Modified Mondays: PALATO-PHARYNGO-LARYNGEAL MYOCLONUS

This Modified Monday features palato-pharyngo-laryngeal myoclonus (a diagnosis related to palatal tremor, but even less prevalent). This disorder can occur from a lesion in the brainstem or the cerebellum that interferes with the Guillain–Mollaret triangle. According to the website Practical Neurology, “The Guillain-Mollaret triangle involves the ipsilateral red nucleus in the midbrain, the inferior olive in the medulla and the contralateral dentate nucleus in the cerebellum: together, these form the dentato-rubro-olivary pathway. Pathology in this triangle disinhibits (and so activates) the inferior olivary nucleus.”  In addition, palate-pharyngo-laryngeal myoclonus can have no known cause as well (essential tremors).

It's apparent on MBSS when someone has this type of myoclonus because they have repetitive and rhythmic movements of the pharynx and palate. This descriptive wording can be used on SLP reports since we cannot diagnose myoclonus. Accompanying the myoclonus, a patient might have dysphonia, dysarthria, and/or dysphagia.

The patient in this Modified Monday had palato-pharyngo-laryngeal myoclonus which occurred after a cerebellar stroke 10 years ago. After the stroke, an ENT also diagnosed him with laryngeal tremor, vocal tremor, dysarthria, and spasmodic dysphonia. Since then, he has been on an altered diet and recently had a repeat MBSS to determine if there was any improvement with his swallow over the past 3 years. Unfortunately, the study showed very similar results to a study performed in 2020.

Treatment considerations for those that are affected by palato-pharyngo-laryngeal myoclonus include anticonvulsants, tranquilizers, and Botox. However, with this particular patient, a delayed swallow and poor bolus control are the primary reasons why he was having difficulty. These medication/treatment options would not be effective in improving swallow function for this patient.

Note: positioning for this patient was difficult which resulted in decreased imaging of the oral cavity for most swallows. On occasion you can see his palate tremors as well.

Post-stroke palatal tremor as a clinical predictor of dysphagia and its neuroanatomical correlates in patients with midbrain and pontine lesions | SpringerLink

Palato-pharyngo-laryngeal myoclonus with recurrent retrograde feeding tube migration after cerebellar hemorrhagic stroke: a case report and review of hypertrophic olivary degeneration | BMC Neurology | Full Text (biomedcentral.com)

Palato-pharyngo-laryngeal myoclonus … an unusual cause of dysphagia | Age and Ageing | Oxford Academic (oup.com)

The Guillain–Mollaret triangle in action | Practical Neurology (bmj.com)