed in the patient reported by Filippopulos et al (1) do not seem to differ from those observed in our patients with BRV-HSN. Thus, the BRV-HSN and aiHSN may lie on the same spectral line due to a common pathomechanism (unstable and asymmetric VSM), rather than distinct disease entities.…”