Motor Speech Apraxia in a 70-Year-Old Man with Left Dorsolateral Frontal Arachnoid Cyst: A [18F]FDG PET-CT Study.

Motor speech apraxia is a speech disorder of impaired syllable sequencing which, when seen with advancing age, is suggestive of a neurodegenerative process affecting cortical structures in the left frontal lobe. Arachnoid cysts can be associated with neurologic symptoms due to compression of underlying brain structures though indications for surgical intervention are unclear. We present the case of a 70-year-old man who presented with a two-year history of speech changes along with decreased initiation and talkativeness, shorter utterances, and dysnomia. [18F]Fluorodeoxyglucose (FDG) Positron Emission and Computed Tomography (PET-CT) and magnetic resonance imaging (MRI) showed very focal left frontal cortical hypometabolism immediately adjacent to an arachnoid cyst but no specific evidence of a neurodegenerative process.