Department of Neurology, University of Munich, Klinikum Grosshadern, Munich, Germany
Address for correspondence: Michael Strupp, M.D., Department of Neurology, Ludwig-Maximilians University of Munich, Klinikum Grosshadern, Marchioninistrasse 15, D-81366 Munich, Germany. Voice: +49-(0)89-7095-2571; fax: +49-(0)89-7095-8883.
mstrupp{at}nefo.med.uni-muenchen.de
Acute unilateral vestibular failure is characterized by rotatory
vertigo, horizontal-rotatory nystagmus, and postural imbalance,
all of which last from days to weeks. These signs and symptoms
are caused by a vestibular tone imbalance between the two labyrinths.
Recovery results from a combination of peripheral restoration
of labyrinthine function (usually incomplete) and central vestibular
compensation (CVC) of the vestibular tone imbalance. Acute unilateral
failure is most often caused by vestibular neuritis, which is
most likely due to the reactivation of a latent HSV-1 infection.
Therefore, therapeutic strategies to improve the outcome of
VN are theoretically based on two principles: (a) vestibular
exercises and drugs to improve CVC and (b) drug treatment of
the assumed viral inflammation. The following conclusions can
be drawn from studies in animals and/or humans: (1) There is
strong evidence that vestibular exercises may improve vestibulo-spinal
compensation. These exercises should begin as early as possible
after symptom onset. Moreover, slower exercises are likely to
be more effective than faster exercises because slower ones
seem to depend more on the vestibular system. (2) Despite extensive
data from animal experiments indicating that drugs have a favorable
effect on CVC, this has not been clinically proven and thus
cannot be recommended yet. (3) Preliminary results of an interim
analysis from an ongoing randomized, prospective study showed
that methylprednisolone (plus an antiviral agent?) may be useful
for improving peripheral vestibular function in vestibular neuritis.
