Diagnosis and Assessment of Chronic Imbalance due to Saccular Disfunction: Using Trapezius cVEMP in a Patient with Surgically-Altered Sternocleidomastoid Muscle

Background/Objectives: Vestibular disorders include a wide range of conditions with overlapping symptoms such as dizziness, vertigo and imbalance, often offering diagnostic challenges when distinguishing between peripheral and central etiology. Accurate differentiation is essential for establishing effective treatment plans. In rare or atypical cases with subtle findings, comprehensive diagnostic tools—such as vestibular tests and structured questionnaires like the Dizziness Handicap Inventory (DHI)—are critical for diagnosis and monitoring patient recovery. Methods: A comprehensive audiovestibular evaluation was performed, including pure tone audiometry (PTA), tympanometry, videonystagmography (VNG), cervical vestibular evoked myogenic potentials (cVEMP), ocular vestibular evoked myogenic potentials (oVEMP), video head impulse testing (vHIT), computerized dynamic posturography (CDP), and magnetic resonance imaging (MRI). The DHI was administered at baseline and post-treatment to monitor subjective symptom changes. Results: Objective testing revealed marked right–left amplitude asymmetry on cVEMP, which were recorded from the trapezius muscle due to prior neck dissection surgery, indicating isolated right-sided saccular hypofunction. Initial evaluation DHI score indicated mild perceived handicap. Following targeted vestibular rehabilitation and pharmacologic treatment, the 3-month reassessment demonstrated resolution of symptoms and a reduction in DHI scores from 24 to 6. Conclusions: Comprehensive vestibular testing, performed in a single diagnostic session, enabled the accurate identification of isolated right-sided saccular hypofunction in this complex post-surgical case. Combining cVEMP, CDP, and DHI assessment provided a complete functional profile, guided targeted rehabilitation, and allowed objective monitoring of recovery, highlighting the importance of integrated vestibular evaluation for precise diagnosis and optimal patient outcomes.