Synonyms:
OPT, formerly oculopalatal myoclonus a.k.a. palatal tremour formerly palatal myoclonus
Diagnosis:
Clinical diagnosis
Clinical features:
- Soft ear clicks heard by patient & examiner. Oscillopsia
- Symmetrical palatal tremour (levator veli palatini muscle)
- +Ocular nystagmus: pendular (same speed in both phases), usually vertical (may be tosional) & sometimes horisontal. May be bilateral or unilateral i.e. dissociated.
MRI & MRA:
- Lesion in dentato-rubro-olivary pathway (Guillain-Mollaret triangle) which lies in the brainstem tegmentum
- Hypertrophic olivary degeneration (unilateral or bilateral): high signal on T2 or proton density, this may return to normal
- Typically develops 2–49 months after the initial insult