Unilateral absent vestibular evoked myogenic potential in a patient presented with balance disorder: a case report

ABSTRACT

A case of 22-years old female patient, who suffered from a sudden onset of imbalance, complained of floating sensation and had a history of falls. Her main difficulty was when using the elevator, where she felt severe imbalance. All other clinical balance assessments were normal, but positive findings were found in Fukuda test, Romberg's test and straight-line test. While the blood investigation, caloric test and MRI of the brain were unremarkable, smooth pursuit, saccade and posturography test were abnormal. Vestibular Evoked Myogenic Potential [VEMP] test was found to be completely absent in the right side but a robust VEMP was found in the left side. Malay version of vertigo symptom scale [MVVSS] analysis showed that her imbalance level was in a severe range. The diagnosis of this patient was very challenging but based on her history of difficulty using the lift and VEMP findings, a right saccular dysfunction was suspected. The patient then underwent Customized Cawthorne-Cooksey exercise [CCCE], together with betahistine tablets. VEMP and MVVSS were reassessed after the patient had a 2-week of intensive CCCE. Surprisingly, VEMP waveform was now clearly visible in the right side. However, the asymmetrical issue was still observed, suggesting that the right side was still [abnormal], as compared to the left side. MVVSS score showed a significant improvement, consistent with VEMP findings. This nevertheless demonstrates that in a case of flat VEMP, combination of an intensive physical vestibular rehabilitation and typical medications can result in rapid recovery of vestibular symptoms