Abstract
Anterior opercular syndrome (Foix-Chavany-Marie syndrome) is characterized by severe dysarthria, impaired voluntary orofacial and pharyngolingual movements, and preserved automatic or emotional movements (automatic-voluntary dissociation). Although classically associated with stroke, its progressive neurodegenerative form is rare and poorly understood. We report two patients to characterize its clinical and neuroanatomical features. The cases were identified retrospectively through review of clinical and neuroimaging records from behavioral neurology centers in the United States and Japan. Both had severe dysarthria and oral-phase dysphagia. Voluntary orofacial movements were markedly impaired, whereas reflexive movements, including coughing and yawning, and emotional movements, including smiling in response to humor, were preserved. Coordination, posture, and gait were initially preserved. Both patients showed predominantly upper motor neuron features without lower motor neuron signs; limb and cranial electromyography was normal in the patient tested. Neuroimaging showed bilateral frontal atrophy and hypometabolism or hypoperfusion involving the anterior operculum. These findings suggest that progressive anterior opercular syndrome may emerge when bilateral opercular regions are affected by neurodegeneration. Recognition of this syndrome may facilitate anticipatory management of dysarthria, dysphagia, and nutritional risk and broaden awareness of speech and orofacial motor syndromes in frontotemporal dementia and related phenotypes.