Palato-Pharyngo-Laryngeal Rhythmic Myoclonus in Neuro-Behcet Syndrome: A Case Report.

[OBJECTIVE] Behcet's syndrome (BS) is a chronic, relapsing multisystemic inflammatory perivasculitis and can affect any tissue, including the nervous system. Neuro-Behcet's syndrome (NBS) most commonly affects the CNS parenchyma and presents with a subacute brainstem syndrome that includes cranial neuropathies. Here we describe a rare case of palato-pharyngo-laryngeal myoclonus as a manifestation of NBS and discuss it from a laryngology perspective.

[METHODS] Case report at tertiary care center. Informed consent was obtained from patient. IRB approved as non-human subjects research.

[RESULTS] A 52-year-old male presented with a progressive history of ataxia, fatigue, apathy, dysphagia, depressed mood, dizziness, poor appetite, subjective fever and recurrent orogenital lesions. He was diagnosed with NBS and treated with methylprednisolone, followed by infliximab and methotrexate. Despite treatment, his severe spastic dysarthria, dysphagia, and aspiration worsened over the next few months, necessitating a gastrotomy tube. With concern for laryngospasm, he was referred to otolaryngology and found to have synchronous and symmetric palatal, pharyngeal, and laryngeal rhythmic myoclonus bilaterally at a frequency of 2 Hz with inappropriate vocal cord closure. Treatment with baclofen and a scopolamine patch improved his breathing and reduced choking events.

[CONCLUSIONS] Palato-pharyngo-laryngeal rhythmic myoclonus can be a presentation of brainstem NBS in the otolaryngology clinic. We theorize perivascular disease in NBS results in a brainstem lesion in the denato-rubro-olivary tract, which results in hypertrophic olivary degeneration and subsequent activation of the inferior olives oscillatory activity, causing palato-pharyngo-laryngeal rhythmic myoclonus. Common symptoms include significant dysarthria, dysphonia, and dysphagia with concern for obstructive sleep apnea and airway compromise. Treatments include pharmacologic therapy, laryngeal botox, and tracheostomy in cases of significant airway compromise.