Ultrasound-Guided Peristyloid Hydrodissection for Eagle Syndrome With 5% Dextrose: A Technical Note Integrating Computed Tomography-Defined Anatomy, Doppler Vascular Mapping, and Orthogonal Sonographic Guidance.

Eagle syndrome is a symptomatic disorder associated with elongation or abnormal orientation of the styloid process and/or ossification of the stylohyoid complex. Clinical manifestations depend on the spatial relationship between the styloid complex and adjacent neural, muscular, fascial, and vascular structures. We describe an ultrasound-guided peristyloid hydrodissection technique using 5% dextrose in water (D5W) that integrates preprocedural computed tomography (CT), sequential landmark-based sonographic localization, live-dual imaging, Doppler vascular mapping, and orthogonal short- and long-axis confirmation. A 24-year-old man presented with more than six months of predominantly right-sided pharyngeal foreign-body sensation and dysphagia, accompanied by cervical pain, headache, and intermittent dizziness. The right styloid process measured 37 mm on CT. D5W hydrodissection was performed once weekly for six weeks. In this index case, 10 mL was delivered to the superior peristyloid tissue plane and 10 mL to the inferior plane at each session, with visible sonographic tissue-plane separation as the procedural endpoint. This 20 mL volume was specific to the index case and should not be extrapolated to future patients. The patient reported gradual improvement in pharyngeal symptoms during the treatment course; pain decreased from 7/10 to 3/10 on the numeric rating scale after six sessions, with maintained subjective benefit at three-month follow-up and no adverse events. This report presents a reproducible image-guided procedural framework rather than evidence of treatment efficacy. Cadaveric validation and prospective studies are required to define injectate distribution, optimal dosing, safety, and clinical effectiveness.