Role of electronystagmography in balance disorders: A clinical study

Aim and Objectives: To evaluate the role of electronystagmography (ENG) in the diagnosis of balance disorders, to localize the level of lesion in cases of vertigo, and to classify the etiology into peripheral and central causes. Materials and Methods: This study included 120 patients who presented with primary complaints of vertigo or dizziness. The inclusion criteria were all patients with complaints of vertigo with satisfactory vision. All patients underwent a thorough examination and appropriate investigations. Patients were subjected to ENG under optimal conditions and the results were obtained in the form of a butterfly chart after analysis of the ENG data. Results and Observations: Of the 120 patients subjected to ENG, we found that half the patients who presented with complaints of dizziness turned up as normal. 39 patients (33%) were diagnosed with peripheral vestibular lesion whereas 17% showed a central lesion of the vestibular system. The presence of a vestibular lesion was confirmed by performing a Dix-Hallpike maneuver. This returned a positive result in 33% of the cases. Canal paresis and directional preponderance, which were taken as the parameters of our study were analyzed in detail and significant correlation between the two was found. For higher values of directional preponderance, the canal weakness assumed greater significance. Conclusion: ENG has proven to be a useful first-line investigation in the diagnosis of vertigo. It can also act as a useful screening tool to differentiate between classical vertigo and other causes of the disequilibrium. It has special significance in localizing the side of the lesion which is especially useful in the further management of disorders like benign paroxysmal positional vertigo.