Electronystagmographic findings in patients with acute cerebral vascular disease and vertigo

Applicability of Oculomotor Tests for Predicting Central Vestibular Disorder Using Principal Component Analysis

The videonystagmography oculomotor test battery is considered useful method for diagnosing vertigo. However, its role in diagnosing central vestibular disorder has not been clarified due to variations in interpretation. Patients (n = 103) with vertigo or dizziness symptoms undergoing the oculomotor tests and brain MRI within 1 month were analyzed. Two otology specialists retrospectively interpreted the oculomotor tests, and three neurology and neuroradiology specialists determined whether central lesions were present on brain MRI. Multivariable logistic regression analysis was performed to determine the factors contributing to discordant interpretation between oculomotor tests and brain MRI. Oculomotor tests predicting central lesions were assessed using principal component analysis. The intra- and inter-rater reliability in oculomotor test interpretation was moderate to good. Age > 60 years and multiple comorbidities were significant predictors of a discordant interpretation between MRI and oculomotor tests. Positive neurological symptoms and a higher oculomotor index (according to saccade (vertical axis), smooth pursuit (horizontal axis), and gaze-evoked nystagmus (horizontal/vertical axes) tests) significantly predicted central vestibular disorder in vertigo patients. Caution is required when interpreting the results of the oculomotor test battery for diagnosis of central lesions in older patients, as well as in those with multiple comorbidities.

Impaired Visual Suppression of Manually Rotated Vestibuloocular Reflex Indicates the Need of Further Evaluation by MRI and MRA in Patients with Vertigo

OBJECTIVE: MRI and MRA are accepted as valuable methods for diagnosing vertigo, although they are costly and time-consuming. Thus, some indicator of the necessity of a detailed evaluation by MRI and MRA is desirable.

STUDY DESIGN AND SETTING: To assess the usefulness of an impairment of the visual suppression (VS) as an indicator, the relation between abnormal findings on MRI and/or MRA and impairment of the VS of manually rotated vestibuloocular reflex (VOR) was retrospectively examined in 40 consecutive patients suffering from vertigo.

RESULTS: 12 of 23 patients with a low VS% were found to have a pathologic condition on MRI and/or MRA, however, no abnormality was found in any of the patients with a normal VS%. The rates of abnormality on MRI and/or MRA significantly differed between the 2 groups ( X2, P = 0.0004).

CONCLUSION: The VS% is thought to be a good indicator of the need for further evaluation by MRI and MRA in vertiginous patients.

Vestibular function in carotid territory stroke patients

Stroke patients may present otoneurological symptoms.

Objective

To assess the vestibular function of subjects with a history of carotid territory stroke.

Method

This historical cohort cross-sectional study enrolled 40 patients; subjects answered the Dizziness Handicap Inventory, were interviewed and submitted to ENT examination and vector electronystagmography.

Results

Mild saccadic movement anomalies were seen in 20 patients (50.0%); nine complained of imbalance and dizziness. Abnormal smooth pursuit gain was seen in 17 cases (42.5%); six subjects reported imbalance and one complained of dizziness. Abnormal directional preponderance during rotational nystagmus was seen in two cases (5.0%), who also reported imbalance. Three patients (7.5%) and two subjects (5.0%) were found to have abnormal labyrinthine predominance and abnormal nystagmus directional preponderance respectively; all five individuals reported imbalance. Ten of the 11 patients without complaints of disordered balance had altered saccadic and smooth pursuit eye movements, while one had unaltered vestibular function.

Conclusion

Patients with a history of carotid territory stroke may suffer from dizziness or imbalance and present signs of compromised eye motility and vestibular function.

Evaluation of patients with vertigo of vertebrobasilar insufficiency origin using auditory brainstem response, electronystagmography, and transcranial Doppler

OBJECTIVES

Vertigo can be a manifestation of underlying vertebrobasilar stroke in older adults. The study objectives were to investigate the correlation, sensitivity, and specificity of the auditory brainstem response (ABR), electronystagmorgraphy (ENG), and transcranial Doppler (TCD) collectively to distinguish between vertigo due to vertebrobasilar insufficiency (VBI) and vertigo due to non-VBI.

DESIGN

Prospective experimental study comparing ENG, ABR, and TCD battery findings between two groups of patients with vertigo and a control group.

STUDY SAMPLE

Participants included 14 patients with vertigo of VBI origin, 14 patients with vertigo of non-VBI, and 11 matched controls.

RESULTS

Participants with VBI had more abnormal findings in the ENG (86%), TCD (72%), and ABR (64%) compared to the non-VBI group (64%, 21%, and 7%, respectively) and the control group. The combined battery revealed positive correlations, 64% sensitivity, and 84% positive predictive value (PPV) in the VBI group, and 100% specificity with lack of correlations in the non-VBI group.

CONCLUSIONS

The modest sensitivity and PPV helps with early detection of VBI, thus preventing risk of vertebrobasilar stroke in 84% to 64% of patients. The 100% specificity in the non-VBI group rules out VBI, thus reducing the referral rate for unnecessary, diagnostic evaluations and ineffective treatment.