Case examples of Palatal Myoclonus (PM)

T. Hain, MD, Professor of Neurology and Otolaryngology

Case ID # Cause Onset Age/Gender Nystagmus
7676 Pontine AVM 72/F Horizontal pendular
0216 Cerebellar Degeneration 30's/F Unknown
5511 Unknown (atrial fib) 60's/M Torsional pendular
6792 Unknown (atrial fib) 76/M Torsional pendular
2617 Brainstem Hemmorage 60's/M Vertical pendular
2808 CP angle meningioma 49/F None

Links: palatal myoclonus page Index page.

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. 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.

Case 6792. A man in his 70's presented for an evaluation of ataxia. His health also affected by atrial fibrillation and a monoclonal gammopathy, neither of which were seriously disturbing to him. 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 tuomr and had facial weakness. Two to three weeks later palatal myoclonus ensued. Multiple MRI scans showed no evidence of 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 Molleret triangle as MRI shows no lesion or olivary hypertrophy.