Negative dystonia of the palate: a novel entity and diagnostic consideration in hypernasal speech

Objective: To present the first documented series of patients with negative dystonia (ND) of the palate, including clinical symptoms, functional MRI findings, and management options.

Study design: Case series ascertained from clinical research centers that evaluated patients with both hyperkinetic and hypokinetic movement disorders.

Methods: Between July 1983 and March 2013, data was collected on patient demographics, disease characteristics, functional MRI findings, long-term management options, and outcomes. We sought patients whose clinical examination demonstrated absent palatal movement on speaking, despite normal palatal activity on other activities.

Results: Five patients (2 males, 3 females) met clinical criteria. All patients presented with hypernasal speech without associated dysphagia. Clinical examination revealed absent palatal movement on speaking despite intact gag reflexes, normal palate elevation on swallowing, and normal cranial nerve examinations. Other cranial and/or limb dystonias were present in four patients (80.0%). Three patients (60.0%) had previously failed oral pharmacologic therapy. Two patients underwent functional magnetic resonance imaging (fMRI) studies, which demonstrated an overall decrease of cortical and subcortical activation during production of symptomatic syllables and asymptomatic coughing. Management included speech therapy (all patients) and palatal lift (2 patients) with limited improvement. Calcium hydroxyapatite injection (1 patient) into the soft palate and Passavants' ridge was beneficial.

Conclusions: This is the first report of ND of the palate. Characteristic findings were task-specific absent palatal movement with speech, despite normal movement on swallowing, coughing, and an intact gag reflex, as well as disorder-specific decreased brain activation on functional MRI. A diagnosis of ND of the palate should be considered for patients who present with hypernasal speech.

Level of evidence: 4.