Case examples of Palatal Myoclonus (PM)

Timothy C. Hain, MD Palatal Myoclonus main page Page last modified: October 15, 2011

Links: oculopalatal myoclonus page movie of ocular nystagmus

Movies of palate in patients with palatal myoclonus

• movie of palate (case 9263)
• movie of palate (case 1198)
• movie of palate movie of palate Case 0169
• movie of palate case PT

Case 7676: A 72 year old woman first came to medical attention when she developed inward turning of her left eye. An MRI scan was obtained which documented a vascular malformation in her pons. An operation was attempted, following which she developed near complete paralysis of horizontal eye movements.  Balance was poor and one eye began to "bob". On an examination done one year later, there was a constant pendular (sinusoidal) nystagmus of one eye, severe unsteadiness, and a one cycle/second up and downward movement of the soft palate (palatal myoclonus), accompanied by contractions of muscles in the throat.  The combination of the "bobbing" ocular nystagmus and palatal myoclonus, defines a case of OPM(ocular-palatal myoclonus). The cause is presumably related to interruption of the central tegmental tract

Case 5511. A man in his 60's began to develop disturbance of his speech. His health was otherwise good, except for atrial fibrillation. Neurological examination documented palatal myoclonus. Over several years, he gradually developed imbalance, and a subtle torsional pendular nystagmus was eventually documented. MRI scanning, intially read as normal, documented hypertrophy of both inferior olivary nuclei on review by a neuroradiologist familar with OPM. One of his cardiac medications was stopped because of concern that it might be the cause of his PM. His PM and nystagmus disappeared several years after his cardiac antiarrythmic was stopped.

Case 6792. A man in his 70's presented for an evaluation of ataxia. His health was also affected by atrial fibrillation and a monoclonal gammopathy, neither of which were seriously disturbing to him. He was taking amiodarone for his atrial fibrillation. Examination documented a torsional pendular nystagmus and palatal myoclonus.

Case 2808. A woman had a large CP angle menigioma removed via a transmastoid approach. Post-operatively she was deaf on the side of the tumor and had facial weakness. Two to three weeks later palatal myoclonus ensued. Multiple MRI scans showed no superior olivary hypertrophy. No nystagmus was observed using very sensitive recording methods. Comment: The mechanism of PM in this patient seems unlikely to be related to a lesion in the Guillain Mollaret triangle as MRI shows no lesion or olivary hypertrophy.

Case 5374. A 76 year old gentleman presented with a 3 year history of unsteadiness, without falls. He also has a "chirping" tinnitus, and each time that he hears the chirp, the horizon "jumps" slightly in the left eye. A thorough workup was performed including VNG (dx BPPV), ECochG (high on left),VEMP (normal), CDP (ataxia), MRI (scattered UBO), TCD (normal), Carotid doppler (normal), SSEP (normal), EMG (mild sensory), B12 (normal). Video ENG in the office documented weak downbeating nystagmus without any change between eyes. However, inspection of the palate revealed a very clear palatal myoclonus. The tinnitus could not be heard by the examiner (i.e. it is not stapedius myoclonus). Comment: This patient's ataxia, in hindsight, is part of the OPM syndrome. It is probable that a more sensitive method of comparing the two eyes would show that there is a discongugate deviation of the eyes during each "chirp". Chirping tinnitus and monocular visual disturbance should suggest to the clinician that OPM may be the cause.

Case PT. In this case, contributed by Dr. Dario Yacovino, palatal myoclonus was seen without an ocular oscillation. It was presumed due to a midline brainstem malformation. movie of palate

Case 0169

This woman was first diagnosed with palatal myoclonus when she was 40. The palatal movement was accompanied by a loud clicking sound. MRI scan initially was read as being normal. On a second, higher resolution scan, the superior cerebellar artery (SCA) was seen to be indenting the root entry zone of the Vth nerve on the left side. Two movies of the palate are included here movie of palate movie of palate.